why we always constructed observatory under a moutain or deep underneath the ground.. For example the newly The Super-Kamiokande neutrino detector is a physics experiment the size of a 15-story building, buried under a mountain in Japan

Question

Curious

In: Physics

Answer 1

This is really only true for neutrino detectors. That’s because neutrinos are extremely hard to detect because they almost never interact with matter at all. About a hundred *trillion* neutrinos pass completely through your body every second and you don’t even know it. Most neutrinos pass completely through the Earth without interacting with it at all. Building the detectors underground isolates the detectors from sources of interference (especially cosmic rays) that can’t penetrate deep underground. That way we can be sure that the detectors are actually detecting neutrinos and not just interference or other random noise.