HOW would you feel if you were told that everything you did today – drinking your morning coffee, meeting your colleagues, your jog – was a holographic projection of another, flat version of you living on a two-dimensional “surface” at the edge of this universe?

Whether we actually live in a hologram is up for debate, but it is now becoming clear that looking at a raft of other phenomena through a holographic lens could be key to solving some of the most intractable problems in physics, including what gives particles mass, the physics that reigned before the big bang, even a theory of quantum gravity. There may be no limit to holography’s reach.