Is There a Fourth Dimension? Experiments Using Lasers and Light Reveal Alternate Reality

Is there a fourth dimension? Robin Utrecht/AFP/Getty Images

Try picturing a fourth dimension. Take a few steps forward. Veer left for a second dimension, then jump up for a third dimension. Then dive off into a fourth dimension, somewhere, somehow, in a direction we don't have a word for because our minds can't grasp even the idea of it. That's a fourth dimension of space, about which two new studies yield some clues.

Scientific experiments can't grasp a fourth dimension any better than we can. But if scientists can design them very, very carefully, their studies can produce shadows of a sort, which suggest a fourth dimension really is there lurking just beyond our grasp.

Two such physics experiments have done just that, according to two new papers published in the journal Nature. (The research was conducted mostly by independent teams tackling similar big questions with very different little questions, although one co-author was involved on both projects.)

The researchers used two different approaches to dance around the idea of a fourth dimension. They looked for a specific type of theorized "fingerprint" that is two-dimensional and therefore within our capabilities instead, as Gizmodo reports. In both cases, the experiments demonstrated phenomena that actually require just two dimensions, nice and mundane.

That said, the tools required to get those phenomena to manifest were anything but mundane. One experiment relied on lasers to trap individual atoms of a highly reactive element called rubidium in a square, like a cat carefully sitting between taped lines. The other experiment used a box full of special glass that manipulates waves of light, wiggling the furthest edge of the box and seeing how the effects rippled throughout the box.

Read more: Universe Is 3-D Because It Got All Knotted After the Big Bang

Both studies let scientists explore fourth dimension theories in new ways. The physicists on both these projects aren't just looking for a nice brainteaser, of course. They want to stretch our knowledge and technology as far as possible. Even if we can't actually experience a fourth dimension ourselves, they think reaching for the fringes of it could offer valuable lessons that we can implement right here in the 3-D world we live in.

"Maybe we can come up with new physics in the higher dimension and then design devices that take advantage of the higher-dimensional physics in lower dimensions," lead author on one of the papers, Mikael Rechtsman, a physicist at Penn State University, told Gizmodo.