In 1915, Einstein published his theory of general relativity, which stated that gravitational fields cause distortions in the fabric of space and time. Because it was such a bold rewriting of the laws of physics, the theory remained controversial until May 1919, when a total solar eclipse provided the proper conditions to test its claim that a supermassive object—in this case, the sun—would cause a measurable curve in the starlight passing by it.
Hoping to prove Einstein’s theory once and for all, English astronomer Arthur Eddington journeyed to the coast of West Africa and photographed the eclipse. Upon analyzing the pictures, he confirmed that the sun’s gravity had deflected the light by roughly 1.7 arc-seconds—exactly as predicted by general relativity.
The news made Einstein an overnight celebrity. Newspapers hailed him as the heir to Sir Isaac Newton, and he went on to travel the world lecturing on his theories about the cosmos. According to Einstein biographer Walter Isaacson, in the six years after the 1919 eclipse, more than 600 books and articles were written about the theory of relativity.