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Can science exist outside politics? On May 29, 1919, British astronomer Arthur Eddington did his best to find out. Eddington was prepared for this day during much of the Great War, trying to separate prejudices from the moment of seeking knowledge. Less than a year ago, Eddington had finalized his test project for a new theory of gravity proposed by a German scientist, even as the German army was pounding Paris and leading one of the bloodiest campaigns in the First World War. World War.
This scientist was Albert Einstein, not yet known enough to serve as a card that allowed Eddington not to be released from prison – and staying out of prison was exactly what Eddington had attempted to do.
In 1918, the British army, desperate to rebuild its workforce after more than three years of fighting, began to review all cases for which it had granted waivers to the project. Eddington's exemption was based solely on his research as director of the University of Cambridge Observatory, but on June 14 a military court told him that the reason was no longer sufficient. Quaker for life, Eddington tried to plead his case as a conscientious objector. The court refused to consider this argument, calling the case "very hard – difficult against Professor Eddington", but set a deadline of 11 July to convince them otherwise.
Eddington had never hesitated to express his Quaker beliefs even when he lived and worked on a Cambridge campus where five undergraduates and fifteen graduate students had been arrested for refusing military service. At a time when a Cambridge professor proclaimed that "the Germans are congenitally unable to read our poetry; the very structure of their organs forbids it ", and the prestigious British newspaper Nature In published articles denouncing the inferiority of German science, Eddington publicly urged British astronomers to separate the horrors of war from their works.
In particular, he defended Einstein's radical new work on gravity. If Einstein's theory were correct, it would replace Isaac Newton's vision of gravity as a force acting in space with the revolutionary idea that gravity is space. Einstein asserted that space and time, instead of being rigid and immutable, can buckle or sag due to the presence of a massive body, in the manner of A heavy sleeper sinking a mattress. A ball rolls toward a heavy body, not because of a force, but because the body has padded the space-time through which the ball has to travel.
As paradoxical as Einstein's theory might seem, Eddington knew there was a way to test it. Einstein himself had suggested the method.
If a body is massive enough – like the Sun – it should be possible to observe the curved or curved path of all objects moving nearby, even particles of starlight. The curvature of starlight would appear as a change in the apparent position of the star relative to its position when the Sun was in another part of the sky. Under normal conditions, the blinding light of the solar disk would completely overwhelm the much weaker light of the surrounding stars. But during those rare moments and places where the mechanical movement of the solar system places the Moon directly between the Sun and the Earth – a total solar eclipse – the stars appear in plain sight.
When the military tribunal reconvened on 11 July 1918 to decide his fate, Eddington presented a letter from Frank Dyson, British astronomer and chairman of the Eclipse standing joint committee of the Royal Society and the Royal Astronomical Society. The carefully crafted note highlights the pursuit of science but also plays on the emotions of Britain in wartime. Dyson asserted that the total solar eclipse of May 1919, visible across Africa and Brazil, was of exceptional importance and that Eddington was in the best position to lead an expedition to observe it – an experiment which would have the effect of counteracting a widespread but mistaken notion that the most important scientific research is conducted in Germany. "
The letter did the business. The local court said he was convinced that Eddington was a true conscientious objector. and that his work was of great importance "not only for this country, but for the whole world – for knowledge in general". For example, during the fiercest fighting of the war, Eddington got the official green light to test Einstein's theory.
The 1919 event had several objectives. The eclipse would last more than six minutes, one of the longest of the twentieth century. In addition, the sun would sit on a rich background of stars, the group of Hyades, offering a multitude of objects to test the prediction of Einstein to light. Another advantage: these stars were relatively bright.
By the time Eddington and his colleagues left to observe the eclipse, the war was over. Eddington and a collaborator traveled to Principe, a Portuguese island off the west coast of Africa, while a second British team traveled to Sobral, in northern Brazil. . At Principe, the clouds almost masked the observations. At Sobral, the lens of the main telescope was distorted, apparently because of the heat of the sun, producing fuzzy photographic plates.
Yet when Eddington and his colleagues returned to England and compared the positions of the stars they could image during the eclipse with the positions when the sun was elsewhere in the sky, they found the amount of light that Einstein had predicted (plus recent claims that Eddington would have falsified data in favor of Einstein proved to be false).
The day after Eddington announced the results at a meeting of the Royal Society in London on November 6, 1919, the cover page of the Time London was full of stories about war and remembrance. Just days before the first anniversary of the armistice, King George V had just invited all the workers to take two minutes of silence from their day to commemorate and honor "the glorious dead." But to the right of these stories appeared an article on rebirth and rebirth. In a three-story title, the normally stopped Time wrote: "Revolution in Science / New Theory of the Universe / Reverse Newtonian Ideas."
The news triggered a chain reaction around the world. the New York Times followed suit with a front page story on November 10: "Lights All Askew in the Heavens. . . The triumphs of Einstein's theory.
A century later, Einstein's theory of gravitation continues to open up unexpected new perspectives on the birth and life of the cosmos. The discovery of gravitational waves – invisible space-time ripples offering a new way to learn about exploding stars and some of the world's most violent collisions – and the existence of black holes and their shadows, one of which was recently imaged the first time – were predicted by Einstein's theory.
International collaborations are now commonplace and an expedition like Eddington would almost certainly include scientists from many countries. But in today's polarized climate, the question may be more important than ever: can science remain separate from politics?
All that scientists can do, is continue to try.
This essay is adapted from the new book of the author Gravity & # 39; s Century: From Einstein eclipse to black hole images, published by Harvard University Press.
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