From: spudnik on
I can do the math, two, if it's just simple differentiation
and algebra (pythagorean theorem), but it is so easy
to grasp special relativity, conceptually:
all atoms have internal (angular) momenta
that are limited by -- or perhaps "at" -- the speed of light.

perhaps the worst clue is that lightwaves cannot have
a (directed) velocity, but only a speed; however,
this is forever obscured by using "rays" of light,
which is assumed to be the path of a photon,
that was called a particle by herr docktor-professor E.

but, how can a massless object have a momentum --
are you going to leave that lump under that carpet?

another problem is the typicla pedagogy of SR,
where it is "simplified by putting the ray of light
onto the x-axis; why, bother?

--BP love's Waxman's new [*] cap&trade, and
Obama is using the spill to impliment [**] it -- and
it's all the fault of Califronictors,
who won't develop their own oil, instead!
* Waxman's '91 cap&trade was for NOx and SOtwo.
** Organized the CCX as a Senator.
http://wlym.com