Free Radicals - Michael Brooks [29]
Dyson had already looked at photographic plates exposed during previous eclipses, but he found nothing that could prove or disprove Einstein’s theory. He had worked out, however, that a total eclipse due in 1919 would provide the required data – as long as the scientists were prepared. For any eclipse, totality occurs only along a narrow strip of the Earth’s surface. The result is that only a few observing sites offer the necessary darkness. To make the observations, Dyson decided, a team of astronomers would need to embark on a long and arduous expedition to Principe, an island off the coast of West Africa.
Dyson told the Military Service Tribunal hearing Eddington’s case that Eddington’s work ranked alongside that of Darwin, and then reminded them that the pre-eminence of British science was in question. There was, he said, ‘a widely spread but erroneous notion that the most important scientific researches are carried out in Germany’. If Britain’s astronomers were given enough time to prepare for and undertake the expedition, the Principe observations would put that matter to rest and restore the pride of Britain. ‘Prof. Eddington is particularly qualified to make these observations, and I hope the Tribunal will permit that important work to be continued.’
The ruse worked – on both parties. The Tribunal allowed Eddington to carry on with his research, and Eddington, to everyone’s relief, accepted the exemption. As Matthew Stanley, one of Eddington’s biographers, has put it, ‘it was an opportunity for him to bring a peace-loving, insightful German to prominence in both science and society’.
In other words, Eddington already believed that Einstein was right, and he was quite prepared to accept a God-given opportunity to prove it. The expedition to Principe was a chance to bring peace on Earth. In a statement Eddington made years later, he pointed out that his confirmation of Einstein’s theory was ‘not without international significance’, because by ‘standing foremost in testing and ultimately verifying the “enemy” theory, our National observatory kept alive the finest traditions of science; and the lesson is perhaps still needed in the world today’.
Having established that Eddington had motive – perhaps the best of motives – for ensuring that Einstein’s theory was validated, we can now look with eyes wide open at what he did to achieve it.
If the Divine Hand did send Eddington to Principe, it did nothing to help with the observations. The expedition was faced with a barrage of rainstorms, and its members had to build waterproof shelters for the equipment. Thanks to the island’s lively insect population, everyone had to work dosed up on quinine and sheltering under mosquito nets. At night, monkeys would emerge from the forest and, fascinated by the telescopes, clamber over them and interfere with the settings. Enraged, the scientists joined the technicians in hunting down and killing these intruders.
And then, on the morning of eclipse, the heavens opened again. Though the rain stopped two hours before totality, a blanket of grey cloud still covered the entire sky. Just in time it cleared a little, and Eddington was able to take some pictures of the Sun through his telescope, but the cloud ‘interfered very much with the star-images’. Not surprisingly, the photographs were a let-down. During the eclipse, Eddington captured sixteen images on photographic plates. A week later he had managed to develop twelve of them, but only two were useable: the majority ‘show practically no stars’,