· Cosmology
What Are Neutrinos? The Ghost Particles That Pass Through You by the Trillion
Neutrinos are the most elusive particles we know of. Thousands of billions stream through your body every second without touching you. Pauli invented them in 1930 to save energy conservation, Reines and Cowan caught them in 1956, and in 1998–2002 experiments showed they change identity in flight, which means they have mass. How much mass, and in what order, is still open.