Rupert ReynoldsNov 5

#ParticlePhysics question. As I understand things, a nucleus can be unstable because there are not enough neutrons--all the particles in a nucleus are subject to the strong force, but this can be almost balanced by repulsion between the positive charges of protons, giving a statistical chance that particles can fly out.

But a nucleus can also be unstable with too many neutrons. If they experience the same strong force, but no repulsion due to their neutral charge, why can't we have, say, helium with dozens of neutrons?

Or is it one of those exclusion things, where every neutron must have a unique quantum state?

Show threadmdrslmr

@RupertReynolds
Quoting:https://en.wikipedia.org/wiki/Nuclear_force
The nuclear force has a spin-dependent component. The force is stronger for particles with their spins aligned than for those with their spins anti-aligned. If two particles are the same, such as two neutrons or two protons, the force is not enough to bind the particles, since the spin vectors of two particles of the same type must point in opposite directions when the particles are near each other and are ...

#ParticlePhysics

Nuclear force - Wikipedia

Nov 6 at 9:56amWeb
Show threadRupert ReynoldsNov 6

@mdrslmr Oh thank you! Fascinating stuff.

I have this difficult old habit of comparing subatomic stuff with the big things and their mostly Newtonian mechanics, so thanks again :-)