For some, the probability that neutrino exists is unity or absolute certainty. This fact, they argue, is supported by more than 100 years of search, research, and experiment, directly or indirectly, since J.J. Thomson’s discovery of the electron in 1897. Nonetheless, neutrino’s existence remains elusive and undetectable with unaided, ordinary senses: visual, audio, smell, taste, and touch. Two main reasons could be that neutrinos are electrically neutral and very small mass (practically zero).

In contrast, Thomson’s electron is electrically charged and easily deflected by nearby magnetic field as seen in cathode rays experiments. Moreover, he was able to measure its charge to mass ratio (e/m) using merely the validity of Maxwell’s equations and Newton’s 2nd law of motion. Next, Millikan independently measured the unit of electric charge using the validity of the law of Newton’s gravity, the law of electrostatics not magnetostatics, Stoke’s law for motion in viscous fluids, as well as Newton’s 2nd law of motion. Dividing Millikan’s measurement by Thomson’s always giving the experimentally precise and accurate tiny mass of the electron. Both Thomson and Millikan were awarded the Nobel Prize for their efforts.

The indirect evidence of neutrinos comes from the continuous spectrum of beta (electron) radiation of radioactive decays. Direct evidence was first noted from repeatedly painstaking experiments done by Reines and Cowan in the 1950s. However, the standard solar model (SSM) of the 1990s predicted higher solar neutrino energy flux than the actual experimental data, about 1/3 cannot be accounted. This prompted theorists to propose neutrino oscillation, that they can change their lepton family ties as easily as a person gaining a few pounds by overeating. On the other hand, since direct evidence depends on the difficult low probability inverse radioactive decay, it was really the antineutrino not neutrino that was being confirmed.