After the discovery of beta radiation by Ernest Rutherford in 1898 and the formulation of the mass-equivalency relation by Einstein in 1905, scientists realized that beta radiation was behaving in an odd way. The expected kinetic energy of the beta particles was less than expected and spread out over a spectrum as opposed to the expected single value. Some thought energy conservation was being violated, but a few scientists thought outside the box and proposed a new elementary particle, the neutrino, that would keep energy conserved and save the physics of beta decay.