It took six minutes, fifty-one seconds for Albert Einstein to become world famous. That’s how long the moon stood suspended before the face of the sun on May 29, 1919, eclipsing its light. Mind you, the astronomers below couldn’t sail back home and develop their photographs for weeks; they then needed months more to analyze the results. Within those few minutes that spring day, the scientists had captured the first hard proof of Einstein’s theory of general relativity—and with that, launched Einstein himself from the darkness of obscurity into the brightness, even glare, of celebrity.
Success did not come easy to Einstein. He received no job offers upon graduating from college in 1900, and even after his annus mirabilis of 1905—when he published papers that laid the foundations for special relativity and quantum mechanics, and derived E=mc2 to boot—it took four more years to find work as a physicist.
Professional struggles aside, Einstein’s scientific work dissatisfied him as well. His 1905 paper on special relativity had unified two previously incompatible fields, Galileo’s laws of motion and Maxwell’s laws of electricity and magnetism. But Newton’s theory of gravity had resisted integration, and after 1905 Einstein labored for another decade to bring gravity into the fold. Even then, despite how nifty general relativity looked on paper, Einstein’s critics complained that there was no proof that it corresponded to reality.
So, rather audaciously, Einstein proposed a way for scientists to disprove his theory—if they could. Relativity predicted that gravity should bend light. As a result, light from distant stars should curve as it passed by the sun. This, in turn, made the stars’ positions in the sky appear shifted compared with their true positions. The sun’s brightness made this shift impossible to observe, of course—except during an eclipse, when stars could peek out from behind its shadow. Search for this shift, Einstein declared, and see if I’m right.
English astronomer Arthur Eddington took Einstein up on this challenge in May 1919, setting up telescopes and cameras on Príncipe, an island off western Africa famed for its cocoa. World War I had just ended, and the premise of the trip—spending British money to test a German scientist’s theories—rankled many. Rain almost scotched the expedition anyway; only an hour before the eclipse did rain clouds lift over Príncipe. And although Eddington scrambled to take sixteen pictures in those six minutes, fifty-one seconds, only two provided useful data.
Nevertheless, they revealed enough: The stars had shifted. When Eddington finally had these results in hand, he called it the greatest moment of his life. And he wasn’t alone in gushing. Newspapers worldwide jumped on the story: “LIGHT ALL ASKEW IN THE HEAVENS,” read one headline, “MEN OF SCIENCE MORE OR LESS AGOG.” Even those who couldn’t grasp relativity’s nuances knew that this Einstein fellow had transformed our understanding of space and time.