Allais and Esclangon light deviations
by Vincent MORIN
INTRODUCTION
Maurice Allais is mainly known after his pendulum experiments, but he
also experimented with optical sightings, and a small part of his 1997 book (l'anisotropie
de l'espace Ed Clément Juglar Paris 1997) is devoted to those experiments.
In fact, in 1927, the french astronomer Ernest Esclangon already
experimented in a similar direction, measuring vertical differences in
north-east and north-west optical sightings.
In both cases, Esclangon and Allais said there was some deviations
periodic in time. Esclangon said there was a sidereal periodicity in his
vertical differences, Allais said his horizontal north to south and south to
north sightings had 24h and nearly 25h periods.
At the time they were made, those measurements were very tedious (Allais
experiments required measuring every 20 minutes 24h a day during one month).
Today, with some adequate tecnical skills and affordable hardware, it is easy
to set up a fully automated experiment where the deviations of a light beam are
recorded continuously for months.
Two experiments have been conducted until now. The first one was a first
low cost trial to see if something interesting happened. The second experiment
is a more refined version of the first experiment. In both cases, the light
beam undoubtedly undergoes periodic deviations, which is not a surprise as we
expect at least the diurnal temperature effect. But it seems that the behaviour
is much stranger than the temperature effect would normally appear, and it
seems equally probable that some non thermal process operates.
AVAILABLE DOCUMENTS
Documents in pdf format describe the first and second experiments. The
first document presents both the setup and three monthly series.
The second document is a technical description of the most recent setup
built with Mr. Thomas Goodey support.
The third document is the preliminary report on more than 5 months data
acquisition. It is the longest series collected to date (to my knowledge). The
document contains many detailed graphs. Though prudence is in order in those
matters, this new data goes in the direction of a confirmation of the first
experiment. It seems fair to recognize the cause of those deviations is unclear,
and multidirectional data appears more complicated than it could be
anticipated. Writing of an analysis is underway and will complete the
preliminary report made available below.
The 4th document is an article submitted to Physica Scripta without answer.
It is especially cautious and put there otherwise discussion will occur years
later.
The 5th document is the raw data collected with the second setup (glass
tubes) from June 2004 to March 2005.
DOWNLOADS
Click here to
download the memoir on first experiments (3 Mb, pdf, in french).
Click here to
download the second setup technical description(2 Mb, pdf, in english).
Click here to
download the preliminary 2005 report on second setup data (4 Mb, pdf, in
english).
Click here to
download the January 2004 article report on December 26th 2004 observation (290
Kb, pdf, in english).
Click here to
download the June 2004 to March 2005 raw data (890 Kb, zip file).
Click here to
download the June 2004 to June 2006 experimental report (19.5 Mb, pdf file).
Vincent Morin (vincent.morin@univ-brest.fr)