[povik]

> I don't really understand the physics of why electrons don't collapse into the positive nucleus, since positives and negatives should attract

My (student of physics) answer to that would be that they are pretty much collapsed as much as they can. It’s just that under quantum mechanics that least energetic state is not the one in which the electron is perfectly co-localized with the positive charge. (As that perfect co-localization is not even physically attainable.)

[JadeNB]

It's maybe worth mentioning that, pre-quantum mechanics, this was so far from being a naïve question as to be one of the motivating concerns of early-20th-century physics. It's not the same thing as, but is closely related to, the ultraviolet catastrophe (https://en.wikipedia.org/wiki/Ultraviolet_catastrophe).

[nextaccountic]

> (As that perfect co-localization is not even physically attainable.)

But then, you have (or would have.. I think it's not experimentally verified) degenerate states of matter, like in a neutron star, where pressure is so big that the electrons collapse into protons to form neutrons.

[perl4ever]

>As that perfect co-localization is not even physically attainable

It seems to me this is simply a statement that an electron is a fermion not a boson, right?

But if a layperson wants an intuitive sense of the situation, then that doesn't really illuminate. It's a fermion, but why should it be?

[povik]

> It seems to me this is simply a statement that an electron is a fermion not a boson, right?

Not really, that's a property of any quantum particle, bosons also. They don't occupy a single point in space like you would imagine classical particles do. They also cannot occupy a single point in space relative to another particle.

> It's a fermion, but why should it be?

Well there's the spin-statistics theorem in quantum field theory which starts from some likely assumptions and then shows that particles with non-integral spin must be fermions while particles with integral spin must be bosons. Other than that I take it simply as an experimental fact. I don't think there's a nice reason for it one could give (today, that is).

[danwills]

Fascinating! I would love to gain more of an intuitive grasp on how subatomic particles all work and fit together, i'm not a physicist though. Could you suggest any good introductory reading?

[perl4ever]

layperson = me.

I like to read Wikipedia and popularized stuff. The problem is I come away unsatisfied, because even the best writing directed at people who aren't good at math, is more about giving the feeling of understanding than actual understanding.

My point about bosons and fermions, is I read the summary on Wikipedia, but they are just labels to me. I don't have the intuition or math except that it says the one kind of thing can "overlap" in ways the other can't.

Richard Feynman's "QED: The Strange Theory of Light and Matter" has been much praised though. What did I get out of it? I guess that quantum mechanics has something to do with multiplying complex numbers.

I'm not sure exactly what I'm missing, but I get the impression that if I could understand Hamiltonians, Lagrangians, or variational calculus, then I would have some insight into modern physics.

Some of it sounds tantalizingly straightforward, but at the same time beyond my mental capacity - imagine a space, a field, etc. - but it's infinite-dimensional or something. Or it's a space of functions.

Still, on Wikipedia you can keep clicking on things - what's a "fiber bundle", etc.

[danwills]

Ah whoops! It sounds like we're in a very similar boat indeed! All good, nice to meet a like-minded soul on HN.

I completely know what you mean about the complex numbers and Hamiltonians etc. A lot of the time I think I could even have a reasonable chance of understanding the concepts given a few graphs/diagrams and some kind of translation to prose/pseudocode (or even just code) but there is so much symbolic syntax in both maths and physics (too much for me!) - I think it's probably hard to become fluent unless you use it every day I reckon.

I can also imagine something like a 'reasonably realistic' subatomic particle simulation framework in a 3D engine where one could fully control time space, energies, polarisation, quantum stuff etc and really examine the events in detail. I think one could perhaps start to get a feel for how it all fits together just by playing with the various interactions and watching/virtually-measuring carefully?