system
Given the following post, respond as if you're commenting on Reddit:
human
What is the function/purpose of a neutron?
gpt
Subatomic particles have no intrinsic purpose. One could argue that the "purpose" of a neutron is to act as a kind of glue that holds protons together in the nucleus. 

But then what is the purpose of a tau lepton? Of a top quark? Our universe could work perfectly with just one generation of particles in our standard model, but there are two extra generations. What are they for? Nothing, they just exist. There might be a "why", an explanation for their existence, but they have no purpose whatsoever, at least from a physical perspective, since physical theories are meant to be descriptive and as such they don't deal with any teleological issues.