🚀 go-pugleaf

dsg@impmh.uucp (Dave Gordon) writes:

>This relates to something I have been wondering about for a while now:
>is there an upper bound on the freqency of electromagnetic radiation?

>Consider a single photon: as its energy increses, its "size" decreases
>(assuming that size is related to wavelength).  Since energy is
>equivalent to mass, at some point it must become so dense that it
>collapses into a black hole!

The "size" that one uses to calculate densities is not the same as
wavelength, so this isn't exactly true (even ignoring the whole
issue of "photon mass," for which the sci.physics FAQ entry on the
subject is illuminating.)  *However,* the thinking among some people
who work on quantum gravity is that gravitational effects may indeed
cut off quantum field theory at very high frequencies.  This would
apply to everything, not just electromagnetic radiation.  The relevant
energy is the Planck scale, which is far above any machine human
technology can currently build-- it corresponds to giving a single
particle an energy roughly equal to the mass of a flea.

Now, if you believe in Lorentz invariance, there shouldn't be anything
wrong with giving a single particle an arbitrarily high kinetic energy.
The place where the cutoff comes in is, roughly speaking, in situations
where the energy transferred from one particle to another in an
interaction is very large.
-- 
Matt McIrvin