Posted on 11/27/2004 1:52:08 PM PST by demlosers
Actually, I didn't. The velocity of light in a vacuum is approximately 3 X 108 meters per second, or 300,000 kilometers per second. Ignoring relativistic effects, it would take just under 354 days to reach that velocity at an acceleration of 1G.
Relativistic effects don't become significant until one reaches a velocity of about 70% of the speed of light. Even accelerating at 1G for a period of two weeks (just over 1,200,000 seconds) will achieve a velocity of less than 12,000,000 meters per second, which is only (!) about 4% of the speed of light. Clocks on board such a spaceship might run a few seconds slow, but that would be about all.
As to the engineering obstacles, I did indeed deliberately ignore them. To take just the most obvious one, the energy required to continuously accelerate a useful spaceship (massing, say, 1,000 metric tons) at 1G for a period of only one day (86,400 seconds) would be enormous (kinetic energy, at a velocity of 850 kilometers per second, would amount to about 3.6 X 1017 joules, or the entire output of a 1-gigawatt generating station running continuously for nearly 11 and a half years - and that's assuming 100% efficiency). I was pointing out only that continuous acceleration removes the problem of supplying artificial gravity.
However, I think the term "inconceivable" is a bit too strong: "Impossible at our current level of technology" would be more accurate.
just a small piece of a black hole, should just about do it. ; ) Maybe Disney has some left over.
Has anyone ever noticed that with a single letter substitution that Minbari becomes Minibar.
There would have to be a gigantic reason for building a manned ship that would accelerate at 1 gee for even an hour. An economic justification. Science itself will have to be content with accelerating very small robot ships to that extent, if even that.
"Any chance on just getting super dense material form somehwere ....
Try DU."
I hope no one misses that!
I'm no rocket scientist, so this is just a low-informed stab at the issue. Dense mass seems to me to be the expensive way to solve the problem. We've all seen artificial gravity from spinning. Motion is the cheaper solution, IMHO. You could combine the two, but in the end, it should depend more on motion and less on mass. Enough energy for that motion is practically free in space, with unfiltered sunlight for solar collecters.
It is those problems that I find most interesting. The suggestion of dense matter raises the opportunity for thought experiments--the most fun part of physics, IMHO. Back-of-envelope calcs show that a piece of "dense matter" at a distance of 5 meters would need to be (about) 1/2,000,000,000,000 the mass of the Earth to effect 1 g. Getting closer than say 3 meters would be very dangerous.
With regard to engineering, I still think inconceivable is better since no one can conceive of a way to build the thing.
Of course the reason it is unconceivable is because our current undertanding of physics makes this "virtually" impossible. Therefore what we need is an improbability drive.
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