Length, width, depth… Knowing these parameters allows us to judge which table will fit into our dining room, which bed is right for our bedroom. We use three measures to describe the space around us, but we rarely ask ourselves whether reality is, in fact, three-dimensional.

It turns out that the magical world behind the looking-glass portrayed in Lewis Carroll’s novel about Alice is real – it has been discovered and described by physicists. So how do we find a way in?