Roberto Martins Searching for the Ether DIO 17
Table 1. Measurements made by Courvoisier in 1926 with the double telescope instrument.
Table 2. Measurements made by Courvoisier in 1927 with the double telescope instrument.
The first series of measurements was made from 31 July and 6 August 1926, with observations spanning between 3 and 20 o'clock sidereal time; the second one, from 28 February to 29 May 1927, with observations covering the period from 21 to 13 o'clock sidereal time. Both series comprised more than 500 measurements. Tables 1 and 2 shows the mean results obtained by Courvoisier for each sidereal time:
Searching for the Ether
The first series comprised 489 observations, and the second series only 67 observations. From the first series, Courvoisier computed the following values:
A = 70° ± 6°; D = +33° ± 11°; v = 493 ± 54 km/s
From the second series, he obtained the results:
A = 22° ± 6°; D = +72° ± 11°; v = 606 ± 45 km/s
Of course, the results obtained from the first series of measurements seemed more reliable than those from the second series, and they exhibited a closer agreement with former measurements.
Notice that, although those measurements attempted to detect the same kind of effects as the astronomical observations - that is, a difference between angle of incidence and angle of reflection in a moving mirror - the star observations used the North-South direction, and the cave experiments employed the East-West direction. The equations were different, and nevertheless Courvoisier obtained a nice agreement between the new device and the former results.
The double mirror experiments
In 1928 Courvoisier built another device to measure the speed of the Earth using the principle of the moving mirror. Instead of using two telescopes, he used a single telescope, with two perpendicular mirrors in front of its objective (Fig. 7).22 The body of the telescope was placed in a horizontal position. The mirrors were adjusted so that it was possible to observe the reflected image of the thread micrometer of the telescope in close coincidence with the real micrometer thread. He predicted that the relative position of the image and the thread should undergo periodic fluctuations, and computed the predicted effect.
From April to June 1928 Courvoisier obtained a series of 53 measurements, both in the North-South and in the East-West directions, and he computed the following values:
A = 74° ± 1°; D = +36° ± 1°; v = 496 ± 10 km/s
22 Leopold Courvoisier, “Bestimmungsversuche der Erdbewegung relativ zum Lichtäther III”, Astronomische Nachrichten, ccxxxiv (1928), 137-44.