Arthur Eddington led an expedition to the island of Principe off West Africa, with a parallel Royal Greenwich Observatory team at Sobral, Brazil, to observe the total solar eclipse of May 29, 1919. The teams photographed stars near the eclipsed sun and found their apparent positions displaced by an amount matching general relativity's prediction that gravity bends light, the first observational confirmation of Einstein's theory.
Facts
Disputed
Key FindingThe observed stellar displacement matched Einstein's general-relativity prediction for how the Sun's gravity bends starlight, rather than the smaller Newtonian prediction, and was reported at the time as the first observational confirmation of general relativity. 2 Sourced to the subject's own accountContemporary critics argued the Sobral data were unreliable and that Eddington favoured the relativistic result; a 1979 re-analysis using modern methods validated Eddington's original conclusions and traced the disputed Sobral discrepancy to a telescope defect recognised by contemporary astronomers. See the paired Dissent record on this fact. MethodSourced to the subject's own accountEddington's team photographed stars near the Sun during the total solar eclipse of 29 May 1919 from Principe, with a parallel Royal Greenwich Observatory team at Sobral, Brazil, then compared the stars' apparent positions to their normal night-sky positions to detect gravitational light-bending. 2 LocationSourced to the subject's own accountPrincipe (Gulf of Guinea) and Sobral, Brazil 2 Cross-Tradition Connections
Sources
Dissenting Readings (1 dissenting reading)
Key Finding
Critics argued Eddington's 1919 data, in particular the simultaneous Sobral observations that sat closer to the Newtonian prediction, were unreliable and that Eddington discounted them because they favoured the relativistic result he expected. A 1979 re-analysis using modern methods validated Eddington's original conclusions and attributed the Sobral discrepancy to a telescope defect that was understood by contemporary astronomers at the time, so this dispute is recorded as raised-and-resolved rather than a live, unsettled disagreement.
A dissenting reading, from Contemporary and later critics of the 1919 eclipse data (resolved by a 1979 re-analysis)Arthur Eddington (Wikipedia), Wikipedia
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