Turtle Universe: Neutrinos again

So now you’ve got this ice, you’ve got these muons made by muon neutrinos, you’ve got this blue glow. The ice below the South Pole is probably the purest and clearest in the world. There’s nothing to compete with this blue light, and it just lights up that ice, traveling a great distance through the crystal clear solid water. And when it comes to a detector (called a DOM for Digital Optical Module), that detector grabs the blue glow and stores it away. You’ve just detected a neutrino!

OK, so what? So you’ve just detected a neutrino. Big deal.

It is a big deal, and here’s why. Neutrinos weigh almost nothing. Almost. We now know that they have a tiny, but real, mass. Why? Because of Einstein again. Any particle with zero mass travels at the speed of light, but any particle with a real mass, no matter how tiny, travels slower.

Of course, any post entitles Neutrinos Again must have a prequel: Neutrinos