robison@uiucdcsb.UUCP (11/04/84)
There is one workable formulation of physics for which there is no speed
limit. In classical physics, velocity is a derived unit. It is derived from
the fundamental units of distance and time (e.g. furlongs per fortnight).
Relativistic velocities in this system do not add linearly, and the sum is
always less than C. If a man is running on top of a train at 1/2 C (in respect
to the train), and the train is moving at 3/4 C in respect to the ground, the
man is not running at 5/4 C in respect to the ground, but rather some speed
less than C (10/11 C if I recall correctly).
There is, however, another approach. Let TIME and VELOCITY be the
fundamental units, and make distance a derived unit. Just as we have a
standard meter in the old system, we can have a standard velocity unit in
the new system. We could, for instance, stretch a standard guitar-string
between two nails at a standard tension. If we strike the string at one
end a wave will propagate down the string. We can use the velocity of
propagation as our standard unit of velocity. (Of course we will then
put it in a glass jar and store it in Paris.)
Now suppose we add two velocities. We start with one velocity-standard
string and propagate a wave down it. We then take a second velocity-standard
and move it along with the wave in the first (so that the wave in the first
standard appears stationary to the second standard). We now pluck the string
on the second standard to start a wave propagating down its string. The
second wave is moving at 2 velocity-units, by our new definition of velocity.
Indeed, by stacking up velocity-standards, we can reach any arbitrary
velocity we wish. (Note that this velocity does NOT directly correspond to
the same velocity in the old system.)
The new system actually works (I use it sometimes), and a lot of the
relativistic equations are much simpler (e.g. momenta and energy).
My freshman physics prof. explained it in class. He also noted if you use
it, other physicists wll refuse to talk with you! (Not because the system
is wrong, just because nobody else uses it.)
Arch @ uiucdcsrobison@uiucdcsb.UUCP (11/15/84)
The following argument is not quite complete: > FTL is impossible due to the following: > 1) As your velocity increases, your mass also increases. As you approach > the speed of light (SOL), your mass approaches infinity. At the SOL, > your mass would be infinite. Since, your mass can not be infinite, > you can not reach the SOL. Since you cann't reach the SOL, you > can not exceed the SOL. The hidden assumption is that your initial velocity is less than C. For a mass which comes into existence at a speed in excess of C, then there is no problem, except that some quantities must be imaginary. There was an article on this possibility in Scientific American sometime (probably one or two decades ago). For superluminal masses, C is a speed limit in the other direction. A mass traveling faster than light can never slow down to speed below C. Arch Robison @ uiucdcs
graves@kcl-cs.UUCP (Tim Graves) (11/20/84)
<Um... Munch Munch Munch... Yum... URP! (EXCUSE ME)>
Being a computer scientist, (I've got A Level Physics though!!!)
I'm curious about the undefinable quantities that movment faster
that light would be. I suppose that they might include Negative
mass ( Long live the positronic robot *). Is this true, any other
ideas, (Simple physics only though please) ??
Tim Graves
(ukc!west44!graves or graves@kcl-cs.uucp)
(* positronic robots were a trade mark of Issac Asimovs U.S. Robots corp)
--
Tim Graves
(ukc!west44!graves or ukc!west44!westf!graves)