Table of Contents
Searching for the Ether: Leopold Courvoiser’s Attemtps to Measure the Absolute Velocity of the Solar System
Roberto De Andrade Martins 3 The Very Early History of Trigonometry Dennis Duke 34
An Early Use of the Chain Rule Dennis Duke 43
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Searching for the Ether: Leopold Courvoiser’s Attempts to Measure the Absolute Velocity of the Solar System
ROBERTO DE ANDRADE MARTINS Physics Department, State University of Paraiba (UEPB), Brazil roberto. andrade .martins@gmail .com
Leopold Courvoisier (1873-1955) was an observer at the Berlin / Babelsberg astronomical observatory from 1905 up to his retirement in 1938. Most of his work was traditional astrometrical observation resulting in the publication of several star catalogues. A relevant part of his publications was devoted, however, to another subject: the attempt to detect the motion of the solar system through the ether.
Most of Courvoiser's search for measurable effects of the ether was based upon two “principles”. According to him, (1) the angles of incidence and reflection of light could be different, relative to the proper reference system of the mirror, if it moved through the ether; and (2) the Lorentz contraction of the Earth due to its motion through the ether produced observable effects relative to the Earth’s reference system. Both “principles”, of course, violate the principle of relativity. Courvoisier presented theoretical arguments attempting to show that there should exist second order measurable effects. He searched for those effects using both astronomical observations and laboratory experiments and claimed that he had measured a velocity of the solar system of about 600 km/s. This paper presents a description and analysis of Courvoiser’s ether researches.
Leopold Courvoisier was bom on 24 January 1873 in Rihen near Basel (Switzerland).1 His father Ludwig Georg Courvoisier was a physician and was in charge of the surgery chair of the University of Basel. Leopold (or Leo, as he was usually called) passed away in the same city where he was bom, on 31 December 1955. However, most of his professional life was spent in Germany.
Courvoisier exhibited an interest for astronomy since he was 15 years old. In 1891 he began his university studies, first in Basel and later in
1 For biographical information, see Courvoisier's obituary: Nikolaus Benjamin Richter, “Leopold Courvoisier”, Astronomische Nachrichten, cclxxxiv (1957), 47-48.