I can't believe I almost let it pass me by, but today is the 90th anniversary of the most ground breaking experiment of the 20th century . On this day in 1919 Arthur Eddington observed the solar eclipse that would ultimately revolutionize our understanding of the universe. A huge part of Einstein's General Theory of Relativity is how gravity itself warps the fabric of space-time itself. According to his then brand new theory, a ray of light passing near a massive object will bend around the object. The classic illustration of this is a heavy bowling ball suspended on a flexible rubber sheet. All around the bowling ball, the sheet bends in because of its mass. Now picture a small marble rolling across the sheet, its path taking it near to the bowling ball. It will curve in where the sheet is bent, deflecting its otherwise straight course. Eddington, with the backing of the Royal Astronomical Society, set out to test this theory and embarked on an expedition to the island of P
brought to you by the American Physical Society