> As far as I can remember, current theories call for a charge carrier
> particle for all four forces. The carriers of electromagnetism (the
> photon), the strong nuclear force (the pion) and the weak nuclear
> force (the intermediate weak boson) have been found. All have zero
> rest mass and all have a set velocity of c, 2.998x10^8 m/s. The
> reason that they are affected by gravity is that they have a mass
> due to their speed -- zero mass and infinite (relativistic) speed
> yields any number for relativistic mass you want... ^_^ Since they
> have mass, black holes can haul them back, and they end up orbiting
> inside the event horizon if they enter it.
Sorry, but this is WRONG! The carriers of the four basic forces of nature are
NOT all charged and they do NOT all have zero rest mass. The photon transmits
the electromagnetic force and has NO CHARGE and is MASSLESS. The strong
nuclear force is not really transmitted by the pion but is in fact transmitted
by gluons which have NO CHARGE and are MASSLESS (they have a property called
COLOUR which is how they interact with other hadrons), although some models of
nuclei do model the force as pion exchange the actual carrier of the force is
the gluon. The weak force is transmitted by the W and Z bosons. The Z boson
has NO CHARGE but a MASS (91 GeV/c2). There are two W bosons (W+ and W-). These
have CHARGE and a MASS of approx. 80 GeV/c2.
The massless bosons (photon, gluon and graviton if it exists) do indeed travel
at the speed of light, have zero mass but a FINITE ENERGY and it is the mass
equivalence of this energy that indicates how they are affected by gravity.
A zero mass paricle particle does NOT have infinite speed, it travels at the
speed of light, and ZERO MASS means just that, the particle has ZERO MASS.
Even if you do consider GammaM as the particles 'mass' this has a FIXED
VALUE determined by the energy. You can't just pick whatever you feel like!
> No one has found the fourth, the 'graviton', because it would be very
> difficult to build a graviton detector. (Can you think of a
> substance that isn't affected by gravity?) However, it is also
> postulated to have zero rest mass and a velocity of c. I believe
> that it is not supposed to be affected by itself (i.e. gravitons
> can escape the effects of black holes), perhaps because it can't
> make sense any other way. I'm not quite sure, but I assume that
> since black holes are postulated to have an effect outside their
> event horizon, gravitons are not affected by gravity. (Perhaps they
> have no mass? Hmmm.)
Sorry, but WRONG again! The reason it is difficult to build a 'graviton
detector' is because the effect of gravity is so small compared to all the
other forces of nature. The comparative strength of gravity to the rest of the
forces varies but is always less than approx 1E-34, hence the difficulty in
detecting it. Particle detectors in use today are made of hadrons and
leptons which ARE affected by the strong and weak forces respectively,
and yet they still detect gluons(indirectly) and W/Z bosons with relative ease!
In fact, if the particle you are trying to detect DOESN'T interact with your
detector HOW ARE YOU GOING TO DETECT IT!
Hope that clears up a few points.
Roger