Re: Fantasy relativity

>From: Static <eshum@??????????????.com>
>         First, I'd like to get down some of the basics.  As one
>approaches the speed of light (I'll use "C" to denote it, but it
>could just as easily be SJ speed), time dialation occurs.  This
>depends on the percentage of C you're travelling.  The Lorentz-
>Fitzgerald contraction (gamma, given by the equation gamma =
>(1-v^2/c^2)^(-1/2)) is the ratio of shiptime to oustide time.
>(For example, at ~0.866C, gamma = 2, so two seconds pass on the
>ship for every observed one second outside.

... there we'd need a longish bit about inertial systems etc. but you're
basically right.

>
>         The "why is it dark" question can be answered by applying
>the above fact.  Since objects give off a certain amount of light
>per unit of time (or reflect an amount per unit time), they will
>appear to get dimmer in relation to the above ratio.  For example,
>for the above ship travelling at 0.866C, two seconds pass for every
>one second on the outside.  So, during those two seconds, the ship
>"saw" only one seconds worth of light.  Objects directly in front
>or behind the ship will therefore seem half as bright.  (Objects
>off to the sides will get dimmer with cosine of the angle multiplied
>by gamma, since their relative speeds arn't as high.)

I think this is wrong as far as special relativity is concerned. That
because any inertial system sees light travel at C speed, so brightness
(number of photons per surface unit per time unit) is unchanged. We have a
relativistic Doppler effect instead (blue shift forward and red shift aft).

>
>   "Why does it always end in tears?" -Crichton

"So we can sell more handkerchiefs."

Silmacar Halfelven
Captain of the Guards of Cardolan

"Since this Galaxy began, vast civilizations have risen and fallen, risen
and fallen, risen and fallen so often that it's quite tempting to think that
life in the Galaxy must be
a) something akin to seasick - space-sick, time sick, history sick or some
such thing, and
b) stupid."



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