Mark Garlick/Science Photo Library/Alamy
In 1998, astronomers made a startling announcement. Space-time, the unified phenomenon that contains our universe and that used to be prior to now understood to be increasing, used to be in reality now not simply rising, however rising sooner and sooner as time went on. In different phrases, its growth used to be accelerating. This used to be the beginning of the cosmic acceleration drawback: what was making this acceleration? It gave the impression to be actually coming from nowhere – from the vacuum.
From the viewpoint of basic relativity, cosmic acceleration may well be defined via pronouncing that vacant space-time has power that drives this growth, that it isn’t utterly empty. This power…