So what are neutrinos?

[quantum dot]

From the little I've read about them, and that's what it says in my Physics textbook, "neutrinos are particles of miniscule mass that were first postulated by Pauli to account for the continous spectrum of beta particles". I don't really get it. Can someone please explain? And if they have hardly any mass and no charge, then what's the point of them?

Thanks,
Sara.

[freeztar]

Here's a good page that should explain it all:
Neutrino - Wikipedia, the free encyclopedia

As far as what the point of them is, I'm not sure how to answer that. They are constantly emitted by the sun and there are probably some passing through your body as you are reading this.

[quantum dot]

Thanks for the link, I read through it but just to make sure that I'm getting this right, neutrinos are simply radioactive decay products just like alpha and beta particles, right? And because they are almost massless and chargeless they were only detected by the fact that the beta spectrum is continuous while it was theoretically supposed to be discontinuous, so they thought, okay, there must be some other particle there?

[freeztar]

Originally Posted by quantum dot

Thanks for the link, I read through it but just to make sure that I'm getting this right, neutrinos are simply radioactive decay products just like alpha and beta particles, right?

Correct. They are formed from beta decay.

And because they are almost massless and chargeless they were only detected by the fact that the beta spectrum is continuous while it was theoretically supposed to be discontinuous, so they thought, okay, there must be some other particle there?

The first paragraph, under "History", of the link I posted above explains that...

The neutrino was first postulated in December 1930 by Wolfgang Pauli to preserve conservation of energy, conservation of momentum, and conservation of angular momentum in beta decay, the decay of a neutron into a proton, an electron and an antineutrino. Pauli theorized that an undetected particle was carrying away the observed difference between the energy, momentum, and angular momentum of the initial and final particles.

They were not detected until 1987. Here's another link that explains neutrino astronomy: Neutrino astronomy - Wikipedia, the free encyclopedia

[quantum dot]

Thank you Freeztar

[freeztar]

You're welcome.

I must make a correction though. The first *supernova* nuetrino was detected in 1987. In 1965, scientists detected a neutrino/cosmic ray interaction in India. (from first link)