But atomic bombs and nuclear power plants—perhaps the two best-known practical manifestations of Einstein's ideas—would not appear for decades. The more immediate consequence of volume 17 was the resuscitation of young Albert's academic career. In 1905 he earned his PhD, and the next year he won an untenured teaching position at the University of Bern. In 1911 and 1912, Einstein moved quickly through professorships at the universities of Zurich and Prague before settling in as a professor at his alma mater, the ETH in Switzerland. There he worked on expanding his special theory of relativity into a general theory of relativity, which explained gravity not as an independent force but instead as a distortion of the geometry of space-time caused by large bodies of matter.
One implication of Einstein's theory was that the gravitation of massive objects would warp space-time, bending light around them. As early as 1911, Einstein suggested that a full solar eclipse might allow scientists to measure this deflection of light; stars that should have been hidden behind the sun would appear to have moved to new positions in the sky, their light having been bent by the gravitation of the sun. (The effect would only be visible during an eclipse, because normally the sun's brightness would make it impossible to see the other stars.) In 1919, a British astronomer named Arthur Eddington traveled to the island of Principe, off the coast of Africa, to observe a full solar eclipse. He produced photographic evidence that Einstein's conjectures had been correct; light from distant stars had turned a corner around the sun, making them appear to shift their positions in the sky.
Albert Einstein's challenging theoretical explanations of the deepest workings of the universe had been vindicated in the most dramatic possible way, with the publication of definitive photographs made possible only by the rarest of celestial events, a total eclipse of the sun. The world reacted with awe. The Times of London, one of the leading newspapers of the English-speaking world, heralded Eddington's findings with a front-page banner headline: "Revolution in Science — New Theory of the Universe — Newtonian Ideas Overthrown." Suddenly Einstein found himself not only a respected physicist but also a true global celebrity. Albert Einstein, the mediocre student and troubled young adult, was gone and forgotten. Albert Einstein, the icon of pure genius, had arrived.