Arthur Eddington

Sir Arthur Eddington (1882–1944) was a British astronomer and physicist perhaps best known for his expedition to Principe (an island situated 200 km or 150 mi off the coast of Gabon) in 1919 to observe the bending of starlight around the sun during a total eclipse. The theory of general relativity of Albert Einstein predicts twice the bending of light around massive objects compared to Newton's theory, and an eclipse is required to darken the sun so that the starlight may be seen in proximity to the sun.

Eddington was a conscientious objector during World War I. This wasn't a popular position at his time. When general conscription was introduced in 1916, Edddington entered his plea to claim exemption on grounds of conscience, but his university had requested the authorities not to withdraw him from his scientific researches. Eddington had declared:

"My objection to war is based on religious grounds. I cannot believe that God is calling me to go out to slaughter men, many of whom are animated by the same motives of patriotism and supposed religious duty that have sent my countrymen into the field. To assert that it is our religious duty to cast off the moral progress of centrutries and take part in the passions and barbarity of war is to contradict my whole conception of what the Christian religion means. Even if the abstention of conscientious objectors were to make the difference between victory and defeat, we cannot truly benefit the nation by wilful disobedience to the divine will."

He was exempted until Aug 1, 1918, and the Astronomer Royal Sir Frank Dyson supported the idea of an expedition - lead by Eddignton - to observe the solar eclipse of 1919.

The next year, Eddignton presented his observations to the Royal Society as a proof of the theory of relativity. Recent analysis of Eddington’s work revealed that he was biased in selecting his data, and that overall his data was inconclusive about the theory of relativity.

Eddington next promoted the theory of relativity to the English-speaking world in his Mathematical Theory of Relativity (1923). As the title suggests, this theory was more a mathematical vision of how the universe should be, rather than what it actually was. When a reporter asked Eddington whether only three people even understood the theory, Eddington supposedly arrogantly retorted, "Who's the third?"

But Eddington did not fare well after that. He strongly opposed a theory about massive stars known as white dwarves put forth by Indian physicist Subrahmanyan Chandrasekhar, but Eddington was proven wrong and Chandrasekhar later won a Nobel Prize for his work. Eddington finally lost all credibility when he first insisted that a physical constant (the fine structure constant) measured to be close to 1/136 must precisely equal 1/136 to make the math easier, but when later measurements suggested a value closer to 1/137 Eddington insisted that it must precisely equal to 1/137 instead. He was wrong both times.