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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Allais effect | 2/2 | https://en.wikipedia.org/wiki/Allais_effect | reference | science, encyclopedia | 2026-05-05T09:14:05.167652+00:00 | kb-cron |
=== Inconclusive or negative results === Louis B. Slichter, using a gravimeter during the solar eclipse of February 15, 1961 in Florence, Italy, failed to detect an associated gravitational signal. During the solar eclipse of July 22, 1990, no anomalous period increase of a torsion pendulum was detected independently by a team in Finland and another team in Belomorsk, USSR. The total solar eclipse of August 11, 1999 had been a good opportunity to solve a 45-year mystery, thanks to an international collaboration. NASA's Marshall Space Flight Center first inquired about experimental protocols to Maurice Allais, in order to coordinate ahead of the event a worldwide effort to test the Allais effect between observatories and universities over seven countries (United States, Austria, Germany, Italy, Australia, England and four sites in the United Arab Emirates). The lead supervisor then stated: "The initial interpretation of the record points to three possibilities: a systematic error, a local effect, or the unexplored. To eliminate the first two possibilities, we and several other observers will use different kinds of measuring instruments in a distributed global network of observing stations." However, after the eclipse, Allais criticized the experiments in his final NASA report, writing the period of observation was "much too short […] to detect anomalies properly". Moreover, the lead supervisor left NASA shortly thereafter with the gathered data and the NASA study has never been published. Further observations conducted by the team led by Xin-She Yang appear to have yielded much weaker evidence of anomalies than their first 1997 study. The authors first posited a more conventional explanation based on temperature changes causing ground tilting, but later suggested that this explanation was unlikely. A possible yet controversial explanation was finally proposed by the same author and Tom Van Flandern which conjectured that the anomaly is due to the gravitational effect of an increased air density spot in the upper atmosphere created by cooling winds during the solar eclipse. They conclude there have been "no unambiguous detections [of an Allais effect] within the past 30 years when consciousness of the importance of [experimental] controls was more widespread." They point out that "the gravitation anomaly discussed here is about a factor of 100,000 too small to explain the Allais excess pendulum precession […] during eclipses" and from this conclude that the original Allais anomaly was merely due to poor controls. Eight gravimeters and two pendulums were deployed across six monitoring sites in China for the solar eclipse of July 22, 2009. Although one of the scientists involved described in an interview having observed the Allais effect, no result has been published in any academic journal. An automated Foucault pendulum was also used during the solar eclipse of July 11, 2010 in Argentina, with no evidence of a precession change of the pendulum's oscillation plane (< 0.3 degree per hour).
== Aether hypothesis ==
Maurice Allais states that the eclipse effect is related to a gravitational anomaly that is inexplicable in the framework of the currently admitted theory of gravitation, without giving any explanation of his own. Allais's explanation for another anomaly (the lunisolar periodicity in variations of the azimuth of a pendulum) is that space evinces certain anisotropic characteristics, which he ascribes to motion through an aether which is partially entrained by planetary bodies. His hypothesis leads to a speed of light dependent on the moving direction with respect to a terrestrial observer, since the Earth moves within the aether but the rotation of the Moon induces a "wind" of about 8 km/s. Thus Allais rejects Einstein's interpretation of the Michelson–Morley experiment and the subsequent verification experiments of Dayton Miller. In particular, the Michelson–Morley experiment did not give a zero speed difference, but at most 8 km/s, without being able to detect any regularity. This difference was therefore interpreted as due to measurement uncertainties. Similarly, Miller's experiments corroborated these results over a long period of time, but Miller could not explain the source of the irregularities. At the time, temperature problems were invoked to explain the cause, as concluded by Robert S. Shankland. By re-analyzing the data from this experiment, Allais reported a periodicity using sidereal time rather than civil time used by Miller (daytime sidereal variation of the speed of light over a period of 23 hours 56 minutes with an amplitude of about 8 km/s). Applying the Titius–Bode law to the Earth–Moon system, which he generalizes to aether, Allais calculates a "wind" of 7.95 km/s, which is comparable to the values found by the experiments of Michelson and Miller. Hence Allais deduces that the aether turns with the stars, as proposed by the aether drag hypothesis, and is not fixed as Hendrik Lorentz thought when inventing his famous transformation and his ether theory. But the majority of scientists at the end of the 19th century imagined that such an aether crossed the Earth so that the rotation of the Earth around the Sun would cause an important variation of 30 km/s. Consequently, since the third postulate on which special relativity is based is the constancy of the speed of light in vacuum, Allais considers it unfounded. In order to measure a change in the speed of light, one would have to get back to the definition of the 1960 meter, since confidence in the theory of relativity nowadays is such that current metrology uses constancy of the speed of light as an axiom. Allais summarized his experimental work in English in his 1999 memoir on behalf of NASA. He detailed his aether hypothesis in the books L'Anisotropie de l'Espace, published in 1997, and L'Effondrement de la Théorie de la Relativité, published in 2004. A book on Allais's scientific legacy has been edited in English in 2011, yet his aether hypothesis has not gained significant traction among mainstream scientists. Nevertheless, after Allais's death in 2010, experiments on the Allais effect continue.
== See also == N-rays Pioneer anomaly
== References ==
== External links ==
Maurice Allais Foundation website (English version) Maurice Allais, Ten Notes published in the Proceedings of the French Academy of Sciences (Comptes rendus hebdomadaires des séances de l'Académie des Sciences), dated 4/11/57, 13/11/57, 18/11/57, 13/5/57, 4/12/57, 25/11/57, 3/11/58, 22/12/58, 9/2/59, and 19/1/59, available in French at http://allais.wiki/alltrans/allaisnot.htm, some also in English translation. Thomas J. Goodey, "Professor Maurice Allais – a genius before his time – as are they all" (Web site claiming to be the internet base of researchers studying and publicizing the Allais effect; includes copies/translations of several of the above papers.) Ed Oberg "www.iasoberg.com" This site has been established by Ed Oberg to facilitate and promote research into the Allais Effect and to distribute the resulting findings. The launch of this site (23 November 2007) coincided with the launch of a hypothetical field model developed by Ed Oberg. Göde Wissenschafts Stiftung "Experimental measuring results with the paraconical pendulum Archived 2006-12-08 at the Wayback Machine