Remembering The Eclipse That Forever Changed Physics

A century ago, an eclipse proved Einstein right—and altered our understanding of the universe.

mid range black and white photo of einstein in his office working over books and papers
Albert Einstein in his office at the University of Berlin. Credit: Wikimedia Commons

This week marks the 100th anniversary of an eclipse that forever changed physics and our understanding of the universe.

In May 1919, scientists set out for Sobral, Brazil, and Príncipe, an island off the west coast of Africa, to photograph the momentarily starry sky during a total eclipse. Their scientific aim was to test whether the sun’s gravity would indeed bend light rays from faraway stars, as predicted by Einstein’s theory of general relativity. After analyzing the data from the brief minutes of darkness, they declared Einstein correct.

Carlo Rovelli, physicist and author, tells Ira the story.

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Christopher Intagliata was Science Friday’s senior producer. He once served as a prop in an optical illusion and speaks passable Ira Flatowese.

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