The Kung-Fu Move that Explains One of Quantum Physics' Strangest Properties

As much as that Feynman quote gets tossed around about no one really understanding quantum physics, there are people in the world making laudable strides towards the development of quantum intuition. One of them is the physicist Felix Flicker, who also happens to be way into kung-fu.

The move demonstrated in the video illustrates a quantum property known as spin, which happens to be one of the stranger yet less-hyped things about particles. This has to do with particles called spinors, like electrons. Spinors spin, obviously, but they don't spin like anything we can experience or even imagine.

As a mathematical space ​can have more than three dimensions, however brain-wracking that is, a spinning particle experiences something sorta similar. Imagine Earth itself as a giant spinor. Wherever you are, within the next 24 hours, the Sun will set and the Sun will rise. Each event will happen once as the non-spinor Earth rotates one time. Spinor-Earth, however, will have rotated just a single time per two sunsets and two sunrises.

In other words, a spinor, which is really better thought of as a mathematical object than a "thing," will have rotated once for every two observed rotations.

"Imagine we have two electrons in a plane," ​Flicker writes in Physics World. "Because all electrons are identical, if we prod our two electrons into switching places, everything will be just as it was, right? Not quite. Electrons are fermions, so the combined two-electron wavefunction picks up a minus sign when the electrons swap places—it is antisymmetric under exchange."

A pair of fermions found within a single system can be thought to share a single wavefunction, which really just means that any two fermions (like electrons) are indistinguishable, perfect twins. In this situation, spinning a single particle (or single particle state) is actually like spinning two particles (two particles sharing a single state), so the whole mess might start to make a little more sense.

But not too much sense. Spin statistics even has its very own quote, this one from the physicist mathematician Michael Atiyah: "No-one fully understands spinors. Their algebra is formally understood but their general significance is mysterious."