Is the Universe a hologram?

How do we know that what we’re seeing in the world around us is real and not merely an illusion? To apply the analogy that writers from The Register used (link), imagine characters on a television show could talk to us – their surroundings would seem like a real 3D world to them, when really it is a 2D image projected onto the television screen. Therefore there has been a theory established known as the Holographic Principle, which states that the space around us is a 2D structure “painted” on the cosmological horizon. We use cosmological horizons to set the scale and size of the observable universe. Continue reading