In this video, I explain why some scientists believe that our universe is a hologram and we really live in the 2-dimensional projection of a higher dimensional space. First, I explain just what physicists mean by the “holographic principle.” The holographic principle says that the degrees of freedom inside a volume of space can be described by information on the surface of that volume at the same resolution. Then I explain that this relation goes back to ideas about the black hole entropy and string theory in space with a negative cosmological constant, the so-called Anti-de Sitter space. I briefly mention what the problems are with these arguments. I then discuss a recent idea of Verlinde & Zurek about how one could test holography experimentally. Finally, I tell you my own opinion about this. As so often, I am highly skeptical that wild speculation will lead to progress.