Big Ideas Simply Explained - The History Book

[",, AS A LAYMAN ,,I WOULD NOW SAY \u2018I THINK WE HAVE IT\u2019. Rolf Heuer, CERN Director General, announcing the discovery of the Higgs boson, July 4, 2012 In September 2012, NASA 20b1i3rfodrN\ufb02\ufb01eurwsintsftteirmcatiens houf mansFeCbursrutiao(a6rsrt.iiy4nstyc2dMm0rraoi1l-rv3l)itenidragene2sp.5uhrinofa-lece 20r1e3isntIonerxjeepcebtreriadmisnetnefutmsncoctneiolrlnsats published the eXtreme Deep Field, the most detailed image of MUeansrticvimher2asut0ese1ian3oPngflnNaadongeaukewtnasocaffertodemllite deep space obtained to date (see 2004). Back on Mars, in February 2013, Curiosity had moved on to analyze subsurface rocks after drilling a 2.5in (6.4cm) hole in the Martian surface. Regenerative medicine took two important steps forward in early 2013: scientists in the US successfully implanted a fully functioning laboratory-grown kidney into a rat, while a team in Bolivia injected stem cells into rats\u2019 brains soon after the rats had strokes and restored full brain function. In China, a new strain of \u201cbird \ufb02u\u201d (see 1997) , called H7N9, infected humans for the \ufb01rst time, causing concern of an epidemic. Meanwhile, new calculations of the age of the Universe were being made. In March, data from the European Space Agency\u2019s Planck satellite re\ufb01ned cosmologists\u2019 estimate of the age of the Universe to 13.82 billion years old\u2014about 100 million years older than previously thought. Searching for the Higgs boson This computer-generated image shows tracks from particle collisions inside the Large Hadron Collider. Analysis of such tracks provided evidence for the Higgs boson. AuCgusuresinoftrdso6iitnm,yg2rt0iohm1ve2easrgNuesrAtsfaSaarActnes\u2019sdodfaMtaars SepputbelmisbheesrTe2thl5ee,sD2cHo0eup1ebe2pb\u2019slFeNeieASXlpStdraAeicmme aege 349","7","352 MEASUREMENTS AND UNITS 360 BIOLOGY 352 Base SI Units 360 Taxonomic Ranks 352 SI Prefixes 360 Domains and Kingdoms 352 Supplementary and Derived SI Units 361 Fungi 353 Common Physical Properties 361 Plants 354 SI Conversion Factors 362 Animals 362 Human Ancestors 355 PHYSICS 364 ASTRONOMY AND SPACE 355 Newton\u2019s Laws 355 Mechanics of Forces 364 The Planets of the Solar System 355 Laws of Thermodynamics 364 Kepler\u2019s Laws of Planetary Motion 355 Temperature Scales 364 Spectral Classification of Stars 356 Gas Laws 365 The Magnitudes of Stars 356 Pressure and Density 365 The Hertzsprung\u2013Russell Diagram 356 Einstein\u2019s Theories of Relativity 356 Maxwell\u2019s Equations 366 EARTH SCIENCE 357 Electricity and Circuit Laws 357 Subatomic Particles 366 The Geological Timescale 357 The Four Fundamental Forces 366 Mineral Classification 357 Common Equations 366 Earth\u2019s Rock Types 367 Tectonic Plates 358 CHEMISTRY 358 The Periodic Table 359 The Elements REFERENCE","REFERENCE MEASUREMENTS AND UNITS MEASUREMENTS AND UNITS BASE SI UNITS SUPPLEMENTARY AND DERIVED SI UNITS The SI (Syst\u00e8me International d\u2019Unit\u00e9s) is the modern form of the metric system The SI is an evolving system in which units are created and de\ufb01nitions are of measurements, and it is used by most countries. It consists of series of units of modi\ufb01ed as the technology and precision of measurement improves. In measurement built around seven interdependant base units of individual physical addition to the seven base SI units, there are two supplementary units and qualities. All other physical qualities are obtained from these units. many other units derived from the SI base units. UNIT SYMBOL DEFINITION SUPPLEMENTARY UNITS SYMBOL DEFINITION Meter m Radian rad This unit is the length of a path traveled by light The unit of measurement of angle; Kilogram kg in a vacuum during a time interval of \u20441 299,729,458 of it is the angle subtended at the center a second. of a circle by an arc equal in length Steradian sr to the circle\u2019s radius. The unit of mass, equal to the mass of the Second s international prototype kilogram. The unit of measurement of solid angle; it is the solid angle subtended Ampere A The second is the duration of 9,192,631,770 periods DERIVED UNITS SYMBOL at the center of a circle by a spherical of the radiation corresponding to the transition Hertz Hz cap equal in area to the square of the Kelvin K between the two hyper\ufb01ne levels of the ground Newton N circle\u2019s radius. state of the cesium-133 atom. Pascal Pa Candela cd Joule J DEFINITION The constant electric current which, if maintained Watt W Mole mol in two straight parallel conductors of in\ufb01nite length The unit of frequency; 1 hertz has and negligible cross section, and placed 1 meter Coulomb C a periodic interval of 1 second. apart in a vacuum, would produce between these Volt V conductors a force equal to 2 \u00d7 10-7 newtons per A unit of force equal to the force that meter. imparts an acceleration of 1 m\/sec\/sec to a mass of 1 kilogram. The unit of thermodynamic temperature, this is the fraction \u20441 273.16 of the thermodynamic A unit of pressure equal to 1 newton temperature of the triple point of water. per square meter. The luminous intensity, in a given direction, of A unit of energy exerted by a force of a source that emits monochromatic radiation 1 newton acting to move an object of frequency 540 \u00d7 1012 hertz and that has a through a distance of 1 meter. radiant intensity in that direction of 1\u2044683 watt per steradian. A unit of power equal to 1 joule per second; it is also the power dissipated The mole amount of substance that contains as by a current of 1 ampere \ufb02owing across many elementary units as there are carbon atoms a resistance of 1 ohm. in 0.012 kilograms of carbon-12. A unit of electrical charge equal to SI PREFIXES the amount of charge transferred by a current of 1 ampere in 1 second. SI pre\ufb01xes and symbols are used to indicate decimal multiples and submultiples of SI units to avoid having to write either very large or extremely small numeric A unit of potential equal to the potential values, from 1018 to 10-18. When the number is written, the pre\ufb01x attaches directly difference between two points on to the name of the unit\u2014for example \u201cnanosecond.\u201d Similarly, a pre\ufb01x symbol can a conductor carrying a current of also be attached to the symbol for the unit\u2014for example \u201cns.\u201d 1 ampere when the power dissipated between the two points is 1 watt; it is FACTOR PREFIX SYMBOL FACTOR PREFIX SYMBOL Farad F equivalent to the potential difference 1018 exa- E 10-1 deci- d Ohm \u2126 across a resistance of 1 ohm when 1015 peta- P 10-2 centi- c Siemens S 1 ampere of current \ufb02ows through it. 1012 tera- T 10-3 milli- m 109 giga- G 10-6 micro- \u03bc A unit of capacitance of a capacitor that 106 mega- M 10-9 nano- n has an equal and opposite charge of 103 kilo- k 10-12 pico- p 1 coulomb on each plate and a voltage 102 hecto- h 10-15 femto- f difference of 1 volt between the plates. 101 deca- da 10-18 atto- a A unit of electrical resistance equal to the resistance between two points on a conductor when a potential difference of 1 volt between them produces a current of 1 ampere. A unit of electrical conductance, the reciprocal of 1 ohm: 1 divided by 1 ohm. 352"]