From anonymity to stardom via a solar eclipse The locations of the now visible stars appeared displaced, due to the fact that their light had to travel to us on the curved space around the sun caused by its gravity, as described by Einstein. The scientists’ measurements during the eclipse showed that, astoundingly, Einstein’s predictions were indeed correct. An eclipse, where the moon blocks the sunlight enough for stars to be seen near the sun, was the perfect opportunity to test this. If the theory were right, the light from stars should be bent by the gravity of the sun and appear displaced.

Then, on May 29, 1919, an expedition of English scientists – led by Sir Arthur Eddington – traveled to the island of Príncipe off the west coast of Africa to observe a total solar eclipse. He had proposed general relativity in 1915, and scientists had been intrigued by the entirely new way of thinking about gravity – for example, the idea that mass causes space to curve – but no one had experimentally proven the theory to be correct. Einstein was relatively unknown at the time. The eclipse is famous for testing Albert Einstein’s theory of general relativity. May 29, 1919, is the date of a solar eclipse that caused a revolution in science. See the tick marks around stars near the eclipsed sun? It was the precise measurement of the positions of these stars that proved the sun bends starlight, in accordance with Einstein’s theory of general relativity. This early photograph shows the total solar eclipse on May 29, 1919.

Curved space graph