your-god-is-too-small May. 2016 | Page 147

The “Don't Ask Don't Tell” of The Soul By - Dean Van Drasek What is a Neutrino, and why is it Hard to Find? A recent advance in particle physics in Japan (Livescience - Neutrino Particles Change Flavors) was based on the detection of just 22.5 electron neutrinos over an extended period of time. I fell in love with neutrinos as a kid, after I read Isaac Asimov’s book “The Neutrino: Ghost Particle of the Atom” (1966) and although the science in the book is somewhat dated, it’s still an excellent read. An electron neutrino has no electric charge, so you can’t detect it through an electromagnetic interaction. The mass is so small that it still has yet to be accurately measured, but most estimates place it at something less than 2.2 eV (electron volts), or maybe significantly less. This is a terribly small quantity of energy. 1 eV is equivalent to 1.6x10(-19) joule (J). By way of comparison, “6.24×1020 eV is the energy consumed by a single 100 watt light bulb in one second. They travel at or near the speed of light (maybe faster), and have been noted theoretically to be able to pass through several light years’ worth of lead before having a statistically relevant chance of interacting with (i.e., hitting) the lead. Keep in mind, a light year is 9.4607×1012 km. If you want to think of this in terms of weight, just divide eV by the speed of light squared (as derived from Einstein’s famous rest mass equation E=mc²) and you get the mass of one eV expressed as 1.783×10 −36 kg. An hydrogen atom, which is the lightest atom, is 1.674x10 −27 kg. A grain of sand is about 3.5x10-10 kg. The only thing usually thought to be lighter than an electron neutrino is the theoretical rest mass of a photon (a single quantum of electromagnetic radiation, i.e. light). P a g e | 147