History of Science & Knowledge

No Shadow of a Doubt: The 1919 Eclipse That Confirmed Einstein's Theory of Relativity

The extraordinary story of the scientific expeditions that ushered in the era of relativity


Published (US):
Mar 9, 2021
Published (UK):
Mar 30, 2021
5.25 x 8 in.
25 b/w illus.
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In 1919, British scientists led expeditions to Brazil and Africa to test Albert Einstein’s new theory of general relativity in what became the century’s most celebrated scientific experiment. The result ushered in a new era and made Einstein a celebrity by confirming his prediction that the path of light rays would be bent by gravity. Yet the effort to “weigh light” during the May 29, 1919, solar eclipse has become clouded by myth and skepticism. Could Arthur Eddington and Frank Dyson have gotten the results they claimed? Did the pacifist Eddington falsify evidence to foster peace after a horrific war by validating the theory of a German antiwar campaigner? In No Shadow of a Doubt, Daniel Kennefick provides definitive answers by offering the most comprehensive and authoritative account of how expedition scientists overcame war, bad weather, and equipment problems to make the experiment a triumphant success.

"Happy 40th, Einstein!

Awards and Recognition

  • Finalist for the PROSE Award in History of Science, Medicine, and Technology, Association of American Publishers
  • One of BBC Sky at Night Magazine's Best Astronomy and Space Books of 2019
  • One of Nature's Top Ten Books of 2019