Physicists report electron is round—what does that mean?

Enlarge / Right now, we don't have a big enough magnifying glass to spot the electron's dipole moment. (credit: Adam West/Harvard)

Last week, or maybe the week before (the days fly by so fast), reporters were all agape with surprise that the electron was round. Very round. I put it on my list of things to write about, took a deep breath, and dived back into the painful process of grading. Grades are now done, and the electron is still round.

What makes a round electron so important? And what do we mean by round anyway?

It’s all about symmetry

The electron is, in most conceptions, a perfect point particle. It has no internal structure—it is simply a point with a negative charge, some angular momentum, and a tiny magnet.