Have you been feeling a bit flat lately?
You think you live in a 3D universe, move about in 3D space, go to 3D movies in theaters that have three whole dimensions, but you might be wrong. Your experience of being a three-dimensional person might just be a result of the limits of your perceptions, like a character on a video game screen you have no way of knowing you’re flat.
Instead, you might live in a 2D hologram, with all of the information about our universe encoded in two dimensions in tiny packets 10 trillion trillion times smaller than an atom (a size called the Planck scale), the “pixels” that make up our universe.
At least that’s what the U.S. Department of Energy’s Fermi National Accelerator Laboratory is going to try to find out. They’ve developed an experiment that will test the theory, called the Holometer.
In quantum theory there’s a built-in uncertainty to matter, because there’s no way to know both the exact location and speed of subatomic particles. If space is indeed a 2D structure with a limited amount of “bits” to store info, then there is a point where it becomes impossible to find more information about the specific location of something. And the uncertainty that makes matter seem to vibrate as quantum waves even if cooled to absolute zero would also apply to space, which means space should have its own “jitter” that can be observed.
“We want to find out whether space-time is a quantum system just like matter is,” said Craig Hogan, director of Fermilab’s Center for Particle Astrophysics and the developer of the holographic noise theory. “If we see something, it will completely change ideas about space we’ve used for thousands of years.”
The Holometer is the most precise device ever built to try to measure the jitter of space. It splits and recombines a powerful laser beam in a way in which there should be fluctuations in brightness if there is motion. Scientists will try to measure those fluctuations to see if they indicate the movement of space.
The challenge will be to get a clean reading. The device is so sensitive that it can be thrown off by radio waves from nearby electronics. But the experiment is designed to eliminate these misleading fluctuations.
“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,” said 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.”
Image of the Holometer from Fermilab