No Shadow of Doubt: Eddington, Einstein and the 1919 Eclipse

In 1919, British scientists led extraordinary expeditions to Brazil and Africa to test Albert Einstein’s theory of general relativity in the century’s most celebrated scientific experiment. The result ushered in a new era and made Einstein a global celebrity by confirming his dramatic prediction that the path of light rays would be bent by gravity. Today, Einstein’s theory is scientific fact. Yet the effort to “weigh light” by measuring the gravitational deflection of starlight during a solar eclipse on May 29, 1919, 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? Whatever their motives, these scientists overcame war, bad weather, and equipment problems to make the experiment a triumphant success. This talk follows Arthur Stanley Eddington on his voyage to Africa through his letters home, and delves with Frank Dyson into how the complex experiment was accomplished, through his notes. Other characters include Howard Grubb, the brilliant Irishman who made the instruments; William Campbell, the American astronomer who confirmed the result; and Erwin Findlay-Freundlich, the German whose attempts to perform the test in Crimea were foiled by clouds and his arrest. The argument is made that the eclipse teams made an unbiased and justified finding which confirmed Einstein's theory and falsified Newtonian gravity.