["1912 ,,1913 The archaeologist Charles Dawson (left) convinced paleontologist Arthur IT IS PERHAPS\u2026 INDELICATE TO ASK\u2026 Smith-Woodward (center) that he had found the ape\u2013human missing link. MOTHER EARTH HER AGE, BUT SCIENCE ,,ACKNOWLEDGES NO SHAME AND\u2026 HAS\u2026 ATTEMPTED TO WREST FROM HER A SECRET WHICH IS PROVERBIALLY WELL GUARDED. Arthur Holmes, British geologist, from The Age of the Earth, 1913 ON FEBRUARY 14, British proteins, and fats, a healthy diet BRITISH PHYSICIST FREDERICK chemical process \ufb01rst described SODDY had worked with Ernest by Fritz Haber (see 1905)\u2014now archaeologist Charles Dawson needed accessory food factors. Rutherford on the nature of known as the Haber\u2013Bosch electron proton radioactivity and identi\ufb01cation process. The factory would (1864\u20131916) uncovered primate Polish-born biochemist Casimir of decay products. He found that reach full production capacity these products had different in 1914. skull fragments and a jaw at Funk (1884\u20131967) proposed a atomic masses, but held positions in the periodic table In December, British physicist the Piltdown gravel pit, England. name for them\u2014vitamines, from that appeared to be occupied Henry Moseley (1887\u20131915) by known elements. Soddy found that elements emit They were reported to be the \u201cvital\u201d and \u201camine.\u201d He thought concluded that they must be characteristic X-rays of varieties of the elements, and wavelengths determined by missing link between humans that they belonged to a class of in 1913 he called them isotopes. the numbered position in the periodic table. His discovery and apes and attracted much chemicals called amines, but Danish physicist Niels Bohr supported Van den Broek\u2019s idea neutron (1885\u20131962) modi\ufb01ed that the position had physical HELIUM ATOM interest from experts at the when it was shown that this was Rutherford\u2019s nuclear model meaning in the form of the of the atom to take into account number of positive charges ATOMIC NUMBER British Museum of Natural not the case, the name was new ideas from quantum in an element\u2019s atomic physics. Bohr proposed that nucleus\u2014its atomic number. Henry Moseley proved that History. More than 40 years later, changed to vitamin. electrons orbiting the atom\u2019s the vaguely de\ufb01ned concept nucleus occupied various shells British geologist Arthur of atomic number related in 1953, Piltdown Man was or energy levels called orbitals. Holmes (1890\u20131965) had to a measurable physical The electrons in the outer shell property of the atomic shown to be a hoax\u2014it was in determined the way elements nucleus, later found to be fact fragments of a modern reacted chemically. the number of protons. For human and an orang-utan. a neutral atom, this equals At the BASF (Badische the number of encircling This year also saw the dawn of Anilinund Soda-Fabrik) electrons. The nucleus is chemical plant in Germany, made up of protons and 186a new way of analyzing chemical chemist Carl Bosch neutrons (neutral particles). structures. German physicists oversaw the \ufb01rst industrial production adopted a radiometric technique Walter Friedrich (1874\u20131958) MILES\/SEC of ammonia for use in for calculating the age of rocks and Paul Knipping (1883\u20131935) agricultural fertilizers. showed that when X-rays were THE SPEED THE Bosch had modi\ufb01ed a pioneered by Bertram Boltwood (see 1907). Holmes scattered through a crystal, the ANDROMEDA Bohr\u2019s atomic model electron published his results in The resulting diffraction pattern Bohr\u2019s model suggested \ufb01rst shell Age of the Earth, but\u2014at GALAXYrecorded on a photographic plate electron \u201cshells\u201d around the 1.6 million years\u2014his nucleus. As electrons move nucleus calculation was still more could be used to identify the MOVES AWAY between the shells, the atom emits than 4,000 times shorter or absorbs electromagnetic radiation. than modern results. positions of the crystal\u2019s atoms. second, FROM THE SUNLater, German physicist Max von outer shell Laue (1879\u20131960) explained the theory for this scattering American astronomer Vesto behavior and used it to show Slipher (1875\u20131969), using a that X-rays were not particles, technique of light analysis but waves with very short called spectroscopy (see 1860), wavelengths. X-ray diffraction observed a shift toward red would be developed as a wavelengths for light coming mainstay of analytical chemistry. from the Andromeda galaxy. British biochemist Frederick This redshift indicated that the Hopkins (1861\u20131947) was galaxy was moving away. experimenting with the diets of Slipher\u2019s studies provided early animals and announced that, evidence for the idea that the along with carbohydrates, Universe was expanding. JaGneuAralmdfrreaymesndc6fogrrWdoiebemeoerpgnsahehcnynoisesanircnttihicsnieteeonnrttyssthuhapavteercsopnlittinent Juvnotenh8waLtaMaXuva-eexrssa,hynsoowat srpearticles SeVpedtseetAmomniSbosdlnermiopsrmtho1rvea7eirtndegasGalaxy JagneuSnate\ufb01urtrriysctteiAsvcmtahHneroetrimndcreaoysnscormibeesmap Apdreqisluca5artinoNbtmeiuesimlcshsimBstroouhdcretul roef JusncWeie1uinl8ntliidsaBetmrrJitwsoioshanhtnetEroroonkcee\ufb01sartnstphotographs KFAnriippetrpdhiirlrnXio2cg-uh1rgeaaWhxynpssaadlhldactPoiierfnwafryrutsahptlcaoatolstefcidtaaiontnoms s JulythH1a5ontpFeakreheidnedssaefaslrotctihocacykdteedsfssaieocttroyrs WiNlloiavBmermaLgahbdgwoeifewrfrxre1apcn1clrcatyeisXnt-sarlasys FrFeedcbeorriuincaskrtSyhoe1di8stdeoyrtmope EAcfpooruloinlgdd1ieec2avdBol: trS\ufb01eiortdsicsottihoefbteosyctduoydloygy pAurbtlhisuhreHosfoTtlhhmeeeAEsgaerth Decemshboeawrtos9mhHiocewnnrauynmMebtlooeesrmtehrleeeenlyXati\u2019-tstreeasmysits 249","1895\u20131945 THE ATOMIC AGE UNDERSTANDING ATOMIC STRUCTURE PARTICLES AND FORCES COMBINE TO MAKE UP ATOMS, THE BUILDING BLOCKS OF MATTER Solids, liquids, and gases\u2014the three main types of matter\u2014are made up of particles called atoms, each so small that several million would fit side by side on the period at the end of this sentence. All atoms are composed of just three types of particles\u2014protons, neutrons, and electrons. In the 19th century scientists became certain of the by an attractive force called the strong nuclear ERNEST RUTHERFORD existence of atoms. The assumption was that atoms force. Different elements have different numbers New Zealand-born physicist Ernest were the smallest parts of matter\u2014the word \u201catom\u201d of protons in the nucleus (see below). Negatively Rutherford discovered the atomic nucleus means indivisible. However, in 1897 the discovery charged electrons orbit the nucleus and are in 1911 and the proton in 1920. of the electron suggested that atoms have inner prevented from escaping by electric attraction to structure. Electrons carry negative electric charge, protons. There are equal numbers of protons and seven neutrons but atoms are neutral overall so a positive charge electrons, so atoms have no overall charge. in nucleus also had to exist. Scientists used alpha particles, which are produced by radioactive substances, to one orbiting electron probe the atom more deeply. In 1911, Ernest Rutherford found that some of the positively one proton charged alpha particles he \ufb01red at a thin metal foil in nucleus bounced back, and proved that this could happen only if each atom has a positive charge concentrated at its center\u2014he had discovered the atomic nucleus. ATOMS AND ELEMENTS seven seven Except in hydrogen (see right), an atom\u2019s nucleus orbiting protons in consists of protons, which are positively charged, electrons nucleus and neutrons, which have no charge, held together HYDROGEN ATOM NITROGEN ATOM ATOMIC SIZES distances from the nucleus, and only certain ,, orbital is a region The nucleus accounts for nearly all the mass numbers of electrons can occupy each orbit. where there is a of an atom but only a tiny proportion of its As a result, atoms with more electrons have volume\u2014it is an atom\u2019s electrons that de\ufb01ne more orbits, at increasing distances from the high probability of this. Electrons occupy orbits at speci\ufb01c nucleus, producing a larger atomic radius. \ufb01nding electrons 25 picometers One atom of PROTONS (trillionths of hydrogen-1 has GIVE AN ATOM a meter) one proton and ITS IDENTITY, no neutrons 298 picometers One atom of ,,ELECTRONS uranium-238 has 92 238 GIVE IT ITS protons and PERSONALITY. 146 neutrons HYDROGEN ATOMS American author Bill Bryson, 55 A Short History of Nearly Everything, 2003 1 electron hydrogen ELECTRONS Cesium ATOMIC MASS Protons and neutrons have identical mass; electrons have ATOMIC RADIUS negligible mass. So the atomic mass is simply the total Hydrogen, the lightest element, has only one electron number of protons and neutrons. Different versions orbiting its nucleus, so it has the smallest atoms. (isotopes) of an element vary in the number of neutrons. A cesium atom has 55 electrons orbiting its nucleus and is about 12 times wider than a hydrogen atom. 250","UNDERSTANDING ATOMIC STRUCTURE one end of dumbell- ELECTRON ORBITALS shaped p-orbital Quantum physics has revealed some key facts about the orbits outer s-orbital of electrons around the nucleus. contains two electrons First, electrons can only occupy certain \\\"allowed\\\" orbits, and nowhere in between. Second, an electron\u2019s exact position cannot be determined, only its probability of existing in a particular place. As a result, electrons actually exist in \\\"orbitals,\\\" which can be thought of as three-dimensional clouds of probability. There are four main types of orbital: s-orbitals, which are spherical; p-orbitals, which are dumbbell-shaped; and d- and f-orbitals, which have more complex shapes. Each orbital can hold up to two electrons. inner s-orbital contains two electrons nucleus containing electron protons and neutrons FLUORINE ATOM An atom of the element \ufb02uorine has nine protons in its nucleus and nine orbiting electrons arranged in two s-orbitals and three p-orbitals. The most common version of \ufb02uorine has 10 neutrons, so it has an atomic mass of 19\u2014nine protons plus 10 neutrons. INCANDESCENCE AND LUMINESCENCE 1 COLLISION particle carrying There are two ways in which matter emits light: energy incandescence and luminescence. Incandescence Luminescence is the production of light from hot matter\u2014things is triggered by a nucleus glow red hot or white hot, for example. In particle carrying contrast, luminescence does not require heat. energy colliding photon orbiting electron Fluorescence, glowing when illuminated by ultraviolet radiation, and phosphorescence, with the atom. lower-energy glowing in the dark after being illuminated, orbit are two familiar examples. Light produced by 2 ELECTRON JUMPS luminescence is the result of energy lost by 3 ENERGY RELEASE electrons \\\"falling\\\" to a lower energy level, An orbiting electron is closer to an atom\u2019s nucleus. given a boost of energy The electron falls back down to a lower orbit and releases its extra and moves into a energy as a photon of light. The higher-energy orbit. light\u2019s color depends on the amount of energy released: for example, a blue photon has more energy than a red one. 251",",,1914\u201315 THE LUMINESCENT PROPERTIES OF NEON\u2026 CONSTITUTE SOURCES OF LIGHT OF GREAT ,,BRILLIANCY. George Claude, Vacuum discharge-tube for lighting purposes, US Patent Office, 1915 A gas-discharge light tube works by applying voltage across the low-pressure gas to create ions (charged particles), which causes a colored, neon, light to be emitted. IN 1914, BELGIAN PHYSICIAN ALFRED WEGENER (1880\u20131930) Blood transfusion kit ALBERT HUSTIN (1882\u20131967) The \ufb01rst anticoagulant-treated blood bank found he could stop blood Born in Germany, Alfred kits\u2014used on the frontline during World War I clotting by adding a reagent Wegener began his career \u2014relied on the knowledge that blood group called sodium citrate. Previously, as a meteorologist, and he O could be used as a universal donor. the danger of coagulation meant participated in several Arctic that transfusions had to be expeditions to investigate glass blood performed directly from donor climate. He is best known for storage jar to recipient. In March, Hustin his theory of continental drift. performed the \ufb01rst safe Wegener collected geological equivalent to gravity and nondirect transfusion using evidence but could not explain citrate-treated blood from storage. how the movement occurred; an outcome was that the during his lifetime the theory In 1915, two German scientists was not taken seriously. effect of gravity was to would change the way we viewed our world. Geologist Alfred bend light. Furthermore, Wegener expanded on a theory of continental drift that he \ufb01rst he argued that strong proposed in 1912 (see below). Physicist Albert Einstein\u2019s gravitational \ufb01elds theory of general relativity was more radical still. His special should distort time and relativity theory (see 1905) had asserted that measurements of appearance; in other tubing for words, they would warp carrying blood distances and time change for making the measurements were a space\u2013time continuum. different frames of reference, moving at different \ufb01xed speeds. even though the speed of light Einstein\u2019s new theory of general Physicists consider space and In the same year, French stays constant everywhere. The relativity accommodated frames of reference referred to acceleration and deceleration time to be related: space makes engineer George Claude situations where the observers effects too. Acceleration is up the three (everyday) received his patent for a new dimensions, and time is the type of lighting: the neon fourth dimension. discharge tube. CONTINENTAL DRIFT Alfred Wegener collected Pathalassic Pangaea North America India breaks Antartica and South America Australia drifts into evidence for his theory that breaks away away Australia are the separates from Africa the Paci\ufb01c Ocean modern landmasses originated Ocean landmass from Eurasia same continent Present day from a prehistoric super- India collided with Asia, creating the Himalayas. South America was continent that fragmented joined to North America across a narrow Central American land bridge. millions of years ago. He saw not only that transatlantic coastlines seemed to match, Tethys but also that geological Sea formations (including fossils) were similar on either side. 200 million years ago 130 million years ago 70 million years ago This suggested that the A single supercontinent called Pangaea By this era, there were several For millions of years, South coastlines were once joined. was formed when ancient landmasses separated continents, including America was isolated as the came together. As tectonic plates India (drifting northward) and Atlantic Ocean opened up to continued to move, it began to fragment. an Australia-Antarctic landmass. separate it from Africa. MaArlpbceehnrro2ftton7rHrad,mun1isr9ssetf1ictnuh4tsebiol\ufb01onrosdt JuPlayat7esR,noo1tlb9iOde1fr4f\ufb01tucUHeeSl.rrGeogocidksdteeatrrfsdor 19s1u4nguEgcerlnseetussstthcRoeunatthtaoeimnrfsoicrpdrotons JaPnaunteaeGonrenytoO1drf9gi\ufb01s,ecc1seh9Car1rle5aggueUisdStteuebrse the MaisrofcofhuN3nA,dS1eA9d)1(5thNeApCreAdecessor SeFpir\u201ctseLftmiotptrbrleBoetrWroitt6iiyls,plh1iee9A\u201dt1ari5mnsktyestedSeAplgbteeeemnrxtegpbErrleaaainrlvinsit2tthyte5heia,neon1rdrd9yee1slos5apfctarirociebneleas\u2013shttiiimhvpiitsebyettoween for 2 5 2 19J1.J4.TBhrmoittmiahssehssodpsnehpspyeisegcirnctfriesooctfmttsheeteprharmanc1eo9Dul1oar4gloeiBtsraitrsaciHonteilesstaymnhtlerciysthtoaelri:ne AmtWehraaitOlcthaaecanrtwsoAahbvsdeiettarrermoy1dnhs9woi1sgmah4hreofdrwsestnasrity observMa\ufb01atrorsrctyh,pbAh1ur9oti,tziot1ogi9nsr1aan5,paotLshatokraoewefncsePeoltalwglhutnettpiohzl,aeendteimt e pRroSebdeeipcrEtttiieonMmnsitslbelpimeikhnraoa\u2019sn1dto5teche,obel1neyo9\ufb01crA1tryr5lmbiocseferttfhfeect 1p9u1b5lisAhlefOrsecCdTeohaWnentescOigno,rhdeneiignentsiisetnntscrheroaenifnbotdiarnlygdorfift","1916\u201317 300 THOUSAND LIGHT YEARS SHAPLEY\u2019S ESTIMATE OF THE DIAMETER OF THE MILKY WAY American astronomer Harlow Shapley\u2019s \ufb01rst measurement of the Milky Way galaxy was an overestimate. It is 100,000 light-years across and contains more than 100 billion stars. alpha particle (2 protons nitrogen atom nitrogen nucleus absorbs In 1917, at the Mount Wilson atoms into a form of oxygen, by the war. Treating blood with and 2 neutrons) \ufb01red with 7 protons a proton and 2 neutrons Observatory in California, the \ufb01ring them with alpha particles. anticoagulant made blood into nitrogen atom and 7 neutrons to produce \u201cheavy\u201d oxygen assembly of the Hooker transfusions faster and re\ufb02ecting telescope\u2014the When the US entered safer. British physician Arthur extra largest in the world at the\u00a0time\u00a0\u2013 World War I in April 1917, Cushny (1866\u20131926) published proton is was \ufb01nished. To this day, its British-born medical of\ufb01cer the \ufb01rst major study of kidney released 100in (254cm) mirror is the Oswald Robertson (1886\u20131966) physiology. He correctly deduced largest solid-glass mirror ever introduced a blood bank system that the organ \ufb01ltered blood and made. The telescope was used to the frontline. The Royal Army reabsorbed nutrients to produced to make the \ufb01rst measurements Medical Corps called it the most waste urine. of stars other than the Sun. important medical advance of 550 ton dome THE FIRST TRANSMUTATION In November, New-Zealand made of thin-sheet born British physicist Ernest steel with a 100ft British physicist Ernest Rutherford was the \ufb01rst person to cause Rutherford achieved a (30m) diameter one element to change into another\u2014a phenomenon called signi\ufb01cant breakthrough in transmutation. He showed that it was possible to change the size atomic physics: the \ufb01rst of an atom\u2019s nucleus by bombarding it with other particles. Later ever man-made scientists exploited this process to release huge amounts of energy. transmutation of elements. He IN 1916, AMERICAN CHEMIST the historic vegetation of peat succeeded in telescope GILBERT LEWIS (1875\u20131946) beds. The study of pollen turning within rigid suggested that when atoms (palynology) is still an important nitrogen steel cradle bonded together to make bigger analytical study used for example molecules, they shared their in forensics. Hooker outer electrons. In 1919, his telescope colleague Irving Langmuir American astronomer Harlow This telescope (1881\u20131957) would expand the Shapley (1885\u20131972) started a was used to idea and call them covalent bonds. photographic survey of star make the \ufb01rst clusters. His systematic measurements of Swedish geologist Lennart von measurements would show star sizes, and to Post (1884\u20131951) explained a that clusters surround our develop the theory new way of studying of an expanding geological deposits. galaxy like a halo, and universe. Different plant are not centered species produce on Earth. distinctly shaped pollen grains, Pollen grain and von Post was The distinctive able to identify sculpturing of pollen to make pollen grains makes conclusions about it possible to identify the source plant species by microscopy. JaAnru\ufb01mrassyrttoyMbr1eleo,ddo1icad9an1tldr6CacRnooosropfyluasesldpioebnrlofuoosrdmings Juvloypn1oP0llo\u2013es1nt5ai,nn1tar9ol1yd6suiLsceesnnart 19F1r6peudASbemulricisecchreCiesclssaeinmPonleeacnnottlsogist 19p1u7obfAlkUirsidrthhinenuesery,TsCdhuefeossrSchmrenicyburienrtigniohenobwy t\ufb01hletration mpidht\u2013ye1sss9itycss1sisu7tatebnFmPmreaeacfunorhlcironLhdeasesnotgueencvtdiininngg OcAtmoJboeeesrseiroctpaf1ahba9nln1Gizs7roehiocneolnsolegotlhiglseitciadlenaiche April 1d9e1bs6ocnGrdiiblibenesgsrctihnhLaeteremiwnreiimgsclaeoslcuottrfeorns July 2d1e,s1c9ri1b6esEoifanrstahtedeemiionaritsiyosnion 19to16phHloeatatrohldgoeirwnasgipSzhhheiamsaptnaltedroycsdslheutataseprtMretemsirloskif,nytehWeay 1917FFerliexndc\u2019hHm\u00e9rievcidlrrloeeubssbdtieaoresoclsoytcteghrbriiasabitotcecptseahrnaiag:es NotveeleOmsbbcsoeeprreuv1asa,ett1odM9ryf1oo,7rCuHntahtloieMfoo\ufb01kirlernssrioatn,tiims e 253","1918\u201319 30 MILLION THE NUMBER OF PEOPLE WHO DIED OF SPANISH FLU IN SIX MONTHS OF 1918 There were so many victims of the Spanish \ufb02u epidemic that several makeshift hospitals\u2014 such as this gymnasium in the US\u2014had to be created. CONFIRMING THE GENERAL THEORY OF RELATIVITY Enigma cipher machine In his theory of general relativity, Einstein had predicted that the strong These machines gravitational \ufb01eld of the Sun would warp space-time. This distortion were used during would de\ufb02ect light coming from the stars, causing their apparent World War II for position to differ from their real position. Independent observations decrypting and by Arthur Eddington and Andrew Crommelin con\ufb01rmed this theory. encrypting During a solar eclipse, they accurately measured the positions of stars con\ufb01dential close to the Sun. They compared their results with the stars\u2019 apparent messages. positions and noticed a slight difference between the two. IN THE WAKE OF WORLD WAR I, and many people lacked the nitrogen atoms yielded small metal a natural global disaster killed immunity to \ufb01ght it. elementary particles. He realized cover to more people than the great that these were equivalent to \ufb01t over plague of the 1300s. Spanish In February 1918, French positive hydrogen ions and later cylinders \ufb02u spread to all the continents, physicist Paul Langevin (1872\u2013 called them protons. It would be and medical science seemed 1946) demonstrated a system to shown that they are responsible motor powerless to stop it. Modern detect the sound of underwater for the positive charge in the cylinders research suggests that it submarines\u2014a technology that nucleus of atoms. originated as a mutated virus would have important implications in wartime. Called the ASDICS During a solar eclipse in seven seven device (Aided Sonar Detection 1919, British astronomer Arthur protons electrons Integration and Classi\ufb01cation Eddington (1882\u20131944) and System), it was the forerunner French astronomer Andrew most nitrogen atoms to sonar (see pp.292\u201393). Crommelin (1865\u20131939) keys to type have seven neutrons too observed that rays of messages In Germany, electrical engineer starlight were bent Balanced charge Albert Scherbius (1878\u20131929) as they passed plugboard setting The number of protons in a invented a cipher machine, close to the altered regularly to non-ionized atom equals the number which he called Enigma. It Sun. This proved change cipher of electrons; this means that an atom, worked by a series of rotating Einstein\u2019s general overall, has no charge. Neutrons are wheels. In 1918, Scherbius theory of relativity particles that have no charge. offered it to the German Navy. (see pp.244\u201345). They began using it in February 1926, and the German Army followed shortly afterward. In 1917, New Zealand-born physicist Ernest Rutherford had found that \ufb01ring alpha particles from radioactive elements at JaAnmuHaeahrrriiylsacoan8ewand,snS1tcasid9hmesh1dantaar8petpoteldeenerueoyoocdmfpfetuotsehhbnretelhEissaMaihtzrieielttkshiysWnoaty FeLbaArnuSgtaoDervImCyinSo1dd\u20149ee1tmrh8neoPsnfaoosunrtleraarrutsenysnseterms JuEnretnhe1aes9tlte1hRm8yudeBtrnhroitetgairserfhoynrppidoahneryxstsipicacllraieseistns MaAyrat2hnC9udr,rEAo1Eimn9tndhd1smder9teieoenwirlgniynt\u2019sootnfgeresetnleartaivlity NoSvpiesamndiebschelra\ufb02r3ue0dp,aa1nt9da1en9meincd Januar\ufb02iydue1np9ta1in\ufb018edSdepmianincKis\ufb01ahrnsstas AprSilc1h8e,rb1iE9u1nms8igoaAmfcGfrheaterihrnscumeihrpatihsonetrNhaevy dJceuhsnecoermfib1eise,lte1scI9trth1vri9eoninaAgnsrmtLrrmioanaeodnnraluiggectcmoeaccemmonuusvliseeartnshlae,tennadtntedbrmond ALmeveernicDsaendceceshcmcoermmbibepiesrosts1nPi,tuh1ioco9lnee1bo9outfisDdeNA 254","1920\u201321 1MILLION THE NUMBER OF ISLETS OF LANGERHANS IN THE PANCREAS OF AN AVERAGE ADULT These clusters of cells, called Islets of Langerhans, are the source of the hormone insulin in the pancreas. AMERICAN PHYSICIST ROBERT BCG vaccine Payne-Gaposchkin (1900\u201379), material that becomes visible red light photon is low GODDARD (1882\u20131945) had Consisting of a who showed that these elements during cell division) to coin a new energy, however bright it is recently published a treatise harmless strain of predominated in a star. scienti\ufb01c term\u2014genome. He promoting the idea of rocket bovine TB bacteria used it in his book on biological blue light space travel. On January 13, (orange), the BCG In Germany, botanist Hans reproduction to refer to a single photons have 1920, the New York Times vaccine stimulates Winkler (1877\u20131945) combined set of genetic material. more energy ridiculed Goddard\u2019s views. the body\u2019s immune the terms \u201cgene\u201d (the particle of A few years later he successfully system. inheritance) and \u201cchromosome\u201d In July 1921, the BCG (Bacille as blue light hits the metal launched a liquid-fueled rocket (solidi\ufb01ed thread of genetic Calmette\u2013Gu\u00e9rin) vaccine surface, electrons are released (see 1926). Later research against tuberculosis (TB) was revealed that ready for its \ufb01rst human trial\u201415 PHOTOELECTRIC EFFECT In 1920, British physician exposure to years after Albert Calmette and Edward Mellanby (1884\u20131955) the Sun\u2019s rays Camille Gu\u00e9rin started developing The emission of electrons showed that a plain oatmeal stimulates the it (see 1906). French physicians from a metallic surface when diet caused a bone-softening formation of Benjamin Weill-Hall\u00e9 (1875\u20131958) light shines on it is called the deformity called rickets. He Vitamin D in the body naturally. and Raymond Turpin (1895\u20131988) photoelectric effect. Albert also found that the effects were administered the vaccine orally to Einstein explained it in terms eliminated by supplementing In the same year, Arthur a newborn infant whose mother of light particles with distinct the diet with cod-liver oil. He Eddington suggested that a had died of TB. It was the start of a quantities of energy called deduced that cod liver must star\u2019s energy comes from the successful vaccination program photons. He said that photons contain a factor that was needed conversion of hydrogen to helium that would extend worldwide. of red light (long wavelength) for essential growth. In 1922, this by nuclear fusion. This was later do not have enough energy to factor was identi\ufb01ed as Vitamin D. supported by the \ufb01ndings of In August, Canadian biologists allow electrons to be emitted, British astronomer Cecilia Frederick Banting (1891\u20131941) but photons of blue light and Charles Best (1899\u20131978) (short wavelength) do. BLOOD SUGAR REGULATION isolated insulin. It was known that the pancreas produced a criteria, and carried it over to the The pancreas releases insulin blood sugar GLUCAGON high blood sugar secretion that regulated sugar next year. In 1922, Albert Einstein when blood sugar concentration raised levels in the body; the active received the Nobel Prize for rises, such as after a meal. This INSULIN promotes ingredient had been called 1921, nearly two decades after prompts the liver to convert adds sugar BLOOD CELLS insulin release \u201cinsuline.\u201d However, the his \u201cmiracle year,\u201d 1905, when he sugar to stored carbohydrate, to the blood pancreas also produced digestive had published several ground- causing the blood sugar to drop. PANCREAS enzymes, and the destructive breaking theories. Einstein was When this happens, another LIVER in\ufb02uence of these had always awarded the prize for his services hormone, glucagon, is released, promotes interfered with the extraction to Theoretical Physics and prompting the liver to break removes sugar glucagon release of insulin. Banting developed a especially for his discovery of the down stored carbohydrate from the blood low blood sugar way of tying off the digestive law of the photoelectric effect. and release more sugar. The ducts so that insulin could combined effect of the two blood sugar be retrieved. hormones regulates the level lowered of sugar in the blood. In 1921, the Nobel Committee for Physics decided that none of the nominations satis\ufb01ed the prize JaTnhureiadGNriocyoedufw1dlae3aYs,rrood1rRc9\u2019ksok2Tbie0dietmertaes FeMberrilucloaakfnareabsytsyvV2iditi7stae,amcs1mac9iurin2nis,b0eDleadEstdebhwryoiadwdreed\ufb01nctii\ufb01eendcyJucnoein3s,t1h9e2t0erEmrnpersottRonutherfordJuWlyrHi1gat9hhr2raetym0flfAeeaUlncnlStgansrtnhdG\ufb02aatodourfewnrstaeehclrreriisianbdtnsgeadyhow OcbtiooDbcroheufermlnem1tam9timse2otrin0snJdagBocdfrvkeitithtviCasiesehmeacsilinplashasuybsseinttegm AuBgadunisstthitcnao1gtv9eaa2rnf1fdaeFchCrtoeshrdabmerllrooeiocnsdkeB\u2014seusigntasrulleinv\u2014els WAapMsrhiuDlisne2egb6uta,omHt1nea9,obr2Dfleo0CNtwwS,ahmeStuoehiCrsntaahtupsalsresHottltihnysiroseoiafaotnoGntnnohrdrymtee,hHaUeeternsbsicevarelrese stAEaudr\u2019dgnsiuunescgnltteeo2ran4gry,sf1uuc9gsog2imoe0nestAsotosrffftrothhohruymamdrtrtahohegeleiunm Wink1let9er2rc0moHignaesnntsohme e FiisJrsupatldryBomCt1eiG8nc,itvsi1taot9uecnb2craee1ingdrecaauinslosst is AmDeerLcioecaemnwbipedhreas1rncm9ert2uiahb1rceeooGsntleroeaargrmncivshosatamuenOcms\u2013eittsttitoycyelasrcltheinomli:ne 255","1922 1923 1924 ,, ,, WE CAN\u2026 THE HISTORY CONSIDER THAT FIRST PIECE OF ,,OF ASTRONOMY IS A ORGANIC SLIME... AS BEINGTHE FIRST HISTORY OF RECEDING HORIZONS. ,,ORGANISM. Edwin Hubble, American astronomer, from The Realm A. Oparin, from Origin of Life, 1924 of the Nebulae, 1936 Edwin Hubble observes the stars through the enormous Hooker Telescope in California. RUSSIAN BIOCHEMIST IN OCTOBER, EDWIN HUBBLE Lewis (1875\u20131946) and Merle amounts of chemical energy THE YEAR BEGAN with another ALEXANDER OPARIN (1894\u20131980) suggested that certain stars Randall (1888\u20131950) published associated with them depending important development in the proposed a theory regarding the of the Andromeda nebula Thermodynamics and the Free on their chemical composition; \ufb01eld of astronomy. In 1920, origins of life. He claimed that were much farther away than Energy of Chemical Substances, this affects their tendency to react. British astronomer Arthur the \ufb01rst living things had evolved previously supposed\u2014even which explained chemical When a chemical reaction occurs, Eddington had proposed that from nonliving matter. He also beyond the Milky Way. His \ufb01ndings reactions in terms of energy. substances change from one form a star\u2019s energy came from the suggested that Earth\u2019s earliest were revolutionary, because at the In the 19th century, American to another\u2014and so does their nuclear fusion of hydrogen to atmosphere was highly reduced\u2014 time scientists thought that physicist Willard Gibbs (1839\u2013 chemical energy. According to form helium, a theory later that is, gases had an abundance the Milky Way was the extent 1903) had shown how the energy the laws of thermodynamics, supported by fellow British of bonded hydrogen atoms, just of the entire universe. associated with chemical the total energy stays the same. like molecules in organisms. The reactions could be quanti\ufb01ed. So if products have less chemical diversity of these gases provided At about the same time, Different substances have varied energy than reactants, then the other elements needed American chemists Gilbert some energy, such as heat, must as building blocks for these be released. In their book, Lewis molecules: methane as a source HYDROCHLORIC ACID SODIUM HYDROXIDE and Merle introduced \u201cfree of carbon, ammonia for nitrogen, energy\u201d values for different and water vapor for oxygen. chlorine oxygen sodium substances, which would enable Oparin suggested that the gases atom atom scientists to calculate energy reacted to form a \u201csoup\u201d of Cl atom changes associated with reactions. organic molecules, from which the O \ufb01rst living cells evolved. In 1953, H hydrogen Chemists also rede\ufb01ned acids American chemist Stanley Miller hydrogen H Na and bases. In 1884, 19th-century (1930\u20132007) would show that atom atom Swedish chemist Svante organic molecules could be made Arrhenius had shown that acids from nonorganic ones. Cl \u2013 hydrogen hydroxyl ion O\u2013 Na + and bases could be recognized by a prevalence of hydrogen Russian physicist Alexander ion H (H+) and hydroxyl (OH-) ions Friedmann (1888\u20131925) was respectively. Now, Danish studying the curvature of space. H+ chemist Johannes Br\u00f8nsted One of his models suggested (1879\u20131947) and British chemist that the radius of the universe hydrogen ion from O the hydroxyl ion Martin Lowry (1874\u20131936) was constantly increasing with hydrochloric acid HH from sodium independently de\ufb01ned them in time. The idea of an expanding hydroxide acts as terms of hydrogen ions alone: universe would be independently acts as an electron WATER MOLECULE an electron donor an acid donates hydrogen ions proposed by Belgian astronomer \u201caccepter\u201d and a base accepts them. Gilbert Georges Lema\u00eetre (see 1927); Lewis took this one step further and a few years later, the ACID\u2013BASE THEORY and explained them in terms American astronomer Edwin of electrons\u2014the negative Hubble would collect evidence This theory de\ufb01nes acids and bases in terms of electrons. Acids are subatomic particles that to suggest that galaxies were electron acceptors: that is, they release positively charged hydrogen determine the chemical indeed receding (see 1929\u201330). ions (protons), which readily combine with negative electrons. Bases properties of all substances. are electron donors\u2014they provide the electrons that the hydrogen ions accept. Many bases\u2014called alkalis\u2014release electron-rich hydroxyl ions, which then react with hydrogen ions to form water. MasuyfgrAoglmeesxtansnotdnhelairvtOilnipfgeatrehinvinoglvsed GialbnpeduratMbnLlCedieshrwthleheimTesRhiFacernarelmdeSaoEuldlnbyesntraagmnycoiecfss AmmeGarteiphcouearambngnldediasetBMhsiciecroirsakdinhbReoirennflgfaPtsihvpyiatsycices-,time SeBpretoelgewmlciaetbrvoesenurlisgk1ge0mepLasrotysouhpitashevardetteies FeIBbNrMueiawsrfYyoou1r4nkded in AlpEerixnoapsntotedushienenarsit\u2019svFpae\ufb01rrriseeesolddedlimuciesttaqisoenutnxnhapttaoaitontndhieng VGaillbeoenfdrcAetestLoacemnrwidbsiistanhnpagecudeSibdMltler\u2013ioscublhtcearetcsousuenrl-eetphsae, iorry OctobeArno6odubrEtsosdemiwdrveeinedtsaHhetunhbeMabbtillutekhlyaeWisay 256","2.5MILLION THE NUMBER OF LIGHT YEARS ANDROMEDA IS FROM EARTH Andromeda lies far beyond our own Milky Way. It has long arms spiraling out from a bulging center. astronomer Cecilia Payne, later, not a simple one, because bigger stars, as the more massive stars WAVE-PARTICLE DUALITY concentric rings on Cecilia Payne-Gaposchkin stars have disproportionately have shorter lifespans. luminescent screen (1900\u201379). In March, Eddington greater luminosities. However, Electrons \ufb01red through a thin sheet published his analysis of the with Eddington\u2019s mathematical In November, French physicist of graphite onto a luminescent relationship between a star\u2019s equation, it became possible to Louis de Broglie (1892\u20131987) screen form a pattern of rings. mass and its luminosity calculate a star\u2019s mass from its published an idea that would These kinds of rings ordinarily arise (brightness). Although a star\u2019s measured luminosity. This had revolutionize scientists\u2019 when diffracted (scattered) waves, brightness increases with its important implications for perception of atoms. He such as those of light, interfere with mass, the link between the two is understanding the life cycle of suggested that matter\u2014like one another. This indicates that light\u2014could have both particle- electrons, conventionally regarded and wavelike properties. He as subatomic particles, must have devised a way to calculate the wavelike properties too. theoretical wavelength of a particle, such as an electron. equivalent to Milky Way. Harlow Shapley and Heber Curtis He found that the wavelength Andromeda stars can be more (1872\u20131942). Shapley had argued values diminished to almost than 20 times the distance of the that the Milky Way de\ufb01ned the negligible levels for particles farthest stars of the Milky Way. extent of the universe, but above the size of an atom, but The revelation settled the Great Eddington\u2019s results supported for subatomic particles they Debate of 1920\u2014held at the Curtis\u2019s view that a multigalactic were more signi\ufb01cant. A few Smithsonian Museum of Natural universe was much bigger. years later, experimental History, Washington, DC, evidence would suggest that between American astronomers de Broglie\u2019s idea was right: electrons diffracted in wavelike ARTHUR EDDINGTON (1882\u20131944) ways, just like light. Born into a Quaker family, At the end of 1924, more than Arthur Eddington studied at a year after he had observed that Cambridge University, UK, certain stars were farther away before pursuing a career in than the other stars in the Milky astronomy. He tested Albert Way, Edwin Hubble announced Einstein\u2019s general theory of that Andromeda was not a relativity during a solar eclipse spiral nebula, as was previously in West Africa, and formulated thought, but an entire galaxy, theories concerning the life of stars. He was awarded a Luminous star knighthood in 1930, followed As a star slowly expodes, nuclear by the Order of Merit in 1938. reactions at its core release energy as light. Eddington\u2019s equation made it possible to determine a star\u2019s mass based on its luminosity\u2014in general, the brighter a star burns, the greater its mass. MaErdrcdehimlna5gatitAsoosrnntsahehnuxidprpllbaueimntwsinetohesenittyheof stars AmphePyrasihcuiicasl\u2014inisEstttwhtxWasacoraltotupmlsitfsagteiiroosatqnindicumglePaevprnseiotnltusoocsmpihipbalslevetaeftotehre NodveheBimstrhopbegaeolrrritey2icd5oleefLs-mowcuraaiitbsvteeesr British pShhyesriroiltnohggetiossnttrCdehitscachrolevreesr\ufb02sex IndiEaiSnnasattnyeedinnGdeeroxarpfmBlfauaoinnnsdceptaahharmeynrseydbiinecnAthitgslahabctlapsveaftiarloolatrerutrcdrieecbl-leaostseorns LentmhnOeaacrtithndoe-tbeJmeronaarnocten1itcsiboBioadnrnnesitdsiJbscionehrhgitbwnaeetseonms Derceepmograbtlseatxrthhie3easu0tM,nAEsiinlvdukedwgyrrgiosWnpeemrsaHetiyesuivndaibbogarbiuegtlasehgbnlayeodtrttthhthoheuagnht 257","1925 1926 ,, THE BEST THAT MOST OF US CAN HOPE TO ACHIEVE IN PHYSICS IS SIMPLY TO MISUNDERSTAND AT ,,A DEEPER LEVEL. Wolfgang Pauli, Austrian physicist, in a letter to Jagdish Mehra in Berkeley, California, 1958 Two ventriloquist\u2019s dolls became the \ufb01rst TV personalities when John Logie Baird demonstrated his television system to scientists of the Royal Institution and members of the press. SCOTTISH ENGINEER JOHN In May, John Scopes (1900\u201370), IN JANUARY, JOHN LOGIE BAIRD The \ufb01rst rocket LOGIE BAIRD (1888\u20131946) had of Tennessee, was arrested for was back showing off his Robert Goddard launched been experimenting with teaching Darwin\u2019s theory of improved television. This time it the \ufb01rst liquid-fuel rocket transmitting moving images and evolution, which was prohibited was to members of the Royal on his aunt\u2019s farm in now, using a semimechanical in the state\u2019s schools. He was Institution in London, UK. He now Massachusetts. Three device, he achieved it. In March, tried, found guilty, and \ufb01ned $100. achieved clearer images with people witnessed the event: television was demonstrated in tonal gradation of grays. his wife, his machinist, and a London department store. At Quantum physics had shown Although the images were still a fellow physicist. \ufb01rst images were silhouettes, but how the electrons of an atom blurred, Baird had increased the by October, he was transmitting existed in \ufb01xed energy levels, but picture frequency, so the of the enzyme urease. pictures with grayscale made Austrian physicist Wolfgang movements were smoother. Enzymes are substances up of 30 vertical lines running at Pauli (1900\u201358) went further found in living tissues \ufb01ve pictures per second. with his Exclusion Principle Austrian physicist Erwin that speed up the saying that no two particles Schrodinger (1887\u20131961) chemical reactions of examined earlier suggestions developed liquid fuel, Goddard\u2019s metabolism. When could occupy the same that matter was both particle- rocket reached a height of 40ft Sumner analyzed his quantum state at the like and wavelike in nature. (12m) in less than three seconds. crystals, he found that same time. Later, two Schrodinger calculated a they were protein. categories of particles particle\u2019s distribution of energy In August, American chemist In this way, he had would be distinguished\u2014 in space\u2014its wave function\u2014and James Sumner (1887\u20131955) demonstrated that matter-associated urged that the wave idea alone made a breakthrough in biological enzymes particles (fermions) that was critical to understanding biochemistry. By grinding up jack were proteins. obeyed Pauli\u2019s principle, reality. His work would be the beans, he had isolated crystals In December, another American and force-associated basis for quantum mechanics. chemist, Gilbert Lewis (1875\u2013 particles (bosons) that 1946), coined the term photon did not (see 1974). Six years after the New York for a unit of radiant energy. It Times had ridiculed his came to be used to describe a The German Atlantic suggestion that a rocket was a particle of light energy. Meteor Expedition began possibility, American physicist PVC, polyvinyl chloride (often to survey the ocean\u2019s Robert Goddard (1882\u20131945) called vinyl), made its \ufb01rst \ufb02oor and discovered an launched one. Using his specially unbroken ridge running from north to south. QUANTUM THEORY Atlantic Ridge The introduction of quantum theory was a pivotal absorbed or emitted by atoms. This is realized as point in early 20th century physics that began with speci\ufb01c wavelengths of radiation, each associated Mid-Atlantic ridge Max Planck\u2019s explanation of black body radiation with particular quanta of energy: red light The complementary shapes (see 1900). The theory is based on the idea that wavelength is transmitted by low-energy parcels of Atlantic coastlines energy exists in discrete parcels, or quanta (from and blue light by high-energy ones. Danish physicist suggest that they were once the Latin quantus, meaning \u201chow much\u201d). These Niels Bohr explained this in terms of the atom\u2019s joined together. This ridge parcels equate to the \ufb01xed quantities of energy electrons moving between energy levels, or orbits. shows where new sea\ufb02oor has pushed them part. MaLrodcgehiem2Bo5anJisrotdhranptuebslitcealellvyision JuhnyFegri1HeidnoDveiliasrmtcatniascmisusiLahhsinooeauwsnAidsndthiEega\ufb01ihltcetirbelnincydness LaAtteElax1mnp9te2iidcd5-iMtAGioetelntraemndotirasicncorvidegres JaLnoudgeaiiemmryoBopf2narho6isrivtsdJreaotpdethuelvnbeselvriicssaiiololnny FeEbnerrxuifcpuaolonraFfydiEnema7sxrmcamhlteouitnewstriaolonbpPeayrrittnihcceliepsle AupghiuynssdFiteecfp2irusme6ntndiPB\u2019dsaaremiuentixletsplDnhylitagranailvacpetaisornticolfes descriAbuegsuiussroteelaJansatziemynmgaenstehdsSesuahermonenwzpyesrmrotheteaitns Miasya5rrbJeeosgthienndsS;ohtnoispJetursliyal1c0lJWausasllyit\ufb01eCacraanBtndiaolcodnooiiaornnfsdfCeathsthsceeramtiebniredsmstoaillisp,id WNolofgveaexnmpglEabPxienacPrsulrulhiisniiscoinple JandueavreyloEprswhiins Smcfahoqtrruhomaednumintluaagmtmteiieocr-canwhloaafvneics G\ufb01ordMsdtaalrridcqhulai1du6-nfRcuhoeebl serrotthckeet 258","1927 ,, I WAS\u2026 ABLE TO TRANSMIT THE LIVING IMAGE, AND IT WAS THE FIRST TIME IT HAD BEEN DONE. BUT HOW TO CONVINCE THE\u2026 ,,SCEPTICAL SCIENTIFIC WORLD? John Logie Baird, Scottish engineer, in The Times, January 28, 1926 A computer-generated simulated image of a particle collision shows matter thought to have been produced microseconds after the Big Bang. green plants take carbon dioxide in THE YEAR STARTED WITH A the more accurately a particle\u2019s When Lema\u00eetre presented his in carbon dioxide the atmosphere MILESTONE in communication position is measured, the less conclusions to the British in photosynthesis, technology. On January 7, accurately it is possible to Association for the Advancement and release it in animals take in carbon a collaboration between the determine its movement, and of Science in 1931, he elaborated with food, and release American Telephone and vice versa. Later, the Copenhagen upon his theory, suggesting respiration it in breathing and Telegraph Company and Britain\u2019s Interpretation stated that it is the Universe had originated their dung General Post Of\ufb01ce opened the impossible to experimentally from a primeval atom. His bacteria, worms, \ufb01rst transatlantic telephone measure wavelike and particle- \u201cexploding cosmic egg\u201d model and fungi give out bodies of dead service. On its \ufb01rst day 31 calls like properties at the same time. anticipated the work of American plants and were made between London astronomer Edwin Hubble (see carbon dioxide animals add and New York. While Baird worked in London 1929) and was the forerunner of as they feed carbon to the soil on his television, the American the Big Bang theory. and respire A further development came Bell Telephone Company was in the \ufb01eld of quantum physics. also developing the technology. WERNER HEISENBERG fossil fuels Erwin Schrodinger had laid In April, Bell had a breakthrough (1901\u201376) (coal, oil, and the foundations of quantum when the company sent the \ufb01rst gas) store carbon mechanics with his description long-distance TV transmission Heisenberg studied physics until burned of the wavelike characteristics using the semimechanical at the universities of Munich of particles. Now, German television from Washington to and G\u00f6ttingen, where he met THE CARBON CYCLE physicist Werner Heisenberg New York. Five months later, Niels Bohr in 1922. In 1925, (1901\u201376) reasoned that the American inventor Philo he developed a mathematical At the heart of Vladimir Vernadsky\u2019s book The Biosphere are wave function of a particle Farnsworth (1906\u201371) way of understanding his ideas about nature\u2019s constant recycling of matter. Elemental could not be localized to a introduced a way of scanning quantum physics called atoms react and recombine in different ways. Carbon atoms in speci\ufb01c point in space and and transmitting electronically. matrix mechanics. He complex organic materials of living things\u2014animals, plants, and have a de\ufb01nable wavelength. Russian-American inventor derived his Uncertainty soil bacteria\u2014are respired into the atmosphere as carbon dioxide, Heisenberg developed this as his Vladimir Zworykin (1888\u20131982) Principle before working on before reacting to make plant sugars in photosynthesis. Uncertainty Principle. Its was working on similar technology the German nuclear energy consequences are extraordinary: at the same time, but it was project in World War II. appearance in its modern form. Biosphere. In it he described Farnsworth who made it a reality. Chemists had been making this some of the main ideas behind a chemical polymer since the concept today referred to as the In April, Belgian astronomer 1800s, but American chemist ecosystem: a system where Georges Lema\u00eetre (1894\u20131966) Waldo Semon (1898\u20131999) found living things interact with published a scienti\ufb01c paper a way of making it malleable and nonliving matter. Verdansky containing a revolutionary theory: less brittle. It would become one recognized that all life on Earth that the Universe is expanding. of the most widely used plastics. relies upon solar energy, and that particles of matter undergo Electron clouds Russian geochemist Vladimir a process of recycling. Modern quantum physics has Vernadsky (1863\u20131945) had revised the idea that atoms\u2014such been working on theories that as this helium atom\u2014have electrons uni\ufb01ed geology and biology, in \ufb01xed orbits. A more realistic Earth and life. He published his interpretation sees electrons thoughts in a book called The existing as clouds of probability. NosvcdeieemXns-tcbpirsrehaitbroyJetBcoosrrhgyhinrtsoiastBwpahehltlrsoongianrltaeprhpyret DeGcitelhbmeerbtteeLrrme1w8pishocotoinns JaBnruPitaoiAsrsmhtyTeOeG7\ufb01lfreer\ufb01itgncsceatreelantrerapapTanhlhendoClsentoaphemthelsaopennartenivcyaicnleadunch MaPracctaehstnyh3tZso1wOtdeBfoe\ufb01mrrcriytaefkiosyirnrhetaVeglliaesdvteiismrisoirn ApdreUislncGriveibeoerrssgeeasnLeexmpaan\u00eetdrieng OcStwoAbentdedhirePesrh1e\ufb01s6kprBisanitlgrefgooMensrastonBill:oooahgflitpsiontroe\ufb01thhnidsstoric VlaBdioimsprirhepecVuryebecrl,linisdnahegdessosckfrTyimhbeiantgter astroncDolaemsceserim\ufb01EeHbdsuewgbriabnBllaeHrxiustiieebssqhb:ulteehnece WdeepscrhcnaFyreleslirbeibcdeHrssuetchaiaoserqenyUnucenba2pnec3etrtPugrlarmtaitneincrtipyle ACpormilp7maBn\ufb01eyrecslhdltaeTlnmoeinlcoeganp-tlshrdttaoiersnnaltesetaemvnsisciseiosnion 2 5 9PhSdieelompttFoe\ufb01eanlrmerssnvttbriseseawiltroeoen7crsttsrthhyosentiecm AmericaMnHoinrovrreitsnootnnormasqnauWdBkaeaerJrtlotlzrhLseTeceaenlpb\ufb01oleohrcprskahtatootnreies","1895\u20131945 THE ATOMIC AGE Bakelite radio single loudspeaker hard molded Bakelite is a good insulator, which is why bakelite shell it is used for electrical appliances such as this 1950s Tesla Talisman radio. It is also tough and shiny, and can be dyed and molded into domestic appliances, including telephones and kitchenware. 1862 Parkesine 1887 Celluloid \ufb01lm 1909 Parkesine buttons Celluloid Bakelite Alexander Parkes American John Hyatt and Englishman American chemist Leo Baekeland develops the \ufb01rst Daniel Spill both develop a material \ufb01rst develops bakelite by treating plastic\u2014parkesine. called celluloid that is similar to phenol resin made from coal tar with It is used to make the parkesine. It is used to make \ufb02exible formaldehyde. It is the \ufb01rst entirely \ufb01rst cheap buttons. \ufb01lm for photographs to replace synthetic plastic. Not only can it glass plates. This is a crucial step be molded, like earlier plastics, but for movie-making. once it sets it is hard and heatproof. 1872 1894 1912 PVC Cellophane This extemely tough Viscose rayon Cellophane, a thin, plastic is \ufb01rst transparent sheet made developed in 1872 Two English chemists of processed cellulose, by German chemist is \ufb01rst developed. Eugen Baumann. produce a synthetic material It provides an airtight It is thought to be wrapping and is useful useless until the 1920s. called viscose (rayon) by for packaging food. reconstituting wood \ufb01bers in sodium hydroxide Viscose and spinning them Golf ball \ufb01bers into thread. Sweet wrappers 260","THE STORY OF PLASTICS THE STORY OF PLASTICS BY THE END OF THE 20TH CENTURY THE AGE OF PLASTICS HAD ARRIVED, TRANSFORMING MANY INDUSTRIES AND THE HOME Plastic is one of the most remarkable of all man\u2013made materials, used in everything from spaceships and computers to bottles and artificial body parts. What gives plastic its special quality is the shape of its molecules. Most plastics are made from long organic molecules known as polymers. In the mid-19th century, people knew that MILLION TONS 32 cellulose (the woody substance in plants) 28 KEY could be made into a brittle substance called cellulose nitrate. In 1862, British chemist Production Alexander Parkes added camphor to it, 24 Recycling producing a tough but moldable plastic 20 called parkesine. In 1869, American inventor John Hyatt created a similar 16 substance called celluloid, which was used to make photographic \ufb01lm by Kodak in 12 1889. Today there are thousands of synthetic plastics, each with their own properties and 8 uses. Many are still based on hydrocarbons (oil or natural gas), but in recent decades 4 carbon \ufb01bers and other materials have been added to create superlight, superstrong 0 1970 1980 1990 2000 2010 plastics such as Kevlar and CNRP. 1960 YEAR Production and recycling of plastics RECYCLING In recent years, there have been concerted attempts to recycle plastics, made easier by the establishment of Plastics are widely used because they are durable recycling centers and collection services. However, the and tough, but they are not biodegradable. Once slight rise in recycled plastic lags far behind the soaring disposed of, they linger in the environment for production of new plastics, as this graph clearly shows. a very long time. The vast amount of waste plastic now in the oceans\u2014maybe hundreds of millions ,, I THOUGHT I SHOULD MAKE SOMETHING of tons\u2014is damaging marine wildlife. It is REALLY SOFT INSTEAD THAT COULD BE important to reduce plastic use and recycle as much as possible. Not all plastics can be recycled ,,MOLDED INTO DIFFERENT SHAPES.\u00a0 easily, and it takes energy to heat the plastic to reform it, so recycling rates are low. Leo Baekeland, Belgian chemist, on inventing bakelite 1926 1935 1937 1966 Vinyl Te\ufb02on Kevlar American chemist Waldo Nylon PTFE, or Te\ufb02on, is invented American chemist Semon exposes PVC by American chemist Stephanie Kwolek spins to heat and a range of American chemist Wallace Roy Plunket. It is not heat-resistant \ufb01bers chemicals to produce made from hydrocarbons from liquid hydrocarbons. vinyl. It is used to make Carothers invents nylon, the \ufb01rst but from \ufb02uorine joined These \ufb01bers can be objects ranging from to carbon, and is often used woven together to make shoes to shampoo bottles. thermoplastic\u2014it is liquid when in frying pans. materials such as Kevlar. hot and sets hard when it cools. Best known for its use in stockings, it has Nylon many other uses. toothbrush Te\ufb02on frying pan Bulletproof Kevlar 1933 1936 1954 1991 Polystyrene Polypropylene CNRP Polyethylene Styrol is the oily This rugged plastic Japanese physicist substance in the resin resists many solvents Sumio Iijima rolls British chemists Eric Fawcett and of Turkish sweetgum and acids. It has carbon molecules trees. In 1936 German uses ranging from into nanotubes. Reginald Gibson create practical chemical company wrapping to bottles These can reinforce I G Farben use it to for medical plastic to make polyethylene in 1933, although it produce polystyrene. chemicals. strong, light CNRP. was \ufb01rst made in 1898. It is tough, soft, and \ufb02exible, and now the most widely Polyethylene Polyproylene Carbon nanotube rope molecule used of all plastics. crop tunnel 261","1928 MY\u2026 PART IN THE STORY WAS THAT I SAW SOMETHING UNUSUAL ,,AND APPRECIATED SOMETHING OF ITS IMPORTANCE SO\u2026 I SET TO WORK ON IT. Alexander Fleming, Scottish biologist, address to the University of Edinburgh, 1952 The Penicillium mold is a common fungus, spread by spores from the capsules seen here; some species produce the penicillin seen by Fleming. ,, THE YEAR BEGAN WITH 1926). Now British physicist Paul system so far: a transatlantic were often ineffective for serious ,, Dirac described a new form of transmission. After several false wounds. As part of his research, EXPERIMENTAL CONFIRMATION Schr\u00f6dinger\u2019s wave equation starts, success came at Fleming had been growing that characteristics and for electrons. As a result, he midnight, London time, on cultures of infectious bacteria. inheritance were determined by predicted a new class of matter February 8, 1928. Baird himself On September 3, in his a chemical substance. British called anti-electrons, which had brie\ufb02y appeared as a fuzzy image laboratory at St. Mary\u2019s Hospital, physician Frederick Grif\ufb01th positive, instead of negative, on screen in America. London, Fleming noticed that (1879\u20131941) studied strains of charges. Dirac\u2019s work was one of his cultures had become pneumonia bacteria, some of the \ufb01rst modern theory of In the wake of World War I, contaminated: a mold had which could cause disease, antimatter. The anti-electrons Scottish biologist Alexander spread on the culture dish. while others were harmless. would later be discovered and Fleming (1881\u20131955) was But signi\ufb01cantly, just around the Grif\ufb01th\u2019s work indicated that a renamed positrons (see 1932\u201333). developing ways of \ufb01ghting spreading mold there was a transforming factor could move It would also become evident infections that went beyond the region that was clear of bacteria. from the harmful bacteria to that corresponding antimatter routine use of antiseptics, which others and make them harmful particles existed for most too (see panel, below). This subatomic particles. ,,IF YOU ARE RECEPTIVE PAUL DIRAC (1902\u201384) factor would later be identi\ufb01ed as DNA (see 1943\u201344). In September the previous year, AND HUMBLE, MATHEMATICS British physicist Paul Dirac Britain\u2019s John Logie Baird had WILL LEAD YOU\u2026 held the Lucasian Chair of Another advance came in sent his technical assistant to Mathematics at Cambridge physics. Austrian physicist Erwin New York to prepare for the Paul Dirac, British physicist, November 27, 1975 University, UK, from 1932 to Schr\u00f6dinger had described the biggest test of his television 1969. He advanced quantum wave function of a particle (see physics by applying it to Einstein\u2019s theory of relativity BACTERIAL TRANSFORMATION Clearly, the mold was producing (see pp.244\u201345). His work on something that had killed the the quantum wave equations Pneumococcus bacteria exist rough harmless smooth deadly heat-killed heat-killed bacteria. Fleming took samples predicted the existence of in harmless (rough) and bacteria bacteria of the mold, cultivated it, and antimatter. In 1993 he shared harmful (smooth) forms. (strain R) (strain S) smooth deadly smooth deadly identi\ufb01ed it as Penicillium. The the Nobel Prize for Physics Frederick Grif\ufb01th found that following year he called the with Erwin Schr\u00f6dinger. bacteria can exchange a (strain S) (strain S active ingredient of his anti- chemical that changes these bacterial mold juice penicillin. A medical breakthrough of a characteristics. Heat-killed rough Despite his efforts, Fleming was different kind came in Sydney, harmful bacteria fail to cause harmless unable to isolate penicillin in its Australia. In 1926, physicians an infection on their own, but (strain R) raw chemical form, but he did Mark Lidwell (1878\u20131969) and if mixed with living harmless preserve his culture of mold. In Edgar Booth (1893\u20131963) had bacteria, a substance moves MOUSE HEALTHY MOUSE DIES MOUSE HEALTHY MOUSE DIES the following decades penicillin devised a portable plug-in from dead bacteria to living would not only be puri\ufb01ed then arti\ufb01cial heart pacemaker. ones, changing them into live strain S bacteria in blood manufactured, but also lauded In 1928 they used it to revive harmful forms that kill the sample from dead mouse as one of the \ufb01rst effective a stillborn infant. mouse and appear in its blood. antibiotic cures of bacterial infection (see 1940\u201341). JaFnrusehadtorerwarybinescoscktffahoGauarrsctmiehfb\ufb01aeaottmchfitotiehcnreaihlatasrlpaupnbessnfteasrnce FePbatruhulaeaDnertixyri-aism1cteapntrteceedrioctfs FepbhRryuassamicc(raipasytantte2cCdrk8heianIasgngncedrdosiiafrb)anpeoshsfeoltkihtgohehnatrsa MaErdpkgoarLreritdvaBiwbvoeleoelatlphsaatuncilsdelebmotahrkneeiirnr ftaont LaHtuepnh1Sgy9zasi2esrio8iondalltoena-igrntGiiivnsy1atog9trA3iavg2lebyca,iaeisdrrdbteveosinthcatriym\ufb01idberiendastCe BJu\ufb01ailrrysdt3dcJoeomlohronntLesoltergavietiseison Dutch sbchioholewomgsiistchtaaFltrspiitgclzaannWlaltelessdn,ualtsauetxeirns JaKnruaaisasklraaaytnan2due6wianApvInponealdcakoarnsneicsia FebrtruaanrsByaa8tilraJdnoshtiencnLTdoVsgs\ufb01iiergsntal SepteFdmliesbmceoirvne3grAasHclpecoxeisdanpeniiScntdatitel.allr,MilnlLyaoarntyd\u2019son 262","1929\u201330 46 BILLION THE SIZE OF THE UNIVERSE VISIBLE FROM EARTH IN LIGHT-YEARS This image taken by the Hubble Space Telescope reveals some of the most distant galaxies in the Universe. They are billions of light-years beyond the foreground stars. BY 1920 ASTRONOMERS HAD other words, the Universe is REDSHIFT AND BLUESHIFT REALIZED that the Universe was expanding. In 1929, US not centered on our Milky Way, astronomer Edwin Hubble The movement of a light- object recedes wavelength but rather that the Milky Way (1889\u20131953) explained this emitting object, such as a is \u201cstretched\u201d was a single galaxy among relationship and noted that the galaxy, affects its visible light many others. As the decade most distant galaxies were spectrum. If an object is light leaves the object REDSHIFT object appears redder passed, another still more receding at the fastest rate. moving away, its wavelengths extraordinary revelation came This later became known as appear stretched out. As object approaches wavelength to light. It appeared that the Hubble\u2019s Law. longer wavelengths belong to is \u201csquashed\u201d Universe did not have a \ufb01xed red light, this is described as a \ufb01nite size. Astronomers had Television technology took redshift. Movement toward the object appears bluer discovered that the light another step forward in June observer squashes up the spectrum of stars carried 1929 when the Bell Laboratory wavelengths, giving a blueshift. light leaves the object BLUESHIFT wavelengths that were in the US demonstrated the \ufb01rst Galaxies exhibit a redshift, so \u201cstretching out\u201d toward the red color image transmission. The they are moving away. end of the spectrum\u2014which they subjects they used were chosen called redshift (see panel, for maximum impact: a woman such as for hoses and \ufb01re- used its \ufb01ltrate to treat right). This redshift indicated that with \ufb02owers and the US \ufb02ag. resistant coatings. eye infections. these stars were moving away. In In April 1930, US chemist Photographs taken at the Paul Dirac (see panel, First color television Elmer Bolton (1886\u20131968) made Lowell Observatory in Arizona opposite) used quantum demonstration one of the \ufb01rst synthetic rubbers. in March 1917 had recorded the physics theory to Open doors reveal the working A derivative of acetylene, it was faint image of a body that correctly predict the parts. Light is directed at the later called neoprene. More became known as \u201cX.\u201d In existence of antimatter. operator through a scanning disk corrosion-resistant than natural February 1930, American In 1930, he published (center) onto photoelectric cells (left). rubber, neoprene was suitable astronomer Clyde Tombaugh Principles of Quantum for use in extreme conditions, (1906\u201397) con\ufb01rmed that X was a Mechanics, which for planet, and in May, it was given decades would be the its name: Pluto. standard textbook. Two years after Alexander Existence of Pluto Fleming made his accidental These two photographs of discovery of penicillin, this new the sky taken in 1930 on antibiotic had its \ufb01rst curative different nights show a use. British physician Cecil \u201cbody\u201d (arrowed) that has George Paine (1905\u201394), a changed position, which former student of Fleming, had indicates that it is closer taken samples of the mold to his than surrounding stars. workplace in Shef\ufb01eld, UK. In The body was a planet and August 1930, he successfully was given the name Pluto. JaCnzubeoacarrhnnyhodobs1lGwlia9ooec2cvgtra9hiltckueyimcaaCocniosis-dretisdidsuCeracsihrnclargnibegexeedrctoise Jupnucebol2lioc7ar, l1tley9l2de9evmiBsioeonlnlstrates De1c9ae2sm9DtrboAtouremneugroeeslma-rersidecisnraadgAtenadsrdaccrtrhieinbawgeeosmlaoegthicoadl sites Fe1b9Tr3ou0tmahCPrebyllaeyaud1xngie8seh,ttecXnocne\ufb01ormf s No1v9Pe3am0\ufb01inrbCpseeeetrrcnceii2ulpcr5Giole,erlitounsrsgtihneeg eMvaidrecnhcH1e5ut,hb1ab9tle2th9die(esHEsUeducnxwbripbiivbnaleeenrs\u2019sdseiLnagw) SepatneRdmoDbbueetrrct1hAH,-tbo1kou9irnt2enhs9roospmnwtBhaayraresninstnisnicdsecuiehosrFcxgtmrlspyeitelaazfsrrinoffrmuosmion DJiarancudaersyhco1rl,ieb1se9,s3lae0tleePprcaotcursaloiltnlreodns AmparEkiellms17ea,rs1By9no3tlr0thouenbtibcer Decemphbyesric4is,pt1rWo9po3ol0fsgAeasuonsefgtxnrPiiesaatuneutnrliicneos 263","1931 1932\u201333 ,, IT IS A MIRACLE THAT\u2026 DIFFICULTIES ,,HAVE BEEN SOLVED TO AN EXTENT THAT SO MANY SCIENTIFIC DISCIPLINES\u2026 ,,CAN REAP ITS BENEFITS. Ernst Ruska, Nobel lecture on electron microscopy, December 8, 1986 Ernst Ruska worked with the German company Siemens and Halske Between these bright galaxies lies to produce the \ufb01rst commercial electron microscope in 1939. invisible dark matter. THE 1930S WITNESSED THE hollow semicircular protons The \ufb01rst working cyclotron Meanwhile, chemistry was ERNEST RUTHERFORD HAD BIRTH OF TECHNOLOGIES that electrode \ufb01nish path Protons enter the cyclotron making advances. German PREDICTED the existence of a would help reveal the secrets here chemist Eric H\u00fcckel (1896\u20131980) second proton-sized subatomic of the microscopic world. \ufb01lament and, as voltage was using quantum physics (the particle (see 1919). In 1932, Physicists had devised ways creates protons switches between physics of ultra-small particles) British physicist James of \ufb01ring charged particles at from hydrogen electrodes, they are to build more realistic ideas Chadwick (1891\u20131974) examined very high speeds so that they drawn from one to the about the nature of chemical a type of radiation that could could study resulting collision other, speeding up each knock protons from atoms and products. They did this with time they cross over. found Rutherford\u2019s missing accelerators that shot particle particle: the neutron. Atomic beams through evacuated tubes hydrogen bonds and proposed a theory capabilities advanced in April, and used electric \ufb01elds to keep gas intake that described them in terms when British and Irish physicists them going. In 1931, American of the behavior of electrons John Cockcroft (1897\u20131967) and physicist Ernest Lawrence hollow semicircular within molecules. Ernest Walton (1903\u201395) split (1901\u201358) invented a new kind electrode lithium atoms into helium of particle accelerator with a atoms (see panel, opposite). spiral center called a cyclotron, problem using radiation with a In November, American designed to shoot hydrogen British physicist Paul Dirac ions. His \ufb01rst model had a smaller wavelength than that chemist Harold Clayton Urey had predicted the existence of diameter of 5in (12.5cm) and anti-particles of electrons (see energized ions with 80,000 protons enter at of visible light\u2014beams of (1893\u20131981) made a discovery 1928). Con\ufb01rmation came in electron volts (energy acquired center and spiral electrons. He used powerful about hydrogen atoms\u2014the August 1932 when American by an electron as it accelerates physicist Carl Anderson through the potential of one outward electromagnetic \ufb01elds instead smallest and lightest of all (1905\u201391) studied trails of volt). Lawrence\u2019s team went charged particles in a detector on to make ever more powerful of glass lenses to bend the elements. He found a heavier called a cloud chamber and cyclotrons. By 1946, his found that some electron-like laboratory at Berkeley, California, tube connected radiation\u2014the stronger the \ufb01eld, variety (isotope) of hydrogen. particles were positive instead of negatively charged. IT MAY to power source the greater the magni\ufb01cation A hydrogen nucleus contains a BRING TO LIGHT... 600,000 A DEEPER that could be achieved. Ruska\u2019s single proton, but this heavier KNOWLEDGE OF THE NUMBER THE STRUCTURE electron microscope allowed isotope (later called deuterium) OF VOLTS NEEDED TO ,,OF MATTER. had built a 173in- (440cm-) extremely large magni\ufb01cations, had a nucleus with an extra new SPLIT THE ATOM Ernest Lawrence, Nobel Prize device powered by 100 million and scientists could examine tiny subatomic particle that would speech, November 29, 1940 electron volts. molecules, possibly even atoms. not be identi\ufb01ed until 1932. The particles targeted by physicists are billions of times DEUTERIUM, OR HEAVY HYDROGEN smaller than the smallest objects that can be seen with Heavy hydrogen (deuterium) single light microscopes. Until 1930, all accounts for fewer than one electron microscopes magni\ufb01ed images in 6,000 of Earth\u2019s hydrogen using conventional optics that atoms. All hydrogen atoms refract (bend) light rays using have a single proton (positively single lenses. However, the wavelength charged particle), so have an HYDROGEN proton of light, which is measured in atomic number of 1 (see panel, single 10 thousandths of a millimeter, 1913). Normal hydrogen has electron restricts the amount of detail only one particle in its nucleus. that can be seen in objects that Deuterium has an additional proton and approach this size. German particle\u2014a neutron (particle neutron physicist Ernst Ruska (1906\u201388) with no charge)\u2014in its nucleus. DEUTERIUM found a radical way to solve this JaEnruunsaecersysytclLt2ohatewro\ufb01rnersntce MaRruecsnhakgca3iohnapEietentrheivdnceereaslGMpelttehrcmaoretxrmtao\ufb01oKganrtnnysnimopt\ufb01leecilclaoertfcoiottsrhncoeownpieth AuAgmHueasBrrtairec1rixaebrpntealoCcarbfoaironcmetMshaigbnrcghoiCiensmtlnatoisentonittsoiaoocnncmkdbey fsrhaugfm\ufb02ienngts FrJeonrlcaiohgdtaip-lamaChttiyumoesrnriaicestirhhsdaaoteytwImsrss,\u00e8hobnientuestttohtJribaanetmkesnseeissuCtrhoandswick Ja1n9up3ha2HyresGypiirecs1toireh,smtneetoxbWannpen-uelracrgnilnneebeuuiersstgoriaotnonnspdmtehusoesdeeslitotfo pAhuygsriuaJcsidastnitoAsKwkmayfarerdvloreiimGscsucaWtoctnhhovaeeemyrMisgniaglklayxy NColvaheyetmoanvbyeUhcrraye2dly6lredoHdigsadecreonouv,ledtlearsrteiurm CDourtnthceahlt-iuApslmaJvneaatrnnseiculNueaascnireetybrlpwois1ohnau9lotog3setggo2orieussasyrtstcnseathnfeorsis 264","22.5PERCENT THE PROPORTION OF THE UNIVERSE THAT IS DARK MATTER lithium helium atom with nucleus 2 protons and (3 protons, 2 neutrons 4 neutrons) proton proton proton fuses with helium atom collides with lithium and the with 2 protons lithium atom and 2 neutrons reaction splits it into helium atoms SPLITTING THE ATOM Transmutation of elements was \ufb01rst achieved by changing nitrogen to oxygen (see 1917). In 1932, John Cockcroft and Ernest Walton used a similar technique to split lithium. Lithium atoms are the lightest of any metal and contain just three protons. When an extra proton collides with an atom, a nuclear reaction occurs: the four-neutron, four-proton total splits into two helium atoms. In 1932, Hans Krebs (1900\u201381), suggested. This indicated the a German-born biochemist, existence of a type of matter not was looking at how the body previously detected. It became processes waste nitrogen. known as dark matter\u2014 Excess amino acids (the building because it neither emits nor blocks of protein) are recycled absorbs light. into carbohydrate. Krebs discovered the cycle of chemical In July 1933, Polish-born reactions used by liver cells to chemist Tadeus Reichstein process the nitrogen content (1897\u20131996) became the \ufb01rst into a compound called urea, person to make a vitamin by which is excreted by the body. arti\ufb01cial means when he made ascorbic acid (vitamin C). Dutch and Swiss astronomers Jan Oort (1900\u201381) and Fritz Positron\u2013electron tracks Zwicky (1898\u20131974) discovered Charged particles appear to shoot an anomaly in galaxies: they upwards and shower down, forming were much larger than the tracks. In a magnetic \ufb01eld, negative quantity of star material electrons coil one way and positive particles (positrons) the other. Fe1b9Cr3uh2eaavJedridaxwyemii2sncet7ckes,endfceoesrcotrhfibethees neutron AuCgadurilssetcAlelo2nacv,dtete1errr9orsnsc3tao-2hllneliekpdeoppsoaitsrivtitiercolenss 19b3io2Bl.oBpSgur.EiibHstviltasaoisnJhllhduodetaheisnonvneCo,lauuutnsioiefnysianorfgy gtheenoertyics Fe1b9pr3ru3doaavFrirdrykiet1zms6Zea,wvttiidecerknyce FfoerVbladrdeueisamlcerricyribt2rZeo4wsn,op1mrr9yiik3nci3crniopslceospoyf SeNpeEtwertnmhZenaebstuaettclrRhaleen1uar1dtehr,-eb1eisro9nfrn3oenorr3dgpfyuhstayusyrisceisint pSheypsticeimsintbAtehlrbee1Ur7GKt, eE1ari9fnmAt3esm3atrenGe\ufb02iynree;irechamaiernriagrinvneNeOasacchztoiebser AWCpoarclitlko1cn4rnos,ufp1tcl9ailt3ent2udhsJeEoorahfntnleoitsmhtiiucmAugOuosrtt 1gf7iov,re1se9xe3divs2aitdrJekeannnmcceeaottfer EFrenFbersretunEac\ufb01srhcrytasle1astl4ntetrag,pol1ohnk9nooi3nnmsg3eteacsrrletosrcvkice TavdJieutraulemysp1Rion1re,tCisc1ha9msr3tta3ie\ufb01kicniniaglly 265","1895\u20131945 THE ATOMIC AGE UNDERSTANDING RADIOACTIVITY THE DISCOVERY THAT SOME ELEMENTS ARE RADIOACTIVE TRIGGERED A REVOLUTION IN PHYSICS In 1896, French physicist Henri Becquerel found that compounds containing uranium produce invisible radiation. Within months, Polish scientist Marie Curie showed that the rays emanate from the uranium atoms themselves, and in 1898 she coined a term to describe the phenomenon: radioactivity. atom of beta particle alpha particle uranium-238 (electron) (two protons and two neutrons) atomic mass (total number of protons and neutrons) unchanged after beta decay atomic mass PIERRE AND MARIE CURIE drops by four Husband and wife team Pierre and Marie Curie carried after alpha out pioneering work in radioactivity, and discovered two decay previously unknown elements: radium and polonium. 238Uranium- 234Thorium- 234Protactinium- 234Uranium- aHyaUiTsenlh-aopad2elthfro3-umasp8l.nidefoideseso:ectrf4raacgu.yod5or.miaebonsaimlilcuiootminnve, , n2druTa4ehnudcedcdialeoairydraey.gescsHot.uiiaesvltlseafin-,bllsgaiefonetad: ntbBt7hoeuehet9ctoaal1puid.drdroTeesethc.cuoaeannyyrd.neceHushramugallofntb-ieglneisefrges: ui2duTs5ehnrba0cednaa,e0pciyru0r.kgo0mHottyoaeo-el2sn9fa3-2anrl4i,lsufpae.mhn:abder Marie Curie showed that the rays produced by 230Thorium- 226Radium- Radon- 218Polonium- uranium could cause air to become electrically charged (ionized). With her husband Pierre, she pTn7dids5reeheou,ccuo0tnaarto0riyysun0o,stmsnalyobbsea-sy.lan2eiHanr3d,lsga0pat.lnhwtfw-daoliofe: rTdrtlihaafeheoddce:riiauoi1ryunem,m6isus0-uc-20all2ti2ndy36ooee0.fta,\u2019hHsresaar.llfp-ha 222 pHd(irRshaaoaaidtulgdlhofighoo-nehllnniyisuft-ueerhm2ca:ro2ld-3irn2d2it\u2019uome-s1cal8iilvcn.eetuuidvtsee)s. found that this \u201cionizing radiation\u201d was also produced by other elements. The source of the AraHrfroacaohcdclmekfou-asnmlrlitcfagheuada:lnhais4oatcaridzorecaeanlteryaisvdasteeo..sfed rays is the atomic nucleus. proton large separation creates THE ATOMIC NUCLEUS small repulsive force The nucleus is composed of two types of \u201cnucleon\u201d particles: protons and neutrons. Protons carry large repulsive force proton positive charge, so they repel each other, but created by close proximity the \u201cstrong nuclear force\u201d binds the nucleons together. The number of protons in the nucleus strong nuclear neutron BALANCE OF FORCES indicates the element to which an atom belongs. force binds proton The repulsive (electrostatic) force between There are different versions (isotopes) of each protons is stronger the closer the protons element, which differ in their number of together protons are to each other. The strong nuclear force neutrons. A particular combination of protons and neutrons binds protons and neutrons tightly together, and neutrons is called a nuclide\u2014or, if unstable, but it only acts over an incredibly short a radionuclide. strong nuclear range. This is the main reason why larger force is stronger nuclei tend to be unstable. than repulsion 266","UNDERSTANDING RADIOACTIVITY RADIOACTIVE DECAY PERCENTAGE OF SAMPLE REMAINING 100 EFFECTS OF RADIOACTIVITY At some point, an unstable nucleus will Radioactivity generates heat, and this is disintegrate, or \u201cdecay.\\\" The two most common 90 harnessed by the radioisotope thermal types of decay are called alpha decay and beta generators that power unmanned space decay (see below). In each case, the nucleus 80 satellites and probes. Radioactive substances always has excess energy to lose, and that energy pose a threat to health because their ionizing is carried away by very short-wavelength, high- 70 after eight days, 50 percent effect can damage chemical bonds in compounds energy gamma radiation. The probability that a of the sample is left essential to life. This can cause a general particular atom will decay is \ufb01xed, but there is 60 malaise, called radiation sickness. Damage to no way of telling when it will happen. However, DNA inside cells can cause mutations that can in a sample containing a large number of atoms 50 after 16 days, 25 percent of result in cancers. Ironically perhaps, radioactive of the same radioactive element, it always 40 the sample remains substances are also used in medicine\u2014 takes exactly the same amount of time for half particularly in radiation therapy to treat cancer. the atoms to decay; that period is known as the 30 element's half-life. 20 10 8 16 24 32 40 TIME (DAYS) HALF-LIFE This graph shows the decay curve of a sample of a radionuclide with an eight-day half-life. Every eight days, the number of atoms of that radionuclide halves. nucleus (protons neutron has become and neutrons) a proton electron electron alpha particle beta particle (two protons (electron) and two neutrons) ALPHA DECAY BETA DECAY RADIATION THERAPY An unstable nucleus jettisons a particle made up of two Inside some unstable nuclei, a neutron may spontaneously During radiation therapy, radiation is used to kill cancer cells. protons and two neutrons: an alpha particle. This makes the become a proton, emitting an electron at the same time. The radiation must be carefully controlled because it nucleus smaller, which sometimes results in greater stability. In this case, the electron is known as a beta particle. can damage healthy cells as well as cancerous ones. RADIOACTIVE DECAY CHAIN 5.6 Elements are de\ufb01ned by the number of protons in the nuclei of their atoms. Decay changes the proton number, so OUNCES OF POTASSIUM ARE the \u201cdaughter\u201d nucleus is of a different element. Often the CONTAINED IN THE HUMAN daughter nucleus is also radioactive, and sometimes the BODY AND AROUND 4,400 process continues in a decay chain like the one shown here. ATOMS DECAY PER SECOND Lead- 214Bismuth- stable nuclide 214 lda2Tde0leehascceomdaa-ruyyi2en.,n\u00a01sHubdu4tiaes\u2019lestlrmsfgo-b.loufeifettehas:-b2e1t4a, 214Polonium- Lead- Palr2ieta7nsoadlmddaoio-alnpia2unihu1cguatm4htivepti-esesa2..rar1Htnl8isacuoellcefm-l,eliaiuftness:d, PisuvHseenoaercslloyfxot-natnslribihdefuelsomem:.r,0te-s.2lho0y1a0h4l0fa-2slifae. 210 lHipbTetyohsaaelealdofll-n-frpl2auiihuf1dneam0is:odtf2-naoe22ubrc1cmyla4eleyi.ediasoderfs. 210Bismuth- 210Polonium- Lead- pudBHeoniaslcdlomfae-nyrluiiguftteoohm:e-p5-2sr21odb10dae0uyt.asc.e bHTirnaehadaeilsfisno-sslauiaufcsesbte:sisvdi1tnea3aanp8stcoidoaeisanhoyssan..s 206 adlTeehsacetdaa-eyb2nlc0edh6noa. ufincthliisedelo, ng 267","1934 1935 The husband-and-wife team Ir\u00e8ne and Fr\u00e9d\u00e9ric Joliot-Curie continued the In the rain forest's ecosystem, the living organisms\u2014vegetation and animals\u2014interact with the nonliving air work of Marie Curie\u2014Ir\u00e8ne\u2019s mother\u2014after she died in 1934. and soil through the release and absorption of carbon dioxide and the exchange of nutrients. FRENCH CHEMISTS Ir\u00e8ne elements captured the neutrons. INSTRUMENTS TO MEASURE 480 MEGATONS (1897\u20131956) and Fr\u00e9d\u00e9ric At the time nobody thought that EARTHQUAKES date back to Joliot-Curie (1900\u201358) neutrons would have enough antiquity, but by the early 1900s THE ENERGY RELEASED IN demonstrated that it was energy to split a heavier atom. seismometers were being used AN EARTHQUAKE MEASURING possible to induce arti\ufb01cial But then, in January 1934, Fermi to detect movements in Earth's 9 ON THE RICHTER SCALE radioactivity. They created succeeded in splitting uranium crust. A sophisticated system nuclear reactions by making by bombarding it with neutrons. of levers generated a paper scale that would make it easier DuPont chemical laboratories high-energy particles collide with Fermi thought he had made trace showing the magnitude to compare the amount of energy in the development of new the nuclei of atoms. In February, the \ufb01rst transuranium element of an earthquake. Working in released by different earthquakes. polymers\u2014long molecules made they published their \ufb01ndings on (an elements with an atomic earthquake-prone California, Initially devised just for local use, by bonding smaller molecular making radioactive isotopes number above 92, uranium), but American physicist Charles the Richter scale was soon building blocks into chains. The (variants) of phosphorus and he had in fact achieved atomic Richter (1900\u201385) developed a applied throughout the world. team had already manufactured nitrogen by \ufb01ring alpha particles \ufb01ssion (see 1938). an arti\ufb01cial silk called polyester, at nonradioactive targets. 10 In February, German but was now working with a German astronomer Walter bacteriologist Gerhard Domagk different kind of building block. Meanwhile, Italian physicist Baade (1893\u20131960) and his causes devastation (1895\u20131964), described a The resulting polymer, called Enrico Fermi (1901\u201354) decided to Swiss counterpart Fritz Zwicky 9 over several hundred chemical dye with powerful polyamide 6-6, could be drawn use recently discovered subatomic suggested that the smallest, antibacterial properties. He out into tough \ufb01laments. It was particles called neutrons (see densest stars that could be miles\/kilometers reported on clinical trials later called nylon (see 1937). 1932\u201333), instead of alpha detected were made of neutrons. suggesting that the dye\u2014later particles, in nuclear reactions. He It was later con\ufb01rmed that a 8 sold under the name Prontosil\u2014 In July, a scienti\ufb01c paper in worked his way up the periodic neutron star is the remnant of causes severe damage could be used as a drug to cure the journal Ecology introduced the table to see how different a star that has exploded and is over larger areas common, dangerous infections. concept of an ecosystem. Its toward the end of its life. Later in the year, Italian author, British botanist Arthur Pistol shrimp 7 causes severe damage pharmacologist Daniel Bovet Tansley (1871\u20131955), combined The snapping sound of this shrimp's While experimenting with up to a range of 62.5 miles (1907\u201392) discovered the two key themes: American enlarged pincer produces enough ultrasound, German scientists chemical basis for Prontosil\u2019s botanist Frederic Clements\u2019s energy in a fraction of a second to H. Frenzel and H. Schultes 6 (100km) effectiveness. He found its active 1916 concept of vegetation as a release heat and light as well as noticed that high-frequency causes slight damage ingredient to be a sulfur-based community of different species stun its prey. sound affected photographic compound called sulfonamide. that changes over time, and 5 felt by many, but Sulfonamides were the most Russian scientist Vladimir plates\u2014indicating light causes little or important antibacterial drugs Vernadsky\u2019s treatise on cycles production. Known as until the introduction of penicillin of matter (see 1926). Tansley\u2019s sonoluminescence, this 4 no damage (see 1940\u201341). ecosystem was an ecological occurs when sound structure in which living creates underwater 3 During 1935, American chemist organisms interacted with bubbles that focus its Wallace Carothers (1896\u20131937) each other as well as with the energy a trillion times, 2 recordable, but not led a team of scientists at creating \ufb02ashes of light generally felt and heat. In the natural world, pistol shrimps 1 use this process to stun their prey. 0 Richter scale By linking measurable earthquake movements to environmental effects, Richter created a scale that could be understood by everybody. JaFneuarcamhriiyeuvEnenwsriiatcttoionmgliyc \ufb01ssion MasuysgIutgtpreisaessnrttaesnrditositvothaonaentoaef runetoraromnasltars Juplhypy4asptiHercroniuesdtntaufgcLocateriinro\u00f3tiganhSn\u2014eaz\u00edmntlhauerecdalnne\ufb01usalcerolsecf aharaibnomb JaCnhuinaavrtrheleyeensatmsrRtaaihcgqshncutiaetaulrkedeefsoorf FeCbaprrruoloaatdhtrueeyrcr2esc8aaplnoWledlyadahllnmiasyciltdeoeena6m-6, JuinlytorfAotrdhtuhecueercsTotashnyessclteeoymncept FebruDatohrmPeyrad1ogea5nkvntGedotileesborisaplhc\u2014cmartiretebhdrneeitas\ufb01lordfsrtug Augusdte1s6crRibuedsoltfhSecluahsboeeelonsfhtmiesoiomeattnoeaaprblioyclziesm aFrtDei\ufb01becosricfuarraliaprindtiysidioo1upna0cucotbtifoilvinsithyed AuOgtuisstB1a5rtCAohnmataeornrlaeidcsrane(Bna9ce2todue3rirvbbdmaeea3lr)tid,sh0uityv2sse8inpfght eare H. SscHoh.nuFolrtleeunsmzdienelesacsnrcdiebnece 268","1936 ,, ,, THOUGH ORGANISMS\u2026 CLAIM OUR PRIMARY INTEREST\u2026 WE CANNOT SEPARATE THEM FROM THEIR SPECIAL ENVIRONMENTS,WITH WHICH THEY ,,FORM ONE PHYSICAL SYSTEM. Arthur Tansley, from Ecology Journal, 1935 At the impressionable stage immediately after hatching, a brood of goslings assumed Konrad Lorenz to be their surrogate mother and followed him everywhere. Retina rods and cones IN 1936, DUTCH BIOLOGIST IT IS A GOOD MORNING Cells on the retina contain NIKOLAAS TINBERGEN (1907\u2013 EXERCISE FOR A RESEARCH pigments for light-absorption; 88) met Austrian biologist rods (sepia) have one kind, Konrad Lorenz (1903\u201389) at a ,,SCIENTIST TO DISCARD A PET but cones (green) collectively symposium, and the two men have three kinds of pigment spent many months discussing HYPOTHESIS EVERY DAY BEFORE for detecting different colors. aspects of animal behavior. BREAKFAST. IT KEEPS HIM YOUNG. Their collaboration marked the method for studying foundation of ethology\u2014 Konrad Lorenz, from On Aggression, 1966 the biochemistry the modern science of animal nonliving environment that of metabolism. behavior. They distinguished a steady state by processes of extreme weather conditions when surrounded them. between innate behavior that was internal regulation. By the early a keeper inadvertently left it out Danish ophthalmologist inherited and learned behavior 1900s it was understood how of its shelter one night. Commonly Rudolf Schoenheimer (1898\u2013 Gustav \u00d8sterberg that became modi\ufb01ed through aspects of the nervous system known as the Tasmanian wolf 1941) was a German biochemist published a study on the experience. Lorenz famously could make the body respond to or tiger, the thylacine was the studying metabolism\u2014the cellular makeup of the demonstrated how goslings can changes in circumstances\u2014for largest carnivorous marsupial. complex pattern of chemical retina at the back of the become attached (imprinted) example, initiating the \u201c\ufb01ght or Relentless hunting had driven reactions in the body. In order eye. In the 19th century, to humans just after hatching; \ufb02ight\u201d response to danger. Selye the wild population to extinction to understand these patterns, German anatomist Max Schultze Tinbergen studied the innate further explained how hormonal some years earlier. he found a way of tagging, or had identi\ufb01ed the layers of the courtship behavior of the changes were associated with marking, substances in the retina and drawn detailed stickleback \ufb01sh. stress, and that these changes The last thylacine body with detectable isotopes illustrations of structures later could affect the function of the Named Benjamin, this was the last (variants) of elements. By tracing called rods and cones (see 1866). The world\u2019s \ufb01rst practical body\u2019s immune system. thylacine in existence. A predator the pathways of the isotopes, \u00d8sterberg recorded the \ufb01rst helicopter\u2014the Focke-Wulf of kangaroos and wallabies, the he was able to work out the accurate count of the rods and Fw61\u2014took its maiden \ufb02ight In September, the last surviving species earned an exaggerated sequences of chemical reactions cones. It was later shown that in June. Built by German aviator thylacine died in Hobart Zoo in reputation for attacking livestock. taking place. Isotopic labeling cones have high sensitivity in low Heinrich Focke (1890\u20131979), Tasmania, after being exposed to would become the standard light intensity, but cannot detect it \ufb02ew using twin rotary blades color. Color-sensitive cones only extending to the left and right work in high light intensity and of the fuselage. Its \ufb01rst \ufb02ight are concentrated in an area of lasted just 28 seconds\u2014but it the retina called the fovea, which was far easier to control than collects light from a point of previous versions. focus at the center of the \ufb01eld of vision to form an image. In July, Hungarian biologist Hans Selye (1907\u201382) was the 7 MILLION \ufb01rst person to describe CONES IN THE HUMAN EYE the scienti\ufb01c basis for physiological stress. In the 130 MILLION 19th century, French physiologist RODS IN THE HUMAN EYE Claude Bernard had proposed that the living body maintained AmbieoMrcie\ufb01hcrraesesnmhdt oititsowhtcsSWrttyehasnnatdtlaeeilytlliliizssestahtielvliirnufse,catinodus NoDvadenimssiecublaoleBcfvooetroifnrvv2sPaee3mrttcohoinadmtteopsiosilntehnet FeSbzar\u00edltuatoaormdrByigcriLivbteieos\u00f3shmtAbhdepmatireanltty AmaseEtrrdipocwnuaoiobnnfmlhtiHshiesthueoregbNisabnellcTaeblhxuueydlacReelead,asrislesmkvi\ufb01igsciaanltgaioxniesJuSneAethnAsduNmebereasdrtodiocnemardnmicispepchyaoyevrsrteiicarcinlseedtvssiCdceaanrlllceedfmoruons SeBpeltanesdjmatiemtbsheinyirnl,a7tcchaienpeti,vity Novenmebureorlo1pg2eisrPtfooErrgtmuagssutMlehoseobeno\ufb01itzrosmt y DPeacteemntbOefr\ufb01nc1eu2crBlereregaiatiLrsicsetcteh\u00f3ihroasSniznf\u00edolarrd ManadrbcNehgikKinotolhcaneoarlassladtTubiLdnooyrbraeoetrfnignabzegnenihomanvailor Jurleyc4ogHnaiaznsessaSsmectlroyeeendsdisciatilon SeOptbesmerbvbaeetrgoiSTrnyhcsheinomPpCiaedalrtolaimtftoeinarlegnrsitachoepe BroNadolcvaaeusmnticnbhgeerCtsheo2\ufb01ilgrerBphvsro-tiisrdtriaieeostg\ufb01hniounsnliaetirrovnice 269","1937 1938 German-born, Professor Hans Krebs emigrated to England in 1933. He is shown at work in the laboratory The coelacanth lives in the deep ocean waters and although it was known at Shef\ufb01eld University where he was based from 1935 to 1954 and carried out much of his research. to local \ufb01shermen, paleontologists knew it only as a fossil. IN JANUARY, ITALIAN physicists ,, ,,A SPECIES IS A STAGE AMERICAN ZOOLOGIST DONALD experimenting with chemical Carlo Perrier (1866\u20131948) and GRIFFIN (1915\u20132003) was transmutation\u2014how one Emilio S\u00e8gre (1905\u201389) reported IN PROGRESS, NOT A studying the migratory behavior element could change into on a new arti\ufb01cial element STATIC UNIT. of bats, but could not understand another through a nuclear formed by atomic reaction. They how they managed to navigate in reaction. Transmutation had had made technetium in a Theodosius Dobzhansky, in Genetics and the Origin of Species, 1937 the dark. In the 18th century, been \ufb01rst demonstrated 20 years radioactive-contaminated part Italian biologist Lazzaro earlier by New Zealand-born of a cyclotron (see 1931). using it commercially to make crude oil using a silica-alumina Spallanzani (1729\u20131799) had physicist Ernest Rutherford toothbrush bristles. based catalyst. Sun Oil started up demonstrated that bats could \ufb02y (see 1916\u201317). But scientists In February, American chemist the \ufb01rst petroleum cracking unit around objects when deprived of believed that there were limits to Wallace Carothers patented In 1927, French\u2013American using the invention in March 1937. sight\u2014but not if their ears were what could be achieved, and that his new chemical polymer\u2014 engineer Eugene Houdry blocked. Working with the smashing the heaviest atoms, polyamide 6-6. By 1938, the (1892\u20131937) had invented a way In September, American American neurologist Robert such as those of uranium, could DuPont Company had called of cracking petroleum from electrical engineer Grote Reber Galambos (1914\u20132010), Grif\ufb01n not make much lighter atoms. this polymer nylon and was (1911\u20132002) built the \ufb01rst radio used a special ultrasound However, toward the end of the telescope. microphone to discover that bats year, Hahn reported that he had emit high-pitched sounds that achieved just that\u2014he split German-born biochemist Hans are beyond the range of human uranium to produce barium, Krebs found that citric acid hearing. Grif\ufb01n\u2019s theory was that a process known as nuclear could keep cells alive and the animals were using a form of \ufb01ssion. The Italian physicist showed that it was a key sonar, listening for echoes of Enrico Fermi had achieved a intermediary in a process that their sounds as they bounced off similar process\u2014although he provided cells with energy. The obstacles or prey. At \ufb01rst, his thought he had synthesized a process became known as the theory was derided, but by 1944 new element (see 1934). Later, citric acid, or Krebs, cycle. the accepted phenomenon was Fermi would oversee the \ufb01rst called echolocation. \ufb01ssion chain reaction (see 1942). Ukrainian biologist Theodosius Dobzhansky (1900\u201375) published The German chemist Otto In December, Marjorie Genetics and the Origin of Species. Hahn (1879\u20131968) was Courtenay-Latimer In it he showed how Darwin\u2019s natural selection (see 1859) could DISTANCE (IN METERS) 20 Echolocation be explained in terms of the in bats genetic makeup of populations 17m Bats hunt for food by and helped lay the foundations of 15 listening for echoes of modern evolutionary biology. their high-pitched calls 10 bouncing off their prey. The \ufb01rst radio telescope 10m The larger the prey, the American Grote Reber built his radio greater is the maximum telescope in his back yard. He used it 5 detection distance. to con\ufb01rm that radio signals could 4m be detected from space. 0 mealworm small moth big moth PREY JaannutdhatereE\ufb01ycmrhCsinlatieoratlrioSuteiPm\ufb01gecrriearlimeeralekme ent, MaKrrcceihbttrisHsicssauhanoecsiwsdsaklteihveaepts BrDitoi(slrahoJttoeshthrchy,niseeHCtnBescorttrreodiroysrwgulstnkscsftaoitaunulols)lrdtoieaengnsogrdcfaXrpi-bhreayy JaRnuuPsaysdorieatydsrnic8ssKprcuiahobppvyeeeissrtirs\ufb02cyaiusoitdf ity Febbrtrihsupetalre\ufb01wrorydtistouh2toc4ctnthoAytbmolonrmbnuyeslyeohamrncriansiadle SepRc\ufb01toerenbsmstetrrbrauecdocritmoGioptrneoleltoeetfestschoepBeritisAhstb\ufb01birouslrtoyXgp-isrrptaoasyWdrtheutdioeglciwrlfuefinarislnaamotgrcfhtsiDeitotNrhnuaAcs,tuare EantahdrelRy\ufb01o1rbs9tet3hre8atxtGpDweaoorlnaiumamlldedbndGotessremicbfo\ufb01hoennnogblsionatcrtasatteion UFSePbarptueoanlyrtraeyOfmgoC1fi\ufb01ra6isdcrtWeeeoart6hsl-leDa6rcusePaotnt HinMdb,eueannrydsb6itunsGgrignertriadogmieir\ufb02dvaseanhalmiioprpesmhsiepnt 270","1939 Made by German company Heinkel in 1939, the \ufb01rst jet aircraft\u2014the He178\u2014was the prototype for later models built for combat at the end of World War II. uranium-235 nucleus smaller product IN APRIL, GROTE REBER the atomic bomb. Einstein had described the behavior of nucleus (barium) DISCOVERED a new kind of prompted what would become electrons in forming ionic bonds astronomical object with his the Manhattan Project: the (different atoms bonding by neutron radio telescope\u2014a radio galaxy Allied program of research and gaining and losing electrons) called Cygnus A. This object development that would and covalent bonds (atoms nucleus splits into remains one of the strongest eventually unleash the only bonding by sharing electrons). In two fragments sources of radio signals that has nuclear weapons so far used particular, Pauling developed the (\ufb01ssion) ever been detected. in wartime combat. idea that shared electrons are not in a \ufb01xed position, but orbit burst of energy from more uranium-235 Six years after Hungarian-born Although many scientists left around both nuclei associated \ufb01ssion releases undergo \ufb01ssion in physicist L\u00e9o Szil\u00e1rd (1898\u20131964) Germany in the months leading with the bond. smaller product chain reaction conceived the idea of releasing up to World War II, others stayed LINUS PAULING nucleus and neutrons shower of ,, SCIENCE IS THE SEARCH (1901\u201394) excess neutrons FOR TRUTH\u2014IT IS NOT A American chemist and peace NUCLEAR FISSION CHAIN REACTION ,,GAME IN WHICH ONE TRIES TO BEAT activist, Linus Pauling is the only person to have received Nuclear \ufb01ssion releases atomic energy\u2014which is maximized HIS OPPONENT OR DO HARM two unshared Nobel Prizes. when the process is done in a way that initiates a chain reaction. TO OTHERS. His work spanned quantum Uranium-235 is favored as it is the most abundant \ufb01ssionable mechanics in chemistry and isotope and has plenty of critical neutrons. When the uranium Linus Pauling, American chemist and peace activist, in Liberation, 1958 the structures of complex nucleus (\ufb01ssionable nucleus) is bombarded with an external biological molecules, such source of neutrons, the uranium nuclei split into smaller energy in a nuclear chain behind to continue their work in as proteins. After World fragments. More neutrons are emitted as by-products, which in reaction, there was growing advancing science and War II he campaigned turn split other uranium nuclei in the chain reaction. concern among scientists that technology. The \ufb01rst jet engine against the further use Nazi Germany would develop an was designed and patented by of nuclear weapons. (1907\u20132004), curator at a with the dinosaurs. The atomic bomb. Italian physicist German physicist Hans von museum in East London, South coelacanth belongs to an ancient Enrico Fermi and German Ohain (1911\u201398). On August 27, Africa, was asked to collect a group of lobe-\ufb01nned \ufb01shes chemist Otto Hahn had already the \ufb01rst aircraft to \ufb02y under specimen from the local \ufb01shing related to the ancestors of the demonstrated that controlled turbojet power\u2014the Heinkel docks. There she found an \ufb01rst vertebrates that evolved to nuclear \ufb01ssion by a chain He178\u2014had its maiden \ufb02ight. unusual \ufb01sh that she could not live on land. Initially, the modern reaction was possible. In August, After the war, von Ohain was identify and, in the absence of coelacanth was known only in German-born physicist Albert one of many German scientists any technical support, reluctantly deep waters of the western Einstein, by now in exile in recruited to help advance had it stuffed. South African Indian Ocean, but a second America and working at scienti\ufb01c research in America as zoologist James Smith (1897\u2013 species was found in Indonesian Princeton University, wrote to part of Operation Paperclip. 1968) later identi\ufb01ed it as a waters in 1997. President Roosevelt expressing coelacanth\u2014a \ufb01sh until then the scientists\u2019 concerns. He later American chemist Linus known only from fossils and urged the US president to enter Pauling published his most thought to have become extinct the race to be the \ufb01rst to make celebrated book: The Nature of the Chemical Bond. In it he SeGpeCtreamdmrelarsbenvcetloehrprniaahb1sWtye5ishsneiacgitzpihsfspeut\u00e4esecninkoieennrrrgaeysa-tcatrions Derecnepuomrcbtlseeacrra1r\ufb017rsyOsinitotgonoHuat hn FeSbwprehuadyanisstrdihhycneOia1suntsbt1ctscdyolieLeGOFanietrsrttrieoism\ufb01\ufb01cMHcsahsanebiehioatxnsnnpieslrareoipnfotrhteed ApdrisCilcyoGgvrneourtsse ArRaedbioergalaxy DeAcmKemeaBrrboilacneHna\ufb02nrdnaoem(nbwpriihngeoeoehrxloitrptnogllagapiesnienitndnsrgihJtpohoaldawmdinseedtmtssae)yrmine OCctoomwbtopehuaarlntd2yp7boaeDlnynucaaomPluloiendndceten6sy-l6on DlifevoceuencmodoebofleafSfrcota2hune3tthhcAoAisafrsitca anFdeCbRarounbaaeadrrniytdaOnAGpmpepdhoeeelyrrisnmsgicchiecriaetiiVnbsinomoteefsleukmurtoprafposfensrsotfar AugusRtwo2orAistleebvseertlottuEraPaibrnneoasisututoietmdmiuensinfcoitnrbgoamn b OctoPbreerusr1igd1ienEngitntRshtoeeoiUtsnhSeewvAeartilttotoeamdsgeitacvoienbl,oomp b dLisacutoesve1ed9rs3a9sthaaPtcaoDunDlttoMTack\u00fcctialllplneoirnbisseoencts 271","1940\u201341 2.2POUNDS THE AMOUNT OF PLUTONIUM NEEDED FOR AN EXPLOSION EQUAL TO THAT PRODUCED BY 20,000 TONS OF CHEMICAL EXPLOSIVE The production method of the glowing radioactive element plutonium was initially kept secret because it was key to the manufacture of early atomic bombs. IN THE FIRST PART OF THE Earth\u2019s core. He stated that a normal bacterium swells cell wall breakthrough in understanding 20TH CENTURY, geologists used rigid but brittle envelope overlaid bacterium and bursts as cell weakens the way living cells process their data from studying seismic a much thicker semisolid layer, wall breaks down energy. In 1941, he reported that waves to conclude that Earth which was hotter toward the a phosphate-rich substance had a distinct core (see 1906). core. Today, it is now known that penicillin penicillin enters bacterium called adenosine triphosphate By studying the way waves were Earth\u2019s layers differ chemically molecule and inhibits enzyme that (ATP) was the chemical key to transmitted during earthquakes, and physically, with a silicon- builds cell wall the process. While ATP had been they deduced that the core was rich rocky surround and a core HOW PENICILLIN WORKS discovered more than 10 years made up of different materials that is roughly 80 percent iron earlier, biologists were only now from the rest of the planet. In (see below). The rigid surround Penicillin is an antibiotic\u2014a member of a group of chemicals able to recognize its function. By 1940, Canadian geologist includes a low-density surface that either prevent the growth of bacteria or kill them altogether. burning calori\ufb01c nutrients, such Reginald Aldworth Daly crust, with a mantle layer These chemicals attack targets that are present only in bacterial as carbohydrates and fats, living (1871\u20131957) published Strength made up of higher-density rock cells and not in infected tissue. Penicillin inhibits the process that cells harness their energy in the and Structure of the Earth, beneath it. many bacteria use to build their cell walls. As a result, the cell phosphate bonds of a pool of in which he identi\ufb01ed a multi- walls weaken, making the bacteria absorb water and burst. ATP molecules. When energy layered arrangement around In 1940, at University of is required\u2014such as for growth California, Berkeley, scientists respectively, after Neptune and Heatley (1911\u20132004) not only or movement\u2014ATP is broken Layers of outer Earth successfully made the \ufb01rst Pluto\u2014the two outer planets of demonstrated that its antibiotic down, unlocking the energy of its Earth\u2019s iron core is surrounded by transuranium elements\u2014those the Solar System. Publication secretion, penicillin, could be phosphate bonds to do the work a thick mantle covered in crust. The with an atomic number higher of the discovery of these used to cure infection (see (see panel, opposite). hard rock of the uppermost mantle than that of uranium (92). By elements was delayed until after panel, above), but that it could be and crust forms the movable plates using a particle accelerator, World War II as it was found that produced and isolated in useful While working at the Dow that account for drifting continents. scientists successfully made plutonium had the potential to be amounts as well. Medical trials Chemical Company, American elements 93 and 94. These used as fuel for an atomic bomb. began in January 1941, and engineer Ray McIntire (1918\u201396) solid inner techniques for the mass had been asked to develop an core new elements were named More than 30 years after production of the antibiotic insulating material as part neptunium and plutonium, Scottish bacteriologist Alexander would be developed by the time liquid outer Fleming had identi\ufb01ed the World War II was at its height. I WAS A core continental crust antibacterial properties of the ,,28-YEAR-OLD Penicillium mold (see 1928), At the same time, German- KID AND I rigid lower lithosphere is rigid Australian biologist Howard born American biochemist Fritz mantle called surface rock composed Walter Florey (1898\u20131968) and Albert Lipmann (1899\u20131986) ,,DIDN\u2019T STOP the mesosphere of low-density crust British biochemists Ernst Boris had been studying the chemistry \ufb02oating on a surface Chain (1906\u201379) and Norman of metabolism and made a TO RUMINATE oceanic layer of high-density ABOUT IT. crust mantle Glenn Theodore Seaborg, American semi\ufb02uid upper scientist, on being part of the team mantle called the that discovered plutonium, 1947 asthenosphere on which the lithosphere\u2019s rigid plates move 19A4l0pduwRaboneltrdgihstiheShnteaEDrslauadrScltytthurerengotfh Au1g9Fu4ls0oatrnHse2dhyo4c,Nowa,EwoanrrrnhcmdsoutWawrBne.p.HbuCaerhcai\ufb01atteelinerdy,iapleinnifceiclltiinon De1c9pe4hm0MybsAcSieMmcenriaiseelb1ntlrwaso4aicnrm,EeagaldneesnwdmydinnpeGtlnhMulteet,.noslinnaztieTue.rma Jatnriuaalsryof1p9e4n1icMilelidnicbaelgin 19L4i1pthmFeraiftnuznnAcdltebiosencrtroibf eAsTP CheFmedbiissractusnosavduMrebSarysartt2tmhai7nenu,cKr1eea9ladc4Rmia0ouerabbnceotnniv-e14 scaienJndutinPsehtsi8lEi,pd1Aw9b4ine0lMstAho.menMedacrinMsicnncaioeolnluvpaentnurcyneioufm bEiorcnhsDetemBci.esCmtdhEebaadseniwcnrtriaabi2brni8deod,tAei1Bcvb9rirrd4ieate0iishnsnihacsbmetaacontfceeria 1941ACneadsnrteaimwdiaaMtnecasKsoetflrlodatneeromemmppaesekrpreaastcuere de1vfi9so4ea1smRaeadwyapMyocltyloIansmttteisyrratreyekcrenaoelfl,oeadm 272","1942 2MILLION TONS THE AMOUNT OF DDT USED THROUGHOUT THE WORLD SINCE 1940 In the 1940s, aircraft were used to spray DDT over the widest possible areas. Its polluting effects lasted for many years. of the war effort. He used a IN 1939, SWISS CHEMIST PAUL 8% 1% Chicago pile-1\u2014built beneath a Manhattan Project\u2014the US material called polystyrene\u2014 HERMANN M\u00dcLLER (1899\u20131965) uranium oxide uranium football stand at the University government-led Allied research a type of plastic originally made had discovered that a chlorine- of Chicago. The reactor and development initiative that from tree resin\u2014and chemically containing chemical called DDT 91% bombarded a sample of uranium produced the \ufb01rst atomic bombs treated it to produce countless (dichlorodiphenyltrichloethane) with neutrons to trigger a chain during World War II. bubbles in the manufacturing was lethal when it came in GRAPHITE reaction, which was controlled process. The resulting foam contact with insects, and could with neutron-absorbing cadmium Enrico Fermi polystyrene, trademarked as possibly be used to control insect Enrico Fermi\u2019s nuclear reactor rods. It ran successfully for four In 1938, Enrico Fermi moved to the styrofoam, was inexpensive pests. In September, the US Neutron-releasing uranium pellets and a half minutes before Fermi US with his Jewish wife to escape and lightweight. received the \ufb01rst stocks of DDT were at the heart of the nuclear chain stopped the process. This event Italy\u2019s anti-Semitic policies. He to begin using it on a wide reaction in Fermi\u2019s reactor. Graphite marked a critical step in the received the Nobel Prize for Physics THE ROLE OF ATP scale. During World War II, blocks slowed the neutrons. the same year. IN METABOLISM DDT was used widely to control lice-born typhus as well as kill bacteria. They investigated the Plant and animal cells contain malaria-carrying mosquitos. process whereby some bacteria powerhouses called In the post-war years, DDT mutate to become genetically mitochondria (sepia). They are application increased further as resistant to infection, and in 1943, packed with membrane folds agriculturalists began using it to explained that this happened that carry the molecular kill crop-eating pests. However, spontaneously, and was not machinery needed to make a by the 1960s, the world had induced by the environment. chemical called adenosine realized that DDT poisoned the triphosphate (ATP) from environment by accumulating in Scientists had already high-energy foods. Energy food chains (see 1962), and the demonstrated the practical from ATP is released to order chemical that had earlier earned possibility of a self-sustained to drive cellular activity, such M\u00fcller a Noble Prize was nuclear reaction in a controlled as building DNA and protein. banned from most countries. setting (see 1938). In December, Italian\u2013American physicist Enrico Two American biologists, Fermi oversaw the operation of German-born Max Delbr\u00fcck the world\u2019s \ufb01rst nuclear reactor\u2013 (1906\u201381) and Italian-born Salvador Luria (1912\u201391), embarked on a collaborative study of bacteriophages (also known as phages)\u2014viruses that infect and ,, ,,THE ITALIAN NAVIGATOR HAS LANDED IN THE NEW WORLD. Arthur Compton, Director of the Metallurgical Laboratory, University of Chicago, in a coded message referring to Enrico Fermi\u2019s success, 1942 No1v9se4cm1BieeAbsnamehttdiroshelwtep1ersai5iacrtGr,hnaeteandifcotfuEergglcdeatewnrseaebsrnydzprTyreaomgtduueulmsaceting FeEbnJrgauldmiasefrhetreysopc2mSht7styatsrhniaceldeisSiyotuHwneayves OcStwoHbeaddeneirwsnsh3ecasrvpiebAhseylfssivni\u00e9cenlilsieqtcutirdosmagnetic DeEcnterhminecuob\ufb01tcheFrlerseetra\ufb012msrrescilthof-navseuinurcsslreeteaaeairsnctreiedoanctinor Sep\ufb01wterisdmtebs-saecmraUplelSeutAsysproeehf,cuDteosDivcfTeroosnfmotrrolilce enOgicnteoeDbBroesrrratnWhu3beeneGr\ufb01ranegrnthrseedmetrsrsWtapuvnleaaocrlucntfoeenVrsrc2mshrfuoolfckaet Max DLelubrria\u00fccdakgeremainsnoeedntsiSscptaormlavnatutedatinaonthtrebiaooatnucstselyria 273","1943\u201344 1945 These are the control panels of the \ufb01rst electronic programmable computer\u2014 Colossus\u2014which was used to decode German messages during World War II. proteins and carbohydrates are harmless bacterium that if proteins and their enzymes passed to harmless bacterium bacterium unchanged were removed from bacteria, another chemical present\u2014 harmful DNA is passed to harmless bacterium DNA\u2014could still cause bacterium is harmless bacterium bacterium becomes transformation. This showed that broken down, harmful genes are made of DNA, not and its DNA protein, as was previously thought. separated from proteins and Quinine, a naturally occurring carbohydrates substance found in the the bark of the South American cinchona DISCOVERING THE NATURE OF DNA tree, had long been valued for its antimalarial properties. Supply Oswald Avery sought to identify the chemical substance that could had become dif\ufb01cult during transform harmless bacteria into harmful bacteria. Avery killed World War II, but in May 1944, harmful bacteria and broke them down into their various chemical American chemists Robert components (protein and carbohydrates and DNA). He added Woodward (1917\u201379) and each component in turn to harmless bacteria, and he found that William Doering (1917\u20132011) only the bacteria\u2019s DNA could cause a change. announced that they had successfully manufactured it. Austrian physician Hans DURING WORLD WAR II, the and inheritance was made in Asperger (1906\u201380) had been pioneering code-breaking work 1944. Canadian-born physician studying mental disorders in of British mathematician Alan Oswald Avery (1877\u201379) wanted children and formalized the Turing (1912\u201354) triggered an to identify the transforming diagnosis of autism. He outburst of computer technology. principle \ufb01rst identi\ufb01ed by examined a group of autistic One of the earliest electronic ,, digital computers was built in WHY DIDN'T AVERY GET THE Britain in 1943: Colossus. ,,NOBEL PRIZE? BECAUSE MOST French engineer \u00c9mile Gagnan (1900\u201379) modi\ufb01ed a gas- PEOPLE DIDN'T TAKE HIM regulator valve for a new use. SERIOUSLY. Working with French biologist Jacques Cousteau (1910\u201397), he adapted the device so that it James Watson, American geneticist, from Nature, April 1983 could be used to control the air supply in an aqualung. This Frederick Grif\ufb01th (see 1928). children who, because of the invention would revolutionize Avery performed similar nature of their way of learning, underwater exploration. experiments to Grif\ufb01th, but he he called little professors. Their A major step forward in analyzed the genetic factor in condition later became known as unlocking the science of genes more detail. He demonstrated Asperger\u2019s syndrome. MaCroCcnohbslte1orPg9suais4cnru3tksiso,ancUtoKoBmfleptucthelrey SuJmancmeqawueqerucsoa1Clm9u4opnu3rgsetsesaeudt-easitrs Fe1b9ar4nu4AdamOMrCyseaaMwr1ncicgaLc,aCelaeddannoiareAdsntsvycaeaiancernrodynedntMim\ufb01sartasmcdlCeytonhflraiontm DNA JuAnsfepoe3lrarm,tgA1eeso9rrpf4beda4ereucHgstoeicasmrrnmi'sebsetkshsynanaotdwwrnoomausled FeDbodrreuocsathchoreryfymibpHeieocsnaditlgchskieltilnricunecntturrael MaArmJcaehLcraoiCcwbahnrnMaeercawnlhrecieeesnlmeCsGmkoilseyrte,nysndetle\u2014lniisrnoo,mlaatneetdhaium Aprtrila1n,s1a9tl4ast3hingatAnitcasetlynsescl(tierSespymIlGphatoSusnAneLcYh)ed WooMdwayaDr1od9e4arn4intdhRgeWodbsieleylosirnacfttrmqhiubeeisniisne Decezmdoeobsleocrgrii1bsb9ete4sDh4otahAnveiamolorcderooriGieifncernbsaictfanaht\ufb01thtosnieolaontnceadrtmion FebprhuyasrimcyLiae1ipnbt6hebRAonyadmidcyoeeimlfsrloiicdcnnreaidblbniyveLesm.raionugth 274","This polarized light micrograph shows crystals of the vitamin folic acid (folacin), which is needed during pregnancy for normal development of the baby in the womb. AS WORLD WAR II ENTERED ,, WHEN YOU SEE SOMETHING THAT ITS SIXTH YEAR, so did the Manhattan Project\u2014the Allies\u2019 ,,IS TECHNICALLY SWEET, YOU GO atomic bomb research project (see 1939). The idea of an AHEAD AND DO IT. THAT IS THE WAY arti\ufb01cial nuclear chain reaction IT WAS WITH THE ATOMIC BOMB. had been developed by J. Robert Oppenheimer, American physicist, testifying in court, 1954 Hungarian-born physicist L\u00e9o Szil\u00e1rd (1898\u20131964), but it did them). Both release energy, but the neutrons emitted by the not become a reality until 1942. only \ufb01ssion could be achieved radioactivity trigger instantaneous Nuclear reactions are processes arti\ufb01cially. Fission happens decay and release massive that change the nuclei of atoms, naturally when radioactive amounts of energy. On July 16, DOROTHY HODGKIN (1910\u201394) either through \ufb01ssion (splitting elements decay, but it can be the US Army exploded the Born in Egypt, Dorothy them) or fusion (combining induced by bombarding Manhatten Project\u2019s \ufb01rst Hodgkin studied chemistry at Oxford University, UK, and elements with neutrons (see atomic bomb in the New Mexico earned a PhD in the study of biological substances called The world\u2019s \ufb01rst atomic bomb 1938). If elements capable of desert\u2014the Trinity Test\u2014 sterols. She studied the The \ufb01rst bomb was exploded by the sustaining a nuclear \ufb01ssion chain witnessed by fewer than 300 three-dimensional structure US Army in the early hours of July reaction (\ufb01ssile material), such people. Three weeks later, two of complex molecules such 16, 1945, at Alamogordo, in the New as uranium or plutonium, are atomic bomb attacks on Japan as cholesterol, penicillin, and Mexico desert. It had the energy condensed to a critical mass, (on Hiroshima, and Nagasaki), insulin. She was awarded the equivalent of 20,000 tons of TNT. 1964 Nobel Prize for her research into vitamin B12. helped bring World War II to an British writer Arthur C. Clarke high-explosive lens conventional end, but hundreds of thousands (1917\u20132008) was looking to the chemical explosive of lives were lost. future. Among his many predictions was the idea that plutonium sub-critical pieces Scientists had already geostationary satellites, core of uranium-235 developed X-ray crystallography, (satellites that would sit at a compressed pushed together a technique that could be used to \ufb01xed point in space relative to work out positions of a crystal\u2019s Earth\u2019s position and rotation atoms (see 1912), and it proved period) could be used for telecommunications. This especially useful for studying became a reality less than 20 years later. IMPLOSION ASSEMBLY GUN-TYPE ASSEMBLY structures of complex biological molecules. By July, British BUILDING ATOMIC BOMBS chemist Dorothy Hodgkin had helped resolve the complex Two methods have been used. In the implosion method (used for structures of both penicillin the Trinity Test and the Nagasaki bomb), explosives compress a and cholesterol. central core of \ufb01ssile material. In the gun-type assembly (used on In August, chemical company Hiroshima), elements were pushed together. The naturally emitted American Cyanamid announced neutrons strike neighboring atoms, causing a chain reaction of that it had made folic acid\u2014 \ufb01ssion events (see 1938), which releases huge amounts of energy. the vitamin needed for healthy growth in the developing fetus. JuTleyUs1tSn6i,uniTcsNhlteeehaweTrr\ufb01Meinrxeisptxtyliocasorit,oi\ufb01ncial AuAgASuAusEFptneiB6morolafAapoetlLroUiGontmiSrtasgteiyiloBsce\u2014ns-bB\u2014d2aoor9smtoyhs)pbeesom(nacbonHldiyreonsahmimeda AuAgmaunesenrtxiocct3urra1aynncscttCeeaysdlastnahonaafmdtfoipitdluhicraias\ufb01ceidd SeApmBteeuLmrroirecbuilaseeisnmrCWcu1ehn3enenrtmnianeimgsrthesiasromicliauatmnedthe HoJCdugalkyrlis2nisc3calierenDynddostertiBsaostrltcihHrstoiyitfasbrchareuhrcfotyohtlureemrseteorfol Augnuaatsmotame9gdiAucBnbso-oectmcykopsbnecda(acrBosFdsd-are2eot9mnpMaNsbmaalynge)adosnaki McaoytnhD\ufb01rorermeo-ptsdheisynmtiHrceuoinlcdlstigiunokrnwienaiotlhfmaap OctColbaergrkeeAcotordhstmeehysnumicdcrruehiCbanr.eoiocsnsfaoaatuitoesnllsite 275","6","THE INFORMATION AGE 1946\u20132013 As electronic devices repeatedly shrank in size and cost, digital power expanded exponentially, ushering in a new era of information technology, global communication, and exploration into the remotest parts of the Universe.","1946 1947 238,000 The Bell X-1 manned airplane was launched from the bomb bay of a Boeing B-29 to reach a record-breaking altitude and break the sound barrier. MILES THE DISTANCE FROM EARTH TO THE MOON, AS SHOWN BY PROJECT DIANA The distance between Earth and the Moon was measured by bouncing a radar signal off the Moon. THE VERY FIRST CONTACT Moon, it demonstrated that within the sample resonate at beam splitter mirror WITH A SPACE BODY was made signals made on Earth could be characteristic frequencies. This on January 10, when the US used to communicate in space. technique was subsequently laser subject Army Signal Corps successfully used to study the structures beam photographic detected the echo of radar The same month saw the of molecules, and was later plate re\ufb02ected from the Moon\u2014just publication of studies of a modi\ufb01ed to produce images of 2.5 seconds after it was sent. phenomenon that would bigger internal structures, such mirror Project Diana was initially revolutionize medical imaging: as those of the living body in MRI established to examine whether nuclear magnetic resonance (magnetic resonance imaging). long-range radar could detect (NMR). Swiss physicists Felix incoming missiles, but it marked Bloch (1905\u201383) and American American biologists Edward the start of the US space physicist Edward Purcell Tatum (1909\u201375) and Joshua program as well. In addition to (1912\u201397) showed that when a Lederberg (1925\u20132008) found determining the distance to the sample is exposed to an intense that bacteria had a sexual process magnetic \ufb01eld, certain nuclei similar to that of more complex organisms. When they combined magnet tube containing control console different strains, a few bacteria HOLOGRAMS creates sample measures developed new abilities that the magnetic resonance original strains were incapable of Hologram technology involves directing a laser beam onto a doing individually. They discovered photographic plate using mirrors. The beam is split so that part of \ufb01eld that bacterial cells were binding it bounces off the subject before hitting the plate, while the other together and exchanging part hits the plate directly. This produces an interference pattern, genetic material in a process which is photographed. A 3-D image is made by shining a laser known as conjugation, thereby onto the negative at the same angle as the original beam. sharing chemical capabilities. radio frequency This process has important IN 1947, AMERICAN PHYSICIST Marinsky (1918\u20132005) announced signal in implications, such as the spread LUIS ALVAREZ (see 1980) the discovery of radioactive of antibiotic resistance. oversaw the construction of the element number 61, named trace recorder \ufb01rst proton linear accelerator promethium after the Greek god In July, the US undertook the in Berkley, California. In the same Prometheus. Promethium is a NUCLEAR MAGNETIC RESONANCE \ufb01rst post-war nuclear test year, American physicist William rare earth element, which closed using the same sort of bomb Hansen (1909\u201349) produced the the gap in the periodic table. The magnetic resonance of atomic nuclei can be used to detect the as dropped on Nagasaki in \ufb01rst electron linear accelerator chemical components of a substance. The atomic nuclei in a test 1945. Called Test Able, it was at Stanford University, California. In October, US Air Force pilot sample that has been placed in a strong magnetic \ufb01eld absorb conducted on the Bikini Atoll in Particle acceleration is used Charles \u201cChuck\u201d Yeager (b.1923) and emit electromagnetic radiation at characteristic frequencies. the Paci\ufb01c Ocean, and was to study the building blocks became the \ufb01rst person to break Scientists can use this to establish the kinds of atoms present in designed to see the effects on of matter, and it has practical the sound barrier. He \ufb02ew Bell the sample and determine its chemical structure. 78 experimental ships anchored applications, such as in the X-1 and achieved a speed of Mach in the lagoon\u2014some carrying treatment of cancer. 1.07 or 815mph (1,311kmph). living test animals. More than 60 nuclear tests would later be In September at the American Hungarian\u2013British physicist carried out in the Bikini Atoll. Chemical Society, Jacob Dennis Gabor (1900\u201379) \ufb01led a patent in December for a JaPnrueoxajtperhecysetrp1isDma0ticaaeernntpatormfroatgahdrreaakrmUs S Fecboarmtupaaurptyree1rs4issEciNnontIrAfoeCdreuncceed Jubloym1bFitressttaattosmeiac Ocrteobcbaoecmtreb1rin9iaaGtiseiondneetisniccribed FirlisnpterpaBorrdeoLurataokccbenecolederlayaettrNoaLratayot,wiroCrniaesalnilfcoernia Secph(te1em9om1fig8sbpa\u2013trep2oJr0ami0Ance5omtt)bhheaeMirnuipnamceroai;urnni\ufb01nsolckdleiyinscgitsainoblltaehteiolnast First NMJRanpsuupaberlciytsrhaed SFeiprstctethrameinambtlsieocrtdahen2esc1rcearrpibyed OcBttoehlbalenXr-s11p4e\ufb02eAiedisrcofrfaassfotteurnd 278","1948 200INCHES THE DIAMETER OF THE PRIMARY MIRROR OF THE HALE TELESCOPE For 45 years, the Hale telescope was the world\u2019s biggest effective telescope. It is still in use today, collecting data on around 290 nights every year. Proton linear accelerator IN MARCH, American physicists Takahe Observatory was ERWIN CHARGAFF The \ufb01rst device to accelerate protons Julian Schwinger (1918\u201394) and Since their rediscovery in 1948, completed. Its dome (1905\u20132002) in a straight line was a 40ft (12m) Richard Feynman (1918\u201388) the New Zealand takahe have been houses the Hale construction. It helped advance introduced a new \ufb01eld of science: moved to predator-free islands as telescope, named after In studying the chemistry research and understanding of quantum electrodynamics. It part of a conservation program. American astronomer of biological molecules, fundamental particles of matter. described how electrically George Hale. This Austrian-born chemist Erwin charged particles interacted with pp.344\u201345) occurred in \ufb01xed telescope\u2014\ufb01rst used Chargaff made breakthroughs theoretical technique for packets of electromagnetic proportions. Hydrogen and helium by astronomer Edwin in a range of topics, such as producing 3D-style images, radiation, called photons. The are still the most abundant Hubble\u2014has aided in the how blood clots. He moved to or holograms. He described conference included the \ufb01rst elements in the Universe today. discovery of quasars and the USA when Nazi in\ufb02uence how to produce an image of an presentations of \u201cFeynman stars of distant galaxies. spread through Europe. object that changed orientation diagrams\u201d to show interactions In June, Caltech\u2019s (California In the same month, Albert 1 Chargaff discovered that depending on the viewing angle. between subatomic particles, Institute of Technology) Palomar became the \ufb01rst monkey DNA varied between species, However, practical application of with time along one axis and astronaut to leave for space but the proportions of key his theory became possible only space along another. onboard a V2 rocket. However, components were \ufb01xed. with the development of the \ufb01rst he died of suffocation 39 miles working lasers in 1960. In April, Russian physicist (63km) into the ascent, before On November 20, English George Gamow (1904\u201368) and reaching the Karman line that ornithologist Geoffrey Orbell American engineer Percy American cosmologist Ralph marks the beginning of space at (1908\u20132007) made a remarkable Spencer (1894\u20131970) was Alpher (1921\u20132007) proposed 62 miles (100km). discovery when he saw takahes involved in radar design with that elements produced when Austrian\u2013American chemist in the mountains of South Island, a company called Raytheon. He the Universe formed (see Erwin Chargaff reported on a New Zealand. These \ufb02ightless accidentally discovered that study of the makeup of DNA\u2014a relatives of rails and moorhens the microwaves produced traces of 0.1% 0.1% traces of other substance that had recently been had been thought to be extinct for by a vacuum tube called a 24% lithium 0.5% elements shown to be the chemical of the previous 50 years. magnetron\u2014a core component heredity. Five years before DNA of radar\u2014heated food. By 1% structure was revealed as a con\ufb01ning the food \u201ctarget\u201d in a double helix, Chargaff\u2019s analysis metal box, Spencer invented the 23% showed that DNA components \ufb01rst microwave oven\u2014patented called bases occurred in \ufb01xed in 1945. Raytheon sold the \ufb01rst 0.5% proportions. The proportions of commercial model in 1947. base adenine matched that of 300,000 YEARS AFTER TODAY, AFTER MANY thymine, while the proportion of THE UNIVERSE FORMED CYCLES OF STAR BIRTH guanine matched cytosine. The double helix model would show 76% AND DEATH that these matches were due to the bases pairing up. Later work 74% revealed that the base sequence along the double helix was the Composition of the Universe KEY Helium basis for inherited information. The \ufb01rst elements formed after the Hydrogen Oxygen Universe formed were the lightest. Lithium Neon Cosmologists theorize that the Carbon Nitrogen heavier elements were formed Iron inside stars by fusion of atoms. DeHcupenhmpgyaabstrieeciranisntts\u2013DBheroniltonisgishraGmabtoerchnique FeDbuGrtuecsarhmamralaydsolt1loKer6nousntiop,ofemiUnrenrdareisnrcmuosov\u2014estrMsiranda AporffieollUr1emnmPiavretoeniportossneraotififostetnphrretohpeosed Jutneielnet3socHooappleeeriastpiount Jubnemeco1om1nkeAeslbyteharestt\ufb011rorsntaut FisirssutoslmdeifctoorroawcCoralemvesevmteaoluevarrenacndina,tlOinhio MFeaelreycnchtmroQaadunryeandniaintamutgrmirocadsmAu, cpserdOilr7gaWnoizraldtieoHsntea(aWblltHihsOh)ed JbuionceheAmuDpsiNsutrtbAiaElibnsrwa-hAseinems Ccaeohcrmciacorapgunoansftfitoifon July 24 W\ufb01rHstOmheoeldtisng Nove(mbirbde)rirn2e0NdieTswacokZvaeehareeladnd its 279","1949 1950 EDSAC was one of the \ufb01rst recognizably modern computers in terms of design, but it nearly \ufb01lled Deployment of the myxoma virus was the \ufb01rst biological control method used a room and needed 60in- (152cm-) long tubes of mercury to help with memory storage. for a mammal pest, dramatically reducing the number of rabbits in Australia. ON MARCH 28, BRITISH he unwittingly gave the name THE YEAR 1950 SAW RAPID And Computer), which became to an idea that would later gain ADVANCEMENT in nuclear the \ufb01rst computer to be used in ASTRONOMER FRED HOYLE almost universal acceptance. technology. On January 31, US predicting weather. It started coined the term \u201cBig Bang\u201d on President Harry Truman the \ufb01rst 24-hour weather BBC radio, while explaining the Dutch\u2013American astronomer announced\u2014largely in response forecast service on March 5. Steady State Theory\u2014his view Gerald Kuiper had established to the Soviet Union\u2019s detonation of In October, British computer that the Universe had an in\ufb01nite that the atmosphere of Mars an atomic bomb in August scientist Alan Turing proposed past and an in\ufb01nite future. He was made of carbon dioxide and 1949\u2014that he had authorized a test for arti\ufb01cial intelligence. disagreed with the theory that Saturn\u2019s rings were made of ice. the development of a hydrogen all matter was created \u201cin one In May, he discovered Nereid\u2014 bomb. Its design would form the Rabbits had become a national big bang at a particular time in the outermost moon of Neptune. basis for all future thermonuclear problem for Australia. A century the remote past.\u201d In doing so, Kuiper later attributed Nereid\u2019s and a half before, European eccentric orbit to its origin in an hypothesized ring of icy bodies FRED HOYLE (1915\u20132001) ,, A COMPUTER WOULD beyond Neptune. The existence DESERVE TO BE CALLED of this ring\u2014called the Kuiper British astronomer Fred INTELLIGENT IF IT COULD Belt\u2014was con\ufb01rmed in 1992. Hoyle was one of the great scienti\ufb01c thinkers of the ,,DECEIVE A HUMAN INTO On May 6, EDSAC (Electronic 20th century, and stimulated Delay Storage Automatic widespread interest in BELIEVING THAT IT Calculator), a new computer cosmology with his support WAS HUMAN. at Cambridge University, UK, of the Steady State Theory. ran its \ufb01rst program. EDSAC This idea has been supplanted Alan M. Turing, British computer scientist, 1950 could work through around by the Big Bang Theory (see 700 operations per second. It pp.344\u201345). However, Hoyle\u2019s weapons. A month later, at the settlers had brought rabbits became the \ufb01rst computer to Stellar Nucleosynthesis University of California, nuclear with them for food. But in a land routinely help scientists with Theory prevails. chemist Stanley Thompson without predators, the rabbit complex calculations. (1912\u201376) and his team created population exploded, wreaking height of 81 miles (130.6km). californium\u2014the 98th element havoc on crops and native In the US, rocket scientists Albert II survived the \ufb02ight, of the periodic table. Despite its wildlife. When shooting, successfully launched the \ufb01rst but he died on return to Earth instability, californium is still the poisoning, and containment with mammal into space (see 1948). due to parachute failure. heaviest element that does not fences failed to control them, Albert II\u2014a rhesus monkey\u2014went quickly decay\u2014and unlike most Frank Fenner (1914\u20132010), a beyond the Earth\u2019s atmosphere other ultraheavy elements, it can microbiologist at the Australian when his V2 rocket reached a be made in quantities visible to National University, oversaw the the naked eye. release of myxoma\u2014a deadly THOUSANDMonkey astronaut virus that caused myxomatosis. Computing science was racing It curbed the rabbit plague, and The V2 rocket carrying a rhesus forward too. The US had ENIAC although rabbits were not monkey went beyond the Karman (Electronic Numerical Integrator Line\u2014the boundary between the 3Earth\u2019s atmosphere and outer space. THE NUMBER OF VACUUM TUBES USED IN EDSAC Maasrctcorhooinnn2so8BmtBBheerCrittRieFsarrhmeddio\u201cHBoigylBeang\u201d May 6\ufb01rEsDt SprAoCgrraumns SeppsptyeucomhbnlitaibostthehrcerieossnAut tsuJ\ufb01resorostholrtnfapollsCibiaytashcndehiuerovmsaitssioanltss BrDitoi(strhhohetechnmrhyCeooteHmflreaoopicmwdseutgnflopkiaocuirintbl)slliatinsrnhudctthuere JaansuptruaaobrbnlytoiohsDumehtueeeatsrdccghhJleaiosnuopdfOrtooohprfetocSsooamllaertsSayst tem Mawretchaheth5ceoFrmirpsprtue2dte4icr-thEiooNunIrAbCy its May 1asDturtocKnhuo\u2013imApemNerreedrrGiiesceoicardfona,Nvlmederpostounne mammJumonnaekl\u2014e1y4a\u2014rFihniresssptuasce DJpaeumcbeelmisshbAeranrdmoAaletmditnhaegonridadcrafgWconehrioclarllheaaoeordgmdliioocLigacsiailtbcsrsbabalyomannpdles UoSrPdererssJiddaehenvynuedtlaroTroprygumem3en1nabntpoohmfybsFiceaibsntrduSetatelaeranmymle9eymnAtTam\u2014hkeoecrmatilchpiafesono9rnn8tiuhm AMugeulvsintpuACbmahllieovsrwihnicacaaandnredbcpshohhceniorsmitipotseitssiuaoytsmnnetodhfeinsis 280","1951 600,000,000 PEAK NUMBER OF RABBITS IN AUSTRALIA BEFORE INTRODUCTION OF MYXOMA Science in\ufb02uenced fashion at the 1951 Festival of Britain, where fabric and wallpaper designs based on X-ray crystallography (see 1945) were exhibited. Sun orbit of Oort IN 1951, the Lancet, a medical Early transistors Oort Cloud Cloud comet journal, published an article Transistors revolutionized by British physician Richard the world of electronic devices Asher (1912\u201369) about a new and circuitry. Their ability to act as POINT-CONTACT mental disorder in which switches also proved to be especially TRANSISTOR sufferers sought attention by valuable in the growing \ufb01eld of fabricating medical ailments. computer technology. Asher called it the M\u00fcnchhausen syndrome\u2014after the 18th- genes in the DNA hold the JUNCTION TRANSISTOR century German baron who instructions for assembling invented wild stories about his particular proteins by linking \ufb01rst transistor in 1947, but it was life that he claimed were true. amino acids together in the the improved design of 1951 that correct order. would become the standard The same year also saw an component of electronic devices important breakthrough in On July 4, American inventor for the next 30 years. the \ufb01eld of molecular biology. William Shockley (1910\u201389), Unraveling the molecular working at Bell Telephone structure of complex biological Laboratories in New Jersey, substances such as proteins had announced the invention of the been one of the challenges of junction transistor. Shockley analytical chemistry. British and his team had made their biochemist Fred Sanger (b.1918) Kuiper planetary studied one particular protein, Belt orbit insulin, which consisted of interlocked chains of smaller Oort Cloud variable components called peptide Made up of billions of comets, the Oort Cloud marks the hypothetical outer amino acids. By chemically bond boundary of the Solar System. Orbits of Oort Cloud comets are more than splitting these chains, Sanger a thousand times bigger than planetary orbits. was able to determine the types of amino acids, and even the eradicated, their numbers never Heezen (1924\u201377) had used sequence in which they were amino recovered to pre-1950s levels. photographic methods to locate linked together. Sanger was the acid In the 1970s, Fenner went on to sunken aircraft from World \ufb01rst scientist to show that this use his skills in disease control War\u00a0II. They went on to map sequence was the same for all AMINO ACID CHAINS and played a crucial role in the the underwater seascape\u2014 insulin molecules, and that World Health Organization\u2019s discovering submerged different kinds of proteins have Protein molecules perform critical roles in the bodies of living successful global elimination mountain ranges along the way. unique amino acid sequences. things, such as driving metabolism and helping cells absorb of human smallpox. It would take scientists more than nutrients. In 1951, Fred Sanger found that the chainlike molecule In this year, Dutch astronomer a decade to fully appreciate the of a certain kind of protein\u2014insulin\u2014consisted of a unique The start of a new decade and physicist Jan Oort (1900\u201392) implications of Sanger\u2019s \ufb01ndings: sequence of amino acids. He also found that different kinds also saw an effort to bring into suggested that comets came that in the living body, individual of proteins have different sequences\u2014this determines how focus the most mysterious part from a cloudlike reservoir at each chain folds into a shape for a particular purpose. of Earth\u2019s surface: the ocean the edge of the Solar System. \ufb02oor. Geologists such as Marie Modern astronomers believe that Tharp (1920\u20132006) and Bruce Oort was right. SeApumtsetFimrcearmobnlibanecyinoxeronorlomtirgnoaitslrttoothFdseriusacrnieanksbAbuitsptroapluialattoion GeWrmtilhlaoeinfH\ufb01btberihoisneoltnolmodigggeieicspstachutrlobicpdllitsaoiohdfneisstics FeRbidrcehussaaycrrnrdydibAreossmhMeer\u00fcinncthhheaLuasnecnet MaanrccdrhdeSeaEtttsahdeinewgtirnshamlerfaodowcrnTo\ufb01ueUnrclclslaleeetmprawtrobrokmabble DuatncpdhsTayzicnonThiohbmoleeolaorgSlggitseiustndtyNpouikfboIlnisshtiensct SebpioptecushmbeelqibmsuehiersentsBcFr\ufb01erirteosidsfthaaSmapnriongtoeerainci(dinsulin) BrAitliasanhrtTmiu\ufb01arctiihnaOeglcmitdnoaetbetsielcclririaigbneensce CeanndgaedisniiaegnenhrsbeJi\ufb01aoorrmhstntepedHaxicocteapemlprnsaakler commFceoermbcripdauuFelateveererlrryeloac(FpnMtiretraiodsrcntkboicym1t)p,haeny eaJln\ufb01eunrclWsotyrtuio4jlnunlciAniacemcmseteinioSnrgnihvcieonatnrcenatkeinloresnyisotfor ASmheorcikclaenhySiisonebvjputetanneictnmotsirobpnWeartitrle2lain5antmsfiosrtor 281","1952 1953 The hydrogen bomb test on the Enewetak Islands in the Paci\ufb01c was the \ufb01rst thermonuclear explosion The polio vaccine, developed in the early 1950s against a virus that attacked that combined atomic fusion and \ufb01ssion. Its mushroom cloud rose 10 miles (17km) into the air. the central nervous system, saved thousands from a lifetime of paralysis. THE YEAR 1952 saw some of highly speci\ufb01c wavelengths. correct a congenital heart defect. IN 1953, SCIENTISTS gained important breakthroughs. Walsh developed the atomic Just over a week later, American insight into how inheritance American microbiologist Alfred absorption spectrometer, surgeon Charles Hufnagel and reproduction worked at Hershey and geneticist Martha which measured this radiation implanted the \ufb01rst arti\ufb01cial heart a chemical level. English Chase worked together at New and detected the tiniest levels valve in a patient with rheumatic scientists James Watson and York\u2019s Cold Spring Harbor of elements in a mixture. The fever, prolonging her life by nearly Francis Crick (see pp.284\u201385) Laboratory to tackle a key spectrometer, patented the a decade. Plans were also made believed that DNA was the key. question in biology: was life\u2019s following year, later became for the \ufb01rst separation of While the chemical makeup genetic material made from a standard tool in forensic conjoined twins. The Brodie of DNA was partially known, protein or DNA? Some scientists science and other \ufb01elds that brothers, fused at the head, had the physical arrangement of been born the year before. Oscar its components had until then 12MEGATONS Sugar and his team separated the been a mystery. that DNA was shaped like a helix. OF TNT twins and saved one of them. In spite of Franklin\u2019s reluctance By 1953, a new technique\u2014 to draw premature conclusions, THE SIZE OF THE On November 1, the \ufb01rst X-ray crystallography\u2014was Watson and Crick began building 1952 IVY MIKE hydrogen bomb test\u2014 being used to produce 3-D images a helical model of DNA based on EXPLOSION codenamed Ivy Mike\u2014was of the structure of complicated the evidence, and published their thought only protein was demanded high-precision conducted by the US on the biological molecules. At Kings results in the science journal suf\ufb01ciently complex to suit the chemical analysis. Enewetak Islands in the northwest College, London, a team that Nature. They depicted DNA as task. Hershey and Chase Paci\ufb01c. It produced a 3 mile (5km) included Rosalind Franklin and two molecular chains entwined examined the genetic material In the US, Walton Lillehei and \ufb01reball and obliterated a small Maurice Wilkins used it to study around one another in a double that phages\u2014viruses that infect John Lewis performed the \ufb01rst island. Previous thermonuclear DNA. Franklin perfected a helix. This model of DNA was bacteria\u2014inject into host cells. open-heart surgery in bombs had used atomic \ufb01ssion technique of preparing samples of ground-breaking, suggesting a They discovered that the injected September. They (see 1938), but Ivy Mike showed DNA that yielded especially clear way living things could reproduce cells contained phosphorus\u2014an induced hypothermia that an explosion could come, results. The early indications were their genetic material. element found in DNA, but not in (cooling below normal at least in part, from fusion (see protein. This indicated that genes body temperature) in 1988\u201389) too. X-ray diffraction image of DNA A month later, another were made of DNA. their patient, giving Franklin\u2019s remarkable, distinct X-ray journal, Science, reported on an them 10 minutes to diffraction image with its striking \u201cX\u201d experiment conducted the year On the other side of the world, pattern clearly indicated that DNA before. American researchers Alan Walsh, a British physicist Arti\ufb01cial heart valve was shaped like a double helix. Stanley Miller and Harold Urey living in Australia, pioneered a The \ufb01rst arti\ufb01cial heart had tried to re-create the origin technique that revolutionized valve was a caged-ball of life in a laboratory. They had analytical chemistry. He explored design. Blood leaves the heated a mixture of ammonia, the practical applications of the heart as the ball is pushed water, methane, and hydrogen in fact that atoms of different against the cage. When the a sealed \ufb02ask, and sparked it with elements absorb radiation heart relaxes, the ball falls electrodes to simulate lightning. back to seal the valve. Within two weeks the mixture was Juolfybm3yapeFapchihrsaessataitnermutincsastaecuulhrnhgidneeeearryrogtnoing Audgetushcsiemrtitb2pria8unnlgPssaetmhpseeisprbsuiaboslniissohffeondrerve SeApmCteehimmraiarcbplraeletansir\ufb01nsH1tcus1uiarftglnhehaeoge\ufb01nearlrsttvalve NohvyEednmrIseoblwgaeeenrntda1sbk,oFnAmirotosbrtltlhi,swUteeSssMttePadarscahit\ufb01acll AppraDiplNep2rAu5dbiWeslimsaahtosdenoodsnuit\u2013nbrCalNertiianhctgkeulrtihexaist Masuytrh6gieneFrhvsiryeuesnaprtgtreoeetr\u2013pdofolenburnynmJhgoAeehmdamnreuatGrsciiicbhnabignnoen Soeppetne-mhepbaeerrrftr2souMr\ufb01mrrignseetndrey,sinota SeptempbaeJgproeeunr2re0dntoeaHicfmleDomrofNsnaGhAsteeetirnyrsa\u2013ieatpCrilunahiblgasPlstimshhehyaasetdidoeliongy InsCDutherhigcceeea\ufb01ogmrnosbs,ctseIocslerlanuipnrj1caoroc7yriienasoset,usidotfuntwloifns dMtehasayctr1pMi5brfrioiPlnoldmeguurbac\u2013sleniUicdmoerafexatuilypmolifaepneitran\u201deoipmodcfeoaer\u201cncnoditrdiitsgiionns 282","1954 The Boeing 367-80\u2014the prototype for the Boeing 707, which was the most successful of the early passenger jetliners\u2014 was donated to the Smithsonian Air and Space Museum in Washington, D.C. after being used to test design innovations. Life in a \ufb02ask that had previously been tried ENCOURAGED BY EARLY 273.16 K damaged Stanley Miller and Harold and found unsuccessful earlier. RESULTS, the US conducted kidneys Urey recreated the dawn a nationwide \ufb01eld trial\u2014the THE of life in a \ufb02ask: their Just as one discovery was being largest medical \ufb01eld trial transplanted \u201cprimordial soup\u201d championed, another was being ever\u2014of Salk\u2019s polio vaccine. On TEMPERATURE kidney produced amino acids demolished. A hominoid skull February 23, a mass vaccination within two weeks. in the Natural History Museum, program involving 1.8 million AT WHICH transplanted London, supposedly excavated in schoolchildren began. In 1955, a WATER, ICE, ureter found to contain amino Piltdown, East Sussex, in 1912 license was issued for its routine AND VAPOR acids\u2014the building and acclaimed as a valuable link use. Salk\u2019s vaccine went on to CAN COEXIST bladder blocks of proteins. in the story of human evolution, protect children from polio This showed that the was exposed as a hoax. The across the world and heralded at the USSR Academy of Sciences Kidney transplant building blocks of life anatomists and paleontologists the World Health Organization\u2019s published their description of In a kidney transplant, the failed could be made from the Kenneth Oakley, Wilfred Le Gros international campaign to maser (microwave ampli\ufb01cation kidney is usually left in place. The simplest of substances. Clark, and Joseph Weiner eradicate polio. by stimulated emission of donated kidney is implanted lower In November, Jonas Salk, an declared that the skull actually radiation)\u2014a system for down the body and connected to a American virologist, announced consisted of a medieval human In May, the American aerospace concentrating beams of radiation. different part of the blood system. a breakthrough of a more cranium, the teeth of a fossil company Boeing rolled out a Maser came to be used in atomic humanitarian nature. He chimpanzee, and the jaw of an new type of jet aircraft. The clocks and helped amplify potential for other uses, such developed a vaccine against orangutan. To this day, no one 367-80 was the prototype for the tiny signals in long-distance as in medical body scanners. poliomyelitis based on a dead knows who perpetrated the hoax 707 passenger aircraft that came television broadcasts. Since then, form of the polio virus. It was a and duped the academic world into use in the 1960s and 1970s. researchers have explored its The year ended with the \ufb01rst far safer version of a live vaccine for so long. Until then, civil aviation had successful kidney transplant, mostly been centered on aircraft carried out by Joseph Murray ROSALIND FRANKLIN (1920\u201358) that were propeller-driven, but in Boston, Massachusetts. the 367-80 demonstrated that jet Trained in chemistry, Rosalind propulsion was the way forward. 60 Franklin applied her skills to study the structure of biological From 1954, scientists worldwide NUMBER OF POLIO CASES IN US 50 molecules. She produced an were able to apply a standard unit 27,726 X-ray diffraction image of of measurement for temperature, 42,033 DNA\u2014\u201cPhotograph 51\u201d\u2014that following the General Conference 33,300 showed a cross pattern. This on Weight and Measures held in 28,386 suggested that DNA was helical France. The conference had been 57,879 in shape. It became a key piece established to oversee what would 35,592 of evidence in Watson and be known as the International 38,476 Crick\u2019s double helix model. System of Units (SI). In 1954, 28,985 Franklin died in 1958, and she \u201ckelvin\u201d (named after British did not share the Nobel Prize physicist Lord Kelvin) was deemed 15,140 awarded for this achievement. to be the SI unit for temperature. 40 Polio vaccinations At the same time, Nikolay 30 The use of Salk\u2019s Basov and Alexander Prokhorov polio vaccine for 20 mass vaccination of children across 10 the US brought down the number 0 of polio cases by 1948 1949 1950 1951 1952 1953 1954 1955 1956 the thousands. YEAR NoNverewemSpYaobaolrenrktksrtgip1Ttuho3iamalritoeaJsnvoatnecaecsisnheis FeFbirarsuntitna\ufb01irpVeyoilrld2gio3itnrviiaaaclcoifne starts Ma3y6t7h1-e48B0B,ooteehiinenggp7ruo0nt7voetyilpse for OcBtaopsbaotephvreoe\u2013rfP3pdm1rroeiankssccherioprirbloeevss DeFciroesrmotgfsbauanecrktcri2edas3nnsesfypullant\u2014 TimtheamtNtahogevaePzimsinlktebduerolelrwpi3sno0raMtshaonax hyUdMrSoacgraecrnohrnibe1oBsmTiokhubienttiaeAsttoll Junheocw4arFisrioyrsloatutdetedpshcchoriltpootrsiooypnnltaohsfetssis OctCaoonbndeferMr5ee\u2013nat1schue4tahroGteenteshsonWtdefeaeteKrneciadegmllaalhvrprteidensruiasntuitre FiorfstadhmoNuecmoutveameonmer,initbnteeeShdryict3lata0Aicnsloegaubagaam, a 283","1946\u20132013 THE INFORMATION AGE UNDERSTANDING DNA A SELF-COPYING MOLECULE CALLED DNA IS THE CHEMICAL CODE OF LIFE ITSELF The characteristics of living things are produced by chemical processes that happen in every cell. Twentieth-century science traced these processes to their source\u2014a molecule that not only carries genetic information but also has the remarkable capacity to copy itself. It is called DNA. By the turn of the 20th century, scientists had By the 1950s, advances in analytical techniques JAMES WATSON AND FRANCIS CRICK discovered that inherited characteristics come meant that the best-known form of nucleic acid, To test their double helix theory, Watson and DNA (deoxyribonucleic acid), could be examined Crick built a model of the structure to check from particles passed down through in ways never before possible. A method called that the chemical pieces would \ufb01t. generations. However, they did not X-ray crystallography even promised to reveal understand the composition of these its three-dimensional shape. was because they were bonded in \ufb01xed ways: units of genetic material, which we adenine with thymine and guanine with cytosine. now know as genes. In 1919, Lithuanian BASE PAIRS This would be key to understanding not only In 1953, results from these new methods how DNA carried inherited information but also biochemist Phoebus Levene dismissed convinced American biologist James Watson and how this information replicated at reproduction. nucleic acid\u2014a material present in the British biophysicist Francis Crick that DNA had a nucleus of every cell\u2014as too simple to helical structure. Evidence indicated two coiled be involved directly in inheritance. But in chains (a double helix) with variable components the decades that followed, experiments (bases) that hold the chains together. Four proved that a form of nucleic acid is, in fact, varieties of bases were always present in certain the substance of genes. proportions. Watson and Crick deduced that this DNA molecule coiled adenine into a double helix double helix wrapped around packaging proteins called histones thymine CHROMOSOMES chromatid Jack 20 40 60 80 100 1000 1500 DNA backbone, When a cell divides, to prevent short arm jumper ant NUMBER OF CHROMOSOMES consisting of entanglement each DNA molecule is bundled into long arm Kangaroo deoxyribose (a form of condensed structures called sugar) and phosphates chromosomes. The number Pill millipede of chromosomes per cell varies from species to species. Human Chromosome micrograph Pigeon Because DNA replication happens before Adders-tongue cell division, every chromosome appears with duplicated \u201cchromatids.\\\" fern 284 0","UNDERSTANDING DNA DNA REPLICATION MAKING PROTEINS 1 strands of coding strand Just before a cell divides, it replicates its A gene is a section of DNA containing entire DNA. Each DNA molecule \u201cunzips,\\\" instructions to assemble a protein DNA separate 2 bases complementary and the paired bases separate. Because molecule to carry out a speci\ufb01c task, of the strict base-pair ruling, the base such as making a pigment. In this template strand to those on DNA template sequence along one strand determines way, genes determine an organism's strand create mRNA strand the sequence along the other: they are characteristics. Before a protein is complementary. Free DNA building blocks assembled, the gene's base sequence instead of thymine, RNA 3 DNA strands are linked to make new complementary must be \u201ccopied\u201d in the cell nucleus, has a base called uracil strands along each existing strand a process called transcription. This rejoin \u201ctemplate.\\\" This creates material for two copy is then sent to the cytoplasm. In new, genetically identical double helices. another process, called translation, mRNA strand At cell division, one double helix goes to the base sequence information is under construction one cell, and one goes to the other. used to assemble the protein. TRANSCRIPTION \u201cparent\u201d 2 tRNA 3 tRNA molecule 4 amino acids are Inside the nucleus, part of a DNA double double helix helix unravels to expose the coding region molecule recognizes bonded together of a gene, ready for \u201ccopying.\\\" This involves free DNA brings in an complementary codon in the ribosome making a strand of nucleic acid called RNA building block amino acid (ribonucleic acid) by bonding together free RNA building blocks. 5 amino acid detaches from the tRNA molecule DNA double old DNA 1 ribosome 6 tRNA molecule helix \u201cunzips\u201d template strand moves along leaves ribosome old DNA mRNA strand template new DNA TRANSLATION strand The so-called messenger RNA (mRNA) strand moves from the nucleus to the cytoplasm, where it settles on a protein-making granule new DNA called a ribosome. The ribosome moves strand along the mRNA, \u201creading\u201d its base sequence and building the correct protein. Speci\ufb01c mRNA strand set of three bases base triplets (codons) dictate speci\ufb01c protein on the mRNA is building blocks\u2014called amino acids\u2014 called a codon collected by transfer RNA (tRNA) molecules. \u201cdaughter\u201d guanine always forms a double helix base pair with cytosine thymine and adenine always form base pairs together cytosine guanine DOUBLE HELIX A DNA molecule can be inches long and consists of two entwined chains held together by breakable \u201cglue\u201d in a hydrogen bond. The outer \u201cbackbones\u201d consist of alternating units of sugar and phosphoric acid. The linear sequence of the inner linked bases determines the genetic information. 285","1955 1956 The \ufb01rst radiometric dating of rock layers, such as these in Bryce Canyon, USA, put estimates 2,244 of Earth's age at only about 2 billion years, far below the actual age of the planet. MILES THE LENGTH OF TRANSATLANTIC TELEPHONE CABLE IN 1955, AMERICAN GEOCHEMIST 4.55BILLION nitrogen CLAIR PATTERSON (1922\u201395) YEARS atom studied the atoms of rocks to carbon estimate the age of Earth. THE AGE atom He focused his analysis on OF EARTH meteorites, which are considered hydrogen atom remnants of an age when the cobalt atom Solar System\u2014and therefore which build up over time. cesium metal. It would make Structure of vitamin B12 Earth\u2014was \ufb01rst made. Patterson Patterson calculated Earth's age time measurement more A model of a vitamin B12 molecule reveals the complexity of it structure. isolated lead from samples as 4.55 billion years\u2014older, and precise than ever\u2014the new This was \ufb01rst revealed by Dorothy Hodgkin, through a method called of rock and studied the relative more accurate than prevailing atomic clock would gain or lose X-ray crystallography (see 1945). metal poisoning. In the years proportions of lead isotopes\u2014 estimates. This changed the way only a second in 300 years. Modern that followed, the disease was linked speci\ufb01cally to mercury variants of the metal. Radioactive scientists viewed our world. atomic clocks are accurate to that had been leaking into the atoms, such as those of uranium, British physicist Louis Essen 1 second in 6 million years. decay at a known rate (see p.267), (1908\u201397), working at the UK\u2019s In December, in the laboratory and thereby provide information National Physics Laboratory, of Swedish geneticist Albert about the age of samples (see designed the \ufb01rst atomic clock. Levan at the Institute of below). Some of these atoms Its time-keeping was based on Genetics in Lund, Sweden, decay into speci\ufb01c lead isotopes, radiation emitted by atoms of visiting Javanese-born American biologist Joe Hin Tjio (1919\u20132001) atom of radioactive atom of new made a discovery that corrected material, uranium-235 radioactive a 50-year error in the \ufb01eld of product, lead-207 genetics: that human cells contained 48 chromosomes. He showed that there are in fact 46 chromosomes in a normal human body cell. Tjio used an original radioactive improved microscopic technique oxygen atom atom remaining to squash cells into single layers, rather than relying on slicing thin A NEW DISEASE affecting a ROCK AT ITS FORMATION ROCK AFTER MILLIONS OF YEARS sections of tissue. He also used \ufb01shing community in Minamata, Japan, was described in May 1956. RADIOMETRIC DATING a technique to spread out the Called Minamata disease, it was characterized by progressive tiny chromosomes in a sample, paralysis reminiscent of many nervous system disorders. It was Radiometric dating is a technique used to date rocks, minerals, so that they separated easily and not until November that the disease was traced to heavy or fossils using natural rates of radioactive decay. Its origins are clearly, without fragmenting. Tjio in the work done by physicists in the early 1900s. Radioactive continued his career in the US, material decays at a known rate. By working out the ratio of a where he became a signi\ufb01cant radioactive material (for example, uranium) to its decay products \ufb01gure in developing the new (lead), the age of the rock can be calculated. branch of biology called cytogenetics (cell genetics). AmCeldaraiirctiaPnnagtgtteeororsceohcneamlucsuiseltastreaadgioemoeftEriacrth Aupghluyassuwitnco2icrsh4kteaLBsborltuiehtiiesashtE\ufb01orsmssteicnclock Madyis1eaMsiendamesactraibed SeLpattureantmenclhsbeaepotrhflao2nn5teiccsaubblemarine ApriAld1m2 iUnSiSsaFtrloakot'idsopnanoaldpioDpvrroauvcgecisne DbeiocleotmhgaibsttehJruo2me2naHJoniatncv4Tae8nilj,loescshdcerios-onbcmtooavroiennsros4m6,es sJturluyc1tu4rVeitisampuinblBis1h2ed 286","1957 ,, ,,\u2026 THE FIRST ARTIFICIAL EARTH SATELLITE HAS BEEN BUILT. Telegraph Agency of the Soviet Union (TASS), published in Pravda newspaper, October 5, 1957 The transatlantic telephone cable was Bleeping signals from Sputnik 1\u2014the world\u2019s \ufb01rst arti\ufb01cial satellite\u2014were laid from a ship in coiled batches. heard by people on their radio sets around the world. \ufb01shing waters from a chemical 22 THE HAMILTON ELECTRIC 500, an impulse (see panel, below) The device emits electrons factory. The mercury had launched in January, was the when stimulated. (negatively charged particles), accumulated in \ufb01sh and \ufb01rst ever wristwatch that which are then absorbed by shell\ufb01sh, and had poisoned the did not need winding. Although On October 4, Russia launched certain gases to produce a signal. people who ate them. This its battery life was relatively Sputnik 1\u2014the \ufb01rst arti\ufb01cial It helped environmentalists detect incident was one of the \ufb01rst short, the innovation proved to satellite to orbit Earth. tiny quantities of atmospheric well-documented cases of the be very popular. pollutants, such as the pesticide effects of toxic chemicals Danish chemist Jens Skou At the start of the nuclear DDT and chloro\ufb02uorocarbons arms race, and prompted by (CFCs)\u2014ozone-depleting (see polluting food chains. THE NUMBER (b.1918) published the basis of US President Eisenhower\u2019s 1973) compounds used in In July, British chemist Dorothy OF DAYS THAT how the nervous system works. \\\"atoms for peace\\\" speech in refrigeration and as propellants SPUTNIK 1 He discovered molecules in the 1953, the United Nations set in aerosol cans. Hodgkin (see 1945) published a cell membranes of crab nerves up the International Atomic study of the structure of vitamin TRANSMITTED that pump ions to \\\"charge up\\\" Energy Agency (IAEA) in July James Lovelock holds ECD B12\u2014a vitamin needed to prevent membrane surfaces, using up 1957 to control and develop The electron capture detector (ECD) pernicious anemia. Using X-ray atomic energy. Thirteen years picked up the tiniest amounts of later, the IAEA would oversee the electron-binding chemicals in the crystallography, she found that SIGNALS BACK cellular energy in the process. Treaty on Non-Proliferation of atmosphere, such as the chlorine the vitamin contained a ringlike TO EARTH This makes the molecules Nuclear Weapons. in pesticides and other compouds. structure, porphyrin, that excitable so that they can carry In the same year, aviation surrounded a central atom company Boeing launched the \ufb01rst commercial jet airliner, of the element cobalt. region of negative negative charge the 707. It marked the dawn of The world\u2019s \ufb01rst underwater resting potential charge a new age of air travel powered by turbine engines that made telephone cable became aeroplanes \ufb02y higher and faster than before. operational on September 25. It In November, American ran between the US and Europe physicist Gordon Gould (1920\u2013 2005) suggested a method of under the Atlantic Ocean. In the amplifying light into an intense beam and coined the term for \ufb01rst 24 hours of operation, it as laser (Light Ampli\ufb01cation by Stimulated Emission of the service hosted 588 London Radiation). An operational laser, however, would not be produced to US telephone calls, which nerve cell region of action positive charge until 1960. were clearer than any previous membrane potential transatlantic communication. British scientist James CREATING A NERVE IMPULSE Lovelock (b.1919) invented In September, IBM launched the electron capture detector (ECD) as an ultrasensitive the 305 RAMAC (Random Access way of analyzing gas mixtures. Memory Accounting Machine)\u2014 Membranes around nerve \ufb01bres are electrically charged because the \ufb01rst computer with a hard they contain protein \\\"pumps\\\" that push ions (charged particles) of disk drive and random access sodium out and pull potassium ions in. This makes positive charge memory. RAMAC weighed over accumulate on the outer surface: a so-called resting potential. a ton and stored 5MB of data When stimulated, protein channels open in the membrane, on a stack of 50 large disks. making positive charge leak in. This reverses the resting potential to create an action potential. The region of action potential \ufb01res down the nerve \ufb01ber membrane as a nerve impulse. SeIBpctMeohmmlaapbrudunetcrdehirsewksid\ufb01thrrisvate Jaonfu\ufb01arrsyt e3leLcaturnicchwatch JuAltyios2me9iscItnaEtbenlreinsrgahyteiodAngaelncy Ocjetottabakeirerlsin2iet8srC\ufb01Boromsetmin\ufb02egigr7ch0ita7l NoAvmGeeomtrrhdibecoeoanrrnyGpoohfuyllsadiscdeisertsscribes MJainpaamnNatortmvaaecedemtiadsbletepaoroshei4seioannviyng SopduimumpF\u2013inepbontreaudrsaivssericuycomevellrsed Octoabrlteai\ufb01rucn4icaRhluesssSastp\ufb01ieaurlstlintteik, 1 ECmDeiascshiunervmeenitcartaatemlcdseotisonsoptfhheere 287","1958 1959 New satellite technology helped explain how Earth\u2019s magnetic \ufb01eld channels energetic solar particles Hidden from the gaze of astronomers since antiquity, the far side of the Moon into a collision course with the atmosphere to produce the aurora borealis, or Northern Lights. was \ufb01nally revealed when USSR\u2019s Luna 3 probe photographed it from orbit. THE SOVIET UNION\u2019S SPUTNIK\u00a01 Sputnik 1 measured the density biology.\u201d They traced what TWO MONKEYS, ABLE AND hemoglobin\u2014the red oxygen- \u2014the \ufb01rst arti\ufb01cial satellite\u2014 of the upper atmosphere, happened to components of DNA BAKER, went up in the US missile carrying pigment of blood\u2014using burned up on January 4, after and Explorer 1 found how when it replicated, and found Jupiter AM-18, and became the techniques that had cracked the spending three months in orbit. Earth\u2019s magnetosphere (see that a double helix molecule \ufb01rst primates to survive a space structure of DNA. He found that The US joined the space race panel, below) could de\ufb02ect unravelled into two strands, \ufb02ight. Meanwhile, the USSR it had four protein chains, each with the launch of Explorer 1 harmful radiation before it each of which was a genetic launched three lunar probes\u2014 with oxygen-grabbing iron. later that month. For the month reached the ground. \u201ctemplate\u201d for making more Luna 1 and 3 achieved \u201c\ufb02yby.\u201d or so of their battery-powered DNA. After replication, each new Luna 3 also took the \ufb01rst Australopithecine skull lives, these satellites sent back In California, Matthew double helix contained one old photograph of the Moon\u2019s far side. Dated at 1.75 million years old, this important information about Meselson (b.1930) and Franklin strand and one new one. This skull belongs to an australopithecine, airspace\u2014a term that refers to Stahl (b.1929) were unlocking method of semiconservative In Cambridge University, UK, also known as \u201cnutcracker man\u201d the realm of the atmosphere the secrets of DNA in what would replication had been proposed molecular biologist Max Perutz because of his large cheek teeth. and the accessible space above it. come to be described as \u201cthe by Watson and Crick in 1953, (1914\u20132002) was studying most beautiful experiment in when they developed the double helix model of DNA. large eye bow shock Earth socket In the same year, a practical solar wind magnetosphere expression of this replication thick tooth magnetopause came with the work of British enamel botanists Frederick Steward THE MAGNETOSPHERE (1904\u201393) and John Gurdon (b.1933). Both teased cells from Earth is enveloped by the magnetosphere, a magnetic \u201cblanket\u201d that mature organisms\u2014Gurdon results from magnetism deep inside the planet. The magnetosphere from a tadpole and Steward de\ufb02ects harmful high-energy particles from the Sun through a bow from a carrot\u2014and grew shock, or shock wave created at the magnetopause\u2014an abrupt clones from them boundary between incoming solar wind and the magnetosphere. as new genetically Without the bow shock, the solar wind would destroy life on Earth. identical plants. It was the \ufb01rst cloning using material from differentiated \u201cbody\u201d tissues. The year also saw a breakthrough in electronic engineering. American electrical engineers Jack Kilby (1923\u20132005) and Robert Noyce (1927\u201390) simultaneously came up with the idea of condensing all the components of an electronic circuit into a single plate of silicon, thereby inventing the microchip. JaSnputuoatErnyaikr4tIhfalls Fewbourrsudteah\u201cdreayi\ufb01inr2rspspTrtahitnciemtef\u201deor JuInanoenD7otfoBhunerlaitt\ufb01lridsarshsptoupdubhinalyidgssinhcoeiassntipcauJpsueCelryo(Nn2Sga9rpteiTaoshcnseeaslAUeAdStsemruionpnisaNturAtaiSctAisona)nd BrFitricesadhcrearbaroriiurotcostlkohtfgreScoientsmelttliwscs\u2014aaotrtmedhdaecctl\ufb01oilconrnsetisng ApornMicloa\ufb011ltro3htsgr\u00e9Ftai-srnreetesvnGppecoelrharobtnrsogtnoeanesttmheimsarprtow AumstPorleieoarcfnuuh-tlbzeaomrerxbnopigoBllaloroiinbgtsiiisnsththMe asxtructure ThEex\ufb01prlsoJtraUenrSuIsa, arlatyeu3lnl1icteh,ed ExCpMoTemrdaairmttnhcioosehn-n\ufb012AwcrnToseothmtafaeclArptrchnlotetisatcseriscntgica biolSoJtgauishltylsp1tMuh5beeAlsmimsseehleeslcrfpo-hiancrapaeanenpnirsldimocnaootfifDonNA AmKeirlibcyaSndeepemntego\ufb01minnrssbetteermrartJ1ieca2srcotkhcehip Mayps2rsui8pcmacTeacwesteos\ufb02sfluiirgvlehliynttu\ufb01gffrrornosrmttthime e JulyM1a7ryBauLrisettiasrkhaelfoyopsdistishilcienhocuvEinenaretssetsrakAnufrlilca 288","1960 35,797 FEET THE DEPTH REACHED BY THE TRIESTE The submersible Trieste was designed to withstand the immense pressures of the deepest part of the Marianas Trench. Until 2012, it was the only manned vessel to get there. JUST AFTER MIDDAY ON sea\ufb02oor pushes lava cools and Sea\ufb02oor spreading JANUARY 23, the US Navy away from solidi\ufb01es to form Lava eruptions create submersible Trieste touched new sea\ufb02oor new mantle along the down at the deepest spot of central ridge length of the mid- the world\u2019s oceans: Challenger Atlantic Ridge, pushing Deep in the Marianas Trench of continental out the sea\ufb02oor on the western Paci\ufb01c Ocean. The crust either side. submersible\u2019s onboard team of Don Walsh (b.1931) and Jacques of images of cloud cover and oceanic crust Piccard (1922\u20132008) spent 20 other aspects of atmospheric minutes there, and saw that some conditions from aerospace. lava erupts along animals were adapted to survive mid-Atlantic ridge even at these great depths. In August, American physicist LOUIS LEAKEY (1903\u201372) Theodore Maiman (1927\u20132007) His method involved using a rod of succeeded in arti\ufb01cially Harry Hess (1906\u201369), a demonstrated a new way of synthetic ruby to produce a series creating chlorophyll II\u2014one British anthropologist Louis geologist with the US Navy, producing a concentrated\u00a0\u201cpencil- of laser pulses. This technology of the main components of the Leakey was instrumental in had studied the ocean depths beam\u201d of light known as a laser was later modi\ufb01ed to produce a green plant pigment that traps advancing the understanding during World War II. In 1960, (Light Ampli\ufb01cation by Stimulated continuous beam that today has light energy for photosynthesis. of human evolution. Together he suggested that the entire Emission of Radiation, see 1957). applications ranging from eye with his wife, Mary, he spent sea\ufb02oor was moving. He later surgery to compact disc players In October, the 11th General much of his career studying stated that the molten magma and supermarket scanners. Conference on Weights and fossils in East Africa. He spewing out of Earth\u2019s crust from Measures published a series showed that humankind underwater ridges was cooling, American chemist Robert of unit standards. Known as Le originated in Africa, and later expanding, and pushing the Woodward (1917\u201379) had spent Syst\u00e8me International d\u2019Unit\u00e9s in his career helped inspire oceanic plates on either side. (SI units), these were adopted the work of primatologists Today, Hess\u2019s theory is accepted the last decade studying by scientists and technologists. such as Jane Goodall and by geologists. It is believed that the chemical structures Dian Fossey. as new mantle forms at a ridge, of complex biological Also in October, British surgeon old mantle plunges back into substances, such as Michael Woodruff (1911\u20132001) Anthropologists Louis and Mary Earth elsewhere. This process cholesterol and quinine. performed the UK\u2019s \ufb01rst kidney Leakey had been excavating is responsible for continental He showed that the rules transplant operation. It was prehistoric stone tools at Olduvai drift, a theory \ufb01rst suggested by of structural chemistry performed between identical Gorge in East Africa for two Alfred Wegener (see 1914\u201315) could be used to produce twins to minimize the risk of decades. In July 1959, Mary found nearly 50 years before. these substances in the rejection. Both donor and a prehistoric skull. It belonged to laboratory. In 1960, he recipient survived the operation an australopithecine, an In April, NASA launched and went on to live many years. ancestor of modern humans who the \ufb01rst successful weather First weather satellite was later thought to be the \ufb01rst satellite, TIROS-1 (Television TIROS-1 carried television \u201capeman\u201d to use stone tools. Infrared Observation Satellite cameras and photographed Program-1). For 78 days, Earth\u2019s weather patterns television cameras aboard from a height of at least the satellite took thousands 435 miles (700km). AubgiosuluosfcegtcriCestshitlsiMinzfuaeinltslieyCo\u2013nhpAeuimnrefhorearrCmibchbasaintnisng vitro JaDnouJnaadcWreqyMsauc2lateseh3rshnoeiaPndadninEiecandceastapro\u00a0Trtehrtdshetenscpho\u2014t Aplarusilan1tcehTlelhisteeiUt\u2014sST\ufb01IrRsOt Sw-e1ather AupghMuyssaoitipcm6iesartAanTmthdioeeenrvoiaecdlaloolnrapesse\ufb01rrst OcStIossbtyamesnreetdesaTamtshrauedbfrolmeirsmehteerdnict OctopbheortL7ousgTinrdhaaeerpoSh3fosptvthriheoeetbMefaoron July AptmuRhboeelbriasiecrhratetin\ufb01sWcchiohiaosoelfdmwscwyhoisnalrottkrhrdooenpshisyll WOoco\ufb01tdrorssbuutefrkfgripde3eon0rnefByoMrrtmiirtcaihssnhaUsepKll\u2019asnt 2 8 9AHmarerryiscHeaanet\ufb02soghsoetiohposNrerltoesahUgspveieSarsoneltrOtaRysfd\ufb01eoiscfneegaorfch","1961 1962 108MINUTES THE DURATION OF YURI GAGARIN\u2019S SPACE FLIGHT Soviet pilot Yuri Gagarin was selected from DDT was developed as a contact poison to control insect pests and was 20 candidates to be the \ufb01rst man in space. claimed to be harmless to people and the environment. IN FEBRUARY, PHYSICISTS at (100,000km) of Venus. It was the organization for wildlife IN JUNE, The New Yorker In July, the multinational the University of California \ufb01rst man-made object to \ufb02y by conservation. They created the magazine began to serialize communications satellite Berkeley succeeded in producing another planet. International Secretariat of a book by American marine Telstar was sent into space atoms of a new heavy element the World Wildlife Fund (WWF) biologist Rachel Carson, titled aboard a NASA rocket. The \ufb01rst of by bombarding a sample of the In April, prompted by the \u2014now known as the World Wide Silent Spring. It proclaimed that its kind, Telstar made it possible element californium with nuclei plight of wildlife in Africa and Fund for Nature\u2014in Switzerland. human activity, particularly the for live television signals to be of boron atoms. They called the elsewhere, a team including The WWF went on to set up use of pesticides such as DDT transmitted across the Atlantic. element lawrencium, after biologist Julian Huxley (1887\u2013 of\ufb01ces worldwide and harnessed (dichlorodiphenyltrichloroethane), The \ufb01rst pictures were seen on American physicist Ernest 1975) and ornithologist Peter the expertise of scientists to threatened the environment with television screens on July 10. Lawrence, the inventor of Scott (1909-89) proposed the protect endangered species. damage and destruction. Carson Telstar became the prototype the cyclotron\u2014a particle establishment of an international explained how the intensive for later, more ef\ufb01cient, models. accelerator. With an toughened body techniques used to satisfy atomic number of antenna to withstand humankind\u2019s demand for food and RACHEL CARSON 103, lawrencium pressure its drive to eliminate pests were (1907\u201364) was the last\u2014and affecting the environment on an the heaviest\u2014of unprecedented scale. Widespread Trained in marine biology, a group of radioactive metals use of pesticides was harming Rachel Carson achieved called actinides. wildlife, and would ultimately acclaim as a writer of popular harm humans too. Carson was natural history books before On April 12, Soviet pilot Yuri concerned about DDT. Developed she became famous for her Gagarin (1934\u201368) became book, Silent Spring. Her work the \ufb01rst cosmonaut when as a contact poison to control led to the establishment he traveled to outer space the spread of insect-borne of the US Environmental aboard Vostok 1. He orbited diseases during World Protection Agency. She was Earth once before returning War\u00a0II, DDT was later posthumously awarded the safely and was awarded his adopted as an agricultural Presidential Medal of country\u2019s highest honor\u2014 pesticide. However, it Freedom in 1980. the title of \u201cHero of the Soviet accumulated in food chains, Union.\u201d He went on to train killing wildlife. Carson\u2019s new cosmonauts in Russia. book, coming a year after the inauguration The USSR launched its of the WWF, Venera program to gather served as an information about Venus. The alarm call. It \ufb01rst probe, Venera 1, is thought to created a new have passed within 62,137 miles environmental Soviet Venera space probe awareness, especially in the US, The Venera probes were among the more where environmental concerns sophisticated of the \ufb01rst interplanetary ultimately precipitated a national space probes. Over the years, Russia would ban on DDT and other highly succeed in landing 10 probes on Venus. potent pesticides. FeLbasrwyunraetrhnyecs1iui4zmedis Appriltiohltse1Yp2\ufb01uarScrsoietGv,hioaeurgtmbairatisnnE,inarth Mapyatso1s9VeesVnecunlosesrea\u00a01 NoFvirIensmtZteoebirodsnelindatroiaetog9imsnoicingioananflgleNCodooftmdaoenesinotmacfnlaadltasuprrdeeicziees FeJbobrheunAcamoGormlryeebre2niist0ncaE\ufb01narsrtttoh Jutlhyceo1\ufb01sm0arsTtmeteluallsnictttieaci,vraei,tsiolanusnched World (WWiWlAdpFlirf)eifloF2uu9nndded May 2a5nTnhoeuUnAcStpeoCoslolallnaonugdprnreacoshmtgshroaeafnmMoonon JunYsoeRerraTkicahehlreieSzbNlaielCetegiwanoinrtnssSoopnfr\u2019sing 290",",, BUT MAN IS PART OF 1963 NATURE, AND HIS WAR Surtsey emerged in a volcanic eruption in 1963. Subsequent eruptions over the next four years ,,AGAINST NATURE built up the island, which\u2014in spite of erosion\u2014boasts more than 60 plant species. IS INEVITABLY A WAR AGAINST HIMSELF. Rachel Carson, marine biologist, from Silent Spring, 1962 Telstar THE BELL COMPANY conventional The world\u2019s \ufb01rst communications developed the \ufb01rst push- subatomic particles, satellite, Telstar transmitted such as protons its signals intermittently from button telephone for public and neutrons, could 1962 to early 1963. Although it use. Scientists also saw explode to create even has ceased to communicate, breakthroughs in science smaller fundamental it remains in orbit to this day. on a grander and more entities. However, no fundamental scale. one could be sure American biologist Gerald them into smaller constituents. what these were. The butter\ufb02y effect Edelman (b.1929) and They found that each Y-shaped Soviet cosmonaut In 1963, American A \u201cLorenz attractor\u201d is a English biochemist antibody molecule was made Valentina Tereshkova physicists Murray butter\ufb02y-shaped graphical Rodney Porter (1917\u201385) up of protein chains. Their work (b.1937) became the \ufb01rst Gell-Mann (b.1929) plot based on mathematical independently made a helped unravel the chemical woman\u2014and the \ufb01rst\u00a0civilian and George Zweig equations that describe a breakthrough that would structure of antibodies. Later \u2014to \ufb02y into space. An amateur (b.1937) independently chaotic system. eventually win them the Nobel work would show how the parachutist, she became an proposed a \u201cquark Prize. They were working on human body produces different honorary inductee into the Soviet model\u201d of matter, In November, change on a antibodies\u2014natural secretions kinds of antibodies to target Air Force before she trained to suggesting that a massive scale was seen in the that help the immune system different kinds of antigens, so pilot Vostok 6. The mission variety of different geographic realm, when an \ufb01ght infection by targeting and that the immune system can helped Russian scientists entities called quarks come island was born near Iceland. \u201cneutralizing\u201d harmful foreign attack speci\ufb01c infections. understand how the female together in combinations to An underwater volcano on the particles called antigens. body reacted to time in space. make subatomic particles. mid-Atlantic ridge erupted to Edelman and Porter analyzed Scientists also reached a Over the next few years, push Surtsey out of the water. antibodies by chemically splitting fundamental turning point in experiments in particle physics This gave scientists a rare chance understanding the nature of indicated that this quark model to study Earth\u2019s active geology The structure of antibodies matter. Experiments conducted was essentially correct. \ufb01rst-hand. In subsequent years, An antibody molecule is made up of in the 1950s had shown that scientists were able to see how two \u201clight\u201d and two \u201cheavy\u201d protein American mathematician life colonized the island in a chains, held together by tight bonds 48 Edward Lorenz (1917\u20132008) process of biological succession in a Y-shaped structure. was revising the way we look to form a new ecosystem. THE NUMBER at systems, such as weather, on a OF TIMES much larger scale. He suggested TERESHKOVA that a small, seemingly ORBITED insigni\ufb01cant change in one place EARTH can have major repercussions in the long term. By alluding to the effect of tiny \ufb02apping wings leading to hurricane-scale devastation, he came up with an evocative name for his idea: the butter\ufb02y effect. With this, he laid the foundation for chaos theory. Jutlryatrn1ass1nimgtTsoneiataBlstsllrtas\ufb01iantrfrarstiiotncmltivetelheeviUsiSon BrBitlibaslchsokycdtnkioontechvtrtreeosentr\u2014aitcJtsaadhbmrceeulateagrassst-sduoissfeedase MaesrotcafhbcElhidsahwoesasrthdfoeLuoonrrdyeantizons JuTne\ufb01erre1tsso6thswVkpaooalmvecaenabtnientcoaotmraevsel Be\ufb01lrltsCetploepumpubhpsliohacnn-lybeyuasdtvettaoovielnbaleobplmesade Noisvlaeapmnlpedbevv\u2014eaoelrlSrcsfuao1arnl4ltbioscAowevenyierne\u2014ugswpeataion AmebrioiccEahddneiesabmlcrmioeoisvlamotengRraiaotsdnhdtedanGuteEepayrnnaogPtflliodibpsrorhtodetireesins TholpimevMerafarosrtrcSrmhatans1rs\ufb01zprllsatnt HardJyucnalerurn1ieg1stJroaaumntse\ufb01psrlsatnt indAGemepleeln-rMidctehaasnnenutnqlpbyuhaapyantuosrdimtkcZfitioswchrteeswpoiaagrrrytdicolfes SVeinpHetaMearmnarysdtbteHhDeaeerr\ufb02wsu7osmso\u2019Fsrcmrtoeshonpden\ufb01roderrmaydoifng animDaultTcpihnmsbyzeceothrohgolooelaodgnngifispimosturtaabsNnlltidbiuskedhohyeaisnvgior 291","1946\u20132013 THE INFORMATION AGE THE STORY OF sonar equipment OCEANOGRAPHY ONE OF THE WORLD\u2019S MOST UNEXPLORED REALMS HAS GRADUALLY BEEN REVEALING ITS SECRETS For a long time, oceans have been the least understood features on Earth. titanium hull However, knowledge of marine life and the topography of the ocean floor protects passengers has gradually accumulated and, in recent years, new exploration techniques have led to several discoveries. The earliest records of sea exploration date back Ferdinand Magellan\u2019s circumnavigation, which 3,000 years to the Phoenicians, who made charts \ufb01nally revealed the extent of the world\u2019s oceans to navigate and used weights to plumb the oceans\u2019 and allowed mapmakers to chart their shapes. depths. Ancient Greek philosopher Aristotle was one of the \ufb01rst to speculate about marine life, and Scienti\ufb01c attempts to study beneath the surface other Greeks developed instruments to help ships of the oceans began in the 19th century. Early locate their position when far from shore. surveys were conducted using sounding chains and sample nets. The introduction of sonar after However, the open oceans remained unexplored World War II helped in mapping the ocean \ufb02oor. by Westerners until the 1400s, when Christopher Recently, improved sonar, satellite techniques, Columbus sailed westward into the Atlantic in the and an array of submersibles have helped add hope of \ufb01nding land on the far side. This paved to our knowledge of marine life and ocean the way for further voyages of exploration, such as currents as well as the oceans\u2019 geography. SONAR lights for video camera The \ufb01rst maps of the ocean \ufb02oor were produced by sonar, a technology sonar emitted manipulator arm for picking developed during World War II to detect from base of boat objects off sea\ufb02oor submarines by picking up re\ufb02ections of sound waves from underwater objects. transmitted Nautile It can also be used to detect schools of sound French miniature submarine \ufb01sh. Nowadays, new systems, such as Nautile is only 26 ft (8 m) side-scan sonar, are being used together sound wave long. However, its tough with GPS to survey vast areas quickly. re\ufb02ected from hull allows it to reach a school depth of 33\/4\u00a0miles (6km), and external robotic school of \ufb01sh arms, video cameras, and \ufb02oodlights enable detailed exploration. 1200\u2013250 BCE Ancient c.80 BCE 1519\u201322 Map of the Strait of Magellan 1842 Phoenician traders Phoenician Antikythera mechanism Strait of Magellan Matthew Maury The \ufb01rst seafarers, coin The Greeks develop Portuguese explorer Considered to the Phoenicians instruments, such Ferdinand Magellan is be the \u201cfather of plumb the seabed as the clockwork the \ufb01rst to sail from oceanography,\u201d to \ufb01nd channels. Antikythera mechanism, the Atlantic to the US naval of\ufb01cer They develop the to plot the movement Paci\ufb01c Ocean, and Maury compiles \ufb01rst coins to of the heavens and to discovers the Strait of sea charts of the facilitate trade. navigate at sea. Magellan on the way. world\u2019s oceans. 500\u2013200 BCE 1492 1769\u201371 Endeavour Greek marine science Columbus\u2019 voyage Captain Cook\u2019s Endeavour Aristotle identi\ufb01es many British naval captain James marine species, such as Italian navigator Cook makes voyages to the crustaceans, mollusks, Christopher Columbus\u2019s Southern Oceans and is the echinoderms, and \ufb01sh. voyage to the Americas \ufb01rst European to reach New shows that it is possible Zealand and Australia. Ancient Grecian bowl showing a sailing boat to cross the Atlantic Christopher Columbus and even sail around the world. 292",",, THE STORY OF OCEANOGRAPHY HOW INAPPROPRIATE TO CALL THIS PLANET EARTH WHEN ,,IT IS QUITE CLEARLY OCEAN. Arthur C. Clarke, British writer, 1917\u20132008 main thruster propellor provides power for forward movement 3 THE NUMBER OF PASSENGERS 26 ft THE LENGTH OF NAUTILE 4.6 miles THE RANGE OF NAUTILE 1956 Trieste 1984 Dumbo Mid-ocean ridge 1960 Nautile octopod Marie Tharp and Bruce Descent to the bottom The bathyscaphe Nautile is 2000\u201310 Heezen, American The bathyscaphe (diving vessel) Trieste used to \ufb01lm the wreck of the Marine census oceanographers, dives 35,797ft (10,911m) down the Paci\ufb01c\u2019s RMS Titanic and search for A Census of Marine Life that discover the mid-ocean Marianas Trench, to make the \ufb01rst descent the \ufb02ight data recorder from catalogued the diversity of life in ridge\u2014an undersea to the deepest part of the ocean. Air France Flight 447, which oceans worldwide is completed ridge running down the crashed into the Atlantic in 2010. This octopod is one of the Atlantic seabed. Ocean in 2009. many strange discoveries. 1872\u201376 1968 1977 2012 HMS Challenger Deep sea drilling Ocean \ufb02oor Deepsea Challenger On its voyage Rock samples taken Marie Tharp and Bruce Heezen Canadian \ufb01lmmaker around the world, the from the mid-ocean make the \ufb01rst accurate relief James Cameron goes HMS\u00a0Challenger collects ridge show map of all the world\u2019s ocean to the bottom of the a huge amount of data magnetic striping \ufb02oors, mainly using data Marianas Trench in the about the oceans. con\ufb01rming that the recorded by sonar. submersible Deepsea ocean \ufb02oor is Challenger and makes Samples from ocean \ufb02oor actively spreading. Map of ocean \ufb02oor a \ufb01lm about life there. 293","1964 1965 ,, ,,WELL BOYS, WE\u2019VE BEEN SCOOPED. Robert Dicke, American physicist, on the accidental detection of microwave radiation by Arno Penzias and Robert Wilson, 1965 A map of microwave radiation emitted after the Big Bang de\ufb01nes Alexey Leonov\u2019s historical spacewalk an expanding universe that is 13.7 billion years old. lasted for 12 minutes and 9 seconds. AMERICAN PHYSICISTS Arno existence of astronomical objects showed how proteins solidi\ufb01ed American chemist Jerome IN MARCH, SOVIET COSMONAUT Penzias (b.1933) and Robert with such compacted mass that in blood when exposed to air Horwitz (1919\u20132012) made a ALEXEY LEONOV (b.1934) became Wilson (b.1936) were studying not even light could escape from due to chemical reactions that drug called azidothymidine (AZT) the \ufb01rst person to walk in space. radio waves from satellites. them. In 1964, these massive involved different clotting factors. that was a modi\ufb01ed component of Tethered to his spacecraft, Despite removing all known objects got a name: black holes. American physiologist Judith Pool DNA. By injecting it into tumors, Voskhod 2, Leonov spent over sources of interference, their In June, a rocket discovered the (1919\u201375) isolated the chemical he hoped it would confuse cancer 10 minutes in extravehicular antenna continued to pick up strongest source of X-rays near factor that was eventually used in cells and stop them from dividing. activity (EVA). He nearly failed to background noise. What they Earth, Cygnus X-1\u2014later shown treating hemophiliacs, people AZT became an effective antiviral get back inside the spacecraft were hearing, by accident, to be a black hole. These holes with impaired blood clotting. treatment for AIDS. because his suit had swelled up was the cosmic microwave are now known to be formed in the vacuum of space. background radiation (CMB) when massive stars collapse. rotating wheel for aluminum left over from the formation of positioning aperture earlike aperture In the late 1950s, astronomers the universe\u2014evidence of the British physician Robert found a celestial object that gave Big Bang (see p.344). Macfarlane (1907\u201387), and Holmdel Horn Antenna off brilliant light. First detected American scientists Oscar Classi\ufb01ed as a National Historic by their radio waves, these For more than a century, Ratnoff (1916\u20132008) and Earl Landmark, this radio telescope objects were called quasars physicists had hypothesized the Davie (b.1927) independently at the Bell Laboratories in New (for quasi-stellar radio sources). Jersey, US, was the \ufb01rst In 1965, however, American cab containing detector of background radiation astronomer Allan Sandage receiver to left over from the Big Bang. (1926\u20132010) found the \ufb01rst measure radio-quiet quasar, which had incoming weak radio emissions, but could signals emit other types of radiation. It took another 20 years for astronomers to identify a quasar as the core of a galaxy with a black hole at its center. Until 1965, biologists thought that human cells could divide continuously. But in March, American biologist Leonard Hay\ufb02ick (b.1928) published evidence that cultures of human cells only went through about 50 rounds of division before stopping altogether. Ten years later, it was found that this happened because each division corroded the ends of chromosomes Jajnouuursanerasylit1sh8teAAtnemnremEriw\u201ccbainnlgac\ufb01krshtole\u201d MadyesBclroiboeddclinotdtientgaiils JuNnaLeva1a\ufb02b6liogCRUrhyeaStgstndoeiruasysrccroXohv-ce1krebtlack hole 294 MAarynWoAmmiPlseieconrrnziocidwaaisnascvaproenhavdbydesaRiraiccoctkiboisogestnrmrot(uiCcnMdB) aAntzrtieidvauoirtstaehcladyimnsfocidedreriHnvaeIeVnlo(dAtprZieesTdal)tatmoteernt","1966 ,, THE SPACESUIT STARTED BEHAVING ABSOLUTELY DIFFERENT FROM WHAT ,,IT DID ON THE GROUND. Alexey Leonov, Soviet cosmonaut, 1965 The endosymbiosis theory proposes that cellular organelles\u2014such as the nucleus and chloroplasts shown here\u2014once lived as independent organisms. Evidence for this comes in the form of their own functioning DNA. Dividing cancer cells IN JUNE, after being rejected mast cell histamine released Cancer cells have a genetic by more than a dozen scienti\ufb01c from vesicles abnormality that makes them journals, a young scientist \ufb01nally allergen (tiny sacs) divide uncontrollably, deviating from managed to publish a theory that (foreign the normal cellular aging process. would eventually revolutionize particle) IgE antibody our understanding of the early until the cells were no longer In the 1960s, scientists cracked history of life on Earth. American ALLERGIC RESPONSE viable. Hay\ufb02ick\u2019s discovery had the genetic code. By 1961 it was biologist Lynn Margulis (then important implications in the known that DNA is a two-chain married to Carl Sagan, see 1970) IgE antibodies are the basis for allergic responses. When \ufb01rst biology of cancer. Cancer cells double helix that carries proposed that components of exposed to an allergen (allergy-causing particle, such as pollen), are abnormal in that their cell information for building proteins. cells\u2014such as the nucleus and white blood cells release IgE antibodies, which then bind to mast division is unchecked\u2014so The sequence of DNA chain chloroplasts\u2014originally had cells. When these IgE molecules bind to a second exposure of the continuous division produces building-blocks, called bases, independent lives. She suggested same allergens, it makes the mast cell release histamine. This a tumor. A modern strategy determines the sequence of that millions of years ago triggers the body\u2019s allergic response symptoms. in cancer treatment involves protein chain units, called amino bacteria-like life forms engulfed exposing the affected cells to acids. Between 1961 and 1966, one another to form the \ufb01rst oversensitive to certain triggers in\ufb02ammation associated with drugs that encourage the natural cell biologists worked out the complex cells, called called allergens. Although they allergic reactions. corrosion of chromosomes. triplet combinations of bases eukaryotes. Today, all animals, help in defending the body that are encoded for all 20 plants, and many microbes are against certain kinds of Meanwhile, in a Mt. Hotham different kinds of amino acids. made up of eukaryotic cells. parasites, IgE antibodies Resort ski hut in Victoria, The \ufb01nal link came in 1965, when Her endosymbiotic theory can also make it overproduce Australia, the discovery of American biochemist Robert was initially resisted by most chemicals such as histamine, a mouse-sized animal was Holley (1922\u201393) unraveled the other scientists. which triggers the massive causing a sensation among structure of tRNA (transfer zoologists. This mountain RNA)\u2014the molecule that provided In July, Japanese husband pygmy possum\u2014the only a physical link between DNA base and wife biologists Kimishige marsupial adapted to the code and assembling protein. (b.1925) and Teruko Ishizaka snow-capped habitats of the (b.1926), working in the \ufb01eld of Australian Alps\u2014was previously 60 immunology, reported that they known only from fossils and had discovered a new class of thought to be extinct for more ROUNDS OF DIVISION 50 antibodies. These substances, than half a century. In 1966, the called immunoglobulin \ufb01rst living specimen was found. 40 Hay\ufb02ick\u2019s graph E (IgE), play a central of cell role in making people proliferation Mountain pygmy possum 30 Normal cells The mouse-sized alpine possum was discovered nurtured in the as a fossil in 1896, but a 20 laboratory soon living animal was found in Australia in 1966. divide to produce 10 a living culture\u2014 but after about 50 0 rounds of division, 10 50 90 130 170 210 250 290 330 reproduction DAYS IN CULTURE stops. Mabretccohowm1a8elskAtilnheexsep\ufb01yarscLteepoenrosvon MaofrecHshatayCb\ufb02olinicsckheelpidmt it Jutnhoeero8irgyEinonsfdeoesusyktamabrblyiisoohttiieccdcell JuTleyIrsJuhaakinpzataaiakbnnaoeddsdeyKisicbcmlioaoivslsoeshgriIgigseEts MarchRoAbmteRerNtriHAc\u2014aoonllfaebntyhioisencetghqeeerunmmeenierscidtceiascroyde aSMsratanardodyinaoAog-mqmeueedireriitscAcaqlonluavaensrasrs a mdFoiisurcsnottvaleiMivnriten.pdgHyigeonxmthsaykamimppro,elesAssoouurfsmttroanlia 295","1967 1968 First detected by their radio signals, pulsars are now known to emit other This image shows tracks made by neutrinos\u2014the most abundant subatomic forms of radiation, such as visible light and, as shown here, X-rays. particles in the universe\u2014caught in a nanosecond inside a bubble chamber. ALTHOUGH IT WAS PRACTICALLY observed pulses of radio signals First heart transplant THE STANFORD LINEAR recorded striking Earth than had IGNORED at the time, American coming from a \ufb01xed position in the South African surgeon Christiaan ACCELERATOR CENTER in been estimated. Italian physicist physicist Steven Weinberg\u2019s sky. They whimsically called them Barnard shows a chest X-ray image California houses the longest Bruno Pontecorvo (1913\u20131993) (b.1933) 1967 study of the forces of LGM-1 (Little Green Men-1). It of 54-year-old Louis Washansky, the linear accelerator\u20142 miles accounted for this discrepancy nature eventually became one was later found that the signals \ufb01rst person to undergo a successful (3.2km) long. In 1968, it provided by proposing that neutrinos had of the most quoted scienti\ufb01c were coming from the radiation heart transplant. the \ufb01rst evidence for the appreciable mass, which allowed papers. In it, Weinberg explained beam of a rotating neutron star existence of fundamental them to change types. Many went how electromagnetism and weak (a dense, compact star thought to and each pulse corresponded to particles called quarks (see undetected by neutrino detectors, nuclear force were just different be composed mainly of neutrons), a single rotation. In 1968, these 1963) by bombarding and which monitored only one type. aspects of a single uni\ufb01ed set stars were termed pulsars. shattering subatomic particles. of \u201celectroweak\u201d forces. He American physician Henry also proposed that breaking the In December, surgeon A solution to the solar neutrino Nadler (b.1936) reported on symmetry of these forces provided Christiaan Barnard (1922\u20132001) problem was proposed in 1968. the \ufb01rst prenatal diagnosis particles with a fundamental performed the world\u2019s \ufb01rst Neutrinos\u2014subatomic particles of Down syndrome using property\u2014their mass. For his successful heart transplant at with no charge and negligible amniocentesis (see panel, work, Weinberg went on to win the Groote Schuur Hospital in Cape mass\u2014are generated by atomic below). His observations were 1979 Nobel Prize in Physics, with Town, South Africa. The patient, reactions in the Sun. However, con\ufb01rmed by direct diagnosis Pakistani nuclear physicist Abdus with diabetes and incurable heart fewer neutrinos were Salam (1926\u201396) and American disease, received a heart from on the fetus. theoretical physicist Sheldon a young road-accident victim. Glashow (b.1932). The recipient survived for just hypodermic needle ultrasound over two weeks, ultimately dying extracts \ufb02uid probe monitors In November, British of pneumonia. Barnard was procedure astronomers Antony Hewish nonetheless celebrated for his amniotic (b.1924) and Jocelyn Bell Burnell achievement, and went on to \ufb02uid amniotic sac perform other similar operations. JOCELYN BELL BURNELL (b.1943) His longest-surviving recipient went on to live for 23 years. British astrophysicist AMNIOCENTESIS Jocelyn Bell Burnell came to prominence as a postgraduate, The amniotic \ufb02uid, which surrounds a fetus, contains cells that when she discovered radio come from the unborn child. Amniocentesis is a method by which pulsars with her thesis a sample of this \ufb02uid is extracted to test for abnormality. In 1952, supervisor, Antony Hewish. British obstetrician Douglas Bevis (1919\u201394) discovered how it could Controversially, Bell did not be used as a diagnostic tool. By the 1960s, scientists could use it to share Hewish\u2019s 1974 Nobel detect chromosome abnormalities, including Down syndrome. Prize for this work. More recently, she served for two years as president of London\u2019s Institute of Physics. AuIrgiPsuhasmntptuo6hrbniyidsiisltgeoircweefiianigedtntahmeersFdnedcreresrag\ufb01idinvbebeakenr-ssiclcyltaahmrteoeer\u201cd;faihctehineer\u201d NoAvpfeoumrlstbhaeerr\ufb01is2r8sotbtsiemreved DeCchperemissruftbtoicraercaarmenns3sssBptfalhuarelnnh\ufb01taerradsrtt ThAec\ufb01ScneteadlxensirfseoattrveodindrLceCeinnecoenefateqrforu,raUtrhSke,s Juclhyfiop1u8mnSdaeenmdufiiacnocCtnuadrlueifcrotrIonnrtiael SeZpostnepdtmao5crbceebiectrerruccarl1ofentm5tc\u2013sheaa2serf2retMyhSliyoenootvg\ufb01oinearEtsnatanimrdtahls BrMiticMsKhogegrengeozaopienphhaydsynepsidsclicciaAsritstmiebtWemeD.ratoiJcenvaacesntmoonneincts Nporevseemntbsehorfis2e0mleSoctdtwerevoelemaonkfaWungenuniicen\ufb01ltbeciseaamrrtgiofaonnrcdes pAermfAoeDdrrmreiiccasahennetmhKasebaruten\ufb01rgttrrrreso6aotwnncsihtpzilladnt Decpehmypsobitpcehuirselta2tJer9oirzAhmemns\u201cWetbhrlhieacecaueknsleehroolfe\u201d pAamrtdeRoerinaciscsshca,arqnliraubdptaeehFrsryketsrsyheinceacminoosrdtgaynngiolzufeodns Then\ufb01erustttoreinxcapopestruuimnredeesnrottslaakren Decedmiuapsbgreeennsroasa1temaHlDnleyoinofworcyrneNntshtyaeends\ufb01dliersrrsottmotieme 296",",,1969 ,,ONE SMALL STEP FOR [A] MAN, ONE GIANT LEAP FOR MANKIND. Neil Armstrong, American astronaut, 1969 IN THE WAKE OF Christiaan First man on the Moon Barnard\u2019s ground-breaking heart Neil Armstrong was the \ufb01rst person transplant (see 1967), American to step on the Moon, followed soon surgeon Denton Cooley (b.1920) afterward by Buzz Aldrin. Television implanted the \ufb01rst arti\ufb01cial images of the event were sent back to heart on April 4. At times when at least 600 million people on Earth. natural hearts were unavailable and surgical intervention urgent, a large plain, the day before. early arti\ufb01cial hearts could give Armstrong and Aldrin spent two the patient time until a donor and a half hours on the surface could be found. The \ufb01rst patient to of the Moon, collecting samples receive an arti\ufb01cial heart survived of lunar rock. They left behind long enough to get a donor. instruments, including a series of re\ufb02ectors for laser-ranging In an event that was televised experiments, which would help live across the world, American determine the distance between astronauts Neil Armstrong Earth and the Moon to a degree (1930\u20132012) and Buzz Aldrin of accuracy never before possible. (b.1930) became the \ufb01rst The astronauts returned to Earth humans to set foot on the Moon on July 24, splashing down in on July 21 Coordinated Universal a module in the Paci\ufb01c Ocean. Time (UTC). Their spacecraft, The entire mission took just over Apollo 11, had touched down on eight days to complete. the Moon\u2019s Sea of Tranquillity, British biochemist Dorothy Structure of insulin Hodgkin (see 1945) specialized Dorothy Hodgkin showed how in working out the structures of the building blocks of insulin were complex biological molecules. spatially arranged to form a \ufb01xed complex shape. After her success with steroids, penicillin, and vitamins, she moved on to a much more complicated substance\u2014insulin, a protein hormone. Fred Sanger had determined the sequential building blocks of insulin in 1951. Ten years later, Hodgkin worked out the 3-D structure of insulin by using X-ray diffraction techniques that had earlier been applied to DNA and other complex structures. JahnouirnamotrfhoytenhPeheesypbpdtroieadtsihencarliabmedus MaNromcrhwBetjepeegoarcikrtaltonineemle\u2013xorseAgnamitmdsoeetpfesoJlgricsai\ufb01lrccoceiaibboldnlbeaabsltyioEnl,Ni\u00f1o MaUyS6S1l6Ra\u2013n\u2019s1dV7oe,n1n9eV6rea9nu5sand Jualsyatr2nto1dhnoeABanpu\ufb01uottzrshlzsletNoAhsel1duui1lrmriAfnaarcnbmeesscottoorfmotwnhegaelMk oon JuplayJleoAoohmunnctethOortDahilscoerebtaagirinnbopcisotimertneddyrpalciisolhktidueincistnss,oaosfaur July 20 UASposlplooanc1et1chrleaanMftdoson dMisacorcvehrt3meh1deoFb\ufb01leoercrstuwmtinlleeaatelerddngrieessshcttoeyaordlrvlgseeaa\u2014rrnesdicpiance Atepmrpilo4rimaDrpeylnaatnorttnis\ufb01Ctchoiaeoll\ufb01ehyresatrt micraonbddioiHlsoucgAodiuvsseotgsrnuyTsFohtrfoeAmbemzaaeceisntrdeiBhceroarsioantccrslkiipbvrieninggs Dor3o-tDhHysoNCtdrroguovkcweitnfumo)ropbetueo(brlfali1itsnehsreuslin 297","1946\u20132013 THE INFORMATION AGE 1957 1959 Luna 2 1962 1963 Tereshkova 1966 Man-made satellite Luna 2 and 3 Mission to Venus First female cosmonaut Landing on the Moon On October 4, USSR The Soviet lunar On December 14, On June 7, Soviet cosmonaut On February 3, Soviet probes Luna 2 and 3 the Mariner 2 Valentina Tereshkova becomes probe Luna 9 becomes launches the \ufb01rst are the \ufb01rst craft to becomes the \ufb01rst the \ufb01rst woman in space. A the \ufb01rst spacecraft to satellite into orbit successfully reach the spacecraft to \ufb02y crater on the far side of the successfully land on the Moon. Luna 3 captures past another planet, Moon is named after her. The Moon. On May 30, the US around Earth, the \ufb01rst images of the revealing Venus as \ufb01rst US female astronaut was Surveyor 1, made the Sputnik 1. Today far side of the Moon. a hothouse planet. Sally Ride, 20 years later. second soft landing. there are over 500 working satellites. 1949 Laika 1961 Yuri Gargarin 1965 Animals in space First person in space First spacewalks The \ufb01rst astronauts were On April 12, Soviet cosmonaut On March 18, Soviet animals. American rocket Yuri Gagarin becomes the \ufb01rst Aleksei Leonov becomes scientists send Rhesus person in space. He completes the \ufb01rst astronaut to monkey Albert II into space one orbit of the Earth in Vostok 1. venture outside his craft. in 1949. Soviet dog Laika In May, Alan Shephard (1923\u201398) American astronaut became the \ufb01rst animal to becomes the \ufb01rst American Edward White completes orbit Earth in 1957. in space. a spacewalk in June. THE STORY OF Edward White SPACE EXPLORATION FROM THE FIRST ARTIFICIAL SATELLITE TO REACHING OTHER WORLDS AND THE EDGE OF THE SOLAR SYSTEM The launch of the Soviet Union\u2019s Sputnik 1 in October 1957 is usually taken to mark the start of space exploration, even though some earlier flights had left Earth\u2019s atmosphere. It was the beginning of a series of adventures that has taken astronauts to the Moon and probes to distant planets. Sputnik 1 was followed a month later by the astronauts Neil Armstrong and Buzz Aldrin VOYAGER 1 AND 2 voyage of the Soviet dog Laika, which became set foot on the Moon. Their \ufb01rst moments there the \ufb01rst animal to orbit Earth. The \ufb01rst human were broadcast live to people around the world. When the two Voyager probes were launched in to travel in space was Yuri Gagarin, who orbited Astronauts returned to the Moon several times in 1977, they were expected to send back useful data Earth in the Soviet spacecraft Vostok 1 in from as far as Jupiter and Saturn. However, they April 1961. These Soviet successes the 1970s, but most voyages of exploration have continued to return data as they traveled threw down the challenge to the US since have been by robot craft, which through the heliosheath\u2014the very edge of the Solar to step up its space exploration have now traveled to every planet in the System\u2014and will soon be in interstellar space. programme. In 1965, the Solar System and some even beyond Voyager 1 may well have left the Solar System in American Mariner 4 sent back that (see panel, right). October 2012. It is the most distant human-made the \ufb01rst close-up pictures of object, nearly 11,495 billion miles (18.5 billion km) another planet, Mars. In hatch through which astronauts away in March 2013. Voyager 2 is not far behind, 1966, a Soviet probe, Luna 9, entered and exited module over 9,320 billion miles (15 billion km) away. made a soft-landing on the Moon and sent back the \ufb01rst Apollo 11 command module pictures from the surface. This was part of the spacecraft that Three years later, American carried Neil Armstrong, Buzz Aldrin, and Michael Collins on their historic mission to the Moon in 1969. ,, IF OUR LONG-TERM SURVIVAL IS AT STAKE, Apollo 11 hatch WE HAVE A BASIC RESPONSIBILITY TO OUR The main hatch on the Apollo Command Module had to provide a ,,SPECIES TO VENTURE TO OTHER WORLDS. perfect seal to protect the crew. It was redesigned to open outward Carl Sagan, American cosmologist, 1934\u201396 after an accident in 1967 in which astronauts were trapped inside the capsule as it caught \ufb01re. 298"]
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