“A hologram is a thin 2-D piece of plastic which, when illuminated correctly, yields a realistic three-dimensional image,” says Greene in this week’s episode of the Geek’s Guide to the Galaxy podcast. “The idea is, we may be that three-dimensional image of this more fundamental information on the 2-D surface that surrounds us.”

This notion, known as the holographic principle, came out of the study of black holes. Scientist Stephen Hawking believes information that enters a black hole is lost forever, but this seems to violate fundamental laws of physics, which led researchers such as Leonard Susskind and Gerard ‘t Hooft to consider alternatives.

“Over the course of many years,” says Greene, “they developed an idea that when an object falls into a black hole, yes indeed, it falls in, but a copy of all of its information content gets in some sense ‘smeared out’ on the surface of the black hole, on the horizon of the black hole. Smeared out in some sense like a series of 0′s and 1′s, the way information is stored in a typical computer.”

 And if three-dimensional objects inside a black hole can be represented by two-dimensional data spread across its surface, the same might be true of our universe as a whole.