A ‘shadow’ cast on the faint, leftover glow of the Big Bang has revealed a giant object in the early Universe that defies our predictions of how the Universe should evolve. It’s a galaxy cluster named SPT2349-56. Spotted a mere 1.4 billion years after the Big Bang, the gas within it is far, far hotter than it should be. The gravitational heating of a galaxy cluster ought to be a slow process that takes billions of years to reach the temperature regime of SPT2349-56. “We didn’t expect to see such a hot object atmosphere so early in cosmic history,” says astrophysics doctoral student Dazhi Zhou of the University of British…