Why Doesn't a Photon's Energy Knock Us Out?

[zoobyshoe]

Thanks, Nereid. Those neutrinos sound like a fine can of worms to try to sort out.

 

[selfAdjoint]

Nereid, the gluons, which of course are not observed, are also massless, along with the photon. These are all bosons. The neutrinos, before the recent discoveries, were regarded as the only massless fermions.

 

[Nereid]

Nereid, the gluons, which of course are not observed, are also massless, along with the photon. These are all bosons. The neutrinos, before the recent discoveries, were regarded as the only massless fermions.

Oops, Clearly my coffee wasn't strong enough (or last night's wine too good).

So the carriers of two of the forces are massless, and the carriers of one quite massive (and the graviton is hypothetical), with all force carriers being bosons.

Does the gluon travel at c?

 

[selfAdjoint]

Does the gluon travel at c?

Necessarily it does, since it's massless, and the standard model obeys special relativity, because the Lorentz transformations require that for a massless body.

 

[zoobyshoe]

Neutrinos are flavorful, gluons are colorful.

"In quantum chromodynamics (QCD), today's accepted theory for the description of the strong nuclear force, gluons are exchanged when particles with a color charge interact. When two quarks exchange a gluon, their color charges change; the gluon carries an anti-color charge to compensate for the quark's old color charge, as well as the quark's new color charge. Since gluons thus carry a color-charge themselves, they can also interact with other gluons, which makes the mathematical analysis of the strong nuclear force quite complicated and difficult. Even though there are theoretically nine unique colour combinations for gluons, (r-ar, r-ag, r-ab, g-ar, g-ag, g-ab, b-ar, b-ag, and b-ab) in reality there are only eight."


Gluon
Address:http://www.fact-index.com/g/gl/gluon.html

 

[selfAdjoint]

That account might be a little confusing unless you know that in QCD, each gluon carries two charges, one of the colors and one of the anticolors. Each gluon is represented by a 3X3 matrix, in a representation of the gauge group SU(3). Rows correspond to the color charges and columns to the anti-color ones. Since there are three choices for each of these, the number of possibilities would seem to be 3X3 = 9. But the requirement that the matrices representing the gluons be unitary means you can derive algebraic relations from which given any eight components you can calculate the ninth. So there are really only eight INDEPENDENT components of the 3X3 gluon matrix.