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Eddington's Eclipse Expedition Confirms Relativity

May 29, 1919 · 20th Century

AstronomyPhysics/Cosmology

On May 29, 1919, British expeditions led by Arthur Eddington and Frank Dyson observed a total solar eclipse from Príncipe (West Africa) and Sobral (Brazil) to test Einstein's general relativity. They photographed stars near the eclipsed Sun and measured light deflection of approximately 1.75 arcseconds — matching Einstein's prediction and twice the value Newtonian theory would produce. Results presented to the Royal Society on November 6, 1919, confirmed that massive objects curve the path of light through spacetime.

Key Figures

Albert EinsteinArthur Stanley EddingtonFrank Watson Dyson

Locations

LondonPríncipe IslandSobral

Topics

astronomyscientific revolutiongravityrelativityeclipse

Connected Events — 1 Connection

Eddington's 1919 observation of starlight bending during a solar eclipse provided the first empirical confirmation of Einstein's 1915 prediction that gravity curves spacetime Einstein Publishes General Theory of Relativity

November 25, 1915 · Physics/Cosmology · 20th Century

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