Quote:
|
Originally Posted by Faultline
I think you're wrong about this.
|
I think I got it right, but apparently we are talking about
different things, so we may both be right:
Quote:
|
You're thinking of relative time.
|
I was referring to
all relativistic effects, not just the time
dilation effect. They come as a package. You have to take all
of them if you take any.
Quote:
The amount of energy needed to move an object increases as
velocity does. It's the very reason why lightspeed is unattainable
by anything with mass.
|
The amount of energy needed to accelerate a mass relative to
an observer not participating in the acceleration increases
with relative speed, yes.
Quote:
While weight reduction from fuel use will be linear, the
increase in required energy for acceleration with be
exponential.
|
If you want to maintain a constant acceleration of 1 g, so
that the force you feel aboard your spacecraft is a constant
1 g, then you must decrease the thrust as your fuel is used
up, or maintain constant thrust if the fuel magically appears
in your fuel tank at the moment it is needed.
Quote:
When you reach the threshold of lightspeed, to actually go
any faster would require infinite energy, so lightspeed is
unattainable through any means known to science.
|
That's what I said:
Quote:
But if you are moving at nearly c relative
to me, I will perceive that your 1 g forward acceleration
doesn't increase your speed relative to me by much.
|
When you maintain a constant acceleration of 1 g, your speed
relative to me asymptotically approaches c. But to you, the
effect is to seemingly increase your speed without limit,
because the Universe appears to become shorter and shorter in
the direction you are moving.
If you were to try to maintain a constant 1 g acceleration
relative to
me, your thrust would have to increase as you say,
but you would experience exponentially-increasing acceleration,
until you are crushed, your spacecraft crumples, and you use up
all the fuel in the Universe, and you still didn't reach c
relative to me.
-- Jeff, in Minneapolis