more about the neutrino

The neutrino as a hypothetical particle was "born to" Wolfgang Pauli in 1930. At that time it was known that many atomic nuclei end their lives by emitting an electron. This process, termed beta decay, was a researcher's headache – it seemed to violate one of the sacred laws of physics, the law of the conservation of energy.
    Pauli offered a "desperate" solution. He proposed that the nucleus not only emits an electron but another particle as well, one that lacks electric charge and reacts very little with its environment. This tiny particle, the neutrino, takes some of the energy with it and disappears without trace. The energy balance is restored provided the share the neutrino has taken with it is included. Pauli thought he had done something terrible by proposing a particle that could never be discovered. But on this point he was, fortunately, too pessimistic.