General relativity : everyone has heard about the theory imagined by Albert Einstein. This year, the theory celebrates its 100th birthday. Few people know that it has been successively praised, attacked, rejected, even forgotten and then finally «rediscovered» during the 1960s.
That story, unknown to the general public, is being told to us by Albert Einstein himself, and by some of the scientists who validated and revived the theory. Like Sir Roger Penrose, one of the most brilliant British mathematician who gave visual representations of a black hole, a strange cosmic object that challenged the theory. Or Jocelyn Bell who, as a student in Cambridge during the sixties, discovered a new range of stars – the pulsars – which matches the predictions of general relativity.

Einstein in the sky. Credit: Naji El Mir/LookatSciences.
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