Question

what is aperture square equal to, like in physics light. I Don't Remember Completely But Is It Intensity Of Light?​

Answer 1

ANSWER:

There is a nice summary of this experiment in a recent post. The upper limit for the mass of an electron neutrino is 1.1 eV where eV is electron-volt; 1 eV=1.6x10-19 J. Note that, although physicists usually call an eV a mass by convention, it is really the rest mass energy of the particle, i.e. mc2. So the upper limit of the mass energy of an electron neutrino is 1.6x10-19/(3x108)2=1.8x10-36 kg. Now, most of the mass (not counting dark matter) of the universe is in protons and neutrons each of which has a mass of about 1 GeV=109 eV, a billion times bigger than the the neutrino. Electrons have a mass of 500 keV=500,000 eV; we would expect there to be about as many electrons in the universe as protons so electrons would only contribute about .025% of the total mass. There are about 337 neutrinos/cm3=337x106 m-3 in the universe, so the mass energy density is about 3.7x104 eV/m3; the average ordinary mass density of the universe is about 4x10-28 kg/m3=3.6x10-11 J/m3=2.25x108 eV/m3. So the neutrinos contribute less than about 3.7x104/2.25x108=1.6x10-4=0.016% of the ordinary mass. Keep in mind that all this represents order of magnitude calculations; the numbers should not be taken too seriously but the relative numbers should be right to better than one order of magnitude.