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> There are no little billiard balls … electrons don't actually orbit

Wait, what? What do they do then? My physical science education ended in high school.



The next useful falsehood on the ladder is that electrons in an atom exist as probability densities around the nucleus. Fire a photon here, and knock an electron off with this probability; fire it there, and get that probability instead. But before they interact with something, electrons aren't anywhere in particular. https://en.wikipedia.org/wiki/Atomic_orbital

The real answer is that constituent parts of bound states like atoms don't really exist as separate things. An atom is a particular very complicated field configuration, and if you want anything deeper than that you're going to have to learn QFT.


If constituent parts of bound states like atoms don't really exist as separate things, how come electrons in metals can move around readily? Is it that they're not really bound, or is it just that they 'attach' and 'detach' easily?

When I think of chemistry, it seems like even if there's some sense in which the bound atom is one big writhing mass of fields, the whole atom doesn't interract in a uniform way with the outside, right? The electrons interract with the outside a lot, the nucleus is harder to get to?

Is it wrong to say the layer of my onion exist as separate entities, when they seem to interract largely independently from the core of the onion, like they do in metals and chemistry?

(I guess the answer is still "you're going to have to learn QFT" :) But the next falsehood down seems fun to ask about too!)


> If constituent parts of bound states like atoms don't really exist as separate things, how come electrons in metals can move around readily? Is it that they're not really bound, or is it just that they 'attach' and 'detach' easily?

Some of both. Valence electrons in a conductor are delocalized over the entire surface.

> When I think of chemistry, it seems like even if there's some sense in which the bound atom is one big writhing mass of fields, the whole atom doesn't interract in a uniform way with the outside, right? The electrons interract with the outside a lot, the nucleus is harder to get to?

Right, at least for stable atoms at low energy scales.


Thank you, this is the first time I've read a description of what an electron probability density means that has made real sense to me.


Field theory: David Tong: Quantum Fields https://youtu.be/zNVQfWC_evg?t=1168


Thank you




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