The neutrino is the most elusive of the known elementary particles. It has no electric charge and, as far as we know, no rest mass. The neutrino hardly interacts with matter at all. It can go through lead with a thickness of 10 000 billion kilometres (one light year) without interacting. The neutrino interacts with matter only through the weak force.
    In 1930 the Austrian, Wolfgang Pauli (Nobel Prize 1945) suggested a new type of particle, the neutrino. Many of those who heard of the new particle received the news with a certain scepticism.
    A few years later, Enrico Fermi, Italy (Nobel Prize 1938) developed the theory for the weak force. Fermi called Pauli’s particle the small, neutral particle – the neutrino.
    In 1956 Frederick Reines and Clyde Cowan, USA, performed an experiment demonstrating the existence of the neutrino.