The five-decade-old paradox — long thought key to linking quantum theory with Einstein’s theory of gravity — is falling to a new generation of thinkers. Netta Engelhardt is leading the way. =============================================================================== In 1974, Stephen Hawking calculated that black holes’ secrets die with them. Random quantum jitter on the spherical outer boundary, or “event horizon,” of a black hole will cause the hole to radiate particles and slowly shrink to nothing. Any record of the star whose violent contraction formed the black hole — and whatever else got swallowed up after — then seemed to be permanently lost. Hawking’s calculation...