On Sun, Jun 1, 2025 at 10:27 PM Alan Grayson <[email protected]> wrote:
>>>> *Test particles have no clocks* > > > *>>>No. Particles do have internal clocks.* > > > >> *T**hey're not pendulums or wrist watches. So how would you describe > them? AG* > > > *> I await your reply.* > *You did? Sorry, I didn't think I really needed to answer a question that had such an obvious answer, but apparently I was wrong. * *> They're not pendulums or wrist watches.* *Both pendulums and wrist watches have something in common, they both change in a constant predictable interval of time. And that's what a clock does. * * > How do you know particles have internal clocks?* > *Because muons change in a constant predictable interval of time. If you had a bunch of muons you could measure how much time had elapsed by measuring the percentage of them that have decayed. * *Not all particles have internal clocks, photons don't, photons have no rest mass so they move as fast as it's possible for anything to move and thus from their point of view Einstein tells us time comes to a complete halt and everything for them happens at the same instant. And that's why from our point of view photons never change unless something external changes them. * *We once thought neutrinos had zero mass and so moved at the speed of light, but then we discovered neutrinos change over time in a periodic way. We mistakenly believed the electron neutrino, the muon neutrino, and the tau neutrino were 3 different particles, but then we discovered there was only one type of neutrino but it oscillated between those 3 different flavors in a predictable periodic way. So neutrinos must have a very small rest mass, although we still haven't been able to measure just how small. All we know is that it's greater than zero and smaller than 0.8 electron volts. The electron is the second lightest known particle and it has a rest mass of 511,000 electron volts. * *Although neither would be very practical you could in theory make a clock out of both muons and neutrinos, but you could never make a clock out of photons if you just observed them and never interfered with them. * *John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis>* jot * Muons are particles and are produced by high energy cosmic rays hitting > atoms of air very high up in our atmosphere. The half-life of a muon is > only 1.5*10^-6 seconds, that's so short that almost none of them should > reach the ground, and yet a significant number of them do. That's because > that half-life figure was determined in a lab that was not moving relative > to the muon being measured, but the average muon made by cosmic rays is > moving at about 99.4% the speed of light, and if you use the formula 1 / > √(1 - (v²/c²) for time dilation you find those muons have a half life that > is 9.14 times longer than the half-life of muons measured in a lab.* > > > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/CAJPayv1THhNYoxqFe2%3DZm%3DvGRHUJNW9gde-krENiLDapbWaVPg%40mail.gmail.com.
