system
Given the following post, respond as if you're commenting on Reddit:
human
Can neutrinos pass through neutron stars like they pass through earth?

Since neutrinos are super-abundant, nevertheless elusive and hard to detect even by brute force, I was wondering what happens when they meet a neutron star where matter is condensed.

Do they pass through as easily?

If not, what happens when they hit a neutron? Since they interact more often, do they make the weak force appear stronger in a neutron star?
gpt
The density of a material affects how likely a neutrino is to interact. Neutrinos interact via the weak force, and only the weak force. The weak force is so named because of the relatively weak nature of the force. The interaction is also dependant on neutrino energy. 

At energies characteristic of beta decays, the mean free path of a neutrino is such that about half of the neutrinos will decay in about 1.5 lightyears **of lead**, or 17 lightyears of water. The theoretically much denser neutron star density would therefore contract the mean free path through the star. However, due to the extreme conditions in the local area of that interaction, the interaction is likely discouraged by the effects causing neutron degeneracy to be favored in the first place: if protons and electrons could survive in the core, they would. Instead, the effects of gravity favor denser neutron degenerate matter. The energy of the neutrino likely isn't enough to allow for a neutron-neutrino interaction to form a proton-electron pair.