From: vincent@reg.triumf.ca (pete)
Subject: Re: What is the speed of light measured from?
News-Software: VAX/VMS VNEWS 1.41    
Organization: dept. of theophysics and cosmogyny
Date: Wed, 2 Sep 1992 11:26:00 GMT

In article <135084@lll-winken.LLNL.GOV>, moon@mozart.llnl.gov 
(Steven Moon) writes...
>In article <1SEP199204185362@reg.triumf.ca>, 
vincent@reg.triumf.ca (pete) writes:
> 
>|> if you board some wonderful rocket, which can sustain constant
>|> acceleration ( in your frame of reference ) and commence 
>|> accelerating, it will seem to you that you just keep getting
>|> faster and faster, and you pass c without incident. The only
> 
>This is not true.  

Yes it is. Work it out.

>In order to measure the velocity of your 'wonderful' rocket
>you must make some measurements.  You take you watch and meter stick and measure
>some object at rest w.r.t. the inertial frame you started in (say the Universe)
>So measure the position of some Star at two different times.  You will not 
>come up with some velocity > c.

Neglecting the engineering problems of high speed travel through an
imperfect vacuum, you can travel light centuries in subjective
hours if you accelerate long enough. If you arrive at the Andromeda
galaxy 2 weeks after leaving earth, you could be justified in
thinking you travelled faster than c. It's just that the rest of 
the universe will have aged 2x10^8 years.

>|> catch is that in the rest of the universe you travel through,
>|> time seems to be going by faster and faster relative to yourself,
>|> such that to observers in other frames, your velocity never
>|> quite reaches c. They also see your time slowing down, so they
>|> can understand why you might think yourself going faster than
>|> c ( for simplicity I've left out all the interesting details
>|> of how times can be compared between reference frames).
> 
>I would suggest brushing up on your SR.  A.P.French's book is, in my 
>opinion, one  of the best.  Some wonderful light reading would include 'Mr.
>Tompkins in Paperback.'  The first story is about a place where the speed of light
>is quite small and SR effects can be observed with a bike.

I will not respond in a similar vein. Rather than impune your 
understanding of physics I will give you the benefit of the doubt 
that you simply misunderstood me.
> 
>|>     Now for light, and anything else travelling at c, duration
>|> of time has slowed to 0 as seen from any other reference frame,
>|> so this can be seen as equivalent to travelling infinitely
>|> fast. This sort of solves the problem that led Einstein to
>|> relativity in the first place - how, if one were in the frame of 
>|> reference travelling with light, and observed the (now stationary)
>|> electromagnetic fields which comprise it, one would see 
>|> the EM fields vary in amplitude periodically
>|> in space, which according to Maxwell's equations shouldn't
>|> be possible without electric charges at the local maxima.
>|> The solution is that in relativity, this frame of reference
>|> is not well defined, and it occupies no time, so it's
>|> never really there to contradict Maxwell. Thus light always
>|> knows how fast to go: as fast as possible.
>|>     The moral of the story is that the world is not at all
>|> as it seems, and nothing like our naive Aristotelian/Newtonian
>|> intuitions.
> 
>I, honestly don't know how to respond to this.  

You could start by losing your atitude.

>Study special relativity.
>Getting all your information second hand from popularized books and TV shows
>is quite dangerous.  

So is learning the math without acquiring a visceral grasp
of the subject.
> 
===========================================================================
A cynic's world is comprised                          Pete Vincent
of fools and other cynics