Wikipedia

Solar eclipse of May 29, 1919

The May 29, 1919 total solar eclipse occurred because the Moon aligned between the sun and the Earth in which they appeared overlapped to a certain population of observers on the Earth. The moon covers the suns light which leads to an absence of light for a small period of time. The solar eclipse which occurred on May 29, 1919 was the longest solar eclipse that had been observed and recorded up until June 8, 1937. This eclipse was visible through locations like Southeastern Peru and northern Chile. This specific total solar eclipse was significant because it helped prove Einstein's theory of relativity.[1] The eclipse was subject to the Eddington experiment. Two groups of British astronomers went to Brazil and the west coast of Africa to take pictures of the stars in the sky once the moon covered the sun and darkness was revealed.[1] Those photos helped prove that the sun interferes with the bend of star light.[1]

Solar eclipse of May 29, 1919
From the report of Sir Arthur Eddington on the expedition to the island of Principe (off the west coast of Africa).
Map
Type of eclipse
NatureTotal
Gamma−0.2955
Magnitude1.0719
Maximum eclipse
Duration411 s (6 min 51 s)
Coordinates4°24′N 16°42′W / 4.4°N 16.7°W / 4.4; -16.7
Max. width of band244 km (152 mi)
Times (UTC)
Greatest eclipse13:08:55
References
Saros136 (32 of 71)
Catalog # (SE5000)9326

Observations and locations edit

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.

As the eclipse of 1919 occurred only 0.8 days after perigee (May 28), the Moon's apparent diameter was larger than usual.[clarification needed]

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), southwestern tip of 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), 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.

Observations edit

 
Eclipse instrument used at Sobral, Ceará
See also: Eddington experiment, Tests of general relativity § Deflection of light by the Sun, and Experimentum crucis

Newton's laws of physics ran on the belief of absolute time and three dimensions of space. [2] This idea meant that time only had one dimension, and that it was universal.[2][3] Einstein had the idea of combining space and time to make a four dimensional world that worked together. [4][5] With Einstein's idea meant that extremely small matter particles could produce massive amounts of energy. [4] If Einstein's theory was correct matter and radiation would be connected to energy and momentum.[6] Meaning that when light was passing a large mass there would be an observable bend to the light. [6]

Albert Einstein's prediction of the bending of light by the gravity of the Sun, one of the components of his general theory of relativity, can be tested during a solar eclipse, when stars with apparent position near the Sun become visible. The stars can not be seen without a solar eclipse because stars passing the sun are drowned by solar glares.[7]

Following an unsuccessful attempt to validate this prediction during the Solar eclipse of June 8, 1918,[8] two expeditions were made to measure positions of stars during this eclipse (see Eddington experiment). They were organized under the direction of Sir Frank Watson 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.[9][10][11] The stars that both expeditions observed were in the constellation Taurus.[12]

The Eclipse of 1919 was almost missed, due to unexpected storms. [13]The astronomers were almost unable to get photos of this eclipse due to a cloud.[14][13] A thunderstorm happened during the morning of the eclipse, and it had been overcast that day and many of the days before hand.[14][13] Only thirty minutes before the eclipse did the clouds begin to dissipate, and even then they were taking many photos through gaps in the clouds.[13]

The photographs taken during the eclipse of May 29, 1919 proved Einstein correct and changed ideas of physics.[15] From the findings from these expeditions Dyson is quoted saying "After a careful study of the plates, I am prepared to say that they confirm Einstein's prediction."[15] He continues to explain that it leaves little doubt about light deflection in the area around the sun and it is the amount Einstein demands in his generalized theory of relativity.[15]

Related eclipses edit

Total solar eclipse of May 29, 1919, as emulated by Celestia.

Earlier eclipses related to the Theory of Relativity edit

Before 1919 there were two eclipses in 1912 where this idea was almost proven, but there were outside factors against astronomers.[16] The first eclipse in 1912 was on April 17, but superstition, underfunding, and time overwhelmed the astronomers on this date.[17] A lot of superstition surrounded the eclipse due to the sinking of the Titanic; however a lack of funding, preparation, and time of total coverage of the sun would've also been a problem for photographic proof. [17] The second eclipse they wanted to photograph was on October 10 1912, and it was unable to be photographed due to rain. [18]

Solar eclipses 1916–1920 edit

This eclipse is a member of a semester series. An eclipse in a semester series of solar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.[19]

Solar eclipse series sets from 1916 to 1920
Ascending node   Descending node
111 December 24, 1916
 
Partial 		116 June 19, 1917
 
Partial
121 December 14, 1917
 
Annular 		126 June 8, 1918
 
Total
131 December 3, 1918
 
Annular 		136 May 29, 1919
 
Total
141 November 22, 1919
 
Annular 		146 May 18, 1920
 
Partial
151 November 10, 1920
 
Partial

Saros 136 edit

Solar Saros 136, repeating every 18 years, 11 days, contains 71 events. The series started with partial solar eclipse on June 14, 1360, and reached a first annular eclipse on September 8, 1504. It was a hybrid event from November 22, 1612, through January 17, 1703, and total eclipses from January 27, 1721, through May 13, 2496. The series ends at member 71 as a partial eclipse on July 30, 2622, with the entire series lasting 1262 years. The longest eclipse occurred on June 20, 1955, with a maximum duration of totality at 7 minutes, 7.74 seconds. All eclipses in this series occurs at the Moon's descending node.[20]

Series members 29–43 occur between 1865 and 2117
29 30 31
 
Apr 25, 1865 		 
May 6, 1883 		 
May 18, 1901
32 33 34
 
May 29, 1919 		 
Jun 8, 1937 		 
Jun 20, 1955
35 36 37
 
Jun 30, 1973 		 
Jul 11, 1991 		 
Jul 22, 2009
38 39 40
 
Aug 2, 2027 		 
Aug 12, 2045 		 
Aug 24, 2063
41 42 43
 
Sep 3, 2081 		 
Sep 14, 2099 		 
Sep 26, 2117

Inex series edit

This eclipse is a part of the long period inex cycle, repeating at alternating nodes, every 358 synodic months (≈ 10,571.95 days, or 29 years minus 20 days). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee). However, groupings of 3 inex cycles (≈ 87 years minus 2 months) comes close (≈ 1,151.02 anomalistic months), so eclipses are similar in these groupings.

Notes edit

  1. ^ a b c Cowen, Ron (2019). Gravity's Century (1st ed.). Cambridge, Massachusetts. London, England: Harvard University Press. pp. 2–3. ISBN 9780674974968.
  2. ^ a b Gates, Sylvester J.; Pelletier, Cathie (2019). Proving Einstein right: the daring expeditions that changed how we look at the universe (1st ed.). New York: PublicAffairs. ISBN 978-1-5417-6225-1.
  3. ^ Dvorak, John (2017). Mask of the sun: the science, history, and forgotten lore of eclipses. New York, NY: Pegasus Books Ltd. ISBN 978-1-68177-330-8. OCLC 951925837.
  4. ^ a b Gates, Sylvester J.; Pelletier, Cathie (2019). Proving Einstein right: the daring expeditions that changed how we look at the universe (1st ed.). New York: PublicAffairs. ISBN 978-1-5417-6225-1.
  5. ^ Dvorak, John (2017). Mask of the sun: the science, history, and forgotten lore of eclipses. New York, NY: Pegasus Books Ltd. ISBN 978-1-68177-330-8. OCLC 951925837.
  6. ^ a b Gates, Sylvester J.; Pelletier, Cathie (2019). Proving Einstein right: the daring expeditions that changed how we look at the universe (1st ed.). New York: PublicAffairs. ISBN 978-1-5417-6225-1.
  7. ^ Steel, Duncan (2001). Eclipse (1st ed.). Washington, D.C.: The Joseph Henry Press. pp. 112–113. ISBN 0-309-07438-X.
  8. ^ Ethan Siegel, "America's Previous Coast-To-Coast Eclipse Almost Proved Einstein Right", Forbes, Aug 4, 2017. Retrieved August 4, 2017.
  9. ^ ”Eclipse 1919”, Web site commemorating the 1919 Solar Eclipse expedition, 2019. Retrieved December 10, 2021.
  10. ^ Longair, Malcolm (2015-04-13). "Bending space–time: a commentary on Dyson, Eddington and Davidson (1920) 'A determination of the deflection of light by the Sun's gravitational field'". Phil. Trans. R. Soc. A. 373 (2039): 20140287. Bibcode:2015RSPTA.37340287L. doi:10.1098/rsta.2014.0287. ISSN 1364-503X. PMC 4360090. PMID 25750149.
  11. ^ Kennefick, Daniel (2019). No Shadow of a Doubt. Princeton University Press. ISBN 978-0-691-18386-2.
  12. ^ F. W. Dyson; A. S. Eddington; C. Davidson (1920). "A Determination of the Deflection of Light by the Sun's Gravitational Field, from Observations Made at the Total Eclipse of May 29, 1919". Philosophical Transactions of the Royal Society of London. CCXX-A 579 (571–581): 291–333. Bibcode:1920RSPTA.220..291D. doi:10.1098/rsta.1920.0009.
  13. ^ a b c d Kennefick, Daniel (2019). No shadow of a doubt: the 1919 eclipse that confirmed Einstein's theory of relativity. Princeton, New Jersey: Princeton University Press. ISBN 978-0-691-18386-2. OCLC 1051138098.
  14. ^ a b Gates, Sylvester J.; Pelletier, Cathie (2019). Proving Einstein right: the daring expeditions that changed how we look at the universe (1st ed.). New York: PublicAffairs. ISBN 978-1-5417-6225-1.
  15. ^ a b c Dvorak, John J. (2017). Mask of the sun: the science, history, and forgotten lore of eclipses. New York (N.Y.): Pegasus Books ltd. ISBN 978-1-68177-330-8.
  16. ^ Kennefick, Daniel (2019). No shadow of a doubt: the 1919 eclipse that confirmed Einstein's theory of relativity. Princeton, New Jersey: Princeton University Press. ISBN 978-0-691-18386-2. OCLC 1051138098.
  17. ^ a b Gates, Sylvester J.; Pelletier, Cathie (2019). Proving Einstein right: the daring expeditions that changed how we look at the universe (1st ed.). New York: PublicAffairs. ISBN 978-1-5417-6225-1.
  18. ^ Gates, Sylvester J.; Pelletier, Cathie (2019). Proving Einstein right: the daring expeditions that changed how we look at the universe (1st ed.). New York: PublicAffairs. ISBN 978-1-5417-6225-1.
  19. ^ van Gent, R.H. "Solar- and Lunar-Eclipse Predictions from Antiquity to the Present". A Catalogue of Eclipse Cycles. Utrecht University. Retrieved 6 October 2018.
  20. ^ SEsaros136 at NASA.gov

References edit

 
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