Re: Lightspeed

> > Another unfortunate occurance, the closer one gets to light speed the less
> > visible one is. Yeah, the speed of light is constant. (186000 miles per
> > second) But see, to be seen the light has to bounce off one and into the
> > eyes of one's observers. Another problem; light from objects to the fore
> > reaches you just as you reach them. You can only see them once you've passed
> > through them.
>
>         All correct, at least according to my physics teachers (like I believe
> them...:)

you shouldn't, they were lying :)

they're right, sort of, but for the wrong reasons. if you travel on a
near-c ship stars (and other objects) will appear dimmer due to time
dilation: consider; a star puts out a fixed number of photons in a given
amount of time. however, when you're travelling near c, time appears to
go more slowly for things you observe than for you. thus in one
shipboard second the star goes through less than one second, puts out
fewer photons, and thus appears dimmer.

the converse of this is a little different: observers of the ship will
see onboard sources of light get dimmer, but there will be no change in
the reflected light because that's coming from a source that isn't time
dilated.

astute readers will have noticed that the ship observes time going more
slowly for the star, and the star observes time going more slowly on the
ship. this is true; an effective restatement of the inaccurately named
twins paradox. (inaccurate, if you're wondering, because it's not a
paradox.)

if you are the one travelling there is also a strange effect where
objects appear to cluster around the fore and aft axes of the ship:
travel as sufficient speed through a uniform starfield and you'll see a
blue cluster of stars in front of you, a red cluster behind you, and
very few to the sides.

by now, hopefully, you should be so confused by special relativity that
you'll agree to leave it out of your SJ campaigns :-P


--
rad.

stand still while i mock you!
                -- dogbert