On Nov 24, 9:25*am, Joe Snodgrass wrote:
Am I correct in my understanding that, although it was discovered in
1998 that the neutrino does indeed have mass, people still don't know
what that mass is? *TIA.

Yes, and although the way that the mass has shown up relates directly
to SRT, I will take the liberty of reviewng it here, where the topic
has risen, rather than our sister newsgroup.

The flux of neutrinos picked up on earth from the sun iin experiments
was much smaller than expected. A curious fact about neutrinos is
tghat they come in different flavors, and the experiment was designed
to detect only the flavor that was predicted to be emitted by the
sun.

An even more curous fact is that neutrinos, in principle, can change
flavors in time -- referred to as oscillation in flavor, and even at
the speed of light, it takes 8 minutes or so for them to travel from
sun to earth. So could the missing neutrinos have simply changed
flavor in transit?

Not if they have no mass, because massless particles travel at c, and
at c, clocks freeze, to put it very loosely..

Someone (no doubt a reader can supply the citation) dared to
speculate, however that maybe they have a tiny bit of rest mass!

The experiment was changed to include detection of the other flavors,
and there there they were.

So, neutrinos have mass (rest mass).

Uncle Ben