545:
uses an interferometer with arms of different lengths and not at right angles. They measure over several seasons and record on photographs to allow better post-measurement study. The
Kennedy Thorndike experiment becomes one of the fundamental tests for SR, proving the independence of light speed wrt
190:
carries out his famous experiment with light travelling through moving water. He measures fringing due to motion of the water, perfectly in line with
Fresnel's formula. However he sees no effect due to the motion of the Earth, although he does not comment on this. Nevertheless this is seen as very
94:
was a proponent of an aether hypothesis. According to Boyle, the aether consists of subtle particles, one sort of which explains the absence of vacuum and the mechanical interactions between bodies, and the other sort of which explains phenomena such as magnetism (and possibly gravity) that are,
80:- aether is lighter than air and is located above it, whereas air is lighter than water, and water is lighter than earth. In Aristotle's view, each element returns to its proper place when displaced, which explains why air rises, why earth and water fall, and why the heavens remain in place.
445:
produces a positive result while attempting to detect the effect of Earth's rotation on the velocity of light. The significance of the experiment remains debated to this day, but this planetary Sagnac effect is measured by ring laser gyros and taken into account by the GPS
658:
Krisher et al., Phys. Rev. D, 42, No. 2, pp. 731–734, (1990) use two hydrogen masers fixed to the earth and separated by a 21 km fiber-optic link to look for variations in the phase between them. They put an upper limit on the one-way linear anisotropy of 100
612:
frequency locked to each other and send the light in two directions. They receive the null result. The experiment is not as precise as earlier light-based MMX experiments, but demonstrates a novel setup that would become much more accurate in the
236:
publishes his first interferometer experiments, using the device for the measurement of extremely small distances. To
Michelson's dismay, his experiment finds no "ether drag" slowing light, as had been suggested by Fresnel.
170:
1830 – Fresnel develops a formula for predicting and measuring aether dragging by massive objects, based on a coupling constant. Such dragging seems to be at odds with aberration however, which would require the Earth
639:
1979 Brillet and Hall use the Townes setup with highly accurate lasers, demonstrating no drift to 3 parts in 10. The experiment also demonstrates a leftover 17 Hz signal, but the authors assume it is linked to the
343:
shows that
Lorentz's theory fulfills the principle of relativity, and publishes the Lorentz transformations. His model was still based on Lorentz's ether, but he argues that this aether is perfectly undetectable.
391:
uses observations of binary stars to determine if the speed of light is dependent on movement of the source. His measurements show that it is not to 10. This is claimed to be additional evidence against aether
159:
can exist. It is important to note that both Newton's particle theory and
Fresnel's wave theory both assume an aether exists, albeit for different reasons. From this point on, no one even seems to question its
409:
1920 – Einstein says that special relativity does not require rejecting the aether, and that the gravitational field of general relativity may be called aether, to which no state of motion can be attributed.
518:
produces a null result using a clever version of the MMX with a step in one mirror that dramatically improves resolution. The resolution is so good that most partial entrainment systems can be eliminated.
354:
theory, but complete with a derivation from principles alone (leaving the ether aside). Einstein also emphasized that this concept implies the relativity of space and time. He later labelled it
129:, so he adds a "fudge factor," claiming that an "Aethereal Medium" is responsible for this effect, and going further to suggest it might be responsible for other physical effects such as
262:(MMX) produces the famous null result. A small drift is seen, but it is too small to support any "fixed" aether theory, and is so small that it might be due to experimental error.
773:
468:
630:
1972 – R. S. Shankland admits he would not likely have given the effort to question Dayton Miller's work had it not been for Albert
Einstein's "interest and encouragement."
474:
Miller proposes two theories to account for the positive result. One consists of a modified aether theory, the other a slight departure from the
Contraction Hypothesis.
315:
1905 – Miller and Morley's experiment data is published. Test of the
Contraction Hypothesis has negative results. Test for aether dragging effects produces null result.
281:
proposes the
Contraction Hypothesis, which suggests that the measurements are null due to changes in the length in the direction of travel through the aether.
76:, in which the aether is briefly described as being an element lighter than air that surrounds celestial bodies. He describes the aether in relation to other
847:
562:
450:
442:
653:
1990 – Hils and Hall repeat the
Kennedy–Thorndike experiment with lasers, taking measurements over the period of a year. They find no shifting in 2 10
605:
performed an analysis of Miller's results and explained them as stemming from systematic errors (Shankland's explanation is now widely accepted).
202:
experiment with one arm in water. He sees no effect at all, and cannot offer an explanation as to why his experiment is so at odds with Fizeau's.
677:
222:
916:
542:
547:
259:
45:
362:
319:
52:
were in general agreement with Michelson and Morley's result. By the 1920s, most scientists rejected the aether's existence.
579:
writes that currently-accepted quantum field theory requires an aether, although he never formulated this theory completely.
294:
1902 to 1904 – Morley and Morley conduct a number of MM experiments with a 100 ft interferometer, producing the null result.
551:
309:
793:
565:, stating that it is improbable that aether would be entrained by translational motion and not by rotational motion.
921:
209:
re-runs Bradley's experiment with a telescope filled with water. He too sees no effect. It appears that aether is
417:
369:
of an object according to one frame does not produce a measurable change of resistance in the object's rest frame
351:
278:
37:
911:
636:
1977 – Brecher repeats Zurhellen's experiment with binary pulsars, showing no difference in light speed to 2*10
233:
122:
666:, a cyclic component in the phase drift between higher-precision caesium-beam clocks on more-or-less the same
647:, but the distance between is relatively short (0.5 km) and they are clocks of the less-precise rubidium type
616:
1964 – Jaseja, Javan, Murray and Townes repeat the earlier experiment with newer and much more precise masers.
503:
716:
627:
as the source. The experiment should detect a shift as small as ~0.00003 of a fringe, and none is measured.
336:
publishes a new theory of moving bodies, without discarding the stationary (electromagnetic) ether concept.
305:
found no signs of double refraction (due to FitzGerald–Lorentz Contraction) of moving bodies in the aether.
754:
240:
178:
152:
708:
515:
388:
144:
for the first time, proving (again) that light has a finite speed as well as that the Earth is moving.
742:
Versuch einer Theorie der electrischen und optischen Erscheinungen in bewegten Korpern (Leyden, 1895)
667:
420:. Miller performs tests with insulated and non-magnetic interferometers and obtains positive results.
322:, another experiment based on electrical effects, does not detect the FitzGerald–Lorentz Contraction.
302:
156:
594:
480:
813:
808:
490:
217:
206:
72:
33:
24:
745:"Elektrodynamik " and " Elektronentheorie " in the Encyk. der Math. Wissenschaften, Band v. 13, 14
406:'s Africa eclipse expedition is conducted and appears to confirm the general theory of relativity.
598:
528:
524:
396:
381:
366:
355:
141:
99:
602:
494:
312:, based on an entirely different concept using electrical forces, also produces the null result
569:
340:
243:
finds Michelson's calculation have errors (i.e., doubling of the expected fringe shift error).
164:
104:
77:
95:
otherwise, inexplicable on the basis of purely mechanical interactions of macroscopic bodies.
788:
538:
produces a null result using an extremely accurate interferometer placed entirely in vacuum.
433:
403:
155:, which proposes light is a transverse wave travelling in an aether, thereby explaining how
148:
739:
Maxwell, Collected Papers, H. A. Lorentz, Archives Neerlandaises, xxi. 1887, and xxv. 1892
590:
486:
424:
347:
333:
727:
675:
229:
1879 – Maxwell suggests absolute velocity of Earth in aether may be optically detectable.
751:
J. Larmor, Phil. Trans. 1894-95-97, and a treatise, Aether and Matter (1900) p. 262
633:
1973 – Trimmer finds a null result in a triangular interferometer with one leg in glass.
891:, ed. Thomas Birch, 2nd edn., 6 vols. (London, 1772), III, 316; quoted in E. A. Burtt,
823:
456:
373:
271:
199:
841:
380:
was considered excellent evidence for aether at the time, but was later explained via
905:
836:
761:
663:
620:
413:
377:
298:
195:
187:
137:
430:
1924 – Miller repeats his experiments at Mount Wilson and yields a positive result.
875:
671:
644:
285:
265:
Many physicists dust off Stokes' work, and dragging becomes the "standard solution"
112:
91:
288:
demonstrates that aether drag is invisible around rapidly moving celestial bodies.
376:
uses a rotating MMX device and receives a clearly positive result. The so-called
783:
778:
662:
1991 – Over a six-month period, Roland DeWitte finds, over a 1.5 km underground
126:
688:
576:
558:
535:
423:
1921 to 1924 – Miller conducts extensive tests under controlled conditions at
49:
851:. Vol. 1 (11th ed.). Cambridge University Press. pp. 292–297.
818:
67:
650:
1988 – Gagnon et al. measure one way light speed and detect no anisotropy
546:
to the speed of the emitting source. The other two fundamental tests are
19:
878:
Translated by R. P. Hardie and R. K. Gaye. The Internet Classics Archive
436:
uses stars for his interferometer light source, getting the null result.
117:
856:
684:
Modern Michelson–Morley Experiment using Cryogenic Optical Resonators
619:
1969 – Shamir and Fox repeat the MMX experiment with the "arms" in
512:
Michelson talks about aether drag and altitude differential effects
803:
798:
624:
609:
291:
1895 – Lorentz proposes independently the Contraction Hypothesis.
895:(Garden City, New York: Doubleday & Company, 1954), 191-192.
130:
108:
hypothesized that light is a wave propagating through an aether.
748:
O. Lodge, " On Aberration Problems," Phil. Trans. 1893 and 1897
840:
686:
at Humboldt University, Berlin. They find no shifting in 10
643:
1984 – Torr and Kolen find a cyclic phase shift between two
44:
was assumed to exist for much of the 19th century—until the
459:
explains the problems with the Stokes aether drag solution.
462:
Miller presents his positive results of the aether drag.
248:
1882 – Michelson acknowledges his interpretation errors.
857:"Dayton Miller's Ether-Drift Experiments: A Fresh Look"
814:
Luminiferous aether (The history of light and aether)
774:
Timeline of special relativity and the speed of light
198:
carries out an improved version of Fizeau's using an
757:, A. Schuster, R. W., General physics of the aether;
682:2003 – Holger Mueller and Achim Peters carry out a
469:
American Association for the Advancement of Science
274:verifies the existence of electromagnetic waves.
893:The Metaphysical Foundations of Modern Science
608:1958 – Cedarholm, Havens, and Townes use two
167:'s "Bright Spot", supporting the Wave Theory.
8:
384:. Good explanations based on SR also exist.
175:to drag the aether in order to be visible.
181:becomes a champion of the dragging theory.
48:returned its famous null result. Further
889:The Works of the Honourable Robert Boyle
868:
483:produces a null result on Mount Wilson
416:conducts aether drift experiments at
223:Treatise on Electricity and Magnetism
7:
191:strong evidence for aether dragging.
509:Miller talks of partial entrainment
784:Electricity (History of discovery)
550:(proves light speed isotropy) and
14:
724:Relativistic Propagation of Light
563:Michelson–Gale–Pearson experiment
443:Michelson–Gale–Pearson experiment
395:1915 – Einstein publishes on the
40:begins in the 18th century. The
623:waveguides and a highly stable
125:. This had trouble explaining
1:
830:External links and references
572:disproves aether entrainment
543:Kennedy–Thorndike experiment
451:National Academy of Sciences
449:1925 April – Meeting of the
397:general theory of relativity
794:History of electromagnetism
548:Michelson–Morley experiment
260:Michelson–Morley experiment
46:Michelson–Morley experiment
938:
704:(Freeman, New York, 1983).
531:and produce a null result.
363:Trouton–Rankine experiment
352:observationally equivalent
320:Trouton–Rankine experiment
28:(light-bearing aether) or
917:Culture-related timelines
709:19th Century Ether Theory
493:produce a null result on
121:, in which he proposes a
38:electromagnetic radiation
726:(Coronado Press, 1976),
702:Relativity and Its Roots
670:; the period equals the
552:Ives–Stilwell experiment
310:Trouton–Noble experiment
234:Albert Abraham Michelson
123:particle theory of light
848:Encyclopædia Britannica
504:Mount Wilson conference
876:"Physics by Aristotle"
554:(proves time dilation)
241:Hendrik Antoon Lorentz
728:WorldCatLibraries.org
713:Einstein for Everyone
523:1929 – Michelson and
179:George Gabriel Stokes
760:Collected Papers of
734:Classical references
303:DeWitt Bristol Brace
163:1820 – Discovery of
153:wave theory of light
809:Luminiferous aether
804:Light (Wave theory)
218:James Clerk Maxwell
207:George Biddell Airy
25:luminiferous aether
529:Pearson experiment
382:general relativity
367:length contraction
356:special relativity
142:stellar aberration
100:Christiaan Huygens
922:Physics timelines
707:Michael Janssen,
570:Hammar experiment
561:publishes on the
516:K. K. Illingworth
389:Walther Zurhellen
279:George FitzGerald
105:Treatise on Light
85:Early experiments
66:4th-century BC –
929:
896:
885:
879:
873:
852:
844:
789:Electromagnetism
722:Wallace Kantor,
700:Banesh Hoffman,
467:1925 December –
434:Rudolf Tomaschek
404:Arthur Eddington
213:dragged by mass.
149:Augustin Fresnel
36:for propagating
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695:Further reading
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591:R. S. Shankland
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487:Auguste Piccard
425:Case University
348:Albert Einstein
334:Hendrik Lorentz
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297:1902 to 1904 –
270:1887 to 1888 –
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151:introduces the
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887:Robert Boyle,
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842:"Aether"
839:, ed. (1911).
837:Chisholm, Hugh
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824:Magnetic field
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350:publishes an
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672:sidereal day
584:Debate slows
527:perform the
418:Mount Wilson
286:Oliver Lodge
221:
210:
172:
157:polarization
116:
113:Isaac Newton
103:
92:Robert Boyle
71:
41:
29:
23:
17:
15:
779:Electricity
640:laboratory.
599:F. C. Leone
541:1932 – the
525:F. G. Pease
441:1925 – the
365:shows that
318:1908 – the
308:1903 – the
258:1887 – the
127:diffraction
50:experiments
906:Categories
863:References
715:course at
577:Paul Dirac
559:Georg Joos
536:Georg Joos
160:existence.
115:publishes
70:publishes
819:Magnetism
603:G. Kuerti
495:Mont Rigi
471:meeting.
392:dragging.
140:measures
68:Aristotle
61:Antiquity
768:See also
668:meridian
78:elements
56:Timeline
20:timeline
719:(2001).
613:future.
589:1955 –
575:1951 –
568:1935 –
557:1934 –
534:1930 –
502:1927 –
479:1926 –
446:system.
412:1921 –
402:1919 –
387:1914 –
372:1913 –
361:1908 –
346:1905 –
339:1905 –
332:1904 –
284:1892 –
277:1889 –
232:1881 –
216:1873 –
205:1871 –
194:1868 –
186:1851 –
147:1818 –
136:1727 –
118:Opticks
111:1704 –
98:1690 -
73:Physics
610:masers
601:, and
327:Change
253:Crisis
42:aether
34:medium
799:Light
625:laser
32:as a
30:ether
659:m/s.
489:and
301:and
131:heat
18:The
717:UMN
211:not
173:not
102:'s
22:of
908::
845:.
711:,
597:,
593:,
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133:.
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