How do scientists use neutrinos to study the weak force?

Neutrinos are exceptionally useful for studying the weak force because they interact only through the weak force and gravity, making them very hard to detect. Large detectors such as Super-Kamiokande in Japan and IceCube at the South Pole observe occasional neutrino interactions in huge volumes of water or ice. By measuring interaction rates and energy patterns, physicists test weak-interaction theory and neutrino properties such as oscillation. The fact that neutrinos pass through Earth almost unhindered is itself a sign of how weak this force is. Neutrino research has become a major part of particle physics and astrophysics.