Another pet peeve of mine, and even science videos like the one I posted do this: show particles like muons or electrons as rotating balls.

They are not rotating balls.

The only reason a video like that one uses rotating balls is because explaining what is happening takes a lot of words.

Just don’t believe things like muons and electrons and such are rotating balls.

They are not rotating balls.

They do have angular momentum (actually , “spin”, but it can be expressed in units of angular momentum).

But not because they are rotating balls.

Because muons (and similar particles) have a charge and have spin, they can precess when put in a magnetic field.

This experiment determined that precession is not what is should have been by some tiny tiny margin.

In that video the talking head speaks while showing an image of a top rotating. But that top is also precessing. It’s that precession which matters.

It’s one of those things in modern physics that is non-intuitive but important: muons (and elections and such) have spin, but they are not balls which are rotating.