h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

http://news.bbc.co.uk/hi/english/sci/tech/newsid_1394000/1394811.stm

Apparently, the Neutrinos were there all along - but wearing false moustaches and putting on an accent. Devious little fellers!

For those who want to know the technical details.
There are three types of neutrinos. Each partners one of three particles, the electron, the muon and the tau. Hence the three neutrinos are called the electron neutrino, the mu neutrino and the tau neutrino.
These 6 particles are the leptons, which along with the 6 quarks and a number of force carring baryons ( possibly 6 but nobody has seen a graviton, and they all become one at high enough energies anyway ) make up all the elementary particles, according to current theories.
Anyway, back to the neutrinos. The hot issue with neutrinos is whether they have a rest mass or not. ( I say rest mass because all moving particles have a mass due to relativistic effects ) Recent research indicates that neutrinos do indeed have a very small rest mass.
This gives them the ability to oscillate between the different types, i.e. an electron neutrino can become a mu neutrino. And mu neutrinos and tau neutrinos are a lot harder to 'see' than electron neutrinos.
Hence, that's where they went.

Sorry

I meant "force carrying bosons" not "force carrying baryons".

Not all moving particles have mass, only those which have rest mass (the photon has no rest mass and therefore has no mass when it travels at relativistic speeds).

A photon has energy, which is related to it's frequency. Relativity showed that energy and mass are equivalent.

PS

Hello Wick, just visited your Personal Space and I was at Manchester University doing Physics also, as an undergradute though.

When were you there?


PPS just realised that my first reply seems a bit terse. Sorry.
I never did go to many General Relativity lectures, it being the only lecture on a Wednesday morning and all, but now I remember that Photons follow the null geodesic, which that do because they have zero mass.

But now I confused because I thought that a photon gas has mass?

cheers again
Mave

I'll have to look into this a bit further. From reading what we have both said, it seems we are both right, and therefore the universe is not self-consistent (something I suspected all along).

Wick