# Re: starship-design: relativity

```> The deal is that the object moving at 0.5c relative to you emits a beam
> of light that appears to move at 1c relative to you and at 1c relative
> to him too.  Other than that, however, you and he have rather different
> ideas of the spacetime coordinates of pretty much everything.

Yes, that's what I was basically saying in the part before my bit of
speculation. By the way, did I get that part right?

> Something to remember is that the speed of light is itself a result of
> the electrical and magnetic properties of the vacuum.

Are you talking about the equation 1/sqrt(u0*e0)? Where u0 and e0 are the
magnetic permeability and dielectric permittivity of free space,
respectively. I seem to recall some thought on modifying this to raise the
local velocity of light...don't remember where at the moment, but it was
all speculation nonetheless. If I remember correctly, it was stated that
causality violation would be avoided if you did this (raised the speed of
light)...but that doesn't make sense to me: you would still be going
globally FTL, wouldn't you?

> And if those properties were different,
> then a lot of the fundamental behavior of atoms would also be different,
> since electrons are bound to nuclei by electrical forces and so on.  In
> other words, if c wasn't a constant, then the properties of matter would
> also be non-constant.

Hmmm...I didn't think of it that way. I wonder if the Lorentz
transformations would nullify the effect that this would have on the matter
of your vehicle? (or whatever was in motion) This seems to be what Lorentz
was getting at with his archaic ether theory. Perhaps one way to put it
would be that the u0 and e0 were set properties of the frame determined to
be at 'true rest,' if you can justify that concept. Then an object in
motion with respect to this frame would be experiencing different
electromagnetic properties of space in his frame of reference. Since the
speed of light can only be 299,792,458 m/s in free space, no more or less,
relative to the rest frame, it cannot add to the speed of the object in
motion, and therefore the c+v argument is impossible. But the Lorentz
transformations, which are a direct result of the altered EM properties of
the moving frame of reference, prevent you from seeing the non-isotropic
speed of light. Now, this is just my speculation, I don't know if it is
fact or not. Probably it is not, but it is interesting to think about.
Unfortunately, I don't know how to develop a mathematical theory for this
idea, and it is just as well...until we find a flaw in relativity, there is
no use for it. I wonder what other effects a change in u0 and e0 would have
on an object. It is definitely something to ponder.

Best regards,
--Kyle R. Mcallister
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