How a total solar eclipse 100 years ago proved Einstein right

Exactly one hundred years ago, one of humankind's most important experiments was carried out. It involved a solar eclipse and the bending of light, and it proved Albert Einstein's theory of general relativity. Our Perspective guest, eminent South African theoretical physicist George Ellis, explains what the experiment involved. He also tells us how it turned Einstein, whose work had been treated with much scepticism until then, into an international celebrity.