Comment by Tagbert
2 years ago
I've heard neutrons described as a union of a proton and an electron based on masses. The reality is probably much more complex.
2 years ago
I've heard neutrons described as a union of a proton and an electron based on masses. The reality is probably much more complex.
> neutrons described as a union of a proton and an electron based on masses
If you squish an electron and proton really hard, you'll get a neutron [1].
[1] https://en.wikipedia.org/wiki/Electron_degeneracy_pressure
And a neutrino: https://en.wikipedia.org/wiki/Electron_capture
If I understand correctly, which I probably don't, this is what releases the final wave of neutrinos in a supernova.
Certainly when a free neutron decays it releases a proton and an electron, but also (probably, hypothetically) an antineutrino.
https://en.wikipedia.org/wiki/Free_neutron_decay
The neutron and the proton are pretty similar. Of course, there's that tiny little bit of extra mass, but other than that:
Strong-force-wise, they are very hard to tell apart.
Weak-force-wise, you have the obvious changes in allowed interactions, but it's all stuff that's plain once you understand the theory of the weak force. No surprises.
Electromagnetism is actually the interesting one: just how neutral is this neutral garbage can? There are some interesting measurements to be made here. ILL in particular has done a lot with neutrons.
And the there's gravity. Gravity, you ask? Really? Yeah! If neutrons are really neutral, they don't interact electromagnetically, it's hard to get the strong force to come out and play, and the weak force only really does its thing here on the predictable* timescales of neutron decay... so all that's left is gravity. And thus, neutrons get used (or, I guess, more commonly just proposed...) as probes for gravitational effects! Fun, huh?
(* Mostly. See neutron lifetime controversy....)
https://en.wikipedia.org/wiki/Nucleon_magnetic_moment