The Perfect Theory by Pedro G. Ferreira Read Free Book Online

“Einstein’s equations.”
    Einstein had completed his trek. He had gradually succumbed to the power of mathematics to reach his final equations. From then on he would let himself be guided not only by his thought experiments but also by the mathematics. The sheer mathematical beauty of his final theory stunned him. He described his equations as “the most valuable discovery of my life.”
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    Eddington had been receiving the slow trickle of offprints coming out of Prague, then Zurich, and finally Berlin from a friend, the astronomer Willem de Sitter, from Holland. He was intrigued, hooked by this completely new way of looking at gravity in a difficult language. Even though he was an astronomer, and his job was to measure and observe things and try to interpret them, he was up to the challenge of learning the new mathematics of Riemannian geometry that Einstein had used to write up his theory. And it was well worth looking into, especially since Einstein had made quite clear predictions that could be used to test his theory. In fact, an eclipse was predicted to occur on the twenty-ninth of May, 1919, an ideal opportunity for such a test, and Eddington would be the obvious person to lead a team of observers.
    There was only one problem, and a massive one at that. Europe was at war, Eddington was a pacifist, and Einstein was in cahoots with the enemy. Or so Eddington’s colleagues wanted him to believe. As the war reached its climax in 1918, the risk of the German army completely engulfing the British and the French grew, leading to a renewed wave of conscriptions. Eddington was called up to fight, but he had something else on his mind.
    While Eddington had become an enthusiastic advocate of Einstein’s new gravity, he faced the antipathy of his colleagues. In an attempt to dismiss German science as having no worth, one of his colleagues declared,“We have tried to think that exaggerated and false claims made by Germans today were due to some purely temporary disease of quite recent growth. But an instance like this makes one wonder whether the sad truth may not lie deeper.” And while Eddington had the support of the Astronomer Royal, Frank Dyson, to lead the eclipse expedition, he had to escape being sent to jail for refusing to fight. The British government convened a tribunal in Cambridge to look into Eddington’s stance. As the hearing proceeded, the tribunal viewed him with increasing hostility. Eddington was going to be refused exemption until Frank Dyson stepped in. Eddington was a crucial player in the eclipse expedition, Dyson said, and furthermore, “under present conditions the eclipse will be observed by very few people. Prof. Eddington is peculiarly qualified to make these observations, and I hope the Tribunal will give him permission to undertake this task.” The eclipse intrigued the tribunal, and Eddington was once again given an exemption for “national importance.” Einstein had saved him from the front.
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    From Einstein’s theory there was a prediction: that the light emitted from distant stars would bend as it passed close to a massive body such as the sun. Eddington’s experiment proposed to observe one such distant cluster of stars, the Hyades, at two different times of the year. He would first accurately measure the positions of the stars in the Hyades cluster on a clear night, with nothing obscuring his view and nothing in the way to bend their light rays. Then he would measure their position again, this time with the sun in front. It would have to be done during a total eclipse, when almost all the bright light of the sun would be blocked by the moon. On the twenty-ninth of May, 1919, the Hyades would lie right behind the sun and conditions would be perfect. A comparison of the two measurements—one with the sun and one without—would show if there was any deflection. And if that deflection was about four-thousandths of a