Re: Speed limit at C a misconception?

On Mon, 22 Aug 2005, Skywise wrote:

> Thanks everyone. I'm getting some great explanations for how
> group and phase volocities work.
>
> Now, about that phrase that started all this fuss, that it
> is a "popular misconception" that Einstein's Special Theory
> of Relativity says nothing can go faster than light.
>
> Is it a "popular misconception"? Because this is the first
> I've heard of it. I hardly think group and phase velocites
> going faster than C is reason to start calling Einstein's
> theories "popular misconceptions".

It's the idea that "nothing can go faster than c", even non-material
things such a envelopes of wave packets, that is the "popular
misconception." The laser-pointer dot on a sufficiently distant screen is
sufficient disproof of the misconception; no need to even resort to
technicalities of waves.

AFAICT, the most popular misconception is the observers see moving clocks
running slow and moving rods shortened. This is the fault of a lot of
presentations of special relativity wherein "observer" is written, but
"coordinate system" is what is meant. What is measured by a set of clocks
and rules filling space is not what the eyeball sees, for sure.

--
Timo Nieminen - Home page: http://www.physics.uq.edu.au/people/nieminen/
E-prints: http://eprint.uq.edu.au/view/person/Nieminen,_Timo_A..html
Shrine to Spirits: http://www.users.bigpond.com/timo_nieminen/spirits.html
.