A total solar eclipse occurred on Thursday, May 29, 1919. With the duration of totality at maximum eclipse of 6 minutes 50.75 seconds, it was the longest solar eclipse that occurred since May 27, 1416. A longer total solar eclipse would later occur on
June 8, 1937. It was visible throughout most of
South America and
Africa as a partial eclipse. Totality occurred through a narrow path across southeastern
Peru, northern
Chile, central
Bolivia and
Brazil after sunrise, across the Atlantic Ocean and into south central Africa, covering southern
Liberia, southern
French West Africa (the part now belonging to
Ivory Coast), the extreme southwestern tip of the
British Gold Coast (now
Ghana),
Príncipe Island in
Portuguese São Tomé and Príncipe, southern
Spanish Guinea (now
Equatorial Guinea),
French Equatorial Africa (the parts now belonging to
Gabon and
R. Congo, including
Libreville),
Belgian Congo (now
DR Congo), northeastern
Northern Rhodesia (now
Zambia), the northern tip of
Nyasaland (now
Malawi),
German East Africa (now belonging to
Tanzania) and northeastern
Portuguese Mozambique (now
Mozambique), ending near sunset in
eastern Africa.
Planets and stars visible during totality The Sun was at about its nearest to
Aldebaran, so that star was potentially visible throughout the eclipse path.
Mars had its conjunction with the Sun twenty days earlier and shone at 2nd magnitude a few degrees to the west. Much brighter
Mercury was several degrees farther west of the Sun than Mars. Those were the only two bright planets visible in Bolivia, where the eclipsed Sun was very low in the east.
Deneb,
Altair,
Fomalhaut and
Achernar were the only 1st-magnitude stars well clear of the horizon;
Vega,
Aldebaran,
Rigel and
Canopus were very low. Observers in western
Africa had a much more impressive eclipse sky with the
Winter Hexagon well up, along with
Canopus.
Venus and
Jupiter were brilliant near
Pollux and
Saturn was close to the west of
Regulus.
Connection to the general theory of relativity Newton's laws of physics ran on the belief of absolute time and three dimensions of space. This idea meant that time had only one dimension, and that it was universal. Einstein had the idea of combining space and time to make a four-dimensional world that worked together. Following an unsuccessful attempt to validate this prediction during the
Solar eclipse of June 8, 1918, two expeditions were made to measure positions of stars during this eclipse (see
Eddington experiment). They were organized under the direction of
Sir Dyson. One expedition was led by
Sir Arthur Eddington to the island of
Príncipe (off the west coast of Africa), the other by
Andrew Claude de la Cherois Crommelin and Charles Rundle Davidson to
Sobral in Brazil. The stars that both expeditions observed, the
Hyades, were in the constellation
Taurus. The solar eclipse of May 29, 1919 allowed Einstein to finalize his theory of relativity. The astronomers were almost unable to get photos of this eclipse due to a cloud. He continued to explain that it left little doubt about light deflection in the area around the Sun and it was the amount Einstein demanded in his generalized theory of relativity. == Eclipse details ==