Popular Science wrote:Fermilab is Building a 'Holometer' to Determine Once and For All Whether Reality Is Just an Illusion
Researchers at Fermilab are building a “holometer” so they can disprove everything you thought you knew about the universe. More specifically, they are trying to either prove or disprove the somewhat mind-bending notion that the third dimension doesn’t exist at all, and that the 3-D universe we think we live in is nothing more than a hologram. To do so, they are building the most precise clock ever created.
The universe-as-hologram theory is predicated on the idea that spacetime is not perfectly smooth, but becomes discrete and pixelated as you zoom in further and further, like a low-res digital image. This idea isn’t novel; recent experiments in black-hole physics have offered evidence that this may be the case, and prominent physicists have proposed similar ideas. Under this theory, the universe actually exists in two dimensions and the third is an illusion produced by the intertwining of time and depth. But the false third dimension can’t be perceived as such, because nothing travels faster than light, so instruments can’t find its limits.
If you didn't understand that, try this (not that it's much better):
Black hole physics, in which space and time become compressed, provides a basis for math showing that the third dimension may not exist at all. In this two-dimensional cartoon of a universe, what we perceive as a third dimension would actually be a projection of time intertwined with depth. If this is true, the illusion can only be maintained until equipment becomes sensitive enough to find its limits.
“You can’t perceive it because nothing ever travels faster than light,” says Hogan. “This holographic view is how the universe would look if you sat on a photon.”
Still no? Maybe this?
More recently, theoretical studies of black holes, and later in string theory and other forms of unification, have suggested that physics on the Planck scale is holographic. It is conjectured that space is two dimensional, and the third dimension is inextricably linked with time. If so, our three-dimensional world is a kind of approximate illusion that emerges only on scales much larger than the Planck length.
It could be that the illusion is imperfect and blurry. The maximum frequency may introduce a particular kind of noise or jitter into spacetime, as measured by the propagation of light in different directions.
Riiiight. Me, neither. Still fun to think about, though.