Maurice Allais

Maurice Allais (1911–2010) was a French polymath, best known as a Nobel laureate in Economics (1988), who also conducted experimental research in mechanics and gravitation. The source compilation on his paraconical pendulum experiments presents him as the originator of the contested Allais Effect and the inventor of the Paraconical Pendulum.

Gravity research

Allais reported an anomalous precession of the plane of oscillation of a Foucault pendulum during the solar eclipse of 30 June 1954, and a second observation during the eclipse of 2 October 1959 using the paraconical pendulum he had invented. The 1959 study earned him the 1959 Galabert Prize of the French Astronautical Society and made him a laureate of the U.S. Gravity Research Foundation for his 1959 memoir on gravity.

He published the work in two parts in Aero/Space Engineering in 1959 under the title "Should the Laws of Gravitation Be Reconsidered?" — Part I on abnormalities in the motion of a paraconical pendulum on an anisotropic support, and Part II on the experiments connected with those abnormalities. He summarised the experimental work in English in a 1999 memoir prepared for NASA (Memoir C-6083).

Allais emphasised the dynamic character of the effects he observed: they are seen only when the pendulum is moving, and are connected with the variation of weight or inertia in the space swept by the pendulum rather than with the intensity of weight (gravimetry). He conceded that static deviations from the vertical are explained perfectly by gravitational theory.

Aether hypothesis

Allais's own explanation for the lunisolar periodicity in variations of a pendulum's azimuth was that space exhibits anisotropic characteristics, which he ascribed to motion through an aether partially entrained by planetary bodies. This led him to reject Einstein's interpretation of the Michelson–Morley experiment and of Dayton Miller's later verification experiments, and to argue that the constancy of the speed of light is an unfounded postulate. The hypothesis is detailed on Aether Anisotropy (Allais); the source notes it has not gained significant traction among mainstream scientists.

He set out the hypothesis in L'Anisotropie de l'Espace (1997) and L'Effondrement de la Théorie de la Relativité (2004). A book on his scientific legacy, Should the Laws of Gravitation be Reconsidered?: The Scientific Legacy of Maurice Allais, edited by Héctor A. Múnera, appeared in 2011.

Criticism and legacy

Allais's claim was directly challenged by Yang and Van Flandern, who concluded there have been "no unambiguous detections" of an Allais effect in the preceding 30 years and that the gravitational anomaly is about a factor of 100,000 too small to explain the reported excess pendulum precession — attributing the original anomaly to poor controls. Allais in turn criticised the NASA 1999 eclipse campaign's observation period as "much too short […] to detect anomalies properly."

After his death in 2010, experiments on the Allais effect continued, including a pendulum experiment during the total solar eclipse of 9 March 2016 over Indonesia. Jean-Bernard Deloly of the Maurice Allais Foundation published a 2016 continuation report on his experimental work.

Related pages

• Paraconical Pendulum
• Allais Effect
• Aether Anisotropy (Allais)
• Allais Effect Claims vs. Evidence: Positive Reports, Negative Results and the Unpublished NASA Study