If you were able to talk directly to characters on a television show about their virtual surroundings, they might not even realize that their apparently three-dimensional world was actually made up of thousands of tiny two-dimensional pixels.
While this is only a curious thought problem, scientists at the U.S. Department of Energy’s Fermi National Accelerator Laboratory are attempting to answer a similar question about our very own three-dimensional reality. By measuring extremely small distances more precisely, researchers hope to determine whether the universe is really a hologram made up of two-dimensional packets of information, like the pixels that show up on a TV screen.
“We want to find out whether space-time is a quantum system just like matter is,” says Craig Hogan, director of Fermilab’s Center for Particle Astrophysics and the developer of the holographic noise theory, in a press release. “If we see something, it will completely change ideas about space we’ve used for thousands of years.”
To determine the nature of the universe, the researchers are relying on Fermilab’s powerful Holometer, a holographic interferometer that is sensitive enough to measure the quantum jiggling of space itself. Their measurements depend upon the uncertainty principle, which says that it’s impossible to know both the exact location and speed of subatomic particles.
If space-time is really made up of two-dimensional units, then they should give off vibrations that the researchers can pick up. Of course, if quantum pixels exist, they would be extremely small—10 trillion times smaller than an atom. So researchers are searching at frequencies of millions of cycles of per second, where noise caused by normal matter shouldn’t cause much interference.
“If we find a noise we can’t get rid of, we might be detecting something fundamental about nature – a noise that is intrinsic to space-time,” says Fermilab physicist Aaron Chou, lead scientist and project manager for the Holometer. “It’s an exciting moment for physics. A positive result will open a whole new avenue of questioning about how space works.”
Even if our universe turns out to be like the on-screen world of our favorite TV characters — or the beautiful mosaic images that emerge from simpler subunits — the way we live our lives might not change all that much. Because, as Albert Einstein pointed out, space-time is all in our minds, not in our hearts: “Time and space are modes by which we think and not conditions in which we live.”
