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Re: starship-design: Genuine STR question
Kyle R. Mcallister writes:
> Relativity, despite what some say, is not easy to understand or learn.
> You will do what I did at first: look at it and say: huh? You'll also
> have a tendancy to say that the observers on earth are somehow more
> privileged than those on the ship, but it is not so. It doesn't really
> make sense at first.
The biggest stumbling blocks for beginners seem to be:
Spacetime (as opposed to Newtonian space) is not Euclidean,
although for everyday life Euclidean geometry is a near-perfect
approximation.
Simultaneity is a completely relative concept. There is only one
reference frame in which two events can be simultaneous. This
turns out to be the resolution to a great many relativistic
"paradoxes".
Other than that, special relativity isn't hard to learn, in that
the math isn't hard and a lot of other Newtonian concepts like
conservation of momentum or conservation of mass remain true. I
see the difficulty as not in the structure of special relativity
theory, but in overcoming some pervasive assumptions.
> To me, it still seems inadequate, so I am waiting
> for a theory of quantum gravity to be found. Or something like it. But
> stick with it, ask people questions if you don't understand something.
> No question, if honest, is ever stupid.
General relativity seems to hold some promise for FTL loopholes,
but even the ones that have been well-postulated are awfully
difficult to exploit (i.e. building an infinitely long ultradense
rotating cylinder or creating a region of negative energy density
are not exactly seen to be feasible). There's no way to tell
whether a theory of quantum gravity will close or widen those
potential loopholes.