array9

How on earth would you find out?

My guess is that if you want to call a halt to the cascade of smaller and smaller particles, then you need at some point to have something which really cannot interact with itself, other than through gravity.  Clearly photons don't.  And so I vote that neutrinos don't.

If you see neutrino's as being the spacial granularity or quantum, then I think you want them to only ever be able to hit absolutely head on, and not scatter.  So you might get reflection.  But I prefer the thought that this does not happen.

You could only tell if you could tell the difference between the neutrinos, colour or whatever.

I feel it is nicer to assume that you can never see a collision, and see what the consequences might be.

Martin