Eclipse Of May Research Articles

The Deflection of Light in the Sun's Gravitational Field

Among the various expeditions sent out to observe the total solar eclipse of May 9, 1929, that of the Potsdam Observatory (Einstein Stiftung) seems to be the only one which obtained photographs suitable for determining the light deflection in the Sun's gravitational field. Two instruments were used, but so far only the results of the larger one, a 28foot horizontal camera combined with a coelostat, have been published. The three observers, Freundlich, von Kliiber, and von Brunn,2 claim that these observations (four plates containing from seventeen to eighteen star images each) lead to a value of 2'.'24 for the deflection of a light ray grazing the Sun's edge; a figure that deviates considerably from the results of the 1922 eclipse, and which is in contradiction to Einstein's generalized theory of relativity. In view of the importance and general interest attached to this problem, a few critical remarks on the Potsdam observations and their reduction should not be out of place here :3

Anomaly in the Radio Transmission during the Solar Eclipse of May 9, 1929

Anomaly in the Radio Transmission during the Solar Eclipse of May 9, 1929

The Eclipse of May 9

The Eclipse of May 9

The Eclipse of May 9

The Eclipse of May 9

Our Astronomical Column

THE TOTAL SOLAR ECLIPSE OF MAY 9.—Unfortunately, the news from the official British parties at Alor Star and Patani are very disappointing. At the latter station nothing could be done owing to thick clouds. At the former the clouds were thinner, and some plates were exposed, but it is feared that they will be of little value.

The Total Solar Eclipse of May 9

The Total Solar Eclipse of May 9

Effect of the Solar Eclipse of May 9, 1929, on Radio Transmission

Effect of the Solar Eclipse of May 9, 1929, on Radio Transmission

THE TOTAL SOLAR ECLIPSE OF MAY 9, 1928

THE TOTAL SOLAR ECLIPSE OF MAY 9, 1928

The Eclipse of May 9, 1929

The Eclipse of May 9, 1929

The Eclipse of May 9, 1929

The Eclipse of May 9, 1929

The Total Solar Eclipse of May 9, 1929

The Total Solar Eclipse of May 9, 1929

The Solar Eclipse of May 9, 1929

The Solar Eclipse of May 9, 1929

THE STARFIELD SURROUNDING THE ECLIPSED SUN AT THE TOTAL SOLAR ECLIPSE OF MAY 9, 1929

THE STARFIELD SURROUNDING THE ECLIPSED SUN AT THE TOTAL SOLAR ECLIPSE OF MAY 9, 1929

Magnetic observations at Bulawayo, May 28–30, 1919

Below are given the results of the magnetic observations which I took on May 28, 29, and 30, 1919, in connection with the solar eclipse of May 29, 1919, and in accordance with the program and forms received from the Department of Terrestrial Magnetism.I think I made a mistake in undertaking too much. After sixteen years of continued stay in this country one ought not to do things which are quite possible to a younger man and not expect to feel it. On the 29th I was very tired. I had given up the idea of taking contact observations. At the last moment a friend offered to take them, and I tried to get my telescope ready for him. Unhappily the 29th turned out to be a cloudy day. From 9 to 11 o'clock (local time), I tried in vain to focus my telescope for him at rare moments when I got a fleeting glimpse of the Sun. At eleven I gave it up and went back to my magnetic hut. I found the fiber broken. I had prepared for this emergency. But as the morning was very windy the new fiber developed a twist which took the better part of the hour to get rid of. In consequence I fear my preliminary determinations were rather hurried.

Observations in the Azores, May 28–30, 1919

Special magnetic observations were made in this Island of S. Miguel (Azores) during the solar eclipse of May 29, 1919, in accordance with the program of the Department of Terrestrial Magnetism.In the garden of my house I have, since 1899, a pier on which I make absolute measurements of the magnetic elements, to compare with those observed at the Magnetic Observatory of S. Miguel, established near Ponta Delgada, under my general direction. In this garden I have also a Mascart declinometer, with which on May 29, during the interval of 9h 58m to 16h 32m, Greenwich civil mean time, were made at every minute observations of the declination. Since the results of these eye‐readings of the declination agree perfectly with those of the eye‐readings, made with a similar instrument at the Magnetic Observatory, only the results of the latter observations are given here. [Table 1 contains the five‐minute means.]

Results and analysis of magnetic observations during the solar eclipse of May 29, 1919.—Summary I

INTRODUCTION.1. The total solar eclipse of June 8, 1918, was the recurrence of the one of May 28, 1900, for which the writer planned and directed the first systematic observations arranged to detect a possible appreciable magnetic effect connected directly with the eclipse of the Sun. For both eclipses, 1900 and 1918, the results were affirmative, as well as instructive. The total eclipse of the Sun on May 29, 1919, was the recurrence of the one of May 18, 1901, the belt of totality of which began in the Indian Ocean, about where the totality‐belt for May 29, 1919, ended, and continued across Sumatra to New Guinea. The international magnetic observations for May 18, 1901, made in accordance with the writer's appeal and directions, again led to positive results and gave additional information.

Magnetic observations at Mauritius, May 28–30, 1919

In accordance with Dr. Bauer's circular letter of February 19, 1919, there are submitted the results of magnetic and meteorological observations made at the Royal Alfred Observatory, Mauritius, in connection with the solar eclipse of May 29, 1919, which it is hoped will be found serviceable. [Five‐minute values of D (declination), H (horizontal intensity), and Z (vertical intensity), from 10h to 16h 30m, G. M. T., were supplied for May 27, 28, 29, 30, and 31. Tables 1, 2, 3, and 4 were derived from these data. Geographic coordinates: Latitude 20°05′.6SN.; longitude, 57° 33′.2or 3h 50m.2E. —Ed.]

Magnetic observations at Dehra Dun, May 28–30, 1919

In response to the co‐operation requested by the Department of Terrestrial Magnetism for special simultaneous magnetic observations during the solar eclipse of May 29, 1919, I have the honor to forward abstracts of the declination, horizontal force, vertical force, and dip observations taken at the Dehra Dun Observatory, India, on the 28th, 29th, and 30th, May, 1919, in accordance with the published program. It will be observed that no unusual changes occurred in the magnetic elements during the observations; I hope, however, that these observations will be of use in the investigation of the effects of the eclipse on the Earth's magnetism.The geographic position of the Observatory is: Latitude, 30° 19′.3:N.; longitude, 78° 03′.3 or 5h 12m.2 E.

Further Results of Analysis of Light Deflections Observed during Solar Eclipse of May 29, 1919

Further Results of Analysis of Light Deflections Observed during Solar Eclipse of May 29, 1919

Preliminary Results of Analysis of Light Deflections Observed During Solar Eclipse of May 29, 1919

Preliminary Results of Analysis of Light Deflections Observed During Solar Eclipse of May 29, 1919