Scientists have now established mathematically that the 3-D external world that we live in is actually a “flat-space” hologram. Holograms are brought about by a trick of the light, a projection of information encoded in just 2-D actually appears in 3-D. This theory that the external world we see is actually a hologram has been around for some time. In the 1990s physicists working with string theory in a complex 5-D space discovered that by reducing the number of dimensions by one they could make gravity disappear. This trick was called “AdS/CFT correspondence” and although it was developed in that complex 5-D space it has since been discovered that it can also be applied to explain the workings of superconductors and why particles have mass in our “real” world.