Neutrino is a kind of basic particle, which plays a very important role in the macro origin and evolution of the universe  Because it has no mass and no charge, and the interaction with other substances is extremely weak, the motion trajectory of neutrino will not change
Those neutrinos from the distant universe, from the edge of black holes or from the birthplace of cosmic rays can tell human beings where sources are and can even help us explore the black hole
Untouchable: invisible neutrinos