Big Ideas Simply Explained - The History Book

1847–48 ,, THE EQUILIBRIUM… BETWEEN ,,HIS INTELLECTUAL FACULTIES AND ANIMAL PROPENSITIES… [HAS] BEEN DESTROYED. John Martyn Harlow, American physician, in Recovery from the Passage of an Iron Bar through the Head, 1868 Following an iron bar penetrating Phineas Gage’s skull and brain, studies on how his personality changed after this accident revealed much about brain function. Advances in anesthesia were IN 1847 Hungarian or destroyed (now known as the astronomer William Bond made by surgeons on both sides first law of thermodynamics). (1789–1859) discovered Saturn’s of the Atlantic. On October 16, physician Ignaz eighth moon, Hyperion. at the Massachusetts General The following year, Scottish Hospital in Boston, American Semmelweis. physicist William Thomson (Lord English inventors John surgeon William Morton Kelvin) formulated the third law Stringfellow (1799–1883) and (1819–68) anesthetized his made an of thermodynamics with his idea William Henson (1812–88) patient, Gilbert Young, sending of absolute zero. He realized flew a model of their steam- him to sleep with fumes from important there must be a temperature at powered aircraft, the Aerial ether while Morton cut out a which all molecular movement Steam Carriage, for 33ft (10m). tumor from his neck. Half an discovery for outlet pipe to ceases and calculated it to be It was the first ever powered hour later Young woke up, −459.67°F (−273.15°C). Thomson flight, but attempts to fly a larger unaware the operation had medicine. He patient’s face used this as the starting point for model were unsuccessful. been done. Others had used realized that if mask a new temperature scale—the anesthetics before, such as Kelvin scale (see 1740–42). Vermont railroad worker American surgeon Crawford doctors washed their hands Phineas Gage survived a 3.3ft Long (see 1842–43) and By 1848, increasingly powerful (1m) iron rod being driven American dentist Horace Wells, this could reduce infection telescopes were revealing through his head, resulting but it was Morton’s demonstration more about the solar system. in intellectual and personality that made an impact. Two by puerperal fever: a disease Astronomers discovered planets changes. This was the first record months later, Scottish surgeon often had more than one moon. of how damage to the frontal lobe Robert Liston (1794–1847) responsible for the deaths William Lassell and American of the brain affected function. performed a leg amputation under anesthetic in London. of many woman during Another important discovery childbirth. His procedures was the production of kerosene, or paraffin, from coal or oil, by were not adapted until Canadian geologist Abraham Pineo Gesnar (1797–1864). In many years later. 1846, Gesnar began experimenting with methods for distilling Scottish surgeon James coal and oil. By 1853, he had perfected a process to produce Simpson realized that a new fuel he named kerosene that was used in lamps. Up until neither ether nor laughing this time most lamps were fuelled by whale oil, but kerosene gas could keep a patient was much cheaper, so people could afford to burn lights unconscious long enough brighter and longer. for a long operation, and as it rolls down, the ball’s potential energy is not lost but converted to kinetic energy, introduced chloroform the energy of movement as an anesthetic. at the top of a German physicist Hermann hill, a ball has gravitational von Helmholtz outlined the potential energy law of the conservation of energy, which was first put forward by Julius von Mayer (see 1841). This stated that POTENTIAL ENERGY KINETIC ENERGY energy cannot be created CONSERVATION OF ENERGY chloroform holder The law of the conservation of energy states that the total amount of energy in the universe is constant. Energy cannot be created Chloroform inhaler nor destroyed, it can only change form. When any work occurs, The chloroform inhaler was energy is converted from one form to another or transferred from developed in 1848. It enabled one object to another. For example, potential energy (in a static surgeons to quickly anesthetize object) can be converted to kinetic energy (motion energy). patients with fumes of vaporized chloroform. Ocstuoprbeggereefroonn1rem6WraAsillmalainaenmroeipscMteahnroearsttioioann under 18p4h7vyosGsnitecacHrisotmeetnlsaHmsnteehhrreovmlaltaatzinwofnonoromf faelnlyergy Ocatsodtbrisoecnroov1me, r1esr8c4Mo7amAreimat eM1r8iit4cca7hneVlIl Juinnvaeen1find8rtoWs4rt8ispllEJoianowmghelnirHseShedtnrflisnoiggnfhemtlloawke the SeApmPteehrmrionidcbeaepanesrrn1Gae3aitl,grr1aoe8taisdn4ug8wrvhoiivrsekhseeraandiron SSNicomovtpetsimsohnbseuursrfe4gos–ero8canh,nl1Joo8arp4moe7feorasrtmion DescuermgeboenraRg2mpeo1ebnprSeuefcorrtoatramttLltioiiasssnnhtaoeunlsnetdgheertic 1847SHemuwnmagseahlrwiinacegnhishidlraodecnbctdioorsrmthtIomginnrefaenezddcutsicoens Will1ia8m4t8hTeShcaoobmtstsiosolhunotpfcehtaezylcesmuircpoliaespttreoasitnutre TheSeAfopmrteetShrmcieciebaAnendcrAve2asi0nss,coee1csm8itaa4teb8inolitnsohfed 199

1849–51 In 1986, the Voyager 2 space probe took these close-ups of Uranus’s five largest moons, including Ariel and Umbriel, discovered in 1851, and the smallest, called Miranda, which was discovered in 1948. IN 1849, FRENCH ASTRONOMER Two other French scientists, mirror to the wheel, the two lens EDOUARD ROCHE (1820–83) physicists Hippolyte Fizeau scientists could calculate the explained why Saturn has rings (1819–96) and Jean Foucault speed of light. camera front as well as moons. If planets and (1819–68), measured the speed moons get too close to Saturn of light in 1849 by bouncing a It was difficult to get Wet plate camera they are ripped apart by tidal beam of light off a mirror, an accurate figure for Working in a portable darkroom, the forces—the changing pull of through slots on a rapidly the speed of light using photographer had under 10 minutes gravity created as they all rotate. rotating wheel, and onto another this method, so in 1850 to take a picture and process it There is a limit to how close mirror approximately 22 miles Foucault replaced the before the plate dried. planets and moons can get (35km) away. The beam was spinning wheel with a without being pulled apart; this reflected through the wheel and rotating mirror. As the a photographic plate with a became known as the Roche onto the first mirror. By the time mirror swiveled, it sticky liquid called collodion in limit. If the planets and moons the beam reached the rotating reflected the returning darkness before each photo was have identical densities, the wheel again, the wheel had beam to a slightly taken. It had the fine detail of Roche limit is 2.446 times the moved on to another slot. different position. This daguerreotypes (see 1837) and radius of the planet. If our Moon By measuring how fast the difference revealed the repeatability of Fox Talbot’s ever strayed closer to Earth than wheel was rotating, the spacing the speed clearly. calotype (see 1835). about 11,476 miles (18,470km), it between the slots, and the Foucault got too would be shredded into rings. distance from the more distant a very close calculation for mirror light the speed of light at source 185,168 miles per second (298,000km per second). outward beam bellows for Further advances in science adjusting focus returning beam toothed include the publication in wheel Germany of physicist Rudolf oil lamps. Scotch-born American wheel rotates as beam Clausius’s (1822–88) 1850 paper inventor John Gorrie (1803–55) travels out and returns on the movement of heat. He laid also introduced refrigeration, foundations for the science of when he created a machine for Fizeau’s apparatus half-silver beam to observer thermodynamics with two basic making ice using circulating liquid Fizeau measured the speed of laws. The first is conservation to draw out heat (see 1872–73). light by reflecting a beam of light of energy—energy is never lost, through the slots in a toothed but simply redistributed. The In 1851, British astronomer wheel, onto a mirror 22 miles second is that heat can never William Lassell (1799–1880) (35km) away, and back. move from a cold place to a discovered two more moons of hot one, only the reverse. Uranus, Ariel and Umbriel, and British sculptor Frederick Scott In 1850, British chemist James Archer (1813–57) introduced Young (1811–83) patented a the wet plate photographic method of distilling paraffin process. This involved coating from coal, which gradually replaced whale oil in domestic 18a4n9mdHoeJfaiepslapiungorhlFeytotteuhceFaiszupeltaeued 18im50gpivJrfooeevrsaentadhnFeaoapsucppccaeaureuradaltttu’osesffiligguhrte 18l5ay0osfRwttuhhitdeehorftmlowfuoCondlbdayauanstsaiiiomcunsliascws s OcWtoidlblisimeacrmooov2eLn4ras,ss1ost8fwe5Ulol1rmanoures e1x8p4la9inEsdoSuaabturydrtniRd’soaclrhifnoegrcses 1850 HmipaepnaodslyuEtre.eoGFtfohizeueelneasecupltlereeicdity 1p8a5t0ednJitassmtialelmisnegYtohpfuraonodrgmaoffficnoal 1851 FinrterdoepdrhuioccketosSgtcrhoaetptwhAiecrtcphpreloarcteess 200

1852–53 1854 A replica of George Cayley’s glider, which made the world’s first fixed-wing This color-enhanced micrograph shows the cholera bacterium, now known flight in 1853 in Yorkshire, England. to be responsible for cholera. ,, I AM WELL CONVINCED THAT the pilot, while others say it was FOLLOWING A SUGGESTION distance between two points is AERIAL NAVIGATION WILL FORM A his footman. Nonetheless, it was a BY BRITISH PHYSICIST William a straight line, in Riemannian MOST PROMINENT FEATURE IN THE historic achievement. Thomson, German physicist geometry angles in a triangle Hermann von Helmholtz add up to more than two right ,,PROGRESS OF CIVILIZATION. 1853 was also an important (1821–94) and British engineer angles and there is no such year for medicine and physiology. William Rankine (1820–72) thing as a straight line along George Cayley, British aeronautical engineer, 1804 French physiologist Claude developed Rudolf Clausius’s a surface. Bernard (1813–78) discovered theory that heat never flows from GREAT AUKS HAD BEEN EASY In 1853 there was another aviation that glucose sugar, the body’s a cold to a hot place. This implies The new algebra of British TARGETS FOR HUNTERS in areas first, the first flight in a full-sized energy food, is stored that heat will ultimately spread mathematician George Boole around the North Atlantic for aircraft—a glider built by the temporarily in the liver in the evenly through the Universe (1815–64) was intended to many years, and by the 1840s British engineer George Cayley form of a starchlike substance and once this happens energy make logic mathematical, not they were practically extinct. (1773–1857), who had pioneered called glycogen, ready to be will not be able to move and the The last bird was spotted off understanding of the theory of released into the blood as Universe will come to a stop 3.19 the coast of Newfoundland in flight. Details of the flight, across glucose when energy is needed. in what is called “heat death Canada in 1852. Brompton Dale in Yorkshire, of the Universe.” OZ/IN3 England, are not clear; some French physician Antoine British physicists James Joule reports say Cayley’s butler was Desormeaux (1815–82) British astronomer George Airy THE AVERAGE (1818–89) and William Thomson developed the endoscope for (1801–92) calculated the density DENSITY OF (1824–1907) discovered the Great Auk surgical operations. This was a of Earth by measuring the swing EARTH Joule–Thomson effect in 1852. The last Great Auk, long metal tube that could be of a pendulum on Earth’s surface This explains the way that one of the largest and 1,257ft (383m) down a coal philosophical. Boole argued gases and liquids cool and birds of the North inserted into the body to mine. Different measurements that any proposition could be expand after flowing through Atlantic at 31.5in make examinations, revealed slight variations in the reduced to just “and,” “or,” and a restriction or throttle. The (80cm) tall, was using light from a effects of gravity, from which he “not,” and worked through to Joule–Thompson effect is central last seen paraffin-fueled lamp obtained the figure 3.795oz/ a conclusion. Today, Boolean to the way refrigerators and air in 1853. in3 (6.566g/cm3). Today’s accepted logic combines with the binary conditioning systems work. reflected in a mirror. figure is 3.19oz/in3 (5.52g/cm3). system of numbers to shape Another Frenchman, surgeon all computer programs. The age of aviation began Two new types of mathematics on September 24, 1852 when Charles Pravaz (1791–1853), were introduced in 1854. One In August, there was an French engineer Henri Giffard and British physician Alexander was the non-Euclidean geometry outbreak of cholera in London’s (1825–82) made the first Wood (1817–84) independently of German mathematician Soho. British physician John powered and controlled fight, invented a practical Bernhard Riemann (1826–66). Snow (1813–58) traced the flying 17 miles (27 km) from hypodermic syringe with a Euclidean geometry applies only source to a single water pump, Paris to Trappes in France. The hollow metal needle that could to flat surfaces; Riemannian thus validating his theory that flight was made in a powered be inserted into the body to geometry is the geometry cholera is water-borne. airship, which consisted of a deliver drugs directly into veins of curved surfaces, important cigar-shaped, hydrogen-filled for much faster effect than because the surface of Earth is balloon that provided the lift, taking the drugs by mouth. curved. In Euclidean geometry, and a steam-driven propeller the angles in a triangle add up to that moved it through the air. two right angles and the shortest 18J5o2TuhlJteohameeamfnsJfedeooscnuWtldeili–lsiTachomvoemrson 18g5li3mdeGfaurnelnoml-resagdikezfleeCsidgathayhtilereicynfir’sarasftt 18A5l3tehxCeahnhadyreplreosdWePorromadviaicnzsvaeynrnidtnge HeHremWlmaitlhnlhihenaooemtlvrathoiztzeRnedaaUneanndabkitovihneueortsftehe GetohregdeeAnisryitymoefaEsaurreths BeinrntgrheoaodrmudceRetsireyRmieamnnannian Gre1a8t5NA2euwTkhfoseeulenandsCltoaafnnfda,da SmeHapektneersmi Gtbhiefefracfir2ord4ns’st,tr1pao8iolr5lwse2hedirpfiegdht 18r5e3aiClsizlsaetusodrtehedaBteingarlsntuhagcerlodylscievoegren 18D53esAconrreetmoanitedneaoesustxchoepe AugusJto3h1ns–oSSounuerotpcbwetreeotmrafakabceeicnsrhLot1holeenrdaon GBeooorlgeeanBlooogleicinantrdodaulgceebsra 201

1855 1856 The Bessemer process revolutionized engineering by making Montgomerie surveyed the Karakoram range as part of the Great Trigonometric steel production cheaper and more efficient. Survey of India. It includes K2, the second-highest mountain in the world. AT THE FOREFRONT Geissler tube hydrogen, hydrogen chloride, THE SCIENCE OF GENETICS passed on from generation to OF SCIENCE in 1855 These gas-filled water, or ammonia molecules. BEGAN WITH THE WORK of the generation through what he was the search for tubes came in an In 1855, English chemist William Austrian monk Gregor Mendel called “factors,” which later the relationship assortment of Odling (1829–1921) added a fifth (1822–84), but his work was not became known as genes, that between atoms, elaborate shapes type, based on methane. This led fully appreciated until years later. are inherited from both parents. light, and and glowed in a German chemist Friedrich Kekulé Mendel began to experiment electromagnetism. variety of colors. (1829–96) and Scottish chemist with pea plants in his monastery Another discovery that was not British Archibald Couper (1831–1892) garden in 1856. He laid the fully appreciated until much mathematician spiral electric to begin developing a structural foundations of genetics as he later, was the discovery of the James Clerk discharge tube theory of molecules. showed how characteristics are first recognized fossil of a Maxwell (1831–79) human ancestor. In August began working on a theory to unify German physicist ,, ATOMS yellow pea with green pea with two electricity, light, and Julius Plücker WERE two dominant recessive alleles (yy) magnetism, while (1801–79) alleles (YY) other scientists investigated spectra ,,GAMBOLLING PARENT PEA conducted practical by studying the glow PLANTS experiments to find (undistorted by air) BEFORE MY out how atoms from electric EYES… the dominant allele emitted light. They sparks. To do this (Y) is expressed had already worked he commissioned Frederich Kekulé, German out that each kind instrument maker chemist, describing a daydream the recessive of atom emits and Heinrich Geissler that led to his structural theory, 1855 allele (y) is hidden absorbs a particular (1814–79) to create range of colors, or a sealed glass tube, The technological breakthrough FIRST spectrum, with dark with a near-perfect of the year was the development GENERATION lines (gaps) at some vacuum and electric of a special furnace, developed wavelengths and terminals at either by the British engineer Henry one in four peas bright lines (peaks) Bessemer (1813–98), which inherit recessive at others. Swedish end. When allowed steel to be made alleles from both physicist Anders switched on, the cheaply and in quantity from parents Ångström (1814–74) electric charge pig iron (a crude form of iron). and American scientist traveled through SECOND David Alter (1807–81) the tube, between In Germany, an unusual fossil GENERATION independently described the terminals, creating was found at Riedenburg. It was the spectrum of hydrogen a bright glow. thought to be a flying reptile until DOMINANT AND RECESSIVE GENES gas, which would prove French chemist Charles 1970 when it was finally shown crucial in the understanding Gerhardt (1816–56) had to have feathers, identifying it Mendel’s work on peas showed that inherited characteristics, of the link between light suggested in 1853 that as the first Archeopteryx ever such as color, are determined by particles, later called genes. and atoms. four basic types of organic discovered. It is evidence that Genes come in different forms, called alleles, that combine in chemicals are created birds evolved from the dinosaurs. different ways in offspring. A dominant Y allele determines yellow by carbon linking with pea color and a single one of these being present is sufficient to make a yellow pea. A recessive y allele determines green pea color and two of these must come together to make a green pea. SwpehÅdynisssgiphcseistcrtötArmunmdpeuorbsflihsyhdersogenAmsceAirelisntcepatairensnctddteDrosaactvohrifeidbhreygsdartshoegesen GeFrrmsietaasdnrtrrotisccurhhgcteoatKumnderieciaksvlumtetlélhooelpeoctrhuyeleosf BrmitiJasathMhmeaoemxnslwaihgCtmeihilscletali,tragbheknneeleegoctirnitysrsmitcowituoyr,nkaitned OcHteopnbapretyerronB1ctees7sstssheeomfBesetrseseelmmaekr ing AuGsrtsertigaoaornntrspmMlhaoeinsnntkrdieneshleearrictahnce AmWeiwlrliiicnaadmncFmirecerutrleeaoltrieooxnlpolgaiisnts AutegaFucusfhhotelsNGrrsoeeiJtlartobmnihoddanneenenrstthifioaeflsman March BriWdtiisislhclioacdvmheyeerPmsmeairsanktuiilnvineeine MBaucynhs1eem0BnuGisinentsrvRmeeonnabtbnseurttrhneer ArcThdheifeosocpsfiRotsreivisielrnetdywrGexeandesbramutragny ThnoamBmraeistsisMtmhhoesonuutHgrnivomtemayaiKonelra1rpiyeaeanandksK2 202

1857–8 Workers inpecting the transatlantic telegraph cable. The first message sent was “Glory to God in the highest; on earth, peace and good will toward men.” THE NUMBER OF HOURS TAKEN TO TRANSMIT THE FIRST MESSAGE 17ON THE 1858 CABLE 1856, quarry workers found IN FRANCE, IN 1857, CHEMIST developed a process known Gray’s Anatomy some bones in a cave and local AND MICROBIOLOGIST LOUIS as pasteurization that The anatomy book now known teacher Johan Fuhlrott (1803–77) PASTEUR (1822–95) published involved killing the identified them as humanlike. his seminal results on yeast microbes with as Gray’s Anatomy was first Named after the Neander Valley fermentation and yeast heat in order to published by British surgeon in Germany where the bones multiplication in 1857. He found prolong the life Henry Gray in 1858. There were found, this human ancestor that when beer and wine ferment of certain foods. have been over 40 editions. is now known as Neanderthal it is not chemicals that are man (Homo neandethalis). responsible, but tiny microbes On February 13, Newfoundland in Canada, went argued that all species Neanderthal man is thought to known as yeast. Pasteur later 1858, British into service in August 1858. on Earth had evolved have lived in Europe between explorers Richard gradually due to a 300,000 and 30,000 years ago, ALFRED WALLACE Francis Burton On July 1, 1858, a scientific process of change but it was some time before (1823–1913) (1821–90) and John paper was delivered to the known as natural many would accept that any Hanning Speke Linnean Society in London. selection—members other humanlike creatures Alfred Wallace is best known (1827–64) became the It combined the ideas of the of the species less had ever lived. for independently conceiving first Europeans to see British naturalists Charles well suited to the a theory of evolution by Lake Tanganyika in Africa, Darwin and Alfred Russel environment either In America, meteorologist natural selection. He also the second largest freshwater Wallace in a new theory—the fail to reproduce or William Ferrel (1817–91) pioneered biogeography, lake in the world. Speke theory of evolution by natural explained how rising warm air the study of species in a continued alone to discover selection. The idea that species die early, thus failing to and Earth’s rotation creates geographical area. His work Lake Victoria. evolved through time was not pass on their inferior traits. spiralling circulations of air in in Indonesia between 1854 new, but Darwin and Wallace Wallace had written to Darwin the mid-latitudes, called Ferrel and 1862 led to the Wallace In the cities, fast-rising from Indonesia in June 1858 cells. These cells drive the Line, which divides Asian populations were putting new with an outline of his idea, but, stormy, westerly winds that are and Australian species demands on engineers and unbeknown to him, Darwin had characteristic of these latitudes. (see pp.204–205). builders. In New York, Elisha already spent two decades Otis (1811–61), inventor of developing the theory. In India, British surveyor a special safety device that The most widely used book in Thomas Montgomerie (1830–78) prevented lifts from falling if the medical history was published began his survey of the cables failed, installed his first in 1858. British surgeon Henry Karakoram Range as part of elevator at 488 Broadway on Gray’s (1827–61) Anatomy: the Great Trigonometric Survey March 23, 1857. In Germany, Descriptive and Surgical has of India that had started in 1802. Friedrich Hoffmann played his been in publication ever since part in speeding up urbanization and is now known simply as British inventor Alexander by patenting the Hoffmann kiln Gray’s Anatomy. Parkes (1830–90) patented the in 1858, which was capable of first plastic, Parkesine, which firing bricks non-stop. Cities 420MILES was made from cellulose treated also began to communicate THE LENGTH with acid and a solvent. across oceans. The first OF LAKE undersea transatlantic TANGANYIKA telegraph cable, laid between western Ireland and IN AFRICA 18c5h7PeamFtshriteiasesnttumccfLreahioscurumrhsiooesebwdnesbtsaytliiovning Fe1b8er5xu8BpaulBSroryrprtTieoet1arinks3nseh,agRrnaeidncahyJciaohkrhadLniankAefrica JuWnaDela1lar8wc5ei8nwfrriotmesItnodonesia Au1g8tu5ras8cntaFsb1ial6rets,ltamnetiscstaegleegisr1as8peo5hnf8tGFrairys’ts pAunbaltiocmatyion ABlreixtppiasalnahtedsitnenirtcvs,ePPntahtaroerkrkefiesrssitne MEalrischha2O3et,ilsi1en’s8vsa5fitNat7rolselretwidsYionrk BZraitmishbLeimvsiMniisgeassxyitopo1nen4ade,ri’ty1si8oDAn5af8rvbiicednaganintusrtahleisotrsyJDouaflryeswve1ioln,el1uca8ttnii5ood8nnWBibsarylipltnariseachtseue’srAnatuleSgdpueskte3V,rice1ta8oc5rhi8aeJsinoLhAanfkreica 18bfi5rr8icinFkpgiakrtbsieltrnniHc,tekocdsaffpmninaoabGnnl-eensrotmofpa,ny 203

1789–1894 THE AGE OF REVOLUTIONS UNDERSTANDING EVOLUTION THE SOURCE OF BIOLOGICAL DIVERSITY, EVOLUTION ALSO PROVIDES A LINK TO OUR PREHISTORIC ANCESTORS Fossils reveal how prehistoric life forms were different from those of today, and studies of different species suggest that all life originated from a single, simple ancestor that lived billions of years ago. Today, scientists understand the biological and genetic processes behind the evolutionary changes that gave rise to the diversity of life. In the early 1800s, the French naturalist Jean- ADAPTIVE RADIATION For example, on newly formed islands there may Baptiste Lamarck suggested, erroneously, that When descendents of a common ancestor adapt be few competitors and new food sources, so features acquired during an organism's lifetime to different circumstances and diversify, it is over many generations a pioneering population could be passed on to its offspring. Later, Charles known as adaptive radiation. It tends to happen of one species can diverge to produce many new Darwin (see 1859) proposed that individuals are most rapidly in habitats where there are many species, each adapted to a slightly different role. born with variations that make some of them opportunities for exploiting new ways of life. “fitter”—more likely to survive and pass on their hooked bill for characteristics. This is called evolution by natural ancestor may have slicing into soft selection. It is now known that characteristics eaten seeds or insects fruits and buds are determined by genes and that random gene mutations cause variation (see pp.284–85). But only probing bill for overbite is useful natural selection can explain how some variations pulling soft seeds for digging up grubs are better adaptations to the environment and from cactus flowers come to predominate in organisms. CONVERGENT EVOLUTION pointed bill for woodpecker finch digs GALAPAGOS FINCHES Physical resemblance can indicate common pecking insects out prey from under On the Galapagos Islands, ancestry but sometimes completely unrelated bark using a stick ancestral finches underwent species evolve independently to become alike. from leaves adaptive radiation—most Known as convergent evolution, this often obviously in the shape of happens when species have comparable roles their bills—to exploit new in the same environment, so natural selection food sources. works on them in similar ways. dark upper body dorsal fin whale is a mammal SEXUAL SELECTION camouflages prevents so breathes air when seen through a blowhole Not all adaptations increase from above rolling an individual's ability to survive. Sometimes, the selective advantage that 1ST GENERATION Male birds with a variety of tail lengths drives evolution comes from Female selects male being better able to attract a with the longest tail KILLER WHALE mate. For instance, showy plumage can make male birds dorsal fin dark upper body camouflages more vulnerable to predators prevents when seen from above but it also makes them more rolling successful at courting. As a result, they father more 2ND GENERATION Male birds with a variety of tail lengths, on average longer than those of the previous generation offspring and the genes for Female selects male with the longest tail Male birds with a variety of tail lengths, on average shark is showy plumage are passed on. even longer than those of the previous generation a fish so GREAT WHITE SHARK breathes water through gills PHEASANT'S TAIL Male pheasants with longer tails KILLER WHALES AND WHITE SHARKS are more attractive to females, so 3RD GENERATION These marine predators have both evolved a streamlined the genes for a long tail get passed Female selects male shape for greater speed when chasing prey and have a darker on and male tail length increases with the longest tail upper body and lighter lower body to provide camouflage. with successive generations. 204

UNDERSTANDING EVOLUTION ASIA PHILIPPINES OKINAWA MAINLAND Edge of Sunda shelf TAIWAN SOUTHEAST ASIA This marks the eastern ANDAMAN ALFRED RUSSEL WALLACE ISLANDS limit of many Asian A British naturalist and animals, such as apes explorer, Wallace traveled extensively in Asia and and rhinoceroses Australasia, noting patterns Sunda shelf of animal distribution. He This was all dry land came up with the idea of during the ice ages, evolution by natural selection when sea levels independently of Darwin, and were lower the two coauthored a paper on the subject in 1858. BORNEO THE WALLACE LINE As a result of his observations, Wallace drew a line on a map to show where he thought there was a boundary between Asian and Australasian regions of evolution. The line roughly corresponds with edge of a continental shelf—the Sunda shelf—which marks the easternmost limit of many Asian animal species. Another shelf—the Sahul shelf—defines the Australasian region. The deep water between the two shelves formed a barrier to migration, even when sea levels were lower. THPEANI-IMNASLUALYA Edge of Sahul shelf This marks the western limit of many Australasian animals, such as wallabies SUMATRA Sahul shelf This was all dry land during the ice ages, when sea levels were lower SULAWESI NEW GUINEA COEVOLUTION JAVA TIMOR Two species may evolve in Wallacea tandem, each adapting to This region between the Sunda and Sahul shelves contains changes in the other. For instance, a many islands that have never been linked by predator may evolve greater speed and its prey land, so animals have island- may, in turn, get faster to avoid being caught. Such hopped to get there coevolutionary relationships may be highly specialized, such as those between some plants and pollinating insects. bee is attracted bee falls into to flower’s fragrance water inside plant fluid in small exit bucket orchid FRAGRANT ATTRACTION FRUITFUL ESCAPE AUSTRALIA A male bee uses the orchid's To escape, the bee must pass fragrant oils to attract a mate sticky pollen, so he leaves —but in collecting them he with oil and with pollen to falls into a water-filled bucket. pollinate the next flower.

1859 Darwin visited the Galapagos Islands in 1835; the animals and plants he observed there are said to have contributed to his becoming an evolutionist, but it wasn’t until 1859 that Darwin consolidated his observations into a book—The Origin of Species. ON NOVEMBER 24, 1859, specific habitats. If habitats In April, two British CHARLES DARWIN (1809–82) change, however, these special archaeologists, John Evans CHARLES DARWIN PUBLISHED advantages may become (1823–1908) and Joseph Darwin trained as a doctor his epoch-making book On weaknesses and as a result Prestwich (1812–96), made a before embarking, as a the Origin of Species. In it he the species could die out. startling discovery that pushed naturalist, on a round-the-world explained in detail his theory of human origins further back voyage in 1831–36 aboard HMS evolution, first introduced in What made Darwin’s theory into prehistory. In St. Acheul Beagle. The voyage sowed the 1858. Darwin’s theory was that such a turning point was that the in northern France, they found seeds for his theory of evolution species change and develop mechanism he proposed worked a stone ax in layers that also by natural selection, which he automatically through a process for all of life, and asserted that contained fossils of extinct finally revealed in 1858. He of natural selection; this idea every organism is descended creatures, including mammoths. also applied his theory to was neatly summed up by the from a common ancestor. If mammoths and humans had humans in The Descent of Man, philosopher Herbert Spencer Although many people accepted existed together, then human published in 1871. (1820–1903) as “survival of the the force of Darwin’s arguments, life must date back tens of fittest.” In his book, Darwin some were bitterly critical and thousands of years. explained how, occasionally, a debate flared up. eyepiece for viewing telescope spectrum chance mutation at birth may telescope with equip some organisms with a eyepiece replaced trait that gives them a better by collimator chance of survival, which means they are more likely to pass 9 the trait onto their offspring. Different mutations will suit (or 8 not suit) particular conditions, so species gradually diversify 7 diffraction grating to Earlier chemists had in the special gas burner and become adapted to suit split light into already realized that devised by Bunsen in 1855. 6 spectrum the range of colors They found that every element Number of species on Earth (spectrum) in the glow has its own unique spectrum, Naturalists have identified 1.25 MILLIONS 5 spectroscope mount of light from heated and realized that spectra can be million living species on Earth chemicals could help used to show the presence of today, and estimate there may 4 Spectroscope identify them. In autumn even tiny traces of chemicals. be over 8.7 million in total. The first instrument for 1859, German scientists By passing sunlight through a 3 analyzing spectra was built Robert Bunsen (1811–99) sodium flame, Kirchhoff also from old telescopes. This and Gustav Robert found that the flame absorbed 2 specially built spectroscope Kirchhoff (1824–87) spectral lines in sunlight in a dates from slightly later. mirror image to those emitted 1 began to study spectra by sodium—showing that the systematically, Sun contains sodium. 0 heating chemicals Estimated Identified species species GeBrumsntaugsndleoynswcsasiynesodntfetGiemsulteassmttRiacevoanbKllteyisrrtcthhehUosGfifnudgsistSaacuvosnvpKeceirrocscnthrttohhasoiancftofstphseeo,dium AparrEiclhvPBaarnreaeisontsilcatsowinhegidnicsthJtsosdtsoJiesoncpheohnvteorols Noirvotehnmie-nhbGFuelrlorlaeinr2dec4,ebTlaahtutelneficsrhhseitpd, FrLeenncohiretnwpgrooi-ndseutercroekÉsettihegenansfioeerlsnitngeine RusKsoiwanalasskwtirodorenkvoeomlouoeftprttshhMeaeaMwrroiaiatlyknatytoioWnay AugTuhsetlsa2or8lga–erSssettpgoterCemoamkmronrbanoiegnwrnrgenet2cotaoincsrdEt,hveent UrbFareinncLheumtVnheadertirhseiecexVorimusvpltaceeratMrnoiencpced,ieoartscpnooeulfeasraxynnp’esltao,irnbit CNhoavOrlenemsthbDeeaOrrSwrp2ipgei4nuicn’biseloissf hised 206

1860,, SEVERAL MINUTES… BEFORE TOTALITY, I... FOUND THAT THE SUN’S IMAGE MAY BE VIEWED WITHOUT THE SLIGHTEST ,,INCONVENIENCE. Warren de la Rue, British Astronomer Warren de la Rue developed a special camera that allowed him to photograph a total eclipse of the sun as seen from Spain on July 18, 1860. THE STIR CAUSED BY THE 41⁄2deck HMSWarrior PUBLICATION OF DARWIN’S With its armor-plated iron hull, Origin of Species came to a head HMS Warrior was the first modern in fierce public debate in June at battleship. It was armed with 26 the Oxford House Museum in muzzle-loading cannons that were Oxford, UK. Opposing Darwin able to fire 68lb (31kg) shot over from a religious perspective was 8,858ft (2,700m). Bishop Samuel Wilberforce graphic. The recording has only INCHES (1805–73); supporting Darwin steam engine iron armour recently been converted to sound and science was the British plating using computer technology. THE WIDTH OF HMS biologist Thomas Huxley water. Each was named after the WARRIOR’S BELT (1825–95). The debate focused brightest colors in their spectra: of sunlight, discovering more British scientist Joseph Wilson OF WROUGHT IRON on whether humans are cesium, from the Latin for than 16 different elements in it. Swan (1828–1914) demonstrated descended from apes, even “sky blue,” and rubidium, Photographs taken of a solar the first working incandescent The launch of HMS Warrior on though Darwin had not actually meaning “dark red.” Kirchhoff eclipse by British astronomer light bulb. The light was created December 29 on the Thames in suggested they were. Huxley is learned more about the sun’s Warren de la Rue (1815–89) by passing an electric current London was a landmark in naval composition from the spectrum proved that the flames, now through a thin carbon filament technology. Warrior was only the generally considered to known as prominences, that inside a vacuum-filled glass second armor-plated, iron- have won the debate. horn for sometimes appear around the bulb, which heated the filament hulled warship to be built, after Following their collecting sound Moon during an eclipse come until it glowed. With only a partial the French ship La Gloire of 1859, breakthrough in 1859, from the Sun’s surface. vacuum in the bulb, however, the and it was on a vastly different Bunsen and Kirchhoff Phonautograph filament quickly burned out. scale from anything that had made further progress in The phonautograph The oldest known recording He made improvements and gone before, at over 417ft used a horn attached of a human voice was made in patented it in 1878 (see 1878–79). (127m) long and weighing the field of spectroscopy. Bunsen to a diaphragm that April 1860 using a phonautograph almost 10,000 tons. discovered two new elements vibrated a stiff made by French bookseller 400,000 from the spectra of light Édouard-Léon Scott de More peacefully, British absorbed by drops of mineral bristle to inscribe Martinville (1817–79) that used THE APPROXIMATE botanist Joseph Hooker an image on a sound vibrations to draw on a NUMBER OF KNOWN (1817–1911) concluded his carbon-coated, lamp-black carbon-coated cylinder. The PLANT SPECIES IN account of the many previously rotating cylinder phonautograph was not designed unknown plants he had (carbon) coated, to play back sound, it was just THE WORLD discovered on his voyages to hand-cranked used for turning sound into a Antarctica, between 1839 and cylinder. 1,500 1843 aboard the naval ships The number of plant species Erebus and Terror. collected on the Antarctic voyages of Joseph Hooker Number of plant species aboard Erebus and Terror New species of plants are being identified all the time; 400,000 are now known. Joseph Hooker added 1,500 on his Antarctic voyages. GeRromdbiascencarfotercvsBoheimuuernmmstshtiesahentneirdesrlpeuembcitderinautms BrSitwifisarhlsnitgsdchweiteombnrkuotiinlsnbstgtJrioanstceeaspnhtdheescent MaAyrJc2ohp6sareesBeptosroShleiontonPigecstriihsseeatstaxytfipwinanicpdLhesorntoodnothnheisRoyal JuNlying9uhortpisTneihngnionagemldLesocaahnst’odSHootl.nospital SeKpaitnrelismGnrteouberfhermcnerhaaC3entm–oiyo,n5infigsartrslsetmsseeting BritaHiscdohciosobkcuoeontrvtaecnoroEfiisnerhtcesiJlsbuoouAdnssneetasthpanhehrdicsstThieciprsror ÉAdporuialmr9da-FkLrveeéosnoicncthhedebreeooMclodpokaehrsrdsotetiinlnnlkaevgnuirlootloewngnhraisph June 3e0voMluatjioorndaetbOaxtefoordve, UrJuKWlyar1r8enBrdietislah Rawdsuutperrriodnonigmsocamionnveeeernrccsleipsse iDroencebWmaatbtrlreeirosrh2,i9lpa,TuHhnMechSed 207

1861–64 The Yosemite Grant, signed by President Abraham Lincoln on June 30, 1864, preserved Red blood cells get their red color from the protein hemoglobin. Felix the natural grandeur of the Yosemite region of California for the public. Hoppe-Seyler discovered its vital role in oxygen transport in 1864. BRITISH PHYSICIST JAMES He began by explaining how an findings in four equations, now THREE-COLOR SYSTEM CLERK MAXWELL REVEALED electromagnetic field is created known as Maxwell’s equations, the pivotal advances he had made by waves that radiate outward. which underpin all calculations Mixing three colors of light— RED GREEN in the science of electricity and He proved that these waves relating to electricity and red, green, and blue—in varying BLUE magnetism in two books: On radiate at exactly the same speed magnetism, in the same way proportions makes every color the Lines of Physical Force (1861) as light, which showed that light that Isaac Newton’s equations in the rainbow. Images can be and A Dynamical Theory of the is also an electromagnetic wave. underpin all studies of motion. reproduced in full color by Electromagnetic Field (1864). Finally, he summed up his registering and then displaying In 1861, Maxwell also took the how much light there is of each first color photograph. of these three colors in each He had already proved part of the picture. Color was that we see colors created this way in everything as varying intensities from the first color photograph of three colors (see to modern phone displays. panel, right), but to demonstrate this he ,, …LIGHT CONSISTS asked photographer IN THE TRANSVERSE Thomas Sutton (1819–75) UNDULATIONS OF THE SAME to take three black and white photographs of a ,,MEDIUM WHICH IS THE tartan ribbon, each one through a different color CAUSE OF ELECTRIC AND filter—red, green, and MAGNETIC PHENOMENA. blue. He then projected all three images James Clerk Maxwell, British physicist, January 1862 together, through filters of the same colors. (1814–74) in 1861, showed that autopsy that revealed damage to The three color images the Sun contains hydrogen gas. a region of the brain now known mixed to recreate the as Broca’s area. picture in full color. In the same year, French The colors found in the physician Paul Broca (1824–80) After fossils of the Glossopteris spectrum of sunlight by discovered a key area of the fern were found in Africa, India, the Swedish physicist brain for speech in a man who and South America, Austrian Anders Ångström had suffered a brain injury that geologist Edward Suess rendered him unable to talk but (1831–1914) theorized in 1861 that The Berlin Archaeopteryx able to understand. When the these three continents were once The Berlin fossil of man died Broca performed an joined by land bridges to create Archaeopteryx, found in 1874, is the most complete. It plainly shows the toothed, dinosaur-like beak and feathered, birdlike wings. 18M61asxtJuwademylloeafsdeCvlaelencrtckreosmthaegnetism 18c6r1ceoaMltoearsxpwthheeolltfiorgsrtaph 18c6o1AmrTcphhleeatefieorfpsottseasrliymlxoofisstfound JaAnmuAaletvrrhaiyenca3wGn1rh,aai1tshe8tar6dmo2wnCoamlraferskrtadrisSciorviuerssB 18l6ig2ehlMet cmatxruwosmet lbalegsnhaeontwicswave 18a6s3HtruBsogtnraogiotrfiimansstsshheaetrsrhehsWeoamiwSmllausieadntmeghaast es Åthnagtstt1rh8öe6ms1hudAyninsdccdroooenvgretsearnsingsas B1r8o6c1aP’satauhrleeBabr,roaacikanenfyoarpmaserptseoefch 1e8xi6s1steuEngdcgweeassortufdspatSeshruoeceuopstnsahtseitnrennt 1R8ic6h1aArdmJe.rGictaahtneliniGngaveitnlnivnteognrgtsun m1a8k6e2sLetoahureilsygPsetarumsdoteifetuhdsriesooefrayse 186V3escrFinereennpcceuhbfiWlwcisetrhieiotekenssrbhiJnoiusoalkefiB,sraFslitlvoeon 208

1865 15 GRAMS THE AMOUNT OF HEMOGLOBIN PER LITER OF HEALTHY HUMAN BLOOD Joseph Lister’s introduction of antiseptic surgery with carbolic acid made operations far safer because the acid killed the germs that spread infection. one giant continent, which he IN 1865, GERMAN PHYSICIST ,, THE ENERGY OF THE named Gondwanaland, before RUDOLF CLAUSIUS made an UNIVERSE IS CONSTANT. the seas rose and they were assertion about heat that was separated. He was right about more significant than most ,,THE ENTROPY OF THE the giant continent, but we now people appreciated at the time. know that they separated through Starting from the second law of UNIVERSE TENDS TO continental drift (see 1915) and thermodynamics (heat flows only A MAXIMUM. not because the seas rose. from hot places to cold), he came JAMES CLERK MAXWELL up with the concept of entropy. Rudolf Clausius, German physicist, from On Various Forms of the At Langenaltheim in Germany, (1831–79) Entropy is a mathematical Laws of Thermodynamics that are Convenient for Applications, 1865 the first almost complete fossil measure of the disorder in any of Archaeopteryx was found. Born in Edinburgh, Scotland, system. To create order, heat on the input of energy from the series of branching treelike This winged, feathered creature British physicist James Clerk needs to be concentrated, and Sun; once the Sun’s fuel has run fibers (dendrites). with reptilian teeth, which lived Maxwell laid the cornerstones this requires energy. So in any out, this input will cease. 150 million years ago, shows the of electromagnetic theory. system, whether it is the human In medicine, British surgeon transition between dinosaurs and With his brilliant math, body or the entire Universe, Another German, Otto Friedrich Joseph Lister (1827–1912) birds. The discovery was a major he showed that electricity, entropy and disorder will Karl Deiters (1834–63), observed pioneered the use of carbolic piece of evidence supporting magnetism, and light are increase unless there is a the basic features of nerve acid as an antiseptic during Darwin’s theory that one species all forms of electromagnetic continuous input of energy cells for the first time under a surgery, to clean instruments evolves gradually into another. But fields. His four equations from outside to maintain the microscope. He noted that each and wounds in order to Darwin’s theory received a major are the basis of all classical concentration of heat. For nerve cell has a main cell body, reduce the chance setback in 1862 when British electromagnetic science. example, life on Earth depends a long tail fiber (axon), and a of infection. physicist William Thomson calculated the age of Earth from during childbirth. Medicine was axon terminal axon terminal from how fast it probably cooled since also advanced in 1864 when another neuron the time it was formed. The figure German physiologist Felix signal is he came up with was no more Hoppe-Seyler (1825–95) carried to the nucleus than 400 million years, and identified the role of the iron- of neuron possibly as short as 20 million containing protein hemoglobin next neuron years ago. Even 400 million years in binding oxygen to red blood was not long enough for Darwin’s cells for transport through the myelin insulates cell body gradual evolution to happen. blood. This was also the year that axon, making the Earth is now known to be closer US president Abraham Lincoln signal travel faster Schwann to 4.5 billion years old. signed the Yosemite Grant, which cell was the first step in creating The structure of a nerve cell In 1862, French chemist Louis California’s now famous National Nerve cells have a main body dendrite Pasteur (1822–95) came closer Park in 1890. (soma), from which sprout two sets to establishing that microbes of fibers (an axon and dendrites) that are responsible for many transmit and receive nerve signals infectious diseases with his through contact with other cells. studies of puerperal fever, an infection often caught by women JuTnheees3NtYa0oab,stli1eiosm8nh6aiet4lesPGYaorraskenmt ite 18T6ht4ohmWe sialoglinaemcoaflEcuarlathtes RuindtiodrloefdaCulocafeuessnituthrseopy JoasnetpisheLpitsitcesruprigoneeryers intr1oek8dle6uey4cceetMrsqoautmxhawetaiegofolnnluesrtoisfm BrAiNtuisgehwuasclpahtnee2drm0iso,istdp1htri8ceoJ6dtoe4auhlbecnlmeeseonfts 1864 FeliixdeHnotpoifipfeehs-eStmheeyolgrelorolebin Otto Dethiteerbsasodificsncfeeoravvteeurrsceeslls GeFrrmiepabdrnoersipncctorzhhuseeKecnmsteeuikasmruterloiéfnloegrcuale 209

1866–67 1868–69 Ernst Haeckel identified one-celled protists as completely separate organisms, The Suez Canal was finally opened on November 17, 1869, after 10 years although the exact definition is still being debated. of labor involving tens of thousands of men. THE INITIAL RELIGIOUS DEBATE persist as they are passed on Also in 1866, German WHILE HE WAS Homo sapien’s skull OVER DARWIN’S THEORY OF through “factors,” now known as microscopist Max Schultze PREPARING This European Early EVOLUTION died down (see 1860), genes. It was not until the early (1825-1974) undertook the A TEXTBOOK Modern Human but scientific doubts persisted. 20th century that scientists fully most important early study on on chemistry in skull is from Cro- One doubt was the question of appreciated the importance of the structure of the retina—the 1868, Russian Magnon cave how traits persist. In 1867, British this in relation to evolution. light-sensitive tissue on the chemist Dmitri in France. Its engineering professor Fleeming inside of the eye. He identified Mendeleyev discovery provided Jenkin (1833–85) argued that Another commentator on the layers of the retina and (1834–1907) evidence that adaptations would eventually evolution was German naturalist humans evolved. blend in with the general Ernst Haeckel (1834–1919), population, getting lost over the who argued, wrongly, in 1866 drew detailed illustrations of its began to wonder generations through what he that stages in embryonic called a “swamping effect.” development retell evolutionary cellular makeup, including the if chemical Mendeleyev could history. He made drawings to Unknown to both Darwin and show similarities between fish individual structure of rods and elements could be use it to predict the Jenkin, Austrian monk Gregor and human embryos. Haeckel Mendel (1822–84) answered this also proposed in 1866 that the cones—the two types of light- arranged in a table existence of three question with his work on peas single-celled organisms called (see 1856), which he completed protists should have a kingdom receiving cells inside the back that linked their as-yet-undiscovered in 1866. Mendel showed that of their own, separate from inherited characteristics plants and animals. of the eye that react to light atomic weights and elements to fill gaps small steam iron bicycle and colors (see 1935). properties. Laying out the in the table. Over the following engine frame In technology, British engineer 60 elements known at the time 16 years, all three missing Robert Whitehead (1823–44) in weight order, he saw that elements—gallium, scandium, developed the first self- certain properties were repeated and germanium—were found, propelled torpedo in 1866, periodically and realized he and since then more than 50 a device that later proved could organize the elements further elements have been devastatingly effective in both into eight groups or “periods” identified and discovered. World Wars. A year later, of elements. Tellingly, the Another new element was Swedish chemist Alfred Nobel elements that appear in discovered in 1868 using the (1833–96), invented the particular positions in each knowledge that every substance explosive dynamite. period have similar properties. glows with its own particular In 1867 Parisian blacksmith Mendeleyev presented his spectrum, or light signature Pierre Michaux (1813–83) idea, now known as the Periodic (see 1884–85). While studying the developed one of the first Table, to a meeting of the spectra of light from the edge of practical bicycles, or Russian Chemical Society on the Sun during a total eclipse, velocipedes, with pedals and March 6, 1869, and it has been a British astronomer Norman a chain. He also invented one key reference ever since. What Lockyer (1836–1920) and French of the earliest motorcycles, made it so powerful was that astronomer Jules Janssen powered by a tiny steam engine. 17MILESEarly motorcycle Dating from between 1867 and 1871, Pierre Michaux’s bicycle was powered by a small steam engine. It is thought to be the world’s first motorcycle. THE DISTANCE GIFFARD’S AIRSHIP TRAVELED 18M6e6hniGsidnrreheelegsproeiutarabrnlcichsehoens 18W6h6aisRteeohlbfe-eaprdrtodpeevlellionpgstorpedo Masurdcreghse1co6rni,bJ1eo8ss6ea7pnBhtirsLietisipsthteirc su1r8gt6ae7lorkyfFswblaieltebehnomDduiiatnnrtggwhJeiinneph’nsrekotrihbniteleaomnrcye JaBnruDitaaitsrrhhwyenoi3nar0ytp,uuo1rbfa8llp6iissa8htneCgsheanhrieslseiss 18p6h8ÅynsStgihwcseiestrsdtöoiAsmlnahdrmesarpspesctrum 18id6e6snetEpifiranerssattpeHrofaartenoicdsmktasepnlaliasmnatls 1867 PiinevrerpenrtoMspitechhreabufiicxrysctNleobMeal ypa7t,e1n8ts67dyAnlfarmedite 1867 FsMPmrLeiecroanhrulcealihasutshu-txeGeex’nsaufigambitirlnitlskaaeetecunemhmtrgoeioenscteoraertcoaytecle Mgeaorlicodhgedini1sstt8icfiL6oCeo8vrdeuoFri-ssrsMkeLetnahalcgeerhnttofieonrtnsstmofan 18iKn6nv8eignBthrtraotiftriinfisJvch.elPni.gthsts 210

102 MILES THE LENGTH OF THE SUEZ CANAL WHEN IT WAS FIRST BUILT (1824–1907) both noticed a of light from the Sun, Eyzies in France where the Technological change gathered Table of elements bright yellow line at a wavelength identifying a thousand remains were found. They are pace as British inventor John This Russian periodic table is based that did not match any known spectral lines in units now more generally known as Peake Knight (1828–86) invented on Mendeleyev’s original table. It substance. Lockyer and Janssen that became known as European Early Modern Humans. traffic lights, and in the US includes his predicted elements— suggested that this indicated an angstroms in his honor. American engineer George gallium, scandium, and germanium. unknown element in the Sun, More controversially, in 1869 Westinghouse (1846–1914) which Lockyer called helium, The debate about Darwin’s half-cousin Francis invented air brakes. Another Mediterranean. When it first after the Greek “helios” for evolution continued. Galton (1822–1911) used American, inventor John Hyatt opened the canal was 102 miles Sun. That year, Swedish physicist Darwin described how Darwin’s theories to suggest (1837–1920), developed celluloid. (164km) long. It took 10 years of Anders Ångström (1814–74) also traits might be passed a hereditary basis for human construction work to complete. mapped the complete spectrum on from generation intelligence, an idea that was The Suez Canal opened to to generation through to lead him to develop the shipping in November 1869, DMITRI MENDELEEV a process called science of eugenics. linking the Red Sea to the (1834–07) pangenesis. He proposed that in the Born in 1834 in Tobolsk, body there are countless Siberia, Dmitri Mendeleyev particles, or gemmules, hiked to St. Petersburg to which are like seeds enroll in the university. that can reproduce Despite suffering from the whole organism. tuberculosis, he became Some claim this has Russia’s leading chemist and similarities with DNA, developed the Periodic Table, the genetic material which earned him worldwide found in every body cell, acclaim and enabled him to which was coincidentally predict the discovery of the identified in cell nuclei elements gallium, scandium, the following year by and germanium. Swiss biology student Friedrich Miescher (1844–95). It is now known that only DNA in the sex, or germ, cells (eggs and sperm) is ever used to make a new organism. In France, geologist Louis Lartet (1840–99) added weight to the idea that humans also evolved, with his discovery of the first identified skeletons of what came to be known as Cro-Magnon man. They were named after the cave near Les 18L6u8pduAwobnuilgisstthBhreioearlsntmzapmakhlaeyenysqnipcuaiislptiberrium AuBgrNuitosiFsrtrhmJe1ana8aencs,nlshte1rsLm8oaeon6sencot8nkrdmtoyisnehecroeromlaivuneedmrr tJihuneltehse Sun 18s6tu9ddiSsaecwcnoiidtvsFse(DrrbisNeioddAlreo)iogcxhyyMriibeosnchueclreic 18C6h9carFrelraeetsnescJhoflssoetwpahtdisiMatigicnriaaanrmds JuAnmJeoe1chre5incl,laH1un8lyoa6init9dtvepnattoernts NojovuberymNnBaborlreimtNrisaa4htn,ua1rLs8eot6rcfoo9knuySoencmrdieeendrce 1868GAemoregreiincWavenensettnsingagiinrheboeruraskees 1869suBgbrgaitesiFssisrhtasfpnoaocrhilsiynemGtreeaaldtllhtiiotganernyce MRDuamsrscitihParine6Mrp,cir1eohe8ndesd6miece9niTlseteastlebehvlmeiseonfts 1P8a6u9lthLGeaenrisgmleeartnhsaponafisntLhdtaohinsleogcgopeivarsehntracsrnesas N1o8op6ve9enmSsubteoezrsch1ai7pn,pailng 211

1789–1894 THE AGE OF REVOLUTIONS curved blade Bronze knife c.600–200 BCE Surgical knives were used in Ancient Egypt—an early center of medical excellence. These knives might also have been used to remove organs prior to mummification. supporting brace Bone saw 16th century In Europe, early amputation saws for cutting cutting through bone were used without anesthetic. edge Patients were given only alcohol to alleviate pain. Many saws had ornate handles, which served only to harbour more germs. serrated cutting blade SURGERY Amputation knife 18th century Before sawing through the bone, surgeons used the inner edge of a curved knife blade to make a round cut through the skin and muscle. FROM ANCIENT TIMES, SURGERY HAS BEEN USED TO INVESTIGATE AND TREAT DISEASE OR INJURY As the most invasive kind of medical procedure, Blood bag surgery is often literally a matter of life or death. 1950s But operations that would have been considered In the early 1900s, it was discovered that a risky 100 years ago are today a matter of routine. substance called citrate could stop blood from coagulating. This made possible Surgery is fraught with three risks: pain, blood loss, and infection. The the storing of blood and blood products history of surgery is largely the story of how science has been able to for routine surgery and emergencies. mitigate these risks. In the 20th century, improved anesthetics and blade to be positioned label with storage and transfusion of compatible blood types meant around head of baby blood type more people survived operations. Germ theory and information effective antiseptics led to a drop in infection rates. screw for Obstetric forceps tightening c.1820 Scottish physician William Smellie designed retractable a type of forceps to help during breech birth, lance in which the baby enters the birth canal buttocks or feet first. Petit tourniquet heated cutting blade Tonsil guillotine button to 18th century bulb used 1850s move blades In 1718, French surgeon to cauterize Removing tonsils was a popular way of treating Louis Petit developed a skin surface ongoing throat infections until the 1950s. It fell out Military cautery and hook screw-type device known as of favor as knowledge of infection changed. 18th century a tourniquet to tighten a limb Cauteries—used to staunch blood strap and stop blood flow. flow and seal damaged skin by searing it—were widely used, treating from bubonic plague victims to wounded soldiers.

SURGERY nozzle Carbolic steam spray scraping Surgical sterilizing 1860s blade equipment water British surgeon Joseph Lister 1860s chamber developed a device to spray On battlefields, a hot flame carbolic acid in the operating from a portable alcohol room. The pungent chemical burner was used to sterilize acted as an antiseptic, surgical instruments supported on a brass stand. reducing the chance of wounds becoming plate for tongue infected. depression reservoir of carbolic acid Barber-Surgeon instruments Late 1860s The scraper and tongue depressor shown here once belonged to a member of the Barber-Surgeon’s Company (a guild created by Henry VIII in 1540). dropping tube Esmarch blade for making incisions sharp blade for chloroform-ether dropper American Civil War surgical equipment cutting muscle c.1890 cranial saw 1860s English surgeon James During the American Civil War, two soldiers died Simpson used chloroform as Surgical suture from disease and infection for every one killed in an alternative anesthetic to 18th century battle. Surgical instruments were used by medical ether in 1847. Although Catgut—actually made from the attendees with limited training. glass dropping bottles intestines of hoofed animals—has delivered more been used for surgical suturing for locking precise doses, thousands of years. When used catch the danger internally, it is absorbed into the of overdosing persisted until system after the tissue is healed. safer anesthetics were developed in the 1950s. scalpel with interchangeable blade curved suture needle graduations on surgical forceps side of bottle Stainless-steel instruments retractor 20th century with blunt Stainless steel surgical instruments became hook available in 1930. They were corrosion-free and easily sterilized surgical instruments 213 could be made. Additional modifications have helped make surgical stainless steel especially smooth and scratch-resistant.

1870–71 ,, THE LIGHT WHICH WE RECEIVE FROM ,,THE CLEAR SKY IS DUE… TO SMALL SUSPENDED PARTICLES WHICH DIVERT ,,THE LIGHT FROM ITS REGULAR COURSE. Lord Rayleigh, English scientist, from On the Light from the Sky, its Polarization and Color, 1871 The sky appears blue because of Rayleigh scattering—the scattering of sunlight by molecules in the air. AROUND 1870, ITALIAN parts of the body. For his work that an electric stimulus applied develop the theory further; his PHYSICIAN CAMILLO GOLGI in this field, Golgi was awarded to different parts of a dog’s ideas resurfaced in German-born (1843–1926) developed a the Nobel Prize in Physiology or brain would cause distinct physicist Albert Einstein’s general technique to stain brain and Medicine in 1906. muscular contractions. theory of relativity (see 1914–15). other tissue to be able to observe them under the microscope. In a related discovery, German The same year, English British astronomer Joseph He used this method to identify scientists Gustav Theodor mathematician William Kingdon Norman Lockyer (1836–1920) neurons (nerve cells) which Fritsch (1838–1927) and Eduard Clifford (1845–79) suggested that and his French colleague Pierre process and transmit information Hitzig (1839–1907) demonstrated energy and matter are caused by Jules César Janssen (1824–1907) between the brain and other the link between electricity and the curvature of space. Clifford independently suggested that brain function. They showed died young, and was unable to certain lines in the Sun’s spectrum were produced by a WITH SAVAGES, THE WEAK IN BODY OR MIND previously unknown element LOUIS PASTEUR ARE SOON ELIMINATED… WE CIVILIZED MEN, ON (see 1868–69). In 1870, Lockyer (1822–95) THE OTHER HAND, DO OUR UTMOST TO CHECK THE named this element helium, after the Greek Sun god—Helios. While working at Lille ,,PROCESS OF ELIMINATION. University, France, Louis Also in 1870, French Pasteur investigated the Charles Darwin, British naturalist, from The Descent of Man, 1871 microbiologist Louis Pasteur problem of beer and wine (1822–95) published a book (and later milk) going sour. He documenting the mysterious found that this was caused by disease killing silkworms, tracing bacteria, which could be killed it back to microbes. This, together by boiling (pasteurization). with the discovery of the anthrax These studies helped Pasteur bacterium (see 1876–77) led to develop the germ theory of the development of germ theory. disease, and the prevention of disease by vaccination. In 1871, English scientist Lord Rayleigh (1842–1919) discovered This year, English naturalist that when light bounces off small Charles Darwin published a particles, it scatters—now called book on human evolution—The Rayleigh scattering. He stated Descent of Man, and Selection in that for visible light to scatter, the Relation to Sex. He had been wary particles must be smaller than of publishing on the topic before, 400 to 700 nanometers, that is, expecting the sort of furor that smaller than the wavelength of had accompanied the publication the light being scattered. of On the Origin of Species in 1859. Ape and man This illustration from an 1863 book by English biologist Thomas Henry Huxley—an advocate of Charles Darwin’s theories—shows similarities between humans and living apes. FeWbiprllruiSeaapsmraeycnKe2tsi1nT,hhg1ieds8oop7rnya0CpolefifrMfoOarntdttehre c.1G8on7leg0uiCirdaoemnnsitliilfinoetshe brain c.1W8ii7lml0itapeBmrcoorhfviCnCteirorsdoolhoovoakgskeccyeusitseuountmsudtiebespsvetueslmoppprecursors MaDraTcrhhwSee1inDl8eep7csu1tciboeClnnihstiahnoreflRseMeslaant,ioanndto Sex 1870FrGHituistsczthiatghvadeTnehdlemienlEeobokdcdrnbutaosreairtintrrcwdaifttueyeenancntdion 1870iNdaenondrtmiJfuyalnsheoesLlloaJiucrakmnsyspeisenrectnthruem 1p8u7b0lSiLsiolhkueWissoSPrtaumsdtiDeeiussreoanse 1871 LorwdhRyRaatyhlyeeliegsihgkhyexisspclbaaltiunteesr—ing pJou1hb8ali7ns1hnehSFsiwrsiaifedsrdpiossramcbipcoieohwvrcehMhrdiyetieeemsoscbfcirslnhoitbueoicrdnlgecienlls 214

1872–73 ,, I THINK LEPROSY TO BE ,,INOCULABLE; I, MOREOVER, THINK THAT LEPROSY IN MOST CASES IS TRANSFERRED BY INOCULATION. Gerhard Hansen, Norwegian physician, from a letter to British social reformer William Tebb, c.1889 This micrographic image shows rod-shaped cells of the leprosy bacterium Mycobacterium leprae— the first bacterium to be identified as a cause of disease in humans. IN 1872, AUSTRIAN PHYSICIST Pacific, where it took samples When the vanes are description of mitosis—the HMS Challenger LUDWIG EDUARD BOLTZMANN from the Challenger Deep—a exposed to light, the process whereby a dividing cell Launched on February 13, 1858, (1844–1906) developed an point near the deepest recorded “light mill” rotates, provides identical copies of its HMS Challenger was primarily equation that described the point on Earth. The expedition with the white side chromosomes (then known as a sailing ship, but was also fitted behavior of a fluid (gas or also catalogued approximately leading the way. nuclear filaments) to each of the with an auxiliary steam engine. liquid) by applying probability 4,700 previously unknown This occurs because daughter cells (see pp.194–95). distributions (see 1652–54) to the species of animals and plants. the dark side of the The first modern refrigeration interactions of large numbers paddle absorbs more compressor evaporator system was designed by German of atoms or molecules. This The following year, Dutch radiant energy and engineer Carl von Linde equation gave a mathematical physicist Johannes Diderik van gets hotter than the (1842–1934) and built by foundation to the second law der Waals (1837–1923) derived white side; some the mechanical engineering of thermodynamics, which an “equation of state,” which of the energy is company Maschinenfabrik states that systems tend toward a described how the liquid and gas transferred to the Augsburg for a brewery in state of equilibrium. states of a substance merge into molecules hitting Munich, Germany. Three years each other. He assumed that the surface, giving the In December 1872, a Royal molecules exist, are of finite size, paddle a kick. The later, Linde designed a more Society expedition set out on and attract each other by a weak same thing happens on the white reliable system—the first board HMS Challenger from force—now called a van der side, but to a lesser degree. practical compressed- Portsmouth, UK. Over the next Waals force. Together, these ammonia refrigerator. The four years, it discovered many ideas helped provide a better The understanding of disease huge commercial success of large features of the planet, understanding of atoms. took a step forward in 1873, when this invention enabled von Linde including the mid-Atlantic ridge Norwegian physician Gerhard to focus on research, becoming in the Atlantic Ocean and the In 1873, Scottish physicist Hansen (1841–1912) discovered the first person to liquify air, Marianas Trench in the western James Clerk Maxwell published the leprosy bacterium— and separate oxygen and A Treatise on Electricity and Mycobacterium leprae. It was nitrogen from it. DEPTH (IN KILOMETERS) 12 11 Magnetism, in which he described previously thought that leprosy 9 8.2 his theory of electromagnetism was either inherited or spread by 6 (see pp.234–35). The theory “bad air” known as miasmas. predicted the existence of 3 radio waves (see 1886), and Meanwhile, the mechanism was a major influence on of heredity was starting to be 0 20th-century science. understood, partly through lowest point lowest the work of German zoologist recorded by recorded William Crookes invented his Anton Schneider (1831–90). Challenger point on Earth radiometer while investigating He gave the first accurate the nature of light as a form of Challenger Deep electromagnetic radiation. This First practical refrigerator HMS Challenger estimated the depth device is a partially evacuated, Von Linde improved on his of Earth’s lowest point—Challenger airtight glass bulb that contains 1873 design by using glycerine Deep—at 5.1 miles (8.2km). Recent a set of vanes mounted on a to seal the compressor estimates suggest 6.8 miles (11km). spindle, like a horizontal windmill. and using ammonia One side of each vane is painted as a refrigerant. white, while the other is black. 18p7u2ebqLluisuahdtewiosingaiBnfuotnlhtdzeamrmmaenonndtyanlamics 18p7h2KyasHlepicutoaihnassagniKladMcraeiapsaonocnrcisrteiizbrseansroctwhoemknaown JuJnodehea1trhn4sWen,tse1aais8sate7lDos3onidpfterlheriqeiskueeivnqdatussnaahtniisodngoafses 18C7r3tohoWekirelalsidaiinmovmenettser 18L7in3thdCreeeafifirnrrlivsgvetoenmnrtasotdioenrnsystem 187re2dEisucgoevnecrBhsaloPuromildyaevni(nnPyVlC) DecCehfmoaulblree-nryge2ea1rr,-s1eleo8xtnP7psgo2eorsduHtcisttMimieooSnnontuaiffitrhoc,mUK M1T8ar7xew3ateJislalempaouennbsdElCiMlselheacergtksrniecAittiysm 1873 GelerphradorisdscyHobvaaencrstseetnrhiuem 18o7b3sAernvteoodsnfucrtShihncerhgobnmceeehoildalsevdoriimovriession 215

,,1874–75 1876–77 NATURE IS ALL THAT A MAN BRINGS WITH HIMSELF INTO THE WORLD; NURTURE IS EVERY INFLUENCE WITHOUT THAT AFFECTS ,,HIM AFTER HIS BIRTH. Francis Galton, from English Men of Science: Their Nature and Nurture, 1874 British scientist Francis Galton’s contributions to science include studies of twins and meteorology. GERMAN MATHEMATICIAN Science: A Treatise on Logic and Silvery white metal Nurture. While he paved the way BRITISH NATURALIST Alfred GEORG CANTOR (1845–1918) Scientific Method, which criticized Gallium is one of the few metals for further scientific enquiry into Russel Wallace (see 1855–58) published On a Characteristic the method of induction as a that occur in liquid form at this subject, Galton was unaware published The Geographical Property of all Real Algebraic source of new scientific ideas near-room temperatures. of the distinction between Distribution of Animals in 1876. Numbers in 1874. This paper laid and instead recommended Like water, this metal monozygotic (identical) twins, Co-founder of natural selection the foundations of set theory, random hypotheses. expands on solidifying. born from one fertilized egg, and theory with Charles Darwin (see and introduced the idea of dizygotic twins born from two. 1859–60), Wallace also made different kinds of infinity. Austrian chemist Othmar Zeidler the end of the year he These studies would only be contributions to biogeography, (1849–1911) synthesized DDT had synthesized carried out in the 20th century. including the concept of warning The same year, Russian (dichlorodiphenyltrichloroethane) pure gallium by coloration in animals and the mathematician Sofia Vasilyevna as a doctoral student at the the electrolysis 0.4 way barriers to hybridization, Kovalevskaya (1850–91) became University of Strasbourg, France, of a solution of such as mountains, contribute the first woman to be awarded in 1874. The importance of gallium hydroxide in PERCENT to the evolution of new species. a doctorate in mathematics, the substance as a powerful potassium hydroxide. which she received from the insecticide was not realized THE American inventors Elisha University of Göttingen, Germany. until the late 1930s. Austrian geologist Eduard PROPORTION OF Gray (1835–1901) and In 1889, she became the first Suess (1831–1914) coined BABIES BORN Alexander Graham Bell (see woman to be appointed French chemist Paul-Émile the term biosphere (see panel, AS IDENTICAL panel, opposite) independently professor of mathematics, at Lecoq de Boisbaudran left) in 1875, defining it as “the TWINS came up with the design of a Stockholm University, Sweden. (1838–1912) plugged a gap place on Earth’s surface where working telephone. However, in Mendeleyev’s periodic table life dwells.” The concept Bell won the race to patent the Meanwhile, British economist of elements (see 1868–69) by was intended to complement device on March 7, 1876. Three William Stanley Jevons (1835– identifying the metal gallium the three geological zones—the days later, he spoke the famous 82) published The Principles of spectroscopically in 1875. Before lithosphere (the rocky outer layer sentence: “Mr. Watson, come of the planet), the hydrosphere here, I want to see you.” into the BIOSPHERE (the layer of water at Earth’s machine, summoning his surface), and the atmosphere assistant from the next room. The term biosphere is used ATMOSPHERE (the gas envelope surrounding to refer to the sum of all Earth). However, the theory made Just about two months later, ecosystems. A closed, ECOSPHERE little impact on the scientific German inventor Nikolaus Otto self-regulating system, HYDROSPHERE LITHOSPHERE community until it was developed (1832–91) completed building the the biosphere shows by Russian geochemist Vladimir first practical four-stroke piston that living things do not BIOSPHERE Vernadsky (1863–1945) in his internal combustion engine exist in isolation from 1926 book, La Biosphere. (see 1807–09). the nonliving world. Devised by Eduard The scientific study of twins In 1876, German neurologist Suess in 1875, the idea began in 1875, when British Karl Wernicke (1848–1905) was developed by James scientist Francis Galton found that damage to a specific Lovelock (b.1919) and (1822–1911) published his part of the brain—now called Lynn Margulis (1938–2011) landmark paper The History Wernicke’s area—resulted in as Gaia theory (see 1979). of Twins, as a Criterion of the language disorders. This area of Relative Powers of Nature and the brain is connected to Broca’s area (see 1861–64) by a nerve 18p7u4obnGlisseheotergsthCheiaosnrwtyoorrk 18K7o4tvhRaaeluwefiisnvarssrsmikdataenawytdSaohaomebfimdeaaocnaocttmtioocserbasete 18s7y4ntOhtehsmizaersZDeDidTler 18P7o5bloisSthatmr–naGiiissntebtorputEmilrcdagauncenaetrsrldldedsivcirsiiboens 18a7n5CdrBrpoarohdiktyiiseosishmcidcseehttveeWermliolilpsiatsma 18W76aTlhAlDaelicfsGreteerpdoibugRubrtualiisopssnhheieoclsfalAnimals 18E7d5uAaursdtrSiuateenrsgmsecobolioiongssipsththee1r8e7p5uFbrliasonhnceitsswhGiniaslstwotuondrkies 18JP7er4vionWnTcirsiplellpiaeautsmibsSolecifSsioSethanncenitLseilfioenTgcychieMce: eaAnthdod Lec1o8q7dd5iesPcBoaovuiesl-rbÉsamugadillrelaiunm AlexanidMseagrfrroGacrrnhatth7eh,eda1mta8e7plBe6aeptlehlnotne 216

English photographer Eadweard Muybridge’s pictures showed the exact position of a trotting horse’s legs for the first time. The original pictures shot in 1877 did not survive. The ones seen here are from 1878. ALEXANDER GRAHAM BELL (1847–1922) refers to large biological learning that his ancestors had 274 molecules that act as catalysts for centuries, and that “each Alexander Graham Bell was and control the rate of chemical individual somehow retains THE NUMBER born in 1847 in Edinburgh, reactions in the cells of living rudiments of the long OF AMINO Scotland. In 1870, he first things (see 1893–94). evolutionary past.” ACIDS IN moved to Ontario, Canada, and TRYPSIN then Boston, US, where he In 1877, German bacteriologist In 1877, English photographer began his career as an inventor. Robert Koch (1843–1910) grew Eadweard Muybridge (1830– American astronomer Asaph Both Bell’s mother and wife Bacillus anthracis—the organism 1904) made a camera with a Hall (1829–1907) discovered the suffered hearing impairments, that causes the infectious disease shutter speed of only one- two moons of Mars in 1877. He inspiring his interest in speech anthrax—in the laboratory and thousandth of a second. With spotted Deimos, the smaller and hearing. This interest led injected it into animals to induce this and an ultrasensitive moon, on August 12, and Phobos him to invent the microphone the disease. This was the first photographic plate he was on August 18. Hall also worked and the telephone. bacterium shown to be the cause able to “freeze” the motion of out the mass of Mars, the orbits of a disease. a trotting horse in a picture. of moons, and measured the fiber bundle called the arcuate German physiologist Wilhelm The picture caused a sensation, rotation of Saturn. fasciculus. Damage to these Kühne (1837–1900) discovered In the world of psychology, proving that all four of the horse’s fibers can leave people able to and named the pancreatic Charles Darwin published legs left the ground at once. Italian astronomer Giovanni understand language, but with enzyme trypsin in 1876. He also Biographical Sketch of an Infant, Schiaparelli (1835–1910) speech that makes no sense. coined the term enzyme, which a 10-page book based on his trumpetlike was also studying Mars observations of his newborn son, mouthpiece in 1877. He reported horseshoe magnet from 37 years earlier. Darwin seeing canali on the speculated that his son went coil of planet. This word, through the same stages of copper wire simply meaning “channels,” was diaphragm mistranslated to “canals,” giving rise to terminal for external a frenzy of speculation connection that Mars was inhabited by wire intelligent beings. It was later discovered that these markings were optical illusions. Bell’s electric telephone Used as both transmitter and receiver, this early telephone converted sound vibrations into electrical signals (and vice versa). MaOytfit1or8spbt7iusf6iotloNdunsrik-etoshntleargouinksee 18l7oc6daiKfbtfereasarreilannWpftherpoaramnsriictaBkoarefottcahae 18d7is6ecnWozvyilemhreeelsmtrthyKepüsphiannnecreatic 18t7akp7eiEcstautdhrweeaofiefrrsadttMprouutbytbliinrsighdeghdeorse Auagsdutrissootcnfo1oMv8mea7rre7ssrAtAhmseaetprwhicoaHmnalolons 18S7cw7hhiGcaahipotaavhnraeennlebnllieisoliboesnveeMrsvaaerrsse MayCrh2ea4tclu,oler1mnn8spg7sle6tetorutTiedtnhhxygeepoaeHUfdMstKihctSieiaoefnontectirefiacns 1id8e7n6tRifioebsetrhotefKaconacuthhsreax p1u8b7l7isoChnehcsahrtliheldes fipDrsasyrtcwhbioonolokgy 1H8e7rm7 SaswnstnaipsreFsfirozsmlohooabpltoosegeznioresvatterntsahoteifneggg phpyusb1icls8iiuss7htp7eEeAsrrsnuaosspnttraiMicpaamencrohotnion 1iEn8dv7ei7snoAtnomri npeTvhrheioocnnamtonsagtsrhaeph 217

1789–1894 THE AGE OF REVOLUTIONS 1815 1888 Gramophone Multicylinder music box Gramophone player First produced in Switzerland Multicylinder music box Invented by Emile Berliner, in 1815, these contain a rotating the gramophone uses disks cylinder covered in spikes that of shellac. They can pluck the teeth of a steel comb. be copied numerous In 1862, a system that allows times from a brass cylinders to be changed to play master without any different melodies is invented. loss of quality. 1857 1876 Player piano 1877 Phonautograph Player piano Edison’s phonograph Édouard-Léon The automatic-playing Thomas Edison’s phonograph Scott invents piano becomes popular is the first device able to play the first device when it is shown at an sounds back as well as record able to record exhibition. It operates them. The vibrations of sound sound but it is by an electromagnet are funneled through a horn unable to play and contains a paper and recorded on a cylinder the sound back. music roll. covered in tin foil. THE STORY OF SOUND RECORDING horn concentrates sound for recording and amplifies it for playback RECORDING SOUND WAS AN ANCIENT DREAM OF MANKIND BUT IT ONLY BECAME A REALITY DURING THE 19TH CENTURY Little more than a century ago, the only music most people heard was performed live. The advent of technology to record sound and play it back has not only transformed the way we listen to music but has also had other applications, including broadcasting, film-making, and sound archiving. Frenchman Édouard-Léon Scott’s phonautograph back. Early sound recording machines worked records that played back at 33 or 45 revolutions of 1857 was the first device capable of recording sound, using a moving needle to trace a line on mechanically—they captured sound by playing per minute (rpm) (early records played back at a carbon-coated surface. In 1877, American Thomas Edison invented the phonograph—the into a horn to make the sound vibrations move 78 rpm). Magnetic devices that recorded sound first device that could record sound and play it a needle to engrave scratches on a disk or cylinder. as varying magnetic patterns on tape rather than In the 1920s, sound recording entered the physical grooves on a disk were also developed. electrical era with the invention of microphones. Sound was soon being reproduced electrically DIGITAL using electromagnet- The next big breakthrough was digital recording Edison and his phonograph driven loudspeakers (see panel, right), which made for much more The phonograph was invented robust, practical systems. These include the first by Thomas Edison in 1877. with improved sound It recorded sounds in grooves quality and volume. compact disks, as well as digital audio formats embossed in tin foil wrapped After 1945, sound such as MP3, which have made it possible to around a cylinder. Later recording of music store vast amounts of music on small devices, cylinders were made from wax-coated cardboard. took off with vinyl and download limitless music from the internet. ,,…I CAN TRANSPORT YOU ,, TO THE REALMS OF MUSIC. The first promotional message recorded on the Edison phonograph, 1877 218

THE STORY OF SOUND RECORDING 1925 1931 1978 Sony Microphone Personal stereo Walkman The horn is replaced by Reel-to-reel tape recorder German–Brazilian Andreas electric microphones, in Pavel’s Stereobelt of 1972 which vibrations move German Fritz Pfleumer invents the plays cassette tapes through electromagnets to create ear phones on a tiny, portable, a varying electrical signal reel-to-reel tape recorder, in which battery-driven player. In 1978, that moves the needle Sony launches a portable music to make the grooves. the fluctuations in the electrical signal player—the Sony Walkman. are recorded in the magnetic coating of moving tape. The AEG company develops it into the Microphone Magnetophone. Magnetophone 1898 1948 1982 1999 Telegraphone Compact disks MP3 players Danish engineer Valdemar Record player CDs digitally store These use digital Poulsen’s telegraphone is the large amounts of recordings stored Ipod nano first device to record and play Long-playing vinyl records, playing sound data that can as computer data, back sound magnetically, using a be read by a laser. enabling music to be wire wrapped around a cylinder to at 33 and 45 revolutions per minute They quickly replace downloaded, or swapped record the varying magnetic fields large, easily scratched from computer to created by sound vibrations. (rpm) instead of 78 rpm, are vinyl records. personal player instantly. introduced. They give much longer playing 1950s times and the sound record Telegraphone quality is better. player apparatus support original sound analog sound wave digital sound wave rises and follows original wave samples recording falls continuously sound wave the original stylus, or wave needle original sound wave analog sound wave digital sound wave SOUND WAVES Sound is created by vibrations in the air down continuously with the wave. Digital that create a rise and fall of air pressure. sound waves are made by repeatedly It can be plotted as a simple wave. taking samples of the original wave at An analog sound wave follows this a very high rate and converting them original sound wave form exactly, with into a series of numbers. They are not the intensity of the signal going up and continuous and have a “staircase” shape. diaphragm turns sound wax cylinder with cylinder shaft waves into physical grooves for recording vibrations (and vice versa) sound recording box Edison Fireside cylinder phonograph, 1909 shaft crank By 1909, Edison phonographs such as this one were a crank handle feature of many homes, and there was a wide range of 219 professional wax-cylinder recordings that could be inserted in the machine and played by turning the handle. Unfortunately, wax-cylinders could only be played a few times before the playback quality started to deteriorate.

1878–79 8 MILES PER HOUR THE SPEED OF THE SIEMENS LOCOMOTIVE This photograph shows people traveling on carriages pulled by the Werner–Siemens locomotive, which was demonstrated at the Berlin Trade Fair in 1879. This locomotive was the first to be powered by electricity. high-resistance BRITISH INVENTOR JOSEPH cathode Crookes tube carbon filament WILSON SWAN received a In this Crookes tube, carbonized patent for his electric light anode electrons stream past fiber filament bulb in 1878, which he had a cross-shaped object demonstrated in 1860. This accidentally discovered a natural to cast a shadow on connecting early version of the modern sweetener, later called saccharin, the fluorescent wire while working with coal tar in glass beyond. light bulb consisted of a the US. Saccharin is about evacuated carbonized filament running 200 times sweeter than sugar. object glass tube through an evacuated glass tube. Passing an German engineer Karl Benz Now known as the Hall effect, evacuated electric current through (1844–1929) developed a this phenomenon is important glass tube the filament made it glow one-cylinder two-stroke gas in semiconductor technology connecting white-hot. The keys to its engine, demonstrated for the and magnetic sensors. wire long life was an improved first time on December 31, 1879. vacuum in the glass tube and the Austrian physicist Josef carbon filament. In November In his 1879 book, Cartography ,,Stefan (1835–1893) formulated 1879, American inventor of Russian Soils, Russian the equation now known as the SWAN’S LAMP EDISON’S LAMP Thomas Alva Edison applied geologist Vasily Dokuchaev Stefan–Boltzmann law, which for a patent for a light bulb that (1846–1905) introduced the concerned the calculation of used similar technology. concept of pedology, the radiation emitted from black In 1878, British chemist scientific study of soil. bodies—surfaces that absorb all and physicist William Crookes the electromagnetic radiation invented the Crookes tube, a American physicist Edwin Hall that strikes them. In 1884, device that helped show that (1855–1938) discovered that a Stefan’s colleague Ludwig electrons travel in straight lines. magnetic field created at a right Boltzmann (1844–1906) explained It later on became the basis of angle to the flow of electric the law using thermodynamics. television and other displays. current would create a voltage In 1878, German chemist difference across the conductor. American scientist Albert Constantin Fahlberg (1850–1910) Abraham Michelson (1852–1931) measured the speed of light Early light bulbs The lamps developed WE WILL MAKE by Swan and Edison ELECTRICITY were almost identical. SO CHEAP THAT After a legal battle over rights, the two ,,ONLY THE RICH inventors formed the Edison–Swan WILL BURN company to jointly CANDLES. market the bulbs. Thomas Edison, American inventor, 1879 18W7i8rlesJtcohoenesiveSeepwlsehaacntpraictelingthftobr ul1b8p7a8etesGpnurtssetsaasnvoeKmaersalscyehline 18D7u8fogBrdaeilredritusiCnselhnleeererknngogdifienntseheigeerntswao-stroke 18s7c8WieAipnllimtoatishnretdeerJrieGcomraisibnnoibagdshyrnpeuasmebaliirscchsheasonnd entropy Fe1b8Fr7au9dhailCssrbcwoyeoner2vsgee7tt,raaesncnctteihindreesanartcatcilfihlycairailn 18H7a9thllEpeddhHsiweseacnaimlnoonlvmideceformefsnenadcogutn,ncauetostirecdtseiecnnhsnoorlosgy 18A7b9MraAitchhlhbeaeemslrsptoenedmoefalsiguhrets Ct1hr8oe7oC8kreWosoiilknlievaesmnttusbe 1F8is7cc8hheEemrmwiipclohaHrelkenfosrymrolmhuayutndltnarhaefzoirne 187p8uLbolirsdvhToheRlseuaomytrhleyeeiogofifhfrSsTothuend 1879 tKwaor-lsBatreponakzteerengctaesfoiverentshgiene 18p7u9bVliasshileysDoCofakRrutuocsghsraiaaepnvhsyoil 187w9thhJaeot sSceatefmfSaetnet–foaBnboedltekzvnmeolawonpnnsalsaw 1879 WtehrenfierrsvtoenleScietrmicelnoscobmuioldtsive 220

1880–81 ,, …THE ANTHRAX VACCINE ,,THAT FIRST SPREAD THROUGH THE PUBLIC MIND FAITH IN THE SCIENCE OF MICROBES. Emile Duclaux, French chemist and microbiologist, from Pasteur: The History of a Mind, 1896 This engraving depicts French bacteriologist Louis Pasteur vaccinating sheep against anthrax at Pouilly-le-Fort, France, in 1881. in air to be 186,327miles per IN 1880, BRITISH LOGICIAN metal wire Seismograph the first modern cesarian second (299,864kmps). This AND PHILOSOPHER John Venn bears pendulum This seismograph—designed in section operation. Both mother estimate matched the prediction (1834–1923) developed the conjunction with John Milne— and baby survived. of British physicist James Clerk concept of the Venn diagram, metal coil roll of paper was made by James White in Maxwell (see 1872–73). which represents sets of things 1885. It records earthquake French microbiologist Louis as circles, with overlapping Conversely, applying an electric vibrations on a roll of paper. Pasteur made a vaccine for German engineer Werner von circles indicating the subsets potential to crystals can make anthrax by using the oxidizing Siemens (1816–92) demonstrated they have in common. Venn them vibrate at a very precise seismograph—an instrument agent potassium dichromate to the first electric locomotive wrote about this concept in frequency. This effect has many used to measure earthquakes. weaken its bacteria. He began using an external power source Symbolic Logic, which was applications, including driving The instrument, developed using British surgeon Edward at the 1879 Berlin trade fair. published in 1881. the vibrating crystals in quartz in collaboration with British Jenner’s term “vaccine” to refer clocks and watches. engineer Thomas Gray to all such artificially weakened THOMAS ALVA EDISON In February 1880, Thomas disease organisms. Jenner had (1847–1931) Alva Edison rediscovered a Known as the father of modern (1850–1908) and properly coined the term in reference to phenomenon that had previously seismology, British geologist known as the Milne-Gray smallpox (see 1796). American inventor Thomas been observed by others. He John Milne (1850–1913), instrument, was based on a Edison is credited with many noticed that electricity would was teaching science and horizontal pendulum design. German scientist Paul Ehrlich inventions, particularly in the flow from a hot filament to a cool engineering in Japan when (1854–1915)—whose cousin, field of telecommunications. metal plate in an evacuated bulb. he became interested in The year 1881 saw two pathologist Karl Weigert, He filed more than a thousand Edison patented this concept, earthquakes. In 1880 he was key advances in the (1845–1904) had been the first patents in the US, and others which came to be known as instrumental in inventing the application of electricity. person to stain bacteria with around the world. Edison the Edison effect. The dyes in the 1870s—found a more applied the idea of mass electricity could flow only one In May, the first effective dye, methylene blue. production and teamwork way, so the setup acted like electric This made it easier to identify to science and developed a valve to control the flow of tramway and investigate bacteria, and the world’s first industrial current in the same way that was opened was used by German physician research laboratory—his a valve in a pipeline controls Heinrich Koch to discover greatest invention. the flow of water. This concept in a suburb in Berlin, the bacteria that causes became the basis of the valves Germany. Later, Godalming, UK, tuberculosis (see 1882–83). used to amplify electrical signals became the first town to have in television and radio before the its streets lit by electricity. invention of the transistor. In September 1881, German The understanding of gynecologist Ferdinand Adolf electricity was also aided by the Kehrer (1837–1914) carried out discovery of the piezoelectric effect by French scientists First electric Pierre Curie (1859–1906) and tramway Paul-Jacques Curie (1856–1941). Developer of the They discovered that voltage first electric train, can be produced by applying Werner von pressure to a suitable material. Siemens also worked on the first electric tram—the Gross-Lichterfelde in Germany. 18A7l9fvoaTraEhaldoigpimshaoattnesbnfiutllefbosr 18in8v0seeJniostsmhntohMgerialnpeh Fe1b8Er8ud0tiahsTkreohnynEeoo1mdrmw3eisin,dasoissasniscoeontfvhfeeerrcsmt, iaolnsioc MaTyhee1leo6wpc,ote1rrn8ilcds8’t1sirnafiGmreswrtmayany 18a8v1aLcociunies fPoarsatenuthrrdaexvelops SeFpeptreedcmrienfosbaranemrdres2Kat5neh,hse1reefi8crr8tsi1ot nmodern 1W8a7l9thGtehererFmtleearmnmmbsiiocnahlgonrgdcoiomsmitnaisttoinsis C1u8r8i0e PdiisecrorevearnepdleiePcztarouiecld-litueJyceagtctreqoincupieetrrysea—stSseyudmr1e8bo8l1cicoJnLocohegnpictV,eoinfnnVtreopndunubcldiisinahggertshaems W1a8ltb8lhae1ecgeACalnapfrmraeobbdporoRuisautens2ss8pteyehmelraaiitolrlsdioango Septembebhrea1cv8oe8mit1seGssottrhdeeaelfibtmsyrisineltlglute,omcUwtirKnni,cattoleigdht 1881 Pauml Eteohthrslytiacleihnnuebsabeclstueeria 221

1882–83 1,595FEET THE SPAN OF THE BROOKLYN BRIDGE The Brooklyn Bridge spans the East River between Brooklyn and the island of Manhattan in New York City. It was the longest bridge in the world when it was built. BUILDING ON the work of British Another medical landmark was German botanist Eduard Quagga surgeon Joseph Lister and French achieved when Russian biologist Strasburger (1844–1912) also A close relative microbiologist Louis Pasteur Élie Metchnikoff (1845–1916) contributed to the understanding of the zebra, (see 1870–71), German physician discovered phagocytosis—the of how cells work. He coined the the quagga Robert Koch (1843–1910) process used by the immune terms cytoplasm for the jellylike had distinctive isolated the organism that system to remove bacterial outer region of a cell, and stripes only causes tuberculosis (TB) in invaders. In phagocytosis, one nucleoplasm for the compact on the front 1882. He discovered that TB was cell engulfs another and, in material of the cell nucleus. of its body. transmitted in water droplets effect, eats it. This discovery led and could quickly spread in to an improved understanding In 1882, Italian volcanologist overcrowded slums. of the immune system. and meteorologist Luigi Palmieri (1807–96) made ,, I CONCLUDE THAT THESE the first observation of the breeding, and was later misused studied fluids. In 1883, he came TUBERCLE BACILLI OCCUR IN ALL element helium on Earth by by the Nazis as an excuse for up with what is now known as TUBERCULOUS DISORDERS, AND THAT conducting spectral analysis their attempted extermination of the Reynolds number, which THEY ARE DISTINGUISHABLE FROM (see panel, opposite) of lava the Jews. The scientific basis for characterizes the way fluids during an eruption at Mount eugenics drew in part on the flow. Today, Reynold’s work is ,,ALL OTHER MICROORGANISMS. Vesuvius, Italy. Previously, the germ line theory developed by important in the designing of element had only been identified August Weismann (1834–1914), pipes to carry different fluids, Robert Koch, German physician, from The Etiology of Tuberculosis, 1882 by analysis of light from the Sun. which stated that characteristics and in shipbuilding, where the were only passed on by egg and behavior of full-size vessels The following year, English sperm cells, and were not must be estimated from models polymath Francis Galton came affected by other cells of the tested in water tanks. body (somatic cells). So, for up with the example, a bodybuilder who On May 24, 1883, the longest controversial develops muscles through bridge of its time, the Brooklyn concept of exercise will not pass on the Bridge, was opened in New York eugenics. His muscles to his children. This City. It was the world’s first steel theory aimed marked the end of Lamarckism, suspension bridge. to improve the according to which acquired human race characteristics could be passed A female quagga, the last by selective on to children (see 1809). surviving member of its species, died in a zoo in Amsterdam in Phagocytosis A more practical contribution 1883. This southern African In this color- to human society was made by species had been extinct in the enhanced Osborne Reynolds (1842–1912), wild since the late 1870s. micrograph, a an Irish-born engineer who lymphocyte (white blood cell) engulfs a yeast cell in the process known as phagocytosis. MaRroacbnhdenri2ostt4ucuKbob,noav1eccec8rehrtc8seyu2hrloioifusstmihse 18S8t2treaErnsmdubucsulaercrgoydetporlapcsloamisnms tahned 18is82NineEtwrloedYcoturrcikecdCliiigtnyh,tUSA 18R8e3aynpOoaofsRplbfldeeousyrridnpnosouen,lbddtlhi’esseshncfleurosimbwibnegr MaTyhBe2ri4Bind,rCNg1oiet8eoywk8o, l3UpyYeSnonArsk 18z8o3RoolGcouheghxrriseomstrmueaWgondgisilethoasemrtlsymeftsahccaattorrrys M18ep8thc2dahiÉgsncolikioceovyfetforssis 1E8a8dr2tehLteufcoigtrsitPhhaeellmfiiurimsetrtioinme 1883 FrantchiestGearmltoenucgoeinnsics Augustq1u2a,g1g8a8di3nieTAshmiensltaaeszrtdoaom 222

1884–85 ,, ,,NEW CELL NUCLEI CAN ONLY ARISE FROM THE DIVISION OF OTHER NUCLEI. Eduard Strasburger, Polish–German botanist, from Über Zellbildung und Zelltheilung (On Cell Formation and Cell Division), 1880 A human sperm fertilizes an egg by delivering a package of its own genetic material (germ line DNA) to combine with the genes of the egg. FRENCH CHEMIST HILAIRE DE 1884, when German physicist and Swiss anatomist Rudolf Rabies vaccine CHARDONNET (1839–1924) Friedrich Löffler (1852–1915), von Kölliker (1817–1905) each This 1885 engraving received a patent for artificial Robert Koch’s colleague, isolated separately identified the cell shows Louis Pasteur silk in 1884. He discovered the the diptheria-causing bacterium nucleus as the origin of heredity. watching as his assistant substance accidentally in 1878, Corynebacterium diphtheriae. Hertwig stated that, from the inoculates Joseph when he knocked over a bottle biological point of view, sex Meister, a shepherd boy of nitrocellulose—a highly Koch and Löffler also is merely a union of two cells who had been bitten by flammable compound. When he formulated Koch’s postulates in (strictly speaking, two nuclei). a rabid dog. started to clean it up, strands 1884, which set out the criteria of nitrocellulose stuck to his for establishing whether an Austrian ophthalmologist Carl the positions of lines cleaning cloth in thin, silklike organism is responsible for a Koller (1857–1944) ushered in the in the spectrum fibers. It was not until the 20th disease. Koch published their era of local anesthesia when of hydrogen—the century that this substance was findings in 1890, and in doing he used cocaine as a surface Balmer series. developed in the form of the so he dramatically refined the anesthetic in an eye operation Using his formula, material known as rayon. science of microbiology. in 1884 (see 1846). While looking Balmer predicted into whether cocaine could the wavelengths The 19th-century understanding Starting in 1884, Eduard be used to wean patients off of lines that were of disease developed further in Strasburger, German zoologist morphine—at the request of his discovered later. Wilhelm Hertwig (1849–1922), colleague at Vienna General Hospital, Sigmund Freud—Koller In the field of EMISSION SPECTRUM OF CARBON discovered the tissue-numbing Milky Way, and that Hartwig’s psychology, German psychologist properties of cocaine. star is a supernova, much Hermann Ebbinghaus (1850– EMISSION SPECTRUM OF HYDROGEN brighter than a nova. 1909) pioneered the experimental On July 6, 1885, French chemist study of memory and developed EMISSION SPECTRUM OF MERCURY Louis Pasteur used the rabies In a key discovery in the fields the concept of the Forgetting vaccine for the first time on a of astronomy and atomic physics, Curve. He published Memory: SPECTROSCOPY 9-year-old boy who had been Swiss mathematician Johann A Contribution to Experimental When hot, each chemical element produces a distinctive set of bitten by a rabid dog. The success Balmer (1825–98), developed a Psychology in 1885. bright spectral lines, like a barcode, that can identify the element. of the treatment paved the way for mathematical formula to describe Cold gases absorb light in exactly the same wavelengths, the widespread use of vaccines. producing dark spectral lines. Analyzing spectra makes it 100 possible to determine the composition of substances in the On August 20, 1885, German laboratory and also to measure the composition of stars. astronomer Ernst Hartwig PERCENTAGE REMEMBERED 90 (1851–1923) observed a bright new star in the Andromeda 80 nebula. A belief that this object was similar to the novas seen in 70 the Milky Way encouraged the idea that the nebula, too, was 60 20 minutes Forgetting Curve part of the Milky Way. In the 50 Ebbinghaus gave 20th century, it was discovered 40 60 minutes people a list of that the Andromeda nebula is a nonsense 3-letter galaxy (see 1924), far beyond the 30 words and 20 measured how 10 long they could remember them. 0 This gave him 4 8 12 16 20 the data for his TIME (HOURS) Forgetting Curve. 18C8ha4arHrtdiifiloacniirnaeel dtsepilaktents 18t8hG4rorTLuehogeaenhnsdwmttohhienceerh, iRPUdOoriKabyi,mnsaielserevMasettaorbridyliisianhned JaAnmuWae.srrGuiyccraac4nen,st1psp8hfe8uyrs5lfioacrpiampnesWntdhilielxiafirmresmt oval AuEgrounbssisntteH2trh0aveer, ts1Aw8nai8gds5ruopmeerdnaovgaalaxy 18m85KecaGthrhelaernBmfiiecranasnzltemcnaagrninuefaecrtures 18E8s5dcihsTthechceoreoivocEledhisrbocsarhcetreicrhiaia 18i8s4olFartieesdrthicehdLbipöatfcflhteeerrriiuam 1884 KcaorclaKinfooelrlaaetnshraeauesfisleorthsscatelttiimc1e884 ALuursedtrfiwinaigenBsBpothohlyltetszzmiSmctiaseantnfannnl–aw PavasJtceucuilnyre6ufs,oe1rs8t8thh5eeLfirorasubtisiteims e 1885 aJofwohraamnvneullBeanarglemtpherserosdfesehnpvyteeidnclortgopragtshleelnin’ses 2 2 31885 HerEmxppauenbrnliAimsEhCebenobsntiantMlrgiPehbmsauyutocisorhyno:ltoogy

1886 1887–88 ,, …MAESTRO MAXWELL WAS RIGHT… THESE MYSTERIOUS ELECTROMAGNETIC WAVES THAT WE CANNOT SEE WITH THE NAKED ,,EYE. BUT THEY ARE THERE. Heinrich Hertz, German physicist, 1887 Lick Observatory, on Mount Hamilton, near San Jose, in California, was the first permanently occupied mountain-top observatory in the world. IN 1886, AMERICAN CHEMIST panel, below), thanks to American THE STUDY OF LIGHT continued HEINRICH HERTZ (1857–94) CHARLES MARTIN HALL physicist William Stanley Jr in 1887 as American scientists (1863–1914) and French scientist (1858–1916). He demonstrated the Albert Abraham Michelson German physicist Heinrich Hertz Paul-Louis-Toussaint Héroult first full AC power generating (1852–1931) and Edward Morley is best known for the series (1863–1914) independently system on March 20, using (1838–1923) carried out an of experiments he carried out developed a technique for it to light the town of Great experiment that showed that the to test James Clerk Maxwell’s converting alumina—the powdery Barrington, Massachusetts. speed of light is not affected by theories of electromagnetism. white oxide of aluminum—into the motion of Earth through These included transmission aluminum using electrolysis. Meanwhile, German physicist space. As predicted by James and detection of radio waves Heinrich Hertz confirmed the Clerk Maxwell’s equations (see and proving that light is a form The same year, German-born existence of long-wave 1867), the measured speed of of electromagnetic vibration. American inventor Ottmar electromagnetic radiation (see light relative to an object always The unit of frequency—cycles Mergenthaler (1854–99) pp.234–35)—a kind of invisible remains the same, irrespective per second—is called the hertz revolutionized the world of light now referred to as radio of whether the object moves (Hz) in his honor. publishing when he developed the waves—that had been predicted head-on into a light beam, is linotype line casting machine. by Scottish physicist James Clerk overtaken by it, or is at any other observations of the phenomenon was a forerunner of the This device could set an entire Maxwell in 1867. angle from it. The Michelson– in the journal Annalen der Physik electronic computer. line of type at a time, reducing Morley experiment would later (Annals of Physics) in 1887. the costs and production time American physicist Henry be taken as confirmation of The same year, American On the last day of the year, of printed material. He was Augustus Rowland (1848–1901) German–born American physicist inventor Herman Hollerith a refracting telescope with a dubbed the “second Gutenberg” analysed sunlight using Albert Einstein’s special theory (1860–1929) received a patent 36-in (91-cm) diameter lens was (see 1450) for his invention. diffraction gratings—glass of relativity (see 1914–15). At the for his punched card tabulating completed at Lick Observatory in plates or mirrors with a number time, it was seen by Michelson machine, which helped tabulate California. It was first used on The linotype and other machines of parallel lines etched onto the and Morley as a failure: they had census statistics. This machine January 3, 1888. At the time, would soon run on alternating surface to diffract light—that he unsuccessfully attempted to it was the biggest in the world. current or AC electricty (see had made himself. confirm the motion through the aether (the substance presumed ALTERNATING CURRENT magnetic wire coil to fill all of space, enabling light to movable mirror fixed field lines travel through a vacuum). mirror When a loop of wire is rotated north pole of between the poles of a magnet, magnet Heinrich Hertz’s work with light incoming light Michelson–Morley alternating electrical current is radio waves led him to discover light beam interferometer generated. The current flowing the photoelectric effect. He Michelson and Morley built in the wire reverses repeatedly light observed that a transmitter’s beam a device consisting of a light (alternates) as it turns. Main, or radio waves generated sparks splitter source, two mirrors, and a three-phase electricity, is south pole between two small metal spheres detector. They used it to generated using three coils slip rings that were almost touching. study interference between oriented at 120 degrees to each We now know that this occurs beams of light moving with other. Domestic power supplies crank turns shaft because electromagnetic Earth and at right angles most commonly alternate 50 holding coil radiation knocks electrons out of a to Earth’s motion. or 60 times a second. metal surface. Hertz published his brushes detector ChHaaTrlloleiunassdhnMseodaipawniPerntaottntioundHalcel-éuonLrnmtoolvuuyienlidrstuti-smaclouvmerina MaSrtfiacrnhtslret2aayc0nl,otsJWemmrr.iplnbilslaiueastitmiilenodngssycotshufterehrmiegnhfot-vroltage AupsstvyriconSh–eKiGAaxretuCaSrrafltimfsiulnttdP-aiERcysnabyiiclsci-nhhFpgaoou’rpsrbdaeltnihsshyi:ced MaArmScuehKlrl3eipicvl,eala1ernn8rs,t8bote7henagecItriohfinisesrghrset–teAtdanaecndhaeeifngagrneHdeeblleinnd 18p8u7pbhHlrioasethdioneieorsliewchchaitsvHrewiecsoretrzfkfeocn1t8taph8nue7dnHcheermd caanrHdotallbeuriltahtipnagtemnatschhiiNnseo1v8Ae8mm7EmebGgrereiiflacrreoanmr8Bnt,teaehidnnre-lvaibgenUonreratSrnomirpsoaptehnotne JaTnhuGeaeSNrooyiganctr2iiaeto7hptn,yeha1iiUl8scS8fo8unded 2 2 4Ottmar Mecrgailsenintnvieotnhntgyatpsmleetrahlcienheine neTwJruisblpuyan3peeAfibrmerNsceetorwtmicoaYeHuonslseriteknnhorteyhtyeRpuoeswinlagnddisfftruadciteisonsugnNrlaoigtvihnetgmcsobneefirlre1mc1tsprHroteehmdieniacregitxcenihsdettHebicnyecrwMtezaaovxfewsell 1M8M8ico7hrAelellsybsoespnruetagaeAbgndbsedorosaEfltuhdltitahwgemahacttrotdihnsesatnant 1A8d8loe7lnfGsFeticrhmkatianinsveptonhltyessraiaotclehoodugnmibtsaytacnttheeye Januarryeb3fer,ac1oc8tm8ine8gsTtohepeleeLsriaccotkipoenal MTaeysi1nla8d8pu8acttNeionikntosmltahoetor

1889 36 INCHES THE SIZE OF THE LICK TELESCOPE LENS, THE LARGEST REFRACTOR AT THE TIME The Eiffel Tower, Paris, was the tallest man-made structure in the world until the Chrysler Building was erected in New York in 1930. Applications of alternating current by the Westinghouse Electric 14The patent was later declared MILES electricity were being developed Company and used to develop by Serbian–American inventor motors, which were widely used invalid because the priniciple had THE LENGTH OF Nikola Tesla (1856–1943). In in industry and household been patented earlier by another THE FIRST LONG- 1888, he patented the induction appliances around the world. Scotsman, Robert Thomson DISTANCE POWER motor. This is a two-phase (1822–73), in France in 1846 and TRANSMISSION machine that uses two alternating Scottish inventor John Boyd the US in 1847. However, Dunlop’s currents to produce the rotating Dunlop (1840–1921) developed were the first practical LINE IN THE US magnetic field that makes the a pneumatic bicycle tire (a tire pneumatic tires. rotor turn. The patent was bought filled with air) in 1887 and patented it in England in1888. fixed coil (stator) GERMAN PHYSIOLOGIST Oskar line in the US was completed. It Minkowski (1858–1931) and was installed in Oregon, between Tesla’s induction motor German physician Joseph von a string of lights in Portland and In this motor, alternating current Mering (1849–1908) showed that a generator at Willamette Falls. supplied to a fixed coil creates Russian physiologist Ivan a rotating magnetic field, the pancreas produces a Petrovich Pavlov (1849–1936) making another coil substance (later identified as began studying conditioning in rotate to turn an insulin) that regulates sugar dogs in 1889. He had noticed that attached shaft. glucose in the body, and that dogs would begin salivating when diabetes occurs when this they saw the lab technician who shaft organ malfunctions. fed them. Pavlov began to signal attached English chemist Frederick Abel their feeding with the sound of a to rotor (1827–1902) and Scottish chemist metronome; soon, the dogs began James Dewar (1842–1923) to salivate each time they heard 18v8e8alorTfiechrimDtseitoeetpsaipmsolufeersreutedasfriffnseogcrttthhee 18H8e8nianGmreicrehms Wtahnaeladcnehayrteoormmoissto1m8p8ea8fiterJpsnontthsepnurthmaDecuatnitcilcaolptires patented cordite—an explosive the metronome (see 1907). designed to burn vigorously and produce high-pressure gases that Irish physicist George could propel bullets and shells. FitzGerald (1851–1901) published Designed by French engineer a paper suggesting that if all moving objects shrank in the Gustave Eiffel, the Eiffel direction of their motion, the Tower in Paris, results of the Michelson–Morley France, was experiment could be explained. opened on March This speculation was based on the 31. At 984ft idea that electromagnetic forces (300m), the tower would squeeze the moving objects. was the tallest Dutch physicist Hendrik Lorentz building in the (1853–1928) came up with a world at the time. similar idea as well; this shrinking On June 3, the emerges naturally from special first long-distance theory of relativity (see 1905). power transmission OsaknaddrispJMcaoonisnvceekrproehwathsvseokinniroMdleiearobifenMttgheaTesortcwoheth3re1ispTouhpbeelEinciefdfel Julnonterga3i-sndUcsiSosm’mtsaispnfislcrieeosttnepdoliwneer GepourtbhgleeisEFhaietrzstGhTe’hsreaAlEtdmthoesrpahnedre Wi1ll8ia8ism8gASrmaenwetraeirdcdapanBaduitdnerivrnneotgnustmgfooh1rars8ch8Ihi8isnAeEmaesrtamicnaadnninemvneatrKnrektopoedrrtaesGknOteehccouetarormgfibereesrrta1ss4ho, 1ot8s8fiw8rshLtaomtuiiossvpLioeeOsePscvirtbeionlrybcmetehraegi3dnr0evae,nn1te8tod8r8aJAophambtneeaLnrlliotpcufaoodnirnittshpeen 1F8ra8ann8dcEnisnagGpmlraieoslspthoetnphrotedyliysscmtcoaoratvritseehtrliasctailon MSatrrocwhignt1eev2flreoeAnfirpmtlhaoeeonrsrnAaaieclumpaetnaoxotmcnehnaattnicge 2 2 5BRruistissehl nsWheaialtseullbcraatociloeoisknpt—ouAnbDlflnairsearhdwteuisrnaislm FredericDkewAaIbvsreatplunaadPtnieeadsnvJltooacfvmocbroedensgidtienitsioihnniisdnoggs

1890 164 FEET THE DISTANCE TRAVELED BY THE ADER ÉOLE Clément Ader’s flying machine was the first piloted, heavier-than-air machine to take off, literally under its own steam, on October 9, 1890. ON OCTOBER 1, THE US Robert Koch (1842–1910), was published in this feat 13 years before the CONGRESS PASSED AN ACT that This lithograph—copied from an 1890. Comprising two volumes Wrights. His machine—the founded the Yosemite National 1890s photograph—shows the and 1,200 pages, the book took Ader Éole—had a batlike design Park in California. This brought German bacteriologist working James 12 years to write and and a wingspan of 46ft (14m). the park, which had existed since on the Rinderpest virus in his covered everything in the field It was powered by a lightweight, 1872, under federal control. laboratory. known at the time. four-cylinder steam engine with The process of meiosis—a tetanus, into an animal caused ,, AN AIRPLANE-CARRYING stage in cell division responsible its blood to produce antibodies for the production of gametes— that gave immunity against the ,,VESSEL IS INDISPENSABLE… had first been described by disease. This provided a practical German biologist Oscar Hertwig counterpoint to German physician IT WILL LOOK LIKE A (1849–1922) during his study of Robert Koch’s (1843–1910) LANDING FIELD. sea urchin eggs in 1876. The theories about the relationship full significance of meiosis in the number of chromosomes between microbes and disease, Clément Ader, French inventor, from L’Aviation Militaire, 1909 reproduction and inheritance (see panel, below). which were published in the was appreciated only with same year. German bacteriologist Contrary to popular belief, the 20 horsepower—that weighed the work of German biologist German bacteriologist Emil Friedrich Löffler (1852–1915) had Wright brothers did not make only 112pounds (51kg). August Weismann (1834–1914) von Behring (1854–1917) and his worked with Koch to develop the first manned flight of On October 9, the aircraft took in 1890. He realized that two Japanese counterpart Kitasato these ideas. a heavier-than-air flying off—with Ader on board—and cell divisions are necessary to Shibasaburō (1853–1931) machine. This accolade goes reached a height of 8in (20cm). transform one diploid cell (with discovered that injecting dead Arguably, the most important to the French inventor Clément It flew uncontrolled for roughly two sets of chromosomes) into or weakened disease-causing book in the history of psychology, Ader (1841–1926), who achieved 165ft (50m). four haploid cells (with one set of bacteria, such as diptheria or The Principles of Psychology, chromosomes each) to maintain by American philosopher and psychologist William James MEIOSIS Meiosis, the division of cells for set of chromosomes chromosomes duplicate, microtubules form microtubules pull each of the two daughter sexual reproduction, produces from mother (blue) forming chromatid at the cell’s poles and chromosome pairs to (new) cells has a unique gametes, such as sperm and and father (red); four pairs, and some of their attach to the pairs either end of the cell genetic make-up, different egg cells. Chromosomes shown for example genes are mixed up from each other and the from two parents undergo parent cells “recombination,” which shuffles the genes to produce nucleus a different genetic combination in each gamete. Meiosis pairs line up in middle cell membrane further divisions known produces four genetically of cell, after nuclear forms across the cell as meiosis II result in four unique cells, each with a membrane dissolves single set of chromosomes. separate daughter cells MEIOSIS II AudgeussctriWbeesismmeainonsis RoidbereearmlstaKaticiboorocnohubsthepistuphabebnleidsthwdeiesseenase FrtahnuactnisfiiqnGugaeeltropnripnrtosvaerse MaSrmAcishOtth1rbsosopenhrivyaasnitcoarly is founded ThPesJPyacrmihnoeclisop,glieys,spbouyfbWliislhlieadm OcUtSopbaCcesorsrNenea1gastrteeitohstnehsaealcYPtoatsorekmite OctobfiAerdsreat9irhrCemmaléavakmineenres-enttdthhaflenig-ht Emil vonimBemShhuriinbniagzsaaatnibodunrKōtietdaceshvanetiolqoupes estabrleiTsJchheeeaitovnhedoasLoftorctahuhBeifrsoeosvrGmaetuimroliiisgzeaonenenmaddauneecmdsghbgfperaorrment bJeugninesUmuSsaiCcnheginnpHseuuensdrcmeBhvaueenrldoeHpcaaoeurldldebryith 226

1891–92 86 BILLION THE AVERAGE NUMBER OF NEURONS IN THE HUMAN BRAIN This color-enhanced scanning electron micrograph shows a roughly triangular neuron cell body from the human cerebral cortex—the outer gray matter of the brain. IN 1891, SOME “KITCHEN SINK” is now known as Homo erectus. Panhard car French inventor Amédee Bollée of atoms, and that atoms are DISCOVERIES were reported in His interpretation of the finds The 1891 Panhard car ushered in (1844–1917) had, however, used not indivisible. the journal Nature. In Germany, was controversial, but is now the era of the modern automobile. the same layout for steam- Agnes Pockels (1862–1935), recognized as a step toward Panhard cars went on to win several powered cars in 1878. British scientist James who had not been able to go to understanding human evolution. races and established many records. Dewar (1842–1921) invented the university because she was a In 1892, French–German vacuum flask, or Dewar flask; woman, had been investigating In the same year, German (1859–1940) patented the engineer Rudolf Diesel and French engineer François the effect of different substances anatomist Heinrich Wilhelm removable pneumatic tire. (1858–1913) received a patent Hennebique (1842–1921) on water surface tension—a Gottfried von Waldeyer-Hartz Their tires were used the same for a forerunner of the engine patented the reinforced concrete result of observations she had (1836–1921) introduced the term year to win the world’s first named after him. The actual technique, which transformed made while washing up. Pockels neuron to describe cells that long-distance cycle race, from diesel engine itself was building technology. sent a letter to the British transmit nerve impulses. Paris to Brest and back. patented two years later. physicist Lord Rayleigh (1842– HENRI POINCARÉ 1919) describing her discoveries In France, the brothers André The first front-engine, Science was also using new (1844–1912) and he had her letter translated (1859–1940) and Édouard Michelin rear-wheel-drive car was technology in 1891. For the first and published in Nature. Pockels produced by Panhard et time, German astronomer Max Known for not always went on to publish another 15 Water walker Levassor, a French car Wolf (1863–1932) used a following through with his scientific papers. This insect does not sink in water manufacturing company. This photographic machine—the many bright ideas, Henri because its low weight is supported car design, known as Système Bruce double-astrograph, a Poincaré did complete Around this time, the Dutch by surface tension—a phenomenon Panhard, became the standard device for comparing two star the three-volume epic New paleoanthropologist Eugene studied by Agnes Pockels. layout for cars for decades. fields to see if objects have Methods of Celestial Dubois (1858–1940) made moved—to find an asteroid. He Mechanics. In this work, a profound discovery in East named the asteroid 323 Brucia, he elaborated on celestial Java, Indonesia. He found after American philanthropist mechanics—a branch of fragments of what he called Catherine Bruce, who paid for astronomy that deals with “a species in between humans the astrograph. orbits and other motions, and apes,” and gave it the name especially under the Pithecanthropus erectus, In 1892, French mathematician influence of gravity. meaning upright ape-man. It Henri Poincaré (1854–1912) published the first volume of New Methods of Celestial Mechanics, which introduced the many techniques used in calculating orbits. Dutch physicist Hendrik Lorentz (1853–1928) applied new ideas on electromagnetism to a theory of the electron as a charged particle. The name “electron” had been proposed by Irish physicist George Johnstone Stoney (1826–1911). Lorentz implied that electrons are part 18P9o1dciAkssceugolnrsvfeaepscruieebstliesanhbseoisount ApNreGilwa1rY8do,er1nk8iB9s1ofotaunnidceadl 18b9r1tohtMpehneircerehsumemploianavttaeibncltteire 18G9o1HttaHnfrreetiezuindrirnoivctnorhsondWfWouircalhenldeseelrmtyvheeerc-teelrlms 18p9h1oMtoagxraWphoylftuosfiensd an asteroid 18L9o2hrieHsonfe“tttnzhhdpeeruoiekbrllyeischtreosn” 18D9e2thwJeaarvmaincevuseunmtsflask Mdeamy 2o0n,st1r8a9ti1onFpiiorcfstutarpmeuboslyvisicntegm as1S8y9s1tbèAymcPeaarPnlahanayhorduartedkt niLsoewuvasnessdor 1891 EurgeemPnieathiDnesuc(banoonofitwwsh,rhdHoaispotcumhosevoeecerraersleclstcutuss) pub1l8is9h2esHoCtefhneNelreeifiswPrtsoiaMtinlveMcotahleurocémdhsaenoifcs 18p9a2tRecnuotdnfovolerfrD“tpmiinaeegvstienhhlgoerdaethtcoeeifnidwavtieoneasdsyweaffoolorrerknt”hgeine 2 2 71p8a9t2enFtrsarneçionifsoHrceendnceobniqcureete

,,1893–94 I WILL FORCE UPON POLITICIANS ,,THE RECOGNITION OF ANTHROPOLOGY IF I HAVE TO DO IT WITH THE STAKE AND THUMBSCREW. Mary Kingsley, British anthropologist, in a letter to anthropologist E.B. Teylor Mary Kingsley—shown here traveling on the Ogowe River in Africa—wrote extensively about the African continent and its people. DECADES AFTER ESPOUSING THE team completed the first studio in Sierra Leone on her first mosquito bites infected person, IDEA that there had once been a for the production of movies. trip to Africa. She drew on taking in gametocytes great continent in the Southern Officially called the Kinetographic her experiences of living with Hemisphere, which he dubbed Theater, it was also known as the indigenous people to give mosquito bites Gondwana (see 1861–64), Austrian The Black Maria—a slang term lectures and write books that uninfected person and geologist Eduard Suess came for police wagons—because both helped debunk the stereotype injects sporozoites into up with a new theory. In 1893, were small, cramped, and dark. of Africans being “savages,” and he suggested that this southern raised questions on the benefits the blood stream continent had been separated The first Ferris wheel, of colonialism. from its northern counterpart, designed by American engineer merozoites mature to Laurasia, by an inland sea he George Washington Gale In 1891, German neurologist form gametocytes named Tethys, after the Greek Ferris, Jr. (1859–96) opened Arnold Pick (1851–1924) had goddess of the sea. A modern in Chicago, Illinois, on June 1, introduced the term dementia merozoites burst approach based on plate tectonics 1893, and it operated until praecox (premature dementia) out, infecting more suggests the existence of a November 6, the same year. to refer to a psychotic disorder blood cells larger version of this, the Tethys beginning in the late teens. In Ocean, in the Mesozoic era, In July this year in Japan, 1893, German psychiatrist Emil sporozoites 251–65.5 million years ago. inventor Kokichi Mikimoto Kraepelin (1856–1926) gave a invade liver cells (1858–1954) produced the first detailed textbook description of On February 1, 1893, American perfect pearl at his farm. Although this condition, later reinterpreted from the blood inventor Thomas Edison and his Swedish botanist Carl Linnaeus and renamed schizophrenia. had cultivated freshwater pearls merozoites sporozoites multiply First motion picture studio in Europe in the 18th century, This was also the year in invade red to form merozoites The Black Maria, as Thomas Mikimoto was the first person to which Austrian psychoanalyst blood cells and Edison’s first motion picture studio cultivate pearls commercially. Sigmund Freud (1856–1939) multiply further was called, operated in West Orange, and Austrian physician Josef New Jersey, from December On August 17, 1893, pioneering Breuer (1842–1925) published MALARIA LIFE CYCLE 1893 to 1901. English anthropologist Mary their paper Über Den Psychischen Kingsley (1862–1900) arrived Mechanismus Hysterischer A malaria-carrying female Anopheles mosquito feeds on a Phänomene (On the Psychical human and injects parasites in the form of sporozoites into Mechanism of Hysterical the bloodstream. These multiply in the liver cells and produce Phenomena), which marked the merozoites, which reproduce in the red blood cells. Some of the beginning of psychoanalysis. infected cells produce gametocytes that are ingested by other The paper was based on Breuer’s feeding mosquitoes, which then become carriers of the disease. work with the patient, Anna O. Freud and Breuer also elaborated manufacture the industrial carborundum in the list of their ideas in a book, Studien über abrasive carborundum, essential 22 patents most responsible Hysterie (Studies on Hysteria), in the manufacture of precision- for the industrial age. first published in 1895. ground, interchangeable metal parts, in 1893. In 1926, the US In 1893, using the technique of American inventor Edward Patent Office would include interferometry, Albert Abraham Goodrich Acheson (1856–1931) Michelson, an American scientist, patented a process to 18S9u3tehEsTesede,tuxhpaiyrsrostdepSnoecsaeesof the FeFbirsrstuutadmrioyot1cioo, nm18pp9ilce3ttuerde MaWyiils1lit8gah9rmcea3anzlJiltpueepdddesaaor ncpfalaaststeepnn-tleofroc,rktheJerunFneerr1i,s1w8h9e3eFliorsptens JuKlyosku1ih8ccich9gei3heM-dqiskuiiamnlioctyutolptievaartilnsg 18d9e3mEemntiliaKpraraeepceolixn describes 18a9n3mdJmeA.aR.ieAsn.tu.teBerMrerefiuncetshohrioîeentmlgssteoatnnrydard FepbrortEAuhcdeecawshrisaneyrdst2doou8nGsm,topr1aocia8nadat9ulerr3afinbacbtochsrrtauuasrnievdeu,m 1893 EdMwaaurnidddeMenratiuMfineidnseimtrhuem JuWlyiplle9ia,rim1c8aas9rrord3euikupDnnamadiifnret(sih-mewetlheoHhemueantabloedrrrtanp)naoetfieant MaryASKuieginrurgsastlLe1ey7o,lna1en8,d9As3frinica anO1dn8Jto9hof3esHeSPyfissgBytmecrrehuiuicnceadMlrFPeprhcuehebuanldinosimhsmena 1893 WtwihlheaevrelemlleanWtigoitnehsninahdtniepidsnbcbmsoeoitvatdywexyroiemsrfeabundlmiaactkion 228

This lamp containing argon—first isolated in 1894—produces a violet discharge when placed in an electric field produced from a high voltage transformer to produce neon lighting. RAMÓN Y CAJAL (1852–1934) In November, Manson mentioned 0.93 as the father of modern the hypothesis to British doctor neuroscience, theorized that Spanish pathologist and Ronald Ross (1857–1932), THE memories do not involve growing histologist, Ramón y Cajal, was who received the Nobel Prize PERCENTAGE new neurons (nerve cells), responsible for identifying a in 1902 for working out the OF ARGON but making new connections type of cell that controls the details of the process. IN THE between existing neurons. The slow waves of contraction that ATMOSPHERE connections between neurons move food along the intestine. In 1784, British physicist Henry came to be known as synapses. He was also a neuroscientist Cavendish had discovered that Royal Institution, London, British and an expert in hypnotism, air contains a small proportion physicist Oliver Lodge (1851– Also in 1894, British physiologist which he used to help his wife of a substance less reactive than 1940) dubbed this the coherer. Edward Sharpey-Schafer (1850 during labor. In 1906, he was nitrogen, but he was unable to Lodge used this invention in –1935) and English physician awarded the Nobel Prize in isolate it. In August 1894, following his work, which became an George Oliver (1841–1915) found recognition of his work on a suggestion by British scientist important part of Italian physicist that an extract from the adrenal the nervous system. Lord Rayleigh, British chemist Guglielmo Marconi’s system gland caused a rise in blood William Ramsay (1852–1916) of wireless telegraphy. pressure. This led them to and J.R. Benoît, Director of the in London, was investigating the reported that he had isolated this identify the hormone epineprine. International Bureau of Weights historical records of sunspots in gas, which he named argon. It In 1894, Spanish histologist and Measures, decided to use 1893 when he discovered that was the first of the so-called (histology is the study of tissues German chemist Emil Fischer wavelengths of light to redefine very few spots had been observed noble gases to be isolated. and cells) Ramón y Cajal, known (1852–1919) in 1894 came a standard of distance. They between 1645 and 1715. This up with the lock and key theory measured the meter—a interval, now known as the French engineer Édouard that explains how enzymes prototype platinum–iridium Maunder Minimum, coincided Branly (1844–1940) had target specific molecules bar of which was kept in Paris, with the coldest part of the Little developed an early radio signal and function so efficiently. France—in terms of the Ice Age (c.1500–1800), a time detector at the beginning of the wavelength of the red light when Earth cooled considerably. 1890s. In 1894, in lectures at the emitted by heated cadmium. In 1894, British parasitologist HOW ENZYMES WORK Edward Maunder (1851–1928), Patrick Manson (1844–1922) a British astronomer working at developed the idea that malaria Enzymes are proteins that act bonds in products the Royal Greenwich Observatory is spread by mosquitoes. as catalysts to increase the rate substrate are leave the of specific chemical reactions. active site They fold into complex shapes weakened that allow smaller molecules ,, THE BRAIN IS A WORLD… to fit into them. The active site substrate [WITH] A NUMBER OF UNEXPLORED where these molecules fit may or reactant CONTINENTS AND STRETCHES either encourage molecules to join together or split apart. active site on enzyme ,,OF UNKNOWN TERRITORY. However, the enzyme remains unchanged and can repeat ACTIVE SITE CATALYZED REACTION PRODUCTS PRODUCED the process indefinitely. Ramón y Cajal, Spanish pathologist and histologist, 1906 18O9l4iimvecprorshLoiegovrnedesagrlet,hdaeerteacdtioor 18C9a4ajbaRaolnauddmtevmbóernelaomyipnsofruiydnecatsion 18e9x4plEaminisl FhoiswcheenrzymAeuRsgaawumrsogstroak1ny8fr9re4opmWorittlhslieaismaoilrating 18O9b4insLeAorrvwiazeotlonlray is founded 18M9a4rarGtcdhoui3aong3tilticfdreeaaelenmnvtesro(lmi1on0pigtmstaea)rbaewllay 1894 EadnwtdhaeGrdheooSrrhgmaeropOneleyiv-eeSprcinihdeaepfnehtrirfiyne 1894 MSahnipcchCoeamsntpaellreitsed NovemMRbaoensrss1od8nsoi9spfa4crmnuePdsaoasRdstqritonhiuncgeikatmorldoealselainria 229

5

THE ATOMIC AGE 1895–1945 The unanticipated discovery of radioactivity revealed that massive amounts of energy are hidden inside atoms, available to be unleashed. New and surprising theories of relativity and quantum mechanics described a Universe of four-dimensional space-time containing interchangeable waves and particles that, at the subatomic level, can never be pinned down with absolute certainty.

1895–96 1897 ,, ,,EVERY DAY SEES HUMANITY ,, MORE VICTORIOUS IN THE STRUGGLE WITH SPACE AND TIME. Guglielmo Marconi, Italian inventor 20th-century botanists classified plant formations, such as vegetation on crumbling sand dunes (shown here), by their ecological characteristics. THE SCIENCE OF PLANT ECOLOGY density of atmospheric nitrogen IN APRIL, BRITISH PHYSICIST antibodies leave antibody– reached a milestone when Dutch was different from that of pure J.J. THOMSON (1856–1940) was white blood cell antigen cluster botanist Eugenius Warming nitrogen made in a laboratory. He studying cathode rays. These and bind to antigen engulfed by (1841–1924) and German botanist found that atmospheric nitrogen rays are produced by the negative macrophage Andreas Schimper (1856–1901) contained traces of argon and electrode (cathode) of an antibodies for published their books on the other unreactive elements later electrically charged vacuum tube, different antigens subject at the end of the century. dubbed noble gases. and are attracted to the positive Together, they showed how electrode (anode). They cause the white activated white blood vegetation could be classified In November, German physicist glass at the far end of the tube to blood cell into different formations based Wilhelm Röntgen (1845–1923) glow. Thomson demonstrated antigen cell makes more “blue” macrophage on climate and soil conditions. discovered that electrically that the rays were composed of charged vacuum tubes emitted particles much lighter than the MOBILIZING antibodies ATTACKING In Britain, physicists Lord rays that made a fluorescent smallest atoms. He concluded Rayleigh (1842–1919) and William screen glow; he called them that these “corpuscles,” as he ANTIGEN–ANTIBODY INTERACTION Ramsay (1852–1916) discovered X-rays. He found that they went called them, were negatively the gas argon. Rayleigh realized through human skin and exposed charged components present in all Paul Ehrlich explained how the immune system could be mobilized that air must contain an unknown photographic plates. This led to atoms; Thomson had discovered to destroy infection. White blood cells carry side-chain antibodies, chemical component, since the the development of medical the first subatomic particles. which bind themselves to foreign particles called antigens. As they radiography. By 1896, scientists They were later called electrons. are bound together, the white cells are prompted to produce more I HAVE SEEN knew that X-rays could ionize antibodies. These then cluster around the antigens and enable (charge up) air. Some physicians In May of the same year, the macrophages—other immune system cells—to destroy them. ,,MY DEATH. even tried firing X-rays at first radio communication over tumors—radiotherapy— water was made across Britain’s Anna Röntgen, wife of Wilhelm, to try to cure cancer. Bristol Channel. Italian inventor on seeing her hand X-ray, 1895 Guglielmo Marconi (1874–1937) Inspired by Röntgen, French had been experimenting with physicist Henri Becquerel wireless technology, and in broadcasting range. Marconi and images. Braun’s tube was the (1852–1908) studied whether 1897, his team of scientists Braun went on to share the Nobel first oscilloscope—a device that phosphorescent substances, succeeded in sending a Morse Prize 12 years later for their work made graphical presentations of such as uranium salts, produced code signal from Flat Holm on wireless radio. electrical signals. It paved the X-rays. He expected radiation to Island to a receiver on the Welsh way for the invention of the be emitted only after exposure coast. Later, German physicist In 1897, Braun was also working television and the development to sunlight, but found that the Karl Braun (1850–1918) improved on vacuum tubes. He modified salts could fog a photographic the technology to increase cathode ray tubes so that the rays that reach plate even in darkness. He rays struck a surface to produce here are deflected had discovered a new by electromagnets phenomenon: radioactivity. anode attracts the rays X-ray of Anna Röntgen’s hand cathode produces Röntgen’s X-ray of his wife’s hand cathode rays shows that the rays penetrated her skin and muscle, but were impeded by denser bones—and her ring. NoWvidelhimsecblomeverRr8sö,nX1t-8gre9an5ys JaAnmuGaerburrribycebaa1ens2td,pce1has8ync9srci6ciebiraenws EittrmheaXilt-inragyMsaJ.rJhc.oh(Twc1hh8oXam9-rrg6saeoyunspdc)aegnsacisroinbiezse FeFbedrreudosianscrcaryiinlbl1deo5ssBcKrtohaapuereln design ApbrioBilcufhGeceerhemmrxnmeteierxsraanitscndtEatte—edtminuoecaonvernidudsoestfnirneacgnteezyfsyeomarstethse MaasyCt1rlboa9nirgAkogmmbeueseritrlidtcAesallnvteahsnecowpoerld’s PaduelssiEcdwhrehirbb-liaccieichsmhshiashfmioniosrufmtnhtheseeortehrsyep, onse Wca1lra8ms9sPi5inlfaygEinnuptggeuesbvnalefimisoguhresfmuetasnatdit,oionns MBeadcrisqccuhoe1vre,er1ls8arc9ac6didHieoenantcartiilvlyity Macoyrm1r8eac9lat6lryRibasoyuinsmgagtloredassnqRtssuomistthsoitatbteidtes Apreixlrpa3lya0sinJas.nJrtee.hgTcaahottomicvmaeptsohposoanedrdteicMolfeasy s1e3nGdusgtlhieelmfirosrtMawadoirircoveoeslnreigiswnsaatler cheAmumgisautaksFcetiesd1l,ia0xlcaGHeteteoyrrflfmsmmaaaalanisrnckyanelsitcpeidrin 232

1898 Marconi formed his Wireless Malaria “oocysts” (blue) in the mosquito stomach lining, first observed by Ronald Ross, Telegraph and Signal company in 1897. burst into cells that infect the insect’s salivary glands—and thereby, its bite. of medical technology, such as AFTER HENRI BECQUEREL 1,000 nm His work demonstrated that the particles). Wien invented a way of the electrocardiogram used for DISCOVERED RADIOACTIVITY, life cycles of the malaria parasite separating the different kinds monitoring heartbeat. Polish–French physicist Marie BACTERIUM (see 1893–94) and certain kinds of ions in electromagnetic fields Curie and her husband, French of mosquitoes were linked. according to their mass and In August, German chemist physicist Pierre Curie (1859– Virus 20–40nm charge. The accuracy of mass Felix Hoffmann (1868–1946), 1906), embarked on a lifelong Meanwhile, Dutch biologist spectrometry has resulted in working at the Bayer career studying radioactivity Size differential between virus Martinus Beijerinck (1851–1931) it being used in fields as diverse pharmaceutical laboratories, at the Becquerel Laboratory. and bacterium made another breakthrough. He as the medical testing of produced a painkilling substance Becquerel had found that pure Viruses are measured in nanometers found that a plant disease called blood and urine to analyzing called acetylsalicylic acid. It was uranium emissions could cause (nm). They lack the cellular structure tobacco mosaic could be spread atmospheric samples in modeled on a related ingredient air to conduct electricity. The of bacteria, being just particles of even when infected plant extract space exploration. derived from certain medicinal Curies discovered that a uranium protein and genetic material. was passed through a filter that plants, such as willow and ore—called pitchblende—was held back bacteria. He deduced MARIE CURIE (1867–1934) meadowsweet, which had been 300 times stronger in this on key discoveries about a deadly that the contagious particles known since Ancient Greece. respect, and deduced that a new disease—malaria. British were smaller than bacteria, and Born in Poland, Marie married The new painkiller was later element present in the ore must physician Ronald Ross (1857– called them viruses. Beijerink’s Pierre Curie in France in 1895. marketed as aspirin (see 1899). be responsible. They named the 1932), working in India, had tobacco mosaic virus would not The couple shared the Nobel element polonium, after Marie’s proved that mosquitoes spread be isolated until the 1930s. Prize in 1903 with Henri Another medical breakthrough native country Poland, and coined the malaria parasite through Becquerel for their work on was made by German physician the term radioactive at the same their bite. The previous year— In Germany, physicist Wilhelm radioactivity. Marie received a Paul Ehrlich. He developed the time. Later that year, the Curies after painstakingly dissecting Wien (1864–1928), second Nobel Prize in 1911 for side-chain theory, which discovered another radioactive mosquito guts—he had found experimenting with the positively the discovery of polonium and explained how the immune element, radium, and managed malaria parasites lodged in the charged rays produced in certain radium. She donated all her system could attack specific to purify quantities of both for stomach walls of these insects. types of vacuum tubes, laid the medals to the World War II infections. It remains the basis of further study. foundations of a new area effort. She died of leukemia immunological theory to this day. of analytical science, mass caused by radiation exposure. By the 1890s, scientists had spectrometry. This was a Cathode ray tube discovered two unreactive technique used to determine Glass vacuum tubes proved useful to noble gases, helium and argon, the make-up of molecules by scientists in the discovery of X-rays but William Ramsay suggested vaporizing them into ions (charged and electrons. Rays pass along the that gaps in the periodic table tube and the pattern formed at the and laboratory analysis of air ,, NOTHING IN LIFE IS TO BE end shows they are negatively pointed to the existence of other FEARED, IT IS ONLY TO BE charged particles (electrons). elements. In 1898, working with ,,UNDERSTOOD. NOW IS THE rays cause British chemist Morris Travers deflection pattern (1872–1961), he discovered TIME TO UNDERSTAND MORE, three more noble gases: SO WE... FEAR LESS krypton, xenon, and neon. In July, the Annual Marie Curie, Polish–French physicist Meeting of the British Medical Association reported DuCthcEhriijtskphtmhdeiayeafidasmnrenic sfio—pitanceebnisrexetfnproraceirbtymrieiodmsrniiseoenfatasael FeMbaCrruuoiearritreeahynaifis1dnn7mdPpiuotehrrreearteruuarrdaanioniuaiucmmtive MaWyia–lnlJiidasuomkMllyraaoyRtnrpeardtmtioshxnseeT,anrenyaolevenoemnrse, nts Jualnysdh1rMo3awodaPriritnoeeiheaerccacwrCoatetmluitevlhrelieieetdeysmhpofierofgonluhomtr,nalianautimuemr DePcideeirmsrraceblodaeavitonreeadrr2ca6MctianvaleerleiweedleCrmaudreiineutm, AmericdaensccrhiebmeosifsttahJeodofeehtxrnhitvreeAaephbcdioetnifrlooemnrpmohnriene ACparmiltihlIlteoaclGieaollnllagutpilehadrryecsssaitcclrrliauaeibpcndetpuGsarorelagtius tracJeustloymt8haelRasoranialaoivlfpdaamrrRyoaosgssqilstauensitdoses WsitdirleehnaelmtlamifitseeWrosfcipeiaeoonlsnsledtmiitazdeibeavspelsdcirssrpogihsabtaeopresstneseiccsbstl,a,erasosnimsdeotfry micrDobeicoelomgbisetcroCiGamnresilrttBmohceeahnntodenardmria 233

1895–1945 THE ATOMIC AGE UNDERSTANDING ELECTROMAGNETIC RADIATION DISCOVERIES IN THE 19TH CENTURY LED TO A NEW UNDERSTANDING OF THE NATURE OF RADIATION Light, infrared and ultraviolet radiation, X-rays, gamma rays, microwaves, JAMES CLERK and radio waves all propagate through space at extremely high speed. MAXWELL They are all different forms of electromagnetic radiation, which can be As well as theorizing understood as waves, but also as particles called photons. the existence of electromagnetic By the 19th century, evidence suggested that oscillating waves, James Clerk light travels as waves and that wavelength electric field Maxwell played a key determines the light waves’ color. Two invisible role in interpreting forms of “light”—longer-wavelength infrared direction of the emerging science radiation (IR) and shorter-wavelength ultraviolet movement of thermodynamics, radiation (UV)—had also been discovered. and took the first oscillating color photograph ELECTRIC AND MAGNETIC FIELDS magnetic field (see 1861). In the 1860s, British physicist James Clerk Maxwell formulated a set of equations that ELECTROMAGNETIC WAVE 2,050 miles describes how electric fields produce magnetic In these self-propagating waves, oscillating fields and how magnetic fields produce electric electric and magnetic fields travel in the same THE DISTANCE COVERED fields. Maxwell realized that his formula was a direction but in perpendicular planes. BY GUGLIEMO MARCONI’S “wave equation,\" describing wave motion. The FIRST TRANSATLANTIC speed of the waves described by the equation and went on to predict the existence of other as RADIO SIGNAL IN 1901 exactly matched the speed of light. Maxwell yet unknown forms of radiation. Within 20 years, concluded that light is an “electromagnetic wave,\" German physicist Heinrich Hertz had produced radio waves—electromagnetic waves with much longer wavelengths than light (see 1887). RADIO WAVES MICROWAVES INFRARED electromagnetic wave WAVELENGTH 1km (0.6 miles) 100m (330 ft) 10m (33 ft) 1m (3 ft 3 in) 10cm (4 in) 1cm (2.5 in) 1mm 100μm 10μm Electromagnetic spectrum Radio telescope Microwave oven Remote controller Visible light represents a tiny part of Large dish Produced by Most remote the whole spectrum of electromagnetic telescopes that magnetrons, controllers use radiation. Every part of the spectrum detect radio waves short-wavelength coded infrared features in some way in the modern provide essential radio waves called radiation to send world; a few representative examples information about microwaves are instructions to are shown here. distant space. used to heat food. electrical devices. 234

UNDERSTANDING ELECTROMAGNETIC RADIATION WAVES AND PARTICLES ,, ,,X-RAYS WILL PROVE Scientists had long debated whether light travels through space as streams of particles or as TO BE A HOAX. waves. The wave theory was in favor in the 19th century, even before Maxwell’s discovery. However, William Thomson (Lord Kelvin), British physicist, 1899 there were phenomena the wave theory could not explain, including the “photoelectric effect.\" electromagnetic USING ELECTROMAGNETIC RADIATION INFARED RADIATION radiation source In addition to ultraviolet, infrared, and radio Cameras sensitive to infrared radiation can produce color- waves, scientists discovered two new forms of coded images that reveal temperature differences—allowing opaque electromagnetic radiation in the 1890s, both engineers to detect heat loss from houses, for example. barrier with very short wavelengths (or high-energy photons): X-rays and gamma rays. RADIO MAP OF THE SKY waves Nonvisible electromagnetic refract Devices that can produce or detect the various radiation provides new forms of electromagnetic radiation have many, windows through which to particles travel and varied, applications. For example, different study the Universe. Normally in straight lines types of radio waves are used to carry television, invisible interstellar dust radio, and telephone signals. In medicine, emits radio waves, so it WAVE-PARTICLE PARADOX penetrating X-rays are used to produce images shows up in this radio map All waves “diffract” or spread out as they pass the edges of the inside of the body, while gamma rays of the sky. of stationary objects. Water waves do this as they enter are used in radiation therapy. harbors, for example. The diffraction of light is hard to plane of the Milky explain if light is understood to be a stream of particles. Way In 1887, Hertz attached two electrodes to a battery and set them a small distance apart in a vacuum tube. When he shone light onto them, an electric current fired between them, but above a certain wavelength it stopped, however intense the light. Albert Einstein explained this effect by proving that electromagnetic radiation exists as particles (photons), and that different colors of light, and different forms of radiation, differ in the amount of energy their photons carry. VISIBLE ULTRAVIOLET X-RAYS GAMMA RAYS 1μm 100nm 10nm 1nm 0.1nm 0.01nm 0.001nm 0.0001nm 0.00001nm Human eye Sunglasses Dental X-ray Power plant Humans only see Most sunglasses X-rays penetrate Nuclear power radiation—light have lenses that soft tissue, but are stations have thick —within a certain block ultraviolet blocked by bones shielding to block range. Some radiation, which and teeth, making gamma radiation, animals can see can damage the them useful for which can be outside this range. eyes' retinas. medical imaging. harmful to health. 235

1899 1900 420FEET THE LENGTH OF THE FIRST ZEPPELIN This car from the 1920s advertises Bayer’s drug bearing a Dutch slogan, Zeppelin LZ1 had its maiden flight which translates as “Overcomes all sufferings.” over southern Germany in 1900. NEW ZEALAND-BORN PHYSICIST 45,000 alpha particle paper stops plastic (or sheet thick lead stops ERNEST RUTHERFORD (1871– alpha particle metal) stops gamma ray 1937) was studying the radiation TONS beta particle given off by uranium salts—first Penetration of radiation discovered by Henri Becquerel THE QUANTITY beta particle Alpha particles cannot penetrate (see 1896). Rutherford was OF ASPIRIN paper, unlike smaller beta particles. interested in the way radioactivity CONSUMED gamma ray Gamma radiation is not made up of caused gases to be able to GLOBALLY particles and its high-energy rays conduct electricity. This happens EACH YEAR THE FRENCH CHEMIST PAUL July saw the first flight of the are stopped only by lead. because the gas becomes VILLARD (1860–1934) announced rigid airship named after the ionized: radiation knocks out new drug for Bayer, a German that he had found a third type of German Count Ferdinand von In October, German physicist Max one or more electrons (negative pharmaceutical company. The radiation only a year after the Zeppelin (1838–1917). Its Planck had a theory that particles), leaving positive drug was aspirin, a painkiller discovery of alpha- and beta- light-alloy framework—buoyed proposed a new way of looking charges behind. Rutherford also that had been developed by radiation. Villard’s rays, emitted by an internal system of at physics. He was interested in discovered that uranium emitted Bayer’s scientists two years by radium salts, were far more hydrogen balloons—proved the science behind an everyday two types of radiation, which earlier. Aspirin would become penetrating: they were similar difficult to control. It hailed the phenomenon—darker objects he named alpha and beta. His the world’s best-selling drug. to X-rays but had shorter start of a period of commercial are warmed more by light than alpha rays were later identified wavelengths and high energy. airship success. The program paler ones. The theoretically as particles that are the nuclei of Effect of ionization Rutherford later called them was scrapped after the fatal darkest object, a so-called black helium atoms, while beta rays Ionizing radiation (alpha and beta gamma rays. Hindenburg crash of 1937. body, absorbs all electromagnetic were found to be streams of particles, gamma rays, and X-rays) radiation, including visible electrons. Both were the carries enough energy to create ions light—and then is a perfect by-products of radioactive decay. (charged particles) from atoms. emitter of this radiation. Planck reasoned that there were In March, the Imperial Patent discrete vibrations of atoms in Office in Berlin trademarked a a body, equivalent to “packages” of energy—which when added ionizing radiation’s there are now electron is ejected from MAX PLANCK (1858–1947) together give the total amount radiation energy excites more positive the atom, carying its of energy emitted. The idea that strikes an electron protons than negative charge Physicist Max Planck studied radiation, such as light, comes in atom in Munich and Berlin, and packages of energy later called negative became a professor at Kiel, quanta was the foundation of electrons then Berlin. He helped quantum physics. organize the first Solvay Conference for Physics in 1911, when scientists met to discuss quantum theory. He was awarded the Nobel Prize in 1918. Unlike many scientists, Planck remained in Germany during the Nazi government. ATOM POSITIVE ION JaRnuudtiahsbreceyortfvaEoerrrrdnayeddosieaftstacilorpnihbaesanhids MaGreOcrfhmafisc6aaeancferobPetrraygasBtiensaantdlyeitcenrysralimaAcsGeapecfiirodirn JaEnrufinraeisdrsteyrtdaaRetdeousirofctmhaerciemsbtreiiofvssofistrhtyidhoainenlf-olfife MaHruecgxheopx2lcdap6rieenewrVsdiiomtirihtfniseehhfGnsoeertrrrsmeeitgdaauoinntlradyctMelianetgenlrdaewl s MapyhRyUestSihectdaAihatrbvenlmiearymWgtuyeeisolanrlslosictsqweoaucrnfiastefitrovurreemidserysd by JuZleyfip2rpaseitrmlssinCahuiicLodpcnZe,es1nmst,asfltanfhikugceelhesr,tiiGogtsveiderrmLaankye NodveesmcarnbidbeeMrgaa6asrrPaiegrideainiCvrdoeaurianumercmitoeeifv,dfelbaraytedron FOesbbrouranreyadAnermisamcderairialibasscteiedaocsvnaanepan:Hrtdepaieenacllvnoapgsorlntpoltyitvovegseecidcoiiinearffstleonbrieycnhtes a reLaaaMncntdadiorsbnctltehohwioen2hde3beraanKrnsgaesiosrretmolreouusifxpmbetldho:oedory Aprirla9diPdadaitesiuosclncoaVrvsliieablgrtleeaaysrrmodhkfmintshoaewranys JunJeoJkcaricpyhastinaTtelhaslieKkezaeeficmirhezsepoitnmiUnheeoiesaprbntnmheadrkoiisannoeel:attoed 236

1901 ,, RADIOACTIVITY IS… ,,ACCOMPANIED BY CHEMICAL CHANGES IN WHICH NEW TYPES OF MATTER ARE… PRODUCED. Ernest Rutherford, Philosphical Magazine, 1902 Radium salt left on photographic plate shows strong radioactivity after development—the yellow tracks are emitting alpha particles. This year also saw the origins of 100% Radioactive decay longer than the estimated age (1864–1915) examined a woman a revolution in biology: several The half-life of a radioactive element of the Universe. exhibiting signs of a severe form biologists rediscovered the laws 50% is the time taken for a particular of dementia—and described of inheritance that had been element to decay into another form. In biology, Karl Landsteiner symptoms of the disease that established by Gregor Mendel 25% Thorium-232 has a half-life of 14 elaborated on his theory of eventually carried his name. (see 1866). Dutch botanist Hugo billion years. blood compatibility. On Following her death in 1906, de Vries (1848–1935) found that Thorium-232 Thorium-232 November 14, he announced that Alzeimer examined her brain and the inheritance of characteristics after 14 after 28 happened in the same way: for he had identified three different observed the abnormal plaques in plants followed rules dictated billion years billion years instance, thorium changes into blood groups, A, B, and O, on that are characteristic of by particles he called pangenes radium. Rutherford identified the basis of compatibility Alzheimer’s disease. (later changed to genes). IN FEBRUARY AND AUGUST, the time it takes for half the patterns. Another rarer blood BRITISH ENGINEER Hubert Cecil radioactive material to decay group, AB, was discovered later. On December 12, Italian Austrian biologist Karl Booth (1871–1955) filed patents into another form, which he inventor Guglielmo Marconi was Landsteiner (1868–1943) for a device that sucked air later named its half-life. Soddy A meeting of the Zoological reported to have sent the first proposed a theory about blood through a filter system. His went on to demonstrate that Society of London reported on radio signal across the Atlantic group compatibility in a invention was the first powered some elements had variants, the discovery of a spectacular Ocean—from Porthcurno, the footnote of a scientific paper. He vacuum cleaner. In November, known as isotopes, which may or new large mammal from the most southwesterly tip of had found that if the serum (the American electrical engineer may not be radioactive. Half-lives forests of Africa. The okapi had England, to Newfoundland, in liquid part of blood) from one Miller Reese Hutchinson, of elements and their isotopes been discovered by explorer North America. Although some person was mixed with another’s (1876–1944), inspired by a friend vary: for some isotopes of Harry Johnston (1858–1927) and people suggested that it was entire blood, it could cause rendered deaf by scarlet fever, beryllium it is a fraction of a was described on the basis of nothing more than interference, clumping of the red blood cells. patented the first electrical second, but for the element examination of its skin and skull. others described it as a This explained why some blood hearing aid. In a modification of bismuth-209, it is a billion times deliberate Morse code signal. transfusions were fatal. Alexander Bell’s telephone In November, German technology, Reese Hutchinson’s psychiatrist Alois Alzheimer De Vries in his garden device transmitted sound from Hugo de Vries experimented with a microphone to the ear via a BLOOD GROUPS breeding plants—as Gregor Mendel set of headphones. had done years before. Although he Red blood cells from some A antigen Anti-B anti-A retired in 1918, he continued his Ernest Rutherford and British people carry surface antibody does antibody research until his death. physicist Frederick Soddy components called antigens. not react does not (1877–1956) found that Karl Landsteiner identified two react radioactive elements changed types—A and B—which can BLOOD GROUP A B antigen into other forms when they trigger the fatal clumping BLOOD GROUP B anti-A emitted radioactivity. This (agglutination) if blood is given antibody does transmutation, as they later to someone with appropriately B antigen anti-B antibody not react called it (see 1916), always sensitive antibodies. Blood does not react group O has no antigens so it can be donated to anyone. A antigen BLOOD GROUP O Blood from group AB has both BLOOD GROUP AB antigens, and can only be given to a person with AB blood. OcHtaosrberoenyfdrLaJsooinntshekdwnwioansnsoAfnfrfloaarrigtcemiadrneennnmattmisafimecdamtaiaonlnot—okapi JaAnmuThaedorreiympcsaac1a(incr8rsieibznMloelgoosdlniiconvthgigsmrioisooemtmnio)eosrsiysome MabyioLBlaoorngkiktiasiesptshiRtiesaryacfoonrfiersmt gsiraffe NoAvldoeeimessacbAorrefllizibrAehesl2ezst6ihmrteeheicemorredre’sddciasseease LaEtreann1esd9stat0tFhr1RrreteauitrdodthetifohreoaeirrccofmkotriruySvdleooadftdedeycay PDlaenccekminbidptereaoracd1koue4fctMedssia(sqotcxhufreeaetnnetear)gy MRaoybBerrpittaiMsrhafiicssnphlidethaeseyesspwliticFnohiograamrtnsdcileciakkuenseess NoreevlegecimstPtrbeiacretfaseorlnra1htM5peOoaiUflrrlfiHSetiacnurebgtRcleaheieidnsseon DecemphbsyeiidscrEiekc1vnnie5ateirnBfiseseJrttiso“tsDsiwstsiernuloheypgtrpethmloapenni-snco”gesaloslemdes 237

1902 1903 Close to the Earth’s surface is the orange-red glow of the troposphere, which contains breathable air and our weather The Wright brothers’ 1903 Flyer first systems. The brownish layer, the tropopause, marks the transition to the gray-blue stratosphere beyond. flew in Kitty Hawk, North Carolina rather than radio signals, and UP TO of the atmosphere. Over a period THE FIRST DESCRIPTION OF was vulnerable to interference. of 10 years he had sent up more A PROCEDURE that would 621 than 200 specially equipped eventually become known as American and German hydrogen balloons. He found that chromatography was presented biologists Walter Sutton MILES: weather systems occurred in a at the Proceedings of the (1877–1916) and Theodor Boveri THERMOSPHERE layer that extended at least 6 Warsaw Society of Naturalists in (1862–1915) independently miles (9km) above the Earth’s 1903. Russian botanist Mikhail identified chromosomes as the up to 31 miles: up to 53 miles: surface. Beyond this layer the air Tsvet (1872–1919) had managed carriers of genetic material. stratosphere mesosphere was thinner and conditions to separate the chemical Nearly 40 years earlier, Gregor calmer. Later, de Bort called the components of plant pigments. Mendel had shown that inherited sea level up to 10 miles: lower layer the troposphere, and He first let the mixture dissolve characteristics were the result of troposphere the upper one, the stratosphere. in petroleum ether and then ran particles (see 1866). Sutton it through a column of finely Micrograph showing cell division looked at sperm-forming cells Layers of Earth’s atmosphere On February 17, the Stanley ground calcium carbonate. As a cell divides, chromosomes are of grasshoppers and saw that The atmosphere is made up of four Motor Carriage Company was The orange, yellow, and green pulled apart, and the genes they moving chromosomes mirrored layers. The gases are concentrated founded in the US for the pigments separated into carry are passed on to the two Mendel’s particles of inheritance. in the thin troposphere. production of a steam-driven different bands: the ones that new cells formed. Boveri saw that sea urchin car first built in 1897; the factory dissolved better in the solvent embryos needed an intact In April, meteorologist Léon closed in 1924. travelled faster and further. ON JANUARY 1, NATHAN chromosome set to Teisserenc de Bort (1855–1913) Tsvet’s technique would later STUBBLEFIELD (1860–1928), a develop properly. reported to the French Academy The Stanley Steamer be adopted as an important Kentucky farmer and inventor, of Sciences on his investigation Early Stanley cars had boilers under analytical tool for separating showed off an electrical device the seats that generated steam. mixtures of substances. that could send voice and music Known as Stanley Steamers, they wirelessly over a distance of half were fuelled by a gasoline burner Humankind’s attempts at a mile. Although it provoked and started by a crank. powered flight reached an scientific discussion, this important breakthrough on ,,wireless technology did not December 17, when American survive because it relied on inventor brothers Orville disturbances generated by (1871–1948) and Wilbur Wright electromagnetic induction, (1867–1912) achieved the first INDIVIDUAL controlled man-carrying CHROMOSOMES flight powered by an POSSESS engine. For many DIFFERENT years pioneers of aviation had ,,QUALITIES. tried hot-air balloons and Theodor Boveri, On Multipolar gliders—with Mitosis as a Means of the Cell varying degrees Analysis, February 17, 1902 of success. The JaNnaudteahdmraeysnvooi1ncSusetnturdtbhawbateltiesrsefiealenenldsdesswly FeTbhsrehuosoaedwirtosysordnf1teBehc7veoahedvtrleeooardpmnimfioonesrtnoantmcotrems al AmpaeBlreaidcoroannrcnteuuoTmmlmyoargeBaininnrsstotnewoodsfnafiursrtus rex SeEpratnenesmdsedtFtbeRroeeceuulraedttymhethoreeifercnfiakrottroitSnhdmoteodsodarcyynhotahtnhagetersfoarnm FeEbrcrnauerlaslastrdyRPiaaututiohlneVrgifloalarmdrdJm’uspanhrEeyais2finyis1rotshlDotogeuvlietescntchtWdroeiclslacerrmdibioegsraph CaFrSertbiaarnguileseayeCrsyoMtma1ob7tpolairsnhyed ApTreBiilosr2stse8tdrrLeeaénstococnrsdipbeheesre AlfreAdAduvrosiantrniDoaenSctbbauilsorotlloeoidlgdlioegssrtaocsnurdipbeAB OScuchttrotoobmnesorpus1hogM7ymgsWeeeinscastdalsealtetlrbi’hernsaahstltaheisweriostafonfce DeecxeSpmceotdbhtiteet’isrosnoARupnaootrtbharieneirvrtcrbettnryisemchaaouctshmteadns McMihkrahoiramncitlharTot2sod1vguercatepshy KonsRtaunsrtsoiinacdknTeesssticsocilreckionboouteuvilssstdtekhrsyotswupdayce 238

,,1904 I NOW FELT… CERTAIN THAT THE DAY WOULD COME WHEN ,,MANKIND WOULD BE ABLE TO SEND MESSAGES WITHOUT WIRES ACROSS THE ATLANTIC. Guglielmo Marconi, Italian inventor, in Messages without Wires, 1901 The equipment at the Marconi wireless station in Massachusetts, US, which transmitted across the Atlantic to Cornwall, England. Wright brothers experimented AFTER THREE YEARS of sending In July, Piero Conti (1865–1939), American astronomer Charles with glider design to maximize transatlantic radio signals— an Italian businessman from the Dillon Perrine (1867–1951) lift and added a lightweight including coherent messages— volcanic region of Larderello, discovered a moon of Jupiter aluminium gasoline engine to Italian inventor Guglielmo Tuscany, demonstrated a steam that was later named Himalia— provide the power. Orville made Marconi (1874–1937) set up the engine that ran on geothermal after a mythical Greek nymph. It the first 12-second flight in first commercial transatlantic is the sixth largest of Jupiter’s their aircraft, the 1903 Flyer, and radio service. By 1907 it had power. Conti succeeded in moons and is thought to have flew 40yd (37m). The same day, become a regular service. producing enough electricity been formed from an asteroid from a dynamo to illuminate captured in the planet’s orbit. Orville and Wilbur Wright The March issue of the five light bulbs. Conti’s legacy The Wright brothers ran a bicycle science journal the Philosophical is that the Larderello region now positive plate shop, but were inspired by early Magazine contained a piece produces 10 percent of the (anode) attempts at aviation. By 1908, they written by British physicist world’s geothermal electricity. had managed an hour-long flight, J.J. Thomson (1856–1940) static electron, cloudlike body In November, British physicist and carried a passenger. in which he described a new or plum —the pudding John Ambrose Fleming way of looking at the atom (1849–1945) filed a patent Wilbur managed 284yd (260m) that accommodated the newly The plum pudding model for the first vacuum in 59 seconds. discovered electron, known Thomson’s model for atomic diode—designed as the plum pudding model. structure was an early attempt at by adding a positive The Wright brother’s first Thomson thought of an atom as suggesting how charged particles electrode (anode) to aircraft was designed to a “pudding” of positive charge, could coexist in a neutral atom. an Edison light bulb. minimize load and maximize in which the negatively charged Electrons from the hot flexibility. It had a spruce ash electron “plums” were His model had a large positive filament bulb flowed wooden frame covered in muslin. embedded. Later in the year, the core, which was orbited by through the bulb’s vacuum The engine gave it enough speed Japanese physicist Hantaro negative electrons, rather like to the cold anode—converting for the wings to generate more Nagaoka (1865–1950) rejected the rings around planet Saturn. alternating current (AC) signals lift than the weight of the the idea that positive and Within a few years, experiments to direct current (DC). This machine: the principle of flight. negative charges could in the UK would show that atoms marked the start of an era of intermingle in this way, and have a dense positive nucleus electronics, and for decades suggested his Saturnian model. with encircling electrons—more improved versions of Fleming’s like Nagaoka’s model. diodes were used in many devices, from radios to the 7,000,000 first computers. In early December at the MILES Lick Observatory in California, THE DISTANCE OF Fleming’s vacuum diode HIMALIA FROM JUPITER The design features a metal plate that acts as an anode (positively charged electrode) to attract electrons from the bulb filament, thereby creating direct current. SeGpestoeurhmggegebaeteDsertadsr2wbt4hyienrEadairotahcitsivity DuCtocsrhunhgseegcollieipfeufsoondstrrtsegKimsctaothonhnmaiuictnpmfmgouusnasigtttiioenr to MaJ.rJdc.ehpTsuhcadrotidombimenssgiocpnmslutormduecltuorfe Jutleyspt4osewPntehieererergofidyrCbsoytnggteeinotehreartomral DeDcitelhlmoenb1Pe0erthr3rminoeodnisocf oJvueprister OBsclstreopuebrcpeeeianrrdge1bp7syoiDcrttksasenvttiesdhseastflisies June BrdietEisssdchuwrnaiabssretpdsrooMptnadaotiumtsenterrdinrbesurotifon GeFrmrdieeasdnmcrrbiiictiboohelcosMhgofiepisnnvltadednrsinitagcienlls ONffioBcvtreheitermiersmgbhvieasiPortlaven1etrie6csfnodttrhFioelJdeoemhning DeNceamgSaabotekuraran5tdoieHamsnacincmrtisbaoterdrosueclatoufre 239

1895–1945 THE ATOMIC AGE netting support for Ornithopter covering of feathers 15th century pedal provides strong hand lever provides Although Italian polymath Leonardo da downstroke of wings weak upstroke of wings Vinci’s ornithopter—an aircraft with flapping wings—could never have flown, it may be the first design for a flying machine. waxed Aerial carriage paper wing 1848 British inventors John Stringfellow and William Wright Flyer flexible wing helps control Henson achieved the first 1903 height and direction powered flight with this Orville and Wilbur Wright, American inventors, achieved the model aircraft, driven first manned, powered, controlled take-off and flight with tailfin 63 ft by a tiny steam engine. their Flyer in North Carolina on December 17, 1903. (19.3 m) high FLYING MACHINES THE DEVELOPMENT OF POWERED FLYING MACHINES LED TO A MILITARY AND TRANSPORT REVOLUTION The dream of flight dates back to the Ancient Greek myth of Daedalus, who flew with wings of feather and wax. It was not until the 18th century that flight became a reality, paving the way for a range of flying machines. Humans first took to the air in 1783, in a hot-air balloon developed by the Montgolfier brothers in France. For a century, aircraft used gas for lift—first in the form of balloons and then steerable airships. Winged aircraft took off under their own power for the first time with the Wright brothers’ historic flight in 1903. envelope filled main rotor blades with helium provide power and lift Skyship 500 HL gondola carries 1984 crew and Airships were the luxury passengers liners of the 1920s, despite Hot-air balloon their slow speed and the Schweizer 300C helicopter Date unknown inflammability of their 1970 Balloons gain lift because lifting gas—hydrogen. Small helicopters such as this one can hover, take they contain a gas—such as Today, smaller airships off and land vertically, and turn on the spot—making helium or heated air—that serve as airborne them perfect for urban flying. is less dense than the air platforms for cameras surrounding the balloon. covering major events. 240 tail rotor allows steering and stability

FLYING MACHINES Vought F4U Corsair Supermarine Walrus 1943 1935 Fast and highly maneuverable, Used for survey missions during World War II, single-engine fighter–bomber the Walrus could be catapulted into the air planes such as the Corsair from the deck of a ship. It could also land were in great demand on water and be lifted back aboard. during World War II. foldable wings fully retractable landing gear light aluminum body metal body Lockheed F-117A Nighthawk 1982 Stealth aircraft such as the Nighthawk are designed to avoid detection by enemy radar. They are shaped and colored to diffract and reflect radar waves indistinctly. faceted wing float body shape Concorde narrow, streamlined fuselage 1976 A British–French engineering collaboration and powered by turbojet engines, the Concorde was one of two supersonic airliners to enter commercial service. It could fly from New York, US, to London, UK, in under three hours. triangular wings, roundly drooping nose cone tapered at the ends allows runway visibility wide body Boeing 747 1970 Until it was surpassed by the A380 in 2007, the Boeing 747 was the world’s biggest airliner, with the capacity to carry up to 680 passengers. high-power, Schleicher ASK13 hold can be tailfin provides low-fuel-consumption 1966 opened in space directional stability Made using strong, US Space Shuttle turbofan engine ultralight modern to release 1982 materials, gliders can fly payload Although it had to be launched by rockets, long, thin wing far and high, using rising the US Space Shuttle was the first spacecraft reduces drag air currents for lift. to land on a runway and to be used for further flights like a conventional aircraft. main engine 241

,,1905 1906 BODIES OF MICROSCOPICALLY Albert Calmette (center) studied animal toxins and developed some of the first VISIBLE SIZE SUSPENDED IN A LIQUID antivenoms. Later he collaborated with Camille Guérin to make BCG vaccine. WILL PERFORM MOVEMENTS OF SUCH A MAGNITUDE THAT THEY CAN BE… ,,OBSERVED IN A MICROSCOPE. Albert Einstein, on Brownian motion, July 18, 1905 ALBERT EINSTEIN PUBLISHED 671 time and space to show that it BRITISH GEOLOGIST RICHARD waves travel much more was compatible. Finally in OLDHAM (1858–1936) studied slowly—and S-waves stop FOUR REVOLUTIONARY PAPERS MILLION November, he published a the seismic shocks that went altogether. In February, Oldham in what became known as his conclusion that arose from his through Earth following suggested this phenomenon Annus Mirabilis (Miracle Year). THE SPEED work on relativity. He suggested earthquakes. At the end of the could be explained by the His first expanded Max Planck’s OF LIGHT that when an object emitted previous century Oldham had presence of a core inside idea from 1900 that energy IN MILES energy, it lost mass too, so identified two kinds of waves: Earth that was composed of existed in minute packets of PER HOUR energy and mass were fast-moving, longitudinal, a different kind of material. energy. Einstein proposed that interchangeable. This primary P-waves and slower, Later studies would show that packets of light energy could he reconciled the constancy of relationship was expressed in transverse, secondary S-waves. Earth has a core located at a help explain the photoelectric the speed of light with the a simple equation: E = mc2. He found that below a certain depth of 1,802 miles (2,900km), effect, in which wavelength (not principle of relativity: the idea depth within Earth, seismic and confirmed that the outer intensity) of light provides the that mechanical processes British biologist William core is fluid. energy needed to eject electrons happened in the same way Bateson (1861–1926) was among TUBERCULOSIS (TB) from a metal surface—later whether at rest or moving. Light a number of scientists interested On Christmas Eve, a Canadian proven experimentally (see 1921). had previously been regarded as in the study of inheritance. In a German physician Robert inventor, working at the US an exception to this principle— letter of April this year he called Koch (1843–1910) identified Weather Bureau, broadcast the Einstein’s second theory but Einstein used an analysis of it genetics. the bacteria that caused TB, first radio program. Reginald explained how the random and was awarded the Nobel Fessenden (1866–1932), a rival of movement of tiny particles in Growing populations needed Prize in 1905. Formerly Guglielmo Marconi, transmitted gas or water was caused by the more food, so the demand for called consumption, TB was his program from Brant Rock, motion of molecules bombarding crop fertilizer increased. German often fatal. It infects the Massachusetts. It included a the particles—Brownian motion. chemists devised a way to make lungs—causing lesions, or voice message and music was In September, Einstein ammonia, the compound that tubercles—and is spread directed to ships in the Atlantic published his theory of special provided nitrogen for plant through droplets dispersed Ocean more used to receiving relativity (see pp.244–45). In it growth. Ammonia is formed by coughs and sneezes. The messages in Morse code. from hydrogen and nitrogen. BCG vaccine was the first ALBERT EINSTEIN (1879–1955) Fritz Haber (1868–1934) protection against TB. At the Institut Pasteur, France, described a key reaction between work began on a program that Born in Germany, Einstein took atmospheric nitrogen and led to the development of a new Swiss citizenship before finding hydrogen. During World War I, vaccine that would protect work at the Bern patent office when natural sources of nitrate millions of peoples from a in 1903. Here he wrote his came under Allied control, Carl deadly disease: tuberculosis ground-breaking papers and Bosch (1874–1940) used Haber’s (TB). French scientists Albert was awarded a doctorate by principle to produce industrial Calmette (1863–1933) and the University of Zurich. He quantities of ammonia. Camille Guérin (1872–1961) had completed his general theory been inspired by the historical of relativity in 1915 and was German chemist Alfred uses of the harmless cowpox as awarded the Nobel Prize in Einhorn (1856–1917) succeeded a way to vaccinate humans 1922. In later years, Einstein in making the local anesthetic against dangerous smallpox (see became a US citizen. procaine, later traded as 1796). They thought that a Novocaine. The drug would similar process could be tried become a standard painkiller. MaByatthWegesieltolneinaermmtciocisns FrTithzTeeHdTcaehhmbsneeciracrrmkaibeploiuGndabmygalnsiamsaRhmroeeeniaasciccasttiiooofnnst,o Jupluytbh1lme8isooEhrtyeiinososnfhteBisirnownian Seppustbeplemischbiaeelsrrhe2il6satEtihvineitosytreyionf NoevxbepelmEatwib=neesmertnch22em1 rEaesilnsastatioennidnsehnipergy: JaEndusdtaadinrtriygisftttoAiincnragtblhsesuttgaruirndssy a FeObfarfinucAaealerfrrsyeetghd1ie3sEttUiiecnrShpsoPraroanlctoeacniantle for GeMrmathxaneWnafimoarslsefttdrdToi5rsno8coj8oamvnAeecarrhssitlelerosid, of EinJpsuhtheniosietnot9hepeluAeoblcbrltyiersirohctfeetsfhfeect OzcotoolboWeloirlgsAisomtnthEedsedryecimXschsXtacruenoranmimbndedoossfXosYmexes DdaiEsnntgiisjniahagrnautHsisaethrnroedtnzsdosbwpmerateurwrnfegsetanrs FOeldhbharasumaarcsyou2rge1g,eTlashttoestomrEbsaahesrotlhiwqnuid SchGweaorrbmszstsaeacnrrhvfpeirlhoddymdseaixccrpiekslnaettinKneirasnrgttolhoeefdage 242

1907 By 1907, Nobel laureate Ivan Pavlov, shown here with his staff and one of the dogs, had received much acclaim for his experiments with reflex responses in animals. site of extent of earth core inferred AMERICAN INVENTOR LEE DE ,, THE later taken up by British geologist earthquake by path of P-waves FOREST PATENTED THE TRIODE, Arthur Holmes (see 1913). which could be used to amplify ,,MATERIAL P-waves electrical signals and act as a The German chemist Emil shadow switch. Until the invention of the OF 1,000 Fischer (1852–1919) succeeded zone transistor years later (see 1947), USES. in linking together the building blocks of proteins. These P-waves some P-waves are diode and triode valves were Leo Baekeland, on Bakelite units—called amino acids— An earthquake refracted by the core used in circuits in radios, came in a variety of types. produces fast-moving televisions, and computers. oil was always a multiple of a tiny Fischer identified many of them waves that slow down and bend had been soaked with ox gall The Belgian-born chemist value: the charge on a single and showed how they bonded in as they pass through Earth’s core, (obtained from cow’s liver) and Leo Baekeland (1863–1944) electron. Millikan published his protein chains. His work was the creating a “shadow” zone where a set out to continue the culture produced the first plastic first results in 1910. foundation of protein chemistry. seismograph cannot detect them. line until it was safe to use. It made from synthetic was 10 years before their BCG Following the discovery that Russian physiologist Ivan out for TB. Calmette and Guerin (Bacille Calmette Guérin) materials. Baekeland’s new radioactive materials decay at Pavlov (1849–1936) converted wanted to use a bovine (cattle- vaccine was ready for use on product, later named Bakelite, fixed rates (see 1901), American his laboratory so that he could borne) form of TB to develop a animals—it was not tried on was heat-resistant and non- scientist Bertram Boltwood concentrate on his study of vaccine against the human form humans until 1921. conductive. It was used for (1849–1936) used this to calculate animal behavior. Using dogs, of TB. They set up cultures of electrical insulation as well as the age of rocks. He found Pavlov had shown that animals bovine TB on potato slices that to make domestic utensils and that ores of uranium could be taught to salivate when children’s toys. (uraninite) contained a they heard a ringing bell, known proportion of lead, and as the conditioned, or learned, French filmmakers Auguste the older the rock, the reflex (see 1889). (1862–1954) and Louis Lumière more lead it contained. (1864–1948) began marketing Lead was a product of a the first commercial color known rate of uranium photographic method. This decay, so it accumulated autochrome (self-coloring) over time. The study of process involved using a negative radiometric dating was plate that was coated with 9,800°F transparent grains of dye- Early color photoraph THE TEMPERATURE OF colored starch, which filtered This autochrome image EARTH’S INNER CORE light before it hit a layer of shows Doug, niece of the photographic emulsion. Lumière brothers, out in her pram with her nurse. Following J.J. Thomson’s It was taken between demonstration that electrons 1906 and 1912. were particles (see 1896), American physicist Robert Millikan (1868–1953) began experiments to calculate their electrical charge. He found that the charge on falling droplets of SwTehedexiotsphdheeorporimhrSyyevsoneifctdiBasblrteoterwgsntdsiaefnsocrmrEiobinteisostnein’s NoAvlpzeuhmbberblidaimeceinrmerer4oepfpAnoartlroiotdadieosupancadetthsieent FePbatrthueDeanetrtryFOioof1dfir8eecsUeftoSrreLgeiseters PaaurtlsrEeenhairtciln-icbghassdleeedevpedilrnougpgssfiocrkness JuLnoceuoiAomsfuLmAguuuemtsrotciecèiahralrenpodsrmtoaedrutLcutmionière OcEtmobboitlenoFrdgiie1sntc8ghheaermridninecoshcaarciinibdsess NoPvaAevcmlRoaubdvoseefissmrSiaec4icnlieeIiavAncantcceneaodsdfethmey NDidcuoetslpckachrnaroosibbdwiSeuonöslcohimtnghngieesgttbefihanracsnttee-ria DeceFmesbseertnh2de4efinRertesnrgtateiAnnrMsatmabldrirniaotmsdaideocnatst FeBborlrtuawadoriooymdBedeterrostifcrcarmdimbainetiesnrgals JulfiyleLmseaohkiBsinampgelaekasteshPtliyoaacndntwtedhfnoiettrhtOicUffiSce NorwHeoiglastnabniodschAhocleawfmruetsdihdseeatdfiFstcrbsAoiycexhuinnedlrciulecvytnyh—rtiivieslfiianteattdemrains C MLaiolFitllie-lked1amtr9cnohe0paae7nesrdRxudporHeeeobvarnetirishmraveetenetycnhehtelaetrcogtreon 243

1895–1945 THE ATOMIC AGE UNDERSTANDING RELATIVITY EINSTEIN'S GROUND-BREAKING THEORIES REVEALED THAT SPACE AND TIME ARE INTIMATELY LINKED In the early 20th century, German-born physicist Albert Einstein published two theories that revolutionized our understanding of space, time, energy, and gravity. The first, known as the special theory of relativity, only applies in certain circumstances; the second is the general theory of relativity. In the 19th century, physicists thought that both measuring the distance between the same ALBERT EINSTEIN “empty” space was actually filled with a two points in space, or the time between the When Einstein published his theory of special substance, which they called ether, and that light same two events, would come up with different relativity, he was working as a clerk at the travels through the ether at a fixed speed. Since answers. Einstein’s relativity also did away with patent office in Bern, Switzerland. our planet is moving, they predicted that the the “stationary” ether and showed that there measured speed of light would differ from its is no absolute reference point in space or time. actual speed—just as a passing car appears to move faster or slower than its actual speed if OBSERVER WITHIN OBSERVER OUTSIDE you are also moving. To test this idea—and in REFERENCE FRAME REFERENCE FRAME an attempt to determine Earth's actual, or “absolute” speed through space—they measured light beam the speed of light in different directions and at different times of the year. But in every case, the mirror speed of light was always exactly the same. mirror SPECIAL THEORY OF RELATIVITY astronaut light beam light takes longer to The fact that the speed of light is constant was bounce between mirrors perplexing, and it challenged common-sense TIME DILATION assumptions about the nature of time and space. A beam of light bounces between mirrors inside a spacecraft observer In his theory of special relativity Einstein showed that is moving past Earth. An astronaut inside the craft on Earth that time and space are indeed “relative” perceives only vertical movement in the light. Viewed from quantities: that two observers in relative motion Earth, it appears that the light travels farther between the mirrors, and takes longer to make the same journey. So, time runs slowly in the “moving” frame of reference. ,, IT FOLLOWED FROM THE SPECIAL THEORY OF RELATIVITY THAT ,,MASS AND ENERGY ARE… MANIFESTATIONS OF THE SAME THING. Albert Einstein, in the film Atomic Physics, 1948 MASS AND ENERGY e=mc2 In working through the mathematical equations in his theory of relativity, Einstein encountered a energy mass speed of light surprising result: the mass of an object increases as it gets faster, and at the speed of light an PARTICLE ACCELERATOR object would have infinite mass. Einstein realized Physicists working with particle accelerators that the speed of light must therefore be the routinely use Einstein’s theory to predict the Universe’s ultimate speed limit. His equations increase in mass of high-speed particles, and to suggested that mass and energy are equivalent work out how much longer it takes for them to to each other, and he defined a new quantity: decay as a result of time dilation (see above). “mass-energy.\" The equivalence of mass and energy is expressed in Einstein’s most famous equation, E = mc², in which E stands for energy, m for mass, and c² for the speed of light squared. 244

UNDERSTANDING RELATIVITY apparent position BENDING SPACE TIME of star The Sun is massive enough to bend the surrounding spacetime to such an actual position extent that starlight passing close by of star is deflected enough to make the star appear in a position slightly different from its actual position. British physicist Arthur Eddington confirmed this prediction of the general theory of relativity in 1919, during a solar eclipse. light from a distant star is effectively bent by warped spacetime as it passes close to the Sun two-dimensional “rubber sheet” represents four- dimensional spacetime; dents in the sheet represent distortion of spacetime by the presence of massive objects GENERAL THEORY spacetime around the Einstein’s special theory only applies Sun is distorted, creating to objects moving in a straight line at a “gravitational well” unchanging speeds and does not take into account gravity. In trying to incorporate gravity Earth and acceleration, Einstein made use of a concept devised by German mathematician Hermann Minkowski. In 1907, Minkowski suggested considering time as a fourth dimension and defined the four intertwined dimensions as “spacetime.\" In the 1910s, Einstein worked out a set of equations that describe gravity as the curvature of spacetime. The equations were the basis of his new general theory of relativity, published in 1916. The general theory accurately predicts how gravity affects time and bends light. THE EQUIVALENCE OF GRAVITY AND ACCELERATION spaceship spaceship spaceship accelerating floating falling freely in space in space toward Earth ball drops ball ball FALLING TO EARTH to ground does not does not Inside a spaceship in freefall, an object will ball move move accelerate downward “drops” to at the same rate as thrust gravity of Earth the spaceship. There the foor canceled out by is no difference ACCELERATING IN SPACE between accelerated ON EARTH Inside an accelerating spaceship, a acceleration motion and gravity. A key part of the general theory is the dropped object would behave in exactly “equivalence principle”: that there is no the same way as an object dropped in FLOATING IN SPACE difference between accelerated motion Earth’s “gravitational field.\" If the spaceship is moving at a constant and gravity. To us, gravity is a force that speed, then a dropped object will not makes things accelerate downward. fall, but instead will remain stationary relative to the hand that releases it. 245

1908 1909 According to some, the inspiration for cellophane came after its inventor, Jacques Brandenberger, saw wine A remarkable repository of some of the oldest animal fossils, Canada’s spilled on a tablecloth. But the film proved more useful in waterproof packaging than for stain protection. Burgess Shale is a record of Cambrian ocean life half a billion years ago. SWISS CHEMIST JACQUES E. ,, IT WAS QUITE THE MOST THE GERMAN DRUG COMPANY the pH scale. This scale rated BRANDENBERGER (1872–1954) Bayer—pioneer of aspirin—was substances according to whether invented a way of producing ,,INCREDIBLE EVENT THAT granted a patent on a sulfur- they were acid (1–6), alkaline sheets of thin waterproof film based drug. The drug was a (8–14), or neutral (7). made from wood cellulose. HAS EVER HAPPENED TO derivative of sulfonamides, a The film came to be called ME IN MY LIFE. class of bacterial agents that The previous year, Louis cellophane (for cellulose would rise to prominence in 1932 Blériot (1872–1936), a French and dominate the preantibiotic engineer, had witnessed the and diaphane, French for Ernest Rutherford, New Zealand-born physicist, from his lecture period. Sulfonamides marked a public manned flights of Wilbur transparent). Brandenberger’s The Development of the Theory of Atomic Structure, 1936 significant step in chemotherapy Wright. Inspired into action, he —the scientific development of set his sights on the English original idea was to spray drugs that cured disease using Channel. French inventor Jean sound pharmaceutical Piere Blanchard had crossed it in liquefied cellulose onto fabric as measuring radioactivity by foils on a stream of alpha principles—but Bayer was a balloon (see 1785) but in July, unaware of their importance. Bleriot became the first person a stain-repellent, but he found scintillation—counting the particles. Marsden’s work using At the same time, German to cross the English Channel in physician Paul Ehrlich and a manned, powered plane. The that he could pull away a dry film flashes of light when the rays gold foil threw up unexpected Japanese biologist Sahachiro Blériot XI left Calais at sunrise on Hata (1873–1978) were working July 25 and landed in Dover that was far more useful. struck a zinc sulfide screen. They results. According to the atomic on their own custom-made drug 36 minutes later. As well as to treat the sexually transmitted receiving international acclaim, New Zealand-born physicist carried out experiments firing structure theory of the time (the bacterial disease syphilis. Blériot won a £1,000 prize from London’s Daily Mail newspaper. Ernest Rutherford’s half-life radiation through barriers, plum pudding model, see 1904) Søren Sørenson (1879–1963), a Danish chemist, was studying In America, paleontologist explanation of radioactivity still enlisting the help of a student alpha particles should have protein—a substance that is Charles Walcott (1850–1927) sensitive to the made an important discovery. commanded attention. He and called Ernest Marsden (1889– passed straight through the gold, effects of acids and alkali. Sørenson German physicist Hans Geiger 1970). Geiger and Marsden but instead a few bounced back. worked on a way of quantifying acidity (1882–1945) had devised a way of studied the effects of metallic Rutherford later said it was, “as and alkalinity and, as a result, devised though you fired a bullet at tissue most alpha particles paper and it bounced back.” His pass straight analysis of Marsden’s results through the foil suggested that the deflected gold particles were striking a very foil dense nucleus at the core of a few particles each atom. hit gold nucleus In August, five years after their and rebound historic maiden flights, the Wright brothers were in the air zinc sulfide again, but this time they had an audience. In an atmosphere of screen scepticism, Wilbur had traveled slit in lead to France to show off their manned, powered aircraft. Over alpha sheet to ensure gold Measuring pH value beam narrow beam atom Indicator paper contains a chemical Marsden’s gold leaf experiment nucleus several days he demonstrated that reacts with acid 1 2 3 4 5 6 7 8 9 10 11 12 13 14 A beam of alpha particles was fired his mastery of flying and the or alkali to produce a at a piece of gold foil. When some most particles pass assembled crowds grew daily: colour to match a strong acid neutral strong alkali particles bounced back from the foil, straight through the Wright brothers became scale according to the physicists saw this as evidence that aviation celebrities. subject’s “strength.” atoms had very dense nuclei. DETAIL OF GOLD FOIL JaGneuWramdirlehaybsena1clsrmp3iihsbWyeossfeicpminioabapnteuhrlegamtioanticgaelnetFiceRsbudrteuhrsaaecGrdrryfieioobi1arge1dceatrEaivmnrcintodeyeu—HtsnhatttohnedersoGbfaemsigiesearosfutrhineg BrWitiaislnhlWidacghmhRayeo(stmrRblaagaeidswmirvottse-nsGna),ryobafuyf tbiscyoarllaal tdietiunmiton LaHtaeEnr1esn9xeGt0phse8esitinrcgMiamefoatrteirelanssrndtosadeflonpmnhseathatoaprwlat rticles FeRbuRrtuohpayeadrrrsyftoicsErlhdreonsawenasdrttheTahhteoalmilupamhsanuclei MaSyøtrh2ee9npSsHoønrceoinnntcroedput ces Mreagyis1Pt8eaortfGessensurtylmOfnoatfnfihnacemesiisde FDWeubticlrlpheurmpaohrdKyyusec2ieec9sissohstmeolliiudm KJapumhlyyeslri1iqlc0iuinsDigfituheHtsOechihnkeneleiusmdemmAanuoadgnnsuW-tcsriatlarbt8reuyOricnraoWgvinrirpltcilrrogeoawhlfltteerfldeigdht DecembeKaranr1dl8LEAaarunwnsdnitsnrotiuaPepnnioiondcspleeeipornvemtirirtyayeloliftis 246

1910 65 THOUSAND THE NUMBER OF SPECIMENS UNEARTHED BY WALCOTT AT BURGESS SHALE The distinctive corkscrew shaped bacteria that cause syphilis were finally conquered by an arsenic-based drug initially known as 606. motor cortex controls auditory cortex somatosensory cortex receives ON MAY 20, HALLEY’S COMET American physicist Robert W. coordinated muscle integrates auditory and analyses nerve impulses came closer to Earth than Wood (1868–1955)—an expert in movements data with memories from touch receptors at any time since 1835. The New optics—was the first to use York Times had warned of an infrared (IR) and ultraviolet premotor cortex creates and other senses sensory cortex processes imminent apocalypse as (UV) radiation to produce the intention to move sensory information astronomers had described the photographs, and published the comet’s poisonous cyanide- first examples. Wood pioneered prefrontal cortex is visual cortex integrates containing tail. However, the this type of photography and the involved in determining visual data with memories event passed without disaster. technology would lead to the personality and thought. and other senses modern-day black lights that The Danish and American emit UV radiation and minimal Broca’s area is associated primary visual cortex astronomers, Ejnar Hertzsprung visible light. with the production of language receives and analyses nerve (1873–1967) and Henry Russell impulses from the eyes (1877–1957), published the PAUL ERLICH (1854–1915) primary auditory cortex Hertzsprung–Russell, or H-R, receives and analyzes nerve the Wernicke’s area is diagram they devised to Starting his career in the associated with language classify star types. The H-R medical study of blood, Paul impulses from the ears diagram is a scatter graph that Ehrlich developed stains for plots the relationship between revealing cells—including BRAIN FUNCTIONS temperature, luminosity, and bacteria. From these studies, size of stars and distinguishes he pursued the “magic This “map” of the most complex part of the brain Sensory areas receive signals from the rest of types of stars as clusters within bullet”—a drug that could came out of the painstaking work of Korbinian the body and motor areas control the dispatch of the chart—white dwarfs, main target a specific infectious Brodmann. The surface of the cerebral signals to muscles. Association areas are those sequence, super-giants, and red organism—initiating the hemispheres—called the cerebral cortex—is involved in complicated, higher processing, such giants. It remains a standard concept of chemotherapy. He divided into sensory, motor, and association areas. as decision-making and language. astronomical tool today. also worked on immunization and proposed a theory that Coming to the end of fieldwork at oldest and best-preserved (1868–1918) had been working In April, Paul Ehrlich explained immune response. Burgess Shale in the Canadian fossil sites, with specimens that on the fine structure of the part announced the completion of Rocky Mountains, Walcott found dated back 500 million years. of the brain called the cerebral his arsenic-based drug, 606, to a large deposit of fossils. Walcott attempted to classify the cortex, which controls higher treat syphilis. By November, the Subsequent investigation animals into known groups, but functions—for example, German drug company Hoeschst revealed it to be one of the scientists have since discovered decision-making and emotion. AG had begun marketing it as that many of them belonged to Using microscopic studies, Salvarsan. Demand for this ancient evolutionary dead ends. Brodmann managed to identify new drug grew quickly as the the different functional regions treatment was more effective German neuroscientist of this part of the brain that than any previous medication. Korbinian Brodmann could be linked to processes However, the toxic dangers of its demonstrated experimentally arsenic component remained a 1,000,000 1 Comparing pH value by other scientists. Brodmann’s concern and, 30 years later, HYDROGEN IONS IN hydrogen Acidity is determined by hydrogen cerebral map formed the basis Salvarsan would be replaced by HYDROCHLORIC ACID ion in ions. The concentration of hydrogen for modern understanding of antibiotics (see 1940). water ions in hydrochloric acid is million higher brain function. times greater than that of water. JupnaRethiAbcoakmlRoceeotgtsertcipssirkcoitdayatHentMteoshdocwarutfaienbcrvtaedaeusirsne JuRnuhetoh1awe7lprgEhfooralrndpdeafsdorteitliscsclceraisbtetesrs AubgaCuchtsdeaterrbFmilooretldoeysoynpngNshcliisthuicrctseaotlfteelresaventrhsamtit DeOcfBefimacmeebpkereelteahrlgaso7itndsidctUfe,toS’rlsrsaPhmtLaeeetraaeokctni-antalglnedad-sBpyranektshesleuittrieec JaAnmuLeaeberrriymocDaa1eound3nsFciiaonrcasarvetedlssnipotfiteorrrsfot rlimveance JuJneaeann2tny1HopFuyharnoeccindiencsvthhaficeprcshVityniseneifccfeeiancnttive OcWtoothbopedehrfiporRutsobotglbiirsenahrfprteahWsrse. d Junaen1d0fiSlPeaahauaplcaahErtsiherearonnlntiHitccfidhoa-brbrtauaacagstn,ee“rd6ia0l6” July 25EnflLgoieluissishactBChrlhoeéasrBsniolnéttherelioint XI ChSaerpdleBitsseucrmWogvfabeoelsesrcssrsoiStltthhsCeaitaleenianda DeJocbehomatanbnneissret nDWwacoinolrhiidsnehs“lmgtehnee” biologJiMsutolTyrhgAoamimnnehadreseircsHiactuafnrrinnbutceitesflinies SpehpytasenimcniosbutenMrca5ersPieiosoCloifsulrharatideioiunm DeLcvieeamuntbHeenerannDsetbuxKvrtisooactmehnekmnSopcdtaeeronoyoDvnfertsahgeon 247

1911 ,, WE WOULD LIKE TO HOPE THAT OUR CONFERENCE WILL… EXERT The delegate list of the first Solvay Conference included many important scientists including Ernest Rutherford, Max Planck, Albert Einstein, and Marie Curie. ,,AN IMPORTANT INFLUENCE ON THE DEVELOPMENT OF PHYSICS. Walther Nernst, Principal instigator of the Solvay Conference, 1911 NEW ZEALAND-BORN PHYSICIST contained a central dense mass electrons Rutherford’s rookery of Emperor Penguins Ernest Rutherford was gathering with a positive charge that was circle round atomic model in midwinter. But in December, a evidence for a new theory of surrounded by electrons. In the central Rutherford Norwegian expedition, led by atomic structure. Experiments 1912, he called this central area nucleus proposed that an Roald Amundsen (1872–1928), had indicated that atoms had a the nucleus, and noted that the atom had a dense reached the South Pole first. dense core, so the plum pudding value of its charge was related dense nucleus nucleus and that The British Polar party all died model was wrong (see 1904). to its atomic mass. Dutch with a positive the electrons on their return journey. Rutherford proposed that atoms physicist Antonius Van den charge orbited the space Broek (1870–1926) suggested around it. German chemist Philip ERNEST RUTHERFORD that the charge value was equal Monnartz described a way (1871–1937) to an element’s atomic number, obvious characteristics, such as were on the chromosomes of producing steel to improve or position in the periodic table. eye color, to help him trace that determined sex. its corrosion resistance. The Born in New Zealand, Ernest Henry Moseley (see 1913) later patterns of inheritance. In 1911, result—stainless steel—would Rutherford worked at McGill proved Van den Broek right. Morgan discovered that the genes In Antarctica, Robert Scott’s be patented in 1912 and in 1913, University, Canada, moving to (1866–1912) British Terra Nova British engineer Harry Brearley the University of Manchester, In 1908, Danish physicist Heike expedition set out for the South (1871–1948) would cast the first England, in 1907. In 1919, Kamerlingh Onnes (1853–1926) Pole. In what was later commercial stainless steel in he was appointed director had liquified helium and was described as “the worst journey Sheffield, England. of Cambridge’s Cavendish now using it as a coolant to study in the world,” they succeeded in Laboratory. Rutherford the electrical properties of part of their mission and found a established the field of frozen mercury. Onnes found nuclear physics with his that at –452°F (–269°C) MORGAN’S FRUIT FLY EXPERIMENT model of the atom, and mercury’s electrical resistance explained that radioactivity dropped to zero—he had Thomas Hunt Morgan’s FEMALE white-eye MALE was caused by atoms discovered superconductivity. breeding experiments revealed WITH RED allele WITH RED decaying into different forms. that the inheritance of a In October, physicists characteristic is linked to EYES red-eye EYES gathered at the first Solvay gender because its gene red-eye allele non-carrier Conference, founded by Belgian occurs on one of the sex allele industrialist Ernest Solvay. chromosomes—usually the X. allele FEMALE MALE This was the first opportunity This can be seen in the eye MALE to debate the new field of color of fruit flies because the FEMALE quantum physics. red-eye variant (allele), is dominant. As a result, in the At Columbia University, first generation, a red-eyed American biologist Thomas female and a white-eyed male Hunt Morgan (1866–1945) was would produce only red-eyed experimenting with heredity offspring, but some will carry in fruit flies. Following on from the white-eye allele. In the the work of Gregor Mendel (see next generation, if a red-eyed 1866) and Hugo de Vries (see female has a white-eye trait 1900), Morgan studied mutations it will show up in her sons. in the insects that caused JaAnmuBaermarridyhacfkia2oghen0rhosadWrlnlmeCiadnvaolekstnnletsnberreoeoetnsfpwstiheneeenphrine Madretcshhcaerm5iHbCmaeabsorentlrhiBaemooresenctdhhaeonsdiigntnoduomsftarkiaeAl psKcraadimllies2ec8rolvHienergiskhesOunpneercsonductivity JuVlaytnh2aad0ntepAnneonulsBetciotrmlienooeaeinurnksitcnshdhteahofirewgnspeeesorfiitosdic table NoTvhMeomomthrbaiagnestarcgnHhe1usrn0unoegmtsgoersesostsmidees FebKreuetatnergrfiyiinnr2esg7etrdeAeClmfemohceraotrrranilicusceattssornatmFat.erostbeirles MadrecshcRd7reuibEnthesresnethreacfesteootnrnmdtue’csrl—eus May 9 RuasnsdidaVenlsascdBriimobareiisrstcurZaRaswninononssgreminydagikticitmnairntaaghgyoetduebe OSmoceltveoatbsdyeiiCsrnco2Bun9srfseuFrsariersansneddtlcisaqettuoiaonnta 248