Everything you know to be true may be an illusion, specifically, an optical illusion, according to scientists who suggest our universe is a hologram. This is not the first time the possibility has been raised, but it is the most convincing.
New research from scientists at the Vienna University of Technology concludes that the holographic principle is possible in the context of a mostly flat space-time continuum. Let’s back up.
The holographic principle was first proposed by theoretical physicists Gerard't Hooft and Leonard Susskind back in 1993. PBS’s Kate Becker explains:
“The holographic principle, simply put, is the idea that our three-dimensional reality is a projection of information stored on a distant, two-dimensional surface. Like the emblem on your credit card, the two-dimensional surface holds all the information you need to describe a three-dimensional object — in this case, our universe.”
The principle serves as a way to solve the black hole information paradox — according to quantum physics, all information is lost within a black hole, but according to the general theory of relativity, information can never be fully destroyed. Again, Becker explains why the holographic principle resolves the quandary:
“All the information in our three (spatial) dimensional universe can be “stored” on a two-dimensional surface. In the context of the black hole information paradox, this suggested that information about the stuff in the black hole could somehow be encoded on the surface of the event horizon.”
Voila, paradox solved.
What a black hole looks like, maybe. Artist's rendition via NASA.
But the holographic principle has been thought to only be possible in a very extreme space-time configuration, far from how we believe our universe to be constructed. Back to our scientists from Vienna, who wanted to find out if the holographic principle is plausible in a space-time continuum that resembles our own. Report co-author Arjun Bagchi explained to Fusion in an email:
“The evidence so far has been confined to gravity theories in peculiarly curved spaces called Anti de Sitter (AdS) spaces… Our work is an attempt to make the Holographic Principle work for space times which are more 'usual' than AdS, specifically flat space times.”
Lead author Daniel Grumiller further explained that the study is the first to find identical results in 2D as in 3D. That result means the holographic principle holds — we can glean the same information in two dimensions as we could in three. Per Grumiller:
"We calculate [a specific physical observable] for the first time in a specific 2-dimensional quantum field theory (without gravity), and independently in a specific 3-dimensional gravitational theory that describes flat spacetimes. We found that both results agree with each other.”
Bagchi added: "This provides evidence that our previous construction was correct and there is a notion of Holography in flat space times.”
Evidence of a possible holographic universe, however, is not proof of one. And we are a long way from proof, said Grumiller:
“A fully fledged mathematical proof of the holographic principle may be too much to ask, though it may be possible to achieve such a proof under simplified circumstances (for instance, in lower dimensions or in highly symmetric toy model theories). I would say that the best procedure is to collect as many independent hints and checks as possible.”
If the universe really is a holographic universe, then we are all holograms. Chew on that.
Danielle Wiener-Bronner is a news reporter.