The principle of relativity; original papers by A. Einstein and H. Minkowski. Translated into English by M.N. Saha and S.N. Bose; with a historical introd. by P.C. Mahalanobis

Hermann Minkowski, Albert Einstein

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iOO efT -Pri * ;b c i^ >5 o ti- uUo^ -y^Si "A! Hi 0/0\ft-Wdu bu V,C. Mr -b\5 HISTORICAL INTRODUCTION Lord Kelvin in in his to the1893,writing preface edition of Hert/ s Researches on ElectricEnglish Waves, " workers and thinkers have tosays many many helped build the nineteenth school of oneup century plenum, ether for and theheat, ;light, electricity, magnetism German and volumes Hertz s electricalEnglish containing the into world the last decade of thepapers, given awill be monument of thecentury, permanent splendid cons jmmation now realised. Ten in we find Einsteinlater, 1905, declaringyears that "the ether will be to be Atproved superflous." first the revolution in scientificsight thought brought aabout in the course of decade to be almostsingle appears careful eventoo violent. A more a reviewthough rapid of the show how the ofsubject will, however, Theory abecame historicalRelativity gradually necessity. Towards the of the nineteenthbeginning century, the luminiferous ether came into as a result ofprominence the brilliant successes of the wave in the handstheory of and Fresnel. In its theYoung stationary aspect elastic solid ether was the outcome of the search for a medium in which the waves "undulate." Thislight may as shown also afforded astationary ether, by Young, ofsatisfactory astronomical aberration.

Sujets

• Theory of relativity

Informations

• Publié par: les_archives_du_savoir
• Nombre de lectures: 13
• Langue: English
• Poids de l'ouvrage: 11 Mo

Extrait

iOOefT -Pri
*
;b c
i^ >5 o
ti-
uUo^ -y^Si
"A! Hi 0/0\ft-Wdu
bu V,C. Mr -b\5HISTORICAL INTRODUCTION
Lord Kelvin in in his to the1893,writing preface
edition of Hert/ s Researches on ElectricEnglish Waves,
"
workers and thinkers have tosays many many helped
build the nineteenth school of oneup century plenum,
ether for and theheat, ;light, electricity, magnetism
German and volumes Hertz s electricalEnglish containing
the into world the last decade of thepapers, given
awill be monument of thecentury, permanent splendid
cons jmmation now realised.
Ten in we find Einsteinlater, 1905, declaringyears
that "the ether will be to be Atproved superflous."
first the revolution in scientificsight thought brought
aabout in the course of decade to be almostsingle appears
careful eventoo violent. A more a reviewthough rapid
of the show how the ofsubject will, however, Theory
abecame historicalRelativity gradually necessity.
Towards the of the nineteenthbeginning century,
the luminiferous ether came into as a result ofprominence
the brilliant successes of the wave in the handstheory
of and Fresnel. In its theYoung stationary aspect
elastic solid ether was the outcome of the search for a
medium in which the waves "undulate." Thislight may
as shown also afforded astationary ether, by Young,
ofsatisfactory astronomical aberration. Butexplanation
ver\ success; rise to a host ofits new allg:ivc questions
on the central of relative motion of etherbearing problem
matter.andII I.F. OK KKI.m \m11 I lilXC
of an The refractive indexexperiment.Aragd prism
ofon the incident velocity lightglass prism depends
and its inside the afteroutside the prism velocity prism
refraction. On Fresnel s fixed ether thehypothesis,
incident waves are situated in the etherlight stationary
outside the and move with c withprism velocity respect
a uto the ether. If the moves withprism velocity
this fixed then the incidentwith to ether, velocityrespect
of with to the should be C H. Thus+light respect prism
the refractive index of the should on ,glass prism depend
withthe absolute of the itsi.e.,velocity prism, velocity
to the fixed ether. theArago experimentrespect performed
in but failed to detect the1819, change.expected
Boacovitc/i water BoscovitchAiry- -telescope experiment.
had still earlier in i7b raised the
t>, very important
of the of aberration on the refractivequestion dependence
of the medium the Aberrationindex filling telescope.
on the difference in the of outsidedepends velocity light
the and its inside the If thetelescope velocity telescope.
latter to a in the mediumowingvelocity changes change
the aberration itself should thatfilling telescope, change,
aberration should on the nature of the medium.
is, depend
in water but1871 filled a withAiry, telescopeup
failed to detect in the aberration. Thus weany change
both in the case of andget Arago pri^m experiment
Boscovitch theAiry- water-telescope experiment, very
result that effects in a mediumstartling optical moving
of theseem to be of thequite independent velocity
to ether.medium with Fresnel srespect stationary
2
Fresnel s conrection /{=] .
coefficient //x Possibly
onsome form of is taking \Vorkingcompensation place.
convecthis Fresnel Offered his famous etherhypothesis,
tion of matterto thetheory. According Fresnel, presence
a within thedefinite condensation of etherimpliesIIISTOKK \l, I.VII.OIUTI ION 111
"
"
matter. This condensed orregion occupied by
is to he carried awave\cr<s of etherportion supposed
with its own of matter. It should bemovingpice,
that the "excess" is carriedobserved only portion away,
while the rest remains a- ;is ever. A-taunant complete
"
convection of the "excess ether with the fullp velocity
u is to a convection of theoptically equivalent partial
total ether with a fraction of the . u.
p, only velocity
if k isFresnel showed that this convection coefficient
2
l index ofl the refractive the thenprism),/fj. (p. being
after refraction within thethe ofvelocity light moving
altered to such extent as would makewould be justprism
of thethe refractive index moving prism quite indepen
of its "absolute" u. Thedent velocity non-dependence
" "
of aberration on the absolute is alsou,velocity very
with the of this Fresnelian convection-
easily explained help
coeflicieut k.
Stoke** viscous ether. It should be remembered, however,
that s stationary ether is fixed and is notFresnel absolutely
at all disturbed the motion of matter it. In thisthroughby
Fresnelian ether cannot be said to behave inrespect any
ledand this infashion, Stokes,respectable physical
a more material of medium.to construct1845-H), type
motion ensues near the surfaceStokes assumed that viscous
of ether and while atof matter,separation moving
sulficifiitlv distant the ether remainsunions wholly
aundisturbed. He >howed how such viscous ether would
in itaberration if all motion wereexplain differentially
in order to the nullirrotational. But explain Arago
Stoke:- ua.- to assume the convectionefl cct. compelled
of Fresnel with an identical numerical value
liNpothesis
I -. Thus the of the Fresnelianfor ./k, namely prestige
convection-cocllicient \va> il theenhanced, anything, by
theoretical o! stokes.inveBti&fctionaIV I KINI U l.K OK RELATIVITY
Fizratf* Soon in it receivedexperiment.. after, J8ol,
direct confirmation in a brilliant ofexperimental piece
work Fizeau.by
If a divided beam of is re-united afterlight passing
two filled withthrough adjacent cylinders water, ordinary
interference will be If the water in onefringes produced.
"
"of the is now made to the condensedcylinders flow,
ether within the water would be convected andflowing
would a shift in the interference Theproduce fringes.
shift observed well with a value ofactually agreed very
l 1k=l . The Fresnelian convection-coefficient nowl^
became asestablished a of a directfirmly consequence
effect. On the other the evidencespositive hand, negative
in favour of the convection-coefficient had also multiplied.
Maxwell and othersMascart, Hoek, for definitesought
in different effects motioninduced thechanges optical by
of the earth relative to the ether. But all suchstationary
tofailed reveal the trace ofattempts slightest any optical
due todisturbance the "absolute" of the earthvelocity
thus that all tne differentproving conclusively optical
effects shared in the out ofgeneral compensation arising
the Fresuelian convection of the excess ether. It must be
noted that the Fresnelian convection-coefficientearefully
assumes the existence of a fixed ether orimplicitly (Fresnel)
at least a atmedium distantwholly stagnant sufficiently
with reference to which alone a convectionregions (Stokes),
can have Thus the convection-velocity any significance.
coefficient some of a orimplying type stationary viscous,
nevertheless "absolute" succeeded inether,yet explaining
all known facts down to 1880.satisfactorily optical
Micftelxoti-Mor In Michelson1881,ley Experiment.
and their classical whichMorley performed experiments
undermined the whole structure of old etherthe theory
and thus served to introduce the new oftheory relativity.