What Is An Electron?

I get asked that question surprisingly often. It is understandable because of all the mysterious, unseen subatomic, elementary particle in our everyday lives, electrons are the ones we either encounter or deal with the most. It is the predominant carrier of electricity, and it used to be what caused our TVs to display images in the old days when we still used cathode ray tubes. So naturally, many of us are familiar with the presence of electrons, but we don't quite know what it is.

This is especially true in light of quantum mechanics. QM has made all subatomic particles, including electrons, mysterious. What we thought we knew, now seems to exhibit behaviors that are rather strange.

Frank Wilczek has a very nice article in last week's issue of Nature addressing "The Enigmatic Electron"[1]. He said something that people who are not trained in science should pay attention to:

Modern quantum theory reinforces Bohr's conclusion that what you see depends on how you choose to look. Electrons are both ideally simple and unimaginably complex. They are understood with precision yet remain mysterious. Electrons are stable bedrock in physicists' world picture, and are playthings that we are learning to fragment and transform.

And that is the central theme here. Something can appear to be mysterious, appear to have strange behavior, etc., but it doesn't mean that we know nothing about that. We have such huge and vast knowledge about electrons, their behavior (especially their collective behavior), etc. This is what drove advances in modern electronics. Yet, based on QM and QFT, there are a lot of things we either don't know, or can't quite reconcile with our classical understanding of the world. So being mysterious is NOT synonymous to not understanding anything about it.

I am emphasizing this because this is identical to what I mentioned earlier when I keep hearing people claim that no one understands quantum mechanics. This is, of course, utterly silly considering that we have a formal theory of quantum mechanics, and we have used it to produce useful applications! This ability is MORE than what can be said about many other things that people seem to think they understood.

Don't miss the Wilczek article if you have access to it.

Zz.

[1] F. Wilczek, Nature v.498, p.31 (2013).