🚀 go-pugleaf

In article <6NOV199212364099@csa1.lbl.gov> sichase@csa1.lbl.gov (SCOTT I CHASE) writes:
>In article <1992Nov6.175022.13136@galois.mit.edu>, jbaez@riesz.mit.edu (John C. Baez) writes...
>> 
>>As the rest of my post indicated, that wasn't the part that I don't
>>buy!!  I can imagine a theory that predicts mixing angles, but not a
>>theory that predicts the speed of light (in any exciting sense - see my
>>previous post).
>
>Why not?   What makes the speed of light any more fundamental than the charge
>of an electron, or the electroweak mixing angle?  And even if it's more 
>fundamental, what prevents you, in principle, from developing a theory which
>predicts the speed of light? 

Gee, you didn't seem to have read the post I referred to.  I didn't say
that the reason was just that the speed of light is "more
fundamental" than mixing angles.  The reason has to do with the fact
that c is dimensionful while the mixing angles are dimensionless.  One
has at least 3 degrees of freedom in choosing units (mass, length,
time), and this means that 3 dimensionful constants of nature can freely
be set to 1.  (I defer discussion as to whether charge and temperature
should raise the total to 5.)  There's nothing especially sacred about
the choice of c, hbar, and G as the three to use.  My point is that the
closest we can come to "explaining" the speed of light is to explain the
(dimensionless) ratio of c to some other speed (possibly one concocted
by multiplying together all sorts of constants of nature, but let's just
call this other speed "the speed of dark").  One can think of the
explanation of this ratio as being an explanation of the speed of light
(if you think the speed of dark is "more fundamental") or as an
explanation of the speed of dark (if you think of the speed of light as
"more fundamental").  My hunch is that if this takes place, people will
call it an explanation of the speed of dark.  But my real point is that
one can't hope to explain ALL dimensionful constants of nature.