Eclipses through the Centuries - Portal do Professor

30) Einstein Eclipse, 1919 CE
See Visibility Map: http://eclipse.gsfc.nasa.gov/5MCSEmap/1901-2000/1919-05-29.gif
This eclipse has definitively revolutionized the history of science in the
twentieth century, as it helped to confirm the General Theory of Relativity by
Albert Einstein (1879-1955 CE). Indeed, one of Einstein’s most remarkable
contributions to science was his General Theory of Relativity (GTR), formulated
between 1913 and 1916 CE. This theory contradicted Newton’s and provided
fundamental new understandings of time and space measurement. GTR was
extremelyy complex to understand though and, in order to be accepted, it
was necessary that Einstein’s theory predicted or explained some observed
phenomenon that the Newtonian theory could not. 101
In this scenario, Eddington came up with the idea that a total eclipse of the
Sun would provide such a unique opportunity to quantitatively test Einstein’s
theory. How? If it were correct, the light from stars would be bent by the strong
gravitational field of the Sun. And what circumstance was necessary to observe
this? Totality and stars appearing close-by because the test required several
bright stars close to the limb of the Sun during the eclipse. The eclipse of May
29, 1919, offered such conditions.
Fig. 35 – Total solar eclipse in Sobral, Brazil, 1919. The large city of Sobral in Ceara, Brazil, as it was
in 1919 (left), and a recent monument to celebrate the eclipse (right). Source: Sociedade Brasileira de
Fisica Web site, http://www.sbfisica.org.br
The path of totality crossed Brazil, in South America, and Principe, an island
owned by Portugal in the Gulf of Guinea, just to the north of the equator and 150
miles from the African coast. In northeastern Brazil, the city of Sobral, Ceara
state, was the best post of observation of the phenomenon and two expeditions
of American and English scientists joined the Brazilians to observe the eclipse.
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