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History - The Timeline Book of Science text 237.pdf

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1909



American physicistWilliam David Cootidgedevelopsa method of

producingfine tungstenwires for useas hlamenmin light bulbs. rrot



t909



Bakelitebecomesthe first thermosettingplastic,one that once set

doesnot softenunderheat.Madeof phenoland formaldehyde,it is

chemist Leo Hendrik Baekeland.

inventedby Belgian-American

Bakelitewill be used frrst for electricalinsulation,then later for a

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numberof consumerproducts.



1909



On July 25, LouisBleriotbecomesthe first to tly acrossthe English

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1910s



As a pioneerof small-animalexperiments,Americanbiochemist

the first white'rat

ElmerVernerMcCollum(1879-1967)establishes

idencolonyin the U.S.for nutritionresearch.He will subsequently

tify vitamins A and B and prove the necessityof trace elements.

McCollumwill also show that a calcium deficiencyproducestetany

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(muscularspasm).



1910s



This decadeseesthe foundationof the influentialNorwegian,or

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Bergen,schoolof meteorology'.



1910



AmericangeneticistThomas Hunt Morgandiscoversthe sexual

differencesin the inheritanceof traits now known as sex-linked

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inheritance.



1910



William Burtonusesthermalcrackingto refinepetroleumoil, om



1910



Duringwork on celestialmechanics,Jules-HenriPoincaredevelops

.r.o.

moderntide theories'



June22,

l9l0



The first commercialflight of a dirigible, or airship, is made, in

Germany.Pilotedpy Countvon Zeppelinand carryingMenty pass e n g e r s ,t h e d i r i g i b l e t r a v e l s f i v e h u n d r e d m i l e s , f r o m

urnt

Friedrichshafento Dusseldorf,in nine hours.



1910



B r i t i s h m a t h e m a t i c i a n sB e r t r a n dR u s s e l la n d A l f r e d N o r t h

Whiteheadbegin publicationof their PrincipiaMathematica,the

most defrnitiveeffort yet at rootingmathematicsin logicand buildrlrll

ing it systematically.



1910



Germanbacteriologistand 1908 Nobel Prize-winnerPaul Ehrlich

producesthe arsenicalcompound salvarsan,the first drug effective

in treatingsyphilis.This discoverymarks the be$innin$of modern

chemotherapy.



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1910



A m er ic an p a l e o n to l o g i s tB a rn u m Bro w n begi ns to excavate

Cretaceousdinosaursat the Red Deer River in Alberta, Canada.

U.S.paleontolotistsCharlesH. Sternbergand sonswill begina separatedig at the samesite in 1912.Brown'sexpeditionsar this rich

sitewill lastthrough1915,the Sternbergs'through

1917.

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1910



British physicistJosephJohn Thomson confirms the existenceof

isotopesby using positivecathoderays to measurethe atomic

massesof two different isotopesof neon. FrederickSoddy (see

l9l3) will furtherdevelopthe conceptof isotopes.

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1910



Universityof Frankfurt psychologistsMax Wertheimer, Kurr Koffa,

and WolfgangKohlerrejectthe prevailingassociationism

dominating Germanpsychologyand togetherfound the school of Gestalt

psychology,dealing mostly with perceptionprocessesand behavior. Gestalttherapistswill seek to restorean individual'snatural

mentalbalanceby heighteningawareness,

emphasizingpresentexperiencesratherthan recollections

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of the past.



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1910



Eric Berne,who will becomeknown as the father of transactional

analysis,is born in Canada(d. l97O). Bernewill advocatethis form

of ps y c ho th e ra p yto h e l p p e o p l e e x c h a ngethei r feel i ngsand

thoughtsmore effectively.Among his popular books will be Games

PeoplePlay (1964).

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1910



ScottishanthropologistJames GeorgeFrazer publishesTotemism

a n d E x o g a m y , w h i c hw i l l i n f l u e n c eV i e n n e s ep s y c h o a n a l y s t

SigmundFreudin Totemand Taboo(1913),in which Freudwill analyze the practicesof "primitive" peoplesto shed light on modern

Westernpeople'sneuroses.

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1910



AmericansociologistRobert Merton is born. A studentof Talcott

Parsons(see 1937),Merton will attempt to unite theoreticaland

empiricalresearch.

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1910



Steelbeginsto be used insteadof wood in car bodies,for the Ford

ModelT.

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1910



The PatheGazette,a movie newsreel,is conceivedby Frenchmen

Charlesand Emile Pathe.Thesenewsreelsare first presentedin

Britishand Americanmarkets.



1910 r



CartoonistJohn RandolphBray patentsthe cel processof animation. Nearlytwo decadeslater, in 1928,AmericanfilmmakerWalt

Disney will licenseit to createthe first Mickey Mousecartoon,

"SteamboatWillie."



1911 l



Using modern archaeological

methods,AmadeoMaiuri beginsthe

excavationof Pompeiiand Herculaneum,destroyedby the eruption of MountVesuviusin 79.

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1 9 11



A meteoritekills a dog in Nakhla,Egypt,in the only recordedcase

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of a mammal'sdeathby a meteorite.



1 9 1I



Working independently,Danish astronomerEjnar Hertzsprung

and, in 1913,U.S.astronomerHenry NorrisRussellplot the magnitudesof starsagainsttheir colorsand spectralclasses.The resulting

diagram will provide important evidencefor

Hertzsprung-Russell

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theoriesof stellarevolution.



1 9 11



AmericangeneticistHermannJosephMtiller begins experimental

breedingof the fruit fly (Drosophil).He will be best known for his

discoveriesof gene mutationscausedby X rays and dire warnings

rto

concerningthe effectof nuclearradiationon humangenes.



1 9 11



A m er ic a ng e n e ti c i s tsT h o ma s H u n t M organand A l fred H enry

Sturtevantdevisethe frrst chromosomemap, found by investigat'

ing the separationfrequencyof chromosomecrossoverfrom one



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gene to another.

Dec. 16 ,

1 9 11



RoaldAmundsenreachesthe AntarcticPolejust ahead of Robert

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FalconScott,who will arriveon January14, 1912.



1 9 1I



Within fifty years

The AmericanNurses'Associationis established.

it will b e th e l a rg e s tp ro fe s s i o n awl o m en' s organi zati oni n the

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world.



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1 9 11



chemistand physicistMarieCurieshowsconclusively

Polish-French

that radium is an element,disprovingWilliam Thomson'sargutfrt

ment. See1906.



1 9 11



British physicistErnestRutherfordproposesa model of the atom in

whic h t h e a to m i s m o s tl y e mp ty s p a ce.A massi ve,posi ti vel y

chargedatomic nucleusis surroundedby outer regionsof negatively charged electronsthat leave the atom electricallyneutral. This

model makesit clearthat alphaparticlesare helium nuclei,not hetHYt

lium atoms.Seealso1915,Gei$erand Marsden.



1911



S c ot t ishp h y s i c i s tC h a rl e sT h o m s o nR eesW i l l i ams i nventsthe

cloud chamber,a devicefor studyin$the paths of particlesof ionDT]Y'

izingradiation.



1 9 11



Millikan calculates the electric

AmericanphysicistRobertAndrews

.)

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chargeof a singleelectron.



1911



DutchphysicistHeikeKamerlinghOnnesdiscoverssuperconductivity, the absenceof electricalresistancein certain substancesat

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temperaturescloseto absolutezero.



t9 t t- 1920 SwisspsychiatristEugenBleulerintroducesthe terms schizophrenia

or split minds, deinto psychiatry.Schizophrenia,

andambivalence

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noteswhat Bleulerconsidersa mentalsplit from reality.

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1 9 11



GermanneurologistAloisAlzheimerdiscoversthe preseniledementia, or irreversiblemental and intellectualdeterioration.that will

bearhis name as Alzheimer'sdisease.



l9t I



FrenchpsychologistAlfred Binet and FrenchphysicianTh6odore

Simon developthe seriesof gradedintelligenceteststo measurea

person'sintelligencequotient,or IQ, that becomesknown as the

Binet-Simonscale.

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r911



AmericanethnologistAlice CunninghamFletcherpublishesThe

Omaho,Tribe,her most important monographon AmericanIndian

culture.

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1 9 11



AmericananthropologistFranzBoaspublishes

TheMind of Primitive Man.



influential work

toc



1 9 11



C. F. Kettering, American businessman and owner of Dayton

Engineering Laboratories (Delco), develops the elecric self-starter,

which will be widely used for automobile and truck engines.

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1 9 1I



The Chevrolet Motor Co. is founded by American automobile pioneer W. C. Durant. The company takes its name from Durant's



partner,Swiss-American

race-cardriver LouisChevrolet.

A sulfateprocessusingalkaliratherthan acidsimprovespaperproduction,resultingin-among other products-a sturdy brown material calledKraft paper.

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1 9 11



1912



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Americanarchaeologist

Hiram Binghamdiscoversthe Inca strong,

holdsof MachuPicchuand VitcosnearCuzco,Peru.

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Harvard astronomer Henrietta Leavitt discovers that the period of

pulsation of a Cepheid variable star, one that varies in brightness in

a r e g u l a r w a y , i n c r e a s e sw i t h t h e s t a r ' s l u m i n o s i t y o r i n t r i n s i c

brightness. This period-luminosity curve, as it is called, will become

the basis for determining the distances of galaxies and distant

stars. See 1914, Shapley.

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1912



Austrian-American

physicistVictor Franz Hessdiscoversevidence

of the existenceof cosmicrays.

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l9t2



DutchphysicalchemistPeterJosephWilliam Debyedevelopsequations describingthe behaviorof polar moleculesor dipoles,molecules with pairs of separatedoppositeelectriccharges.His work

leadsto the conceptof the dipolemoment,the productof the positive charge and the distance between charges.

241



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geologistAlfred L. Wegenerproposesthe theory of contiF+German

nental drift, arguingthat the granitecontinentsfloat on the basalt

oceanfloor, changingpositionover the ages.He claimsthat all the

continentsonce formed a singlelandmasscalledPangaea.At first

rejected,his ideasbear similaritiesto the theory of plate tectonics

(see1960,Henry H. Hess),which holdsthat it is platesbearingcontinents,not the continentsthemselves,

that move.

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r912



For the next two years,RussianK. Silovskiappliesultrasonictechrrrflr

niquesto detecticebergsand submergedice.



1912



A compendiumon the hydrologyof the Mediterranean

Sea,including numeroustemperatureand salinitystations,is publishedby N.

reril

Nielson.



A p r .1 5 ,

t9t2



Followingthe sinkingof the Titanicon the night of April 14-15, underwateracousticsand communicationsbecomesa rapidly grow'

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ing area of study.



1912



BritishbiochemistSir FrederickG. Hopkinsand Dutch physician

ChristianEijkmanestablishthe role of the accessoryfood factors

calledvitaminsand are the frrstto pinpointa dietary-deficiency

disease.Polish-American

biochemistCasimirFunk, theorizingthat

some diseasesare causedby a lack of certain substancesin the

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diet, coinsthe term vitaminfor thesemissingsubstances.



t912



Englishamateurarchaeologist

CharlesDawsonclaimsto have discoveredthe missinglink betweenapesand humansat Piltdownin

Sussex,England.This so-calledPiltdownman skullwill fool paleontologistsuntil 1953,when it will be shown to be a hoax, an artful

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combinationof an ape'sjaw and a modernhuman skull.



t9t2



GermanphysicistMax Theodor Felix von Laue discovershow to

use crystalsfor X'ray diffraction,permitting measurementof the

wavelengthof X rays.

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t9r2



British physicistJosephThomson studiescanal rays (see1886,

Goldberg),which he calls positiverays, since they are streamsof

positivelychargedatomic nuclei.He discoversalsothat thereare at

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leasttwo differentvarietiesof neon atoms.



r9t2



Formsof ReligiousLiJe,a

Emile Durkheim publisheshis Eleme:ntary

major work in the developmentof culturalanthropology.



c.l9l2



GermanchemistCarl Boschimprovesthe Haber processfor making am m o n i a (s e e1 9 0 8 ) a n d i m p l e mentsi t i n l arge i ndustri al

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plants.



19t2



Germanchemist FriedrichBergiusdevelopsa coal hydrogenation

processin which coal and heavy oil are treated with hydrogen to

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producegasoline.

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t9r2



AmericanchemistIrving Langmuirfinds that rungstenfilamentsin

light bulbs filled with inert gaseslast longerthan those in vacuum

light bulbs.

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1912



T h e f i r s t a e r o b o a t ,o r a m p h i b i o u sa i r c r a f t ,

German-American

engineerGroverLoening.



1912



devel oped,by

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An effectivehigh-vacuumtube, which amplifieselectriccurrent,is

developedby AmericanphysicistH. D. Arnold.

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The Alpha Beta Food Market and Ward's Groceteria,two selfopen indeservicegrocerystores,the forerunnersof supermarkets,

pendentlyin California.

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DanishastronomerEjnarHertzsprung

discoversthat a Cepheidvariablestarof absolutemagnitude-2.3 hasa periodof 6.6 days. rrlro



t9l3



BritishchemistFrederickSoddyand, independently,

Polishchemist

Kasimir Fajansstate the radioactivedisplacementlaw, which describesthe loss of mass and electricchargeincurredby radioactive

atoms.Soddycoinsthe term isotopesfor atoms of the sameelement

that havea differingmassand differingradioactiveproperties. crrrn

AmericanchemistTheodoreWilliam Richardsfinds that the atomic

weightof leadvariesaccordingto the quantiryof radioactivematerial

in the leadores,a findingthat supportsthe corcept of isotopes.cxrr



1913.

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GermanchemistsLeonorMichaelisand Maud LenoraMentenfor/ mulatethe Michaelis-Menten

equationdescribingthe rate at which

enzyme-catalyzed

reactionstake place.

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FrenchphysicistCharlesFabry provesthe existenceof an ozone

layer in the upper atmosphere.

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t 9 t 3 - 1 9 1 7 Largenumbers of bottles are launchedto study surfacecurrents in

the SeaofJapan.

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1 9 r 3 - 1 9 1 9 Dutch mathematicianLuitzen EgbertusJan Brogwerdevelopsllis

theoryof intuitionism,in which mathematicsis consideredro begin

with a basic intuition of natural numbers.Truth claims are then

made throughconstructivityrather than consistency,as advocated

by GermanmathematicianDavidHilbert.See1900.

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1913



I n a b o o k o n t h e R i e m a n n s u r f a c e ,G e r m a n m a t h e m a t i c i a n

HermannWeyl developsnew conceptsand definitionsthat will be

importantto later researchon manifolds.

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1913



GermansurgeonA. Salomandevelopsthe techniqueof mammography,an X-rayprocedureto detectbreastcancer.

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Autopsiesbecomelegalin China.



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DanishphysicistNielsBohr



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applies

rheoryto rhe srrucrure

,il of the atom, describingelectron

orbits and electronexcitationand

de-excitation.



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GermanphysicistJohannesStarkdiscoversthe Starkeffect,a multitrfvl

plicationin spectrallinescausedby stron$electricfields.



1913

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JohannesHans Geigerand Ernst Marsdenprovide supportingevi."' dencefor Rutherford'smodel of the atom (seel9l1) when they direct a beam of alphaparticlesat a pieceof gold foil and note that a

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few of the particlesare deflected.



1913



t a r l G u s t a vJ u n g b r e a k sw i t h h i s t e a c h e r ,

S w i s sp s y c h i a t r i s C

SigmundFreud,and developshis own theories.He will classify

1 peopleas introvertsand extrovertsand theorizethat certainideas,

which he will call archetypes,are inheritedfrom the distant past

referredto as the collecand are a part of all peoples'unconscious,

tive unconscious.



t9t3



B. Watsonexplainshis theoryof behavior'

AmericanpsychologistJ.

ism in an articleentitled "Psychologyas the BehavioristViews It."

For Watson,psychologyis the "scienceof behavior,"not the tradiWatson'saim is to predict

experience."

tional"scienceof conscious

and control behaviorrather than describeand explain it. He also

wishesto eliminatethe traditionalbehaviordistinctionbetweenhumansand animals.



t9t3



.



Russian engineer lgor lvan Sikorsky builds and flies the first multillqr

en$ined aircraft.



1915



American physicist William David Coolidge invents the Coolid$e

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tube, a device for manufacturing X rays.



1913



Diesel-electriclocomotives, invented by Rudolf Diesel, are put into

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operation in Sweden.



1913



In the United States, soap-laden steel wool pads are marketed unrrcll

der the name Brillo pads, by the Brillo Manufacturing Corp.



Oct. 7,

t9t3



',;d In Detroit, the Ford Motor Co. uses the assembly line System to build

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cars, which reducesassembly time from 12.5 to 1.5 hours.



1914



American astronomer Vesto Melvin Slipher discovers that thirteen

of fifteen galaxies are receding from ours at hundreds of miles per

rfiro

second.



1914



U.S. astronomer Walter Sydney Adams invents the technique of

Spectroscopicparallax for determinin$ a Star'Sdistance by comparing its apparent magnitude with its absolute magnitude as derived

from its spectral characteristics.



t9l4



U.S. astronomer Harlow Shapley correlates the absolute magnitude

and period of Cepheid variable stars, thereby providin$ a yardstick

for determining galactic and stellar distances. See also 1912,

Leavitt,and 1952, Boode.

244



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1914



British physicistHenry Gwyn JeffreysMoseleyarrivesat the con,-,\cept

of atomic number, a number representingthe positive charge

tr' of the atomic nucleus.The periodictable of elemenrs(see1869)is

henceforthrevisedin order of atomic number, beginningwith hyqiln

drogenat I and endingwith uraniumat 92.



19l4



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BritishphysicisrsWilliam Henry Braggand William LawrenceBragg

discover that sodium chloride and certain other compoundr r"irt

as groupsof ions boundby electromagnetic

interaction.

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1914



ChemistsP. Dudenand J. Hessmanufactureaceticacid synthetically.

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t9l4



GermangeologisrBenoGutenbergdemonstratesthe existenceof a

boundaryin the lower depthsof the earth'ssurfacethat he callsa

discontinuity,becauseit causesan abrupt alterationin properties.

Belowthe Gutenbergdiscontinuiryis the earth'sliquid core, above

it the earth's mantle.

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1914



GermanmathematicianFelix Hausdorffpublisheshis BasfcFeatures

oJ Set Theory,a systematicexposition that inrroducesthe concepr

of Hausdorfftopologicalspacesand marks the developmentof

point set topologyas a distinctdiscipline.

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t9l4



AmericanbiochemistEdwardKendallisolatesthyroxin,the thyroid

hor m one, w h i c h w i l l b e u s e d to tre a t th yroi d i nsuffi ci enci es.

Kendall'swork with hormoneswill leadhim to isolatecortisone,an

anti-inflammatoryused widely in medicine.In 1950, Kendalland

AmericanphysicianPhillip Hench will jointly receivethe Nobel

Prizefor their work on cortisone.



1914



t9t4



RenownedGermanpaleontologistFriedrichvon Huene endorses

H. G. Seeley's1887 classification

oFdinosaursinto two indepenVon Huene'ssupport pro. dent orders,Ornithischiaand Saurischia.

motesthe generalacceptance

of this system.

?^uo

, BritishphysicistsWilliam Henry Braggand William LawrenceBragg

show how to determine the wavelengthsof X rays from diffraction



by crysmls.

1914

t9l4



{ BritishphysicisrJameschadwick showsthat beta parricles,unlike

alphaparticles,are emittedin a continuousrangeof energies. rfrv3

, British physicistErnest Rutherfordgives the name proton to the

positivelychargednucleusof the hydrogenarom, which is now

seento be, in a sense,the fundamentalatom, as prout had suggested in 1815.Scientistsof rhe rime theorizethat the nucleiof all other atomsare composedof a combinationof protonsand electrons,

but this theorywill be revisedwith the discoveryof rhe neutronby

Chadwick in 1932.



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1914



GermanphysicistsJamesFranckand GustavHertz perform experitrfY!

mentsconfirmingNielsBohr'Smodelof electrons'orbits.



1914



Englishanrhropologisrw. H. R. Riverspublisheshis History of

MelanesianSociety,a classicwork based on his researchin the

toc

SouthPacifrc.



t9t4



By rhe beginningof World War I, all the major Europeanpowershave

submarinesand continueto improveupon them, the researchand

developmentfocusingonly on their suitabilityfor war purposes. ilclr



19l4



inventor

The teletypemachineis developedby German-American

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EdwardE. Kleinschmidt.



A u g . 5 1, - The Panama Canal opens to traffic, carrying ships between the

Atlantic and Pacific oceans. Operating by a system of locks, the

1 9 1 4 {r*.tr(

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canal spans 50.7 miles.

19l5



Scottish astronomer Robert Innes discovers Proxima Centauri, a

faint companion to the double star Alpha Centauri. N 4.5 light'

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years away it is the closest Star to earth except the sun.



1915



U.S. astronomer Walter Sydney Adams demonstrates that the Star

Sirius B is extremelv hot, dense, and small, what is called a white

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dwarf.



1915



Swedish biochemist Svante Arrhenius publishes the influentiaL

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Quantitative Laws in Biochemistry.



FrederickWilliam Twort and Felix Hubert

1 9 1 5 - 1 9 1 7 Canadianbacteriologists

a type of virus able to

r d'Herelleseparatelydiscoverbacteriophages,

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or$anism.

present

in

an

normally

infest and kill bacteria

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s h o m a sM o r g a n ,C a l v i nB r i d g e s ,A l f r e d

A m e r i c a ng e n e r i c i s t T

S t u r t e v a n t ,a n d H e r m a n n M ( i l l e r p u b l i s h T h e M e c h a n i s mo f

MendelianHeredity,claiming that invisiblegeneswithin the chromosomesof the cell nucleusdeterminean offspring'shereditary

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traitS.

1915



identify the first

Japanese scientists K. Yamagiwa and K. Ichikawa

of a long line of cancer-producing agents called carcinogens by exntD

posing rabbits to coal tar for long periods of time.



t9t5



American paleontolo$ist Richard Swann Lull publishes his Triassic

Ltfe of the Connecticut Vattey (revised 1953), a classic monograph

on the ancient flora and fauna of that region. In it he revises an earlier study of fossil tracks (see 1848, Hitchcock), ascribing them not



to birds but to dinosaurs.

246



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STELLAR NEIGHBORS

bout 1752, French astronomer Nicolas-Louis de Lacaille

(1713-1762) discovered Alpha Centauri, which at a distance of

4.35 light-years was believedfor a time to be the star neerest the



solar system.Thenin 1915afaint star calledProxima centauri was discoveredat only 4.225 light-yearsdistance,about25 trillion miles.

As it turns out, Protcimacentauri and Alpha centauri are part of one

triple-sta"rsystemcalledthe centauri system.Alpha centauri is actually

nvo stars revolvingaround each other eyery eightyyears. Proxima, separatedJrom its two siblings by a much greater distance,revolvesaround

themonceeverymillionyears.

Couldany of these stars support li"fe?The trvo stars of Alpha Centauri

might. Oneis a type G2star, about the sizeand color of our yellow sun; the

other, a type K0, is a somewhatcoolerorangestar but might still be hot

enoughto support liJe.However,Proxima Centauri,which is a red dwarf

(Upe M5), is probablytoo small and cool to sustainliving things.

Despiteits probablebleahness,

Proxima Centauriis our neareststellar

neighbor.Evenso, at thefastest rates of mannedspacetravelyet achieved,

it would taheabout 110,000years to reachit, Iong enoughfor the crew's

descendants

and their relativeswaiting backhometo haveevolvedinto separate species.unlessspacetravel becomes

faster by severalordersof magnitude,don't expectto Eeea visit to the neareststar any time soon.



GermanphysicistArnoldJohannesWilhelm Sommerfeldproposes

that electronstravelin ellipticalorbits.He combinesquantumtheory and relativitytheory in revisingthe model of the atom, resulting

in what is known as the Bohr-Sommerfeld

atom. Sommerfeldand

Bohr work out the arrangementof electronsaroundan atom's nucleus,definingeach in terms of three quantumnumbersthat vary

in value.Seealso 1925,Pauli.

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Americanphysicistwilliam DraperHarkinscalculatesthat four hydrogennucleican fuse to form a heiium nucleus,releasinga great

deal of energyconvertedfrom the excessmass.

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Americanpsychophysicist

stanley smith stevensformulatesthe

power law of psychophysics.

His developmentsin auditoryscaling

methodsdeterminethat physicalcontinuausuallyconform ro a

psychophysical

power law ratherthan GustavFechner'slogarirhmic

Iaw. The power functionwill prove controversialin psychophysics

for more than thirty years.

247



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American neurologistand physiologistWalter Cannon presentsa

theoryof emotionin his book entitled

critiqueof the James-Lange

BodilyChangesin Painl,Hunger,Fear, and Rage. Cannon's substitheory, that a physicalresponsepretute for the James-Lange

c edest h e a p p e a ra n c eo f e mo ti o n , w il l become know n as the

Cannon -Ba i rdth e o ry o f e m o ti o n . It s tatesthat emoti on i s an

emergencyreactionto help humanscope in a crisis,not a followtrrcrl

up to physicalstimuli.



r9 1 5



1 9 1 5 - 1918 B r it is ha n th ro p o l o g i sBt ro n i s l a wM a l i n ow skidoes fi el d research

with the TrobriandIslanders.He will developrhe theory of functoc

in the 1920sand 1930s.

tionalismwith his ethnographies



195

r



The first use of poisonousgas,asa military weaponoccurswhen the

GermansusechlorinegasagainstFrenchtroopsin World War I. rrcr



1915



borosilicateglassis developedin the

Heat- and shock-resistant

United Statesby the CorningGlassWorks and sold as cookingimtrql

plementsunder the tradename Pyrex.



t9l6



U.S. astronomerEdward ErnersonBarnarddiscoversBarnard's

rfiro

Star,a star with the largestknown propermotion.



t9l6



physicistAlbert Einstein'sgeneraltheory of relaGerman-American

anomalyabout

rivity (see1916,physics)accountsfor a long-standing

rmo

the orbitalmotion of the planetMercury.See1846,Vulcan.



t9t6



The EcologicalSociety of America is founded.



t916



Americanchemist Gilbert Newton Lewis shows how variationsin

the number of electronsin the outermostshellof an atom lead to

the formationof chemicalbonds,throughelectrontransferor sharing. He explainsthat the most stableelementsare those in which

the outer shellhas either eight or two electrons,whereaselements

are more or lessreactive.Lewis'swork

with differentarrangements

e x p l a i n st h e v a l e n c e so f e l e m e n t s .A m e r i c a nc h e m i s t I r v i n g

L a n g m u i ri n d e p e n d e n t l yd e v i s e sa s i m i l a r m o d e l . S e e 1 8 5 2 ,

oiln

Frankland.



t9t6



the ftrst

Americanfeministand nurse MargaretSangerestablishes

f,lD

New

York.

Brooklyn,

in

clinic,

Americanbirth-control



1916



.{



physicistAlbert Einsteinproposeshis general

German-American

which

extendshis specialtheoryof 1905to sysof

relativity,

theory

tems moving at changingvelocitiesrelativeto eachother.The general theory accountsfor gravitationalinteractions,arguingthat

massgeneratesa gravitationalfield that curvesspace.The predic'

tions of Einstein'stheory are closeto those of Newton's,but with

severaldifferencesthat are testable,and subsequenttestssupport

theory.Seee.g.,May29,1919,and 1925,Adams. tllv3

Einstein's

248



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