One night after seeing a movie were a vacuum occurs in space i had a thought, if you use a water wheel with a tank of gas would you be able to spin the wheel thus giving power to the tool. and if so how strong would the vacuum be? Powerful enough to spin a chainsaw? Strong enough to give electricity to a ship? This could be used to the advantage of space travel.

Does anyone think it is feasible?

I do not think this is possible. To explain why, I will have to explain what a vaccuum is. A vaccuum is any space where there exists no gasses or any other matter. A vaccuum (the commercial kind) works by creating an absence of air so objects will be sucked into it via the law of diffusion, where if there is more of one gas in one area, it will want to move into the other area to equal it out.

With this definition, I do not think that creating a situation where there is no air would effectively create enough energy to power something. There must be something moving, like a chain or a rotor, inside, and I think that our current combustable engines work well enough. If there were some easier way to create a vacuum other than creating a combustion engine and then a vacuum, this might be feasable, but the creation of the vacuum would not save any energy; actually, it would probably loose more energy than just a combustion engine.

if we're going to be getting energy from space I should think that we would be getting it from the sun in some shape or form. (I don't mean by solar panels) Like by putting something in a close(ish) orbit around it. Of course we don't have anything like the technology for something like that.. not only because it would be near impossible to make such a thing, but because even if it did work we couldn't expect to see a return on it for a good thousand years or so. (due to the great distances)

No, i didnt mean make the vacuum, i meant use the existing one in space. if u have a valve that releases a small amount of air into a chamber that has a pinhole in a water wheel at the base of the paddle the vacuum of space would suck the air hard an make the wheel spin.

Am i right?

PS. ill draw a pic an post it soon.

Oh, now I understand what you are saying. I still think that it would not work because you would have to bring a lot of gas on board to make it effective. All of this gas is lost matter (well, lost to us). The ship would need to be massive to hold enough gas to make this even feasible. I think our better bet would be to use nuclear power and just throw the waste into space somewhere. Nuclear power uses very little (respectively) matter to make an immense amount of electricity. Good thinking though, it was a creative concept.

beatgammit is correct. Not only is this a very inefficient way of harnessing energy but you pay (too much) for it all in lifting all this gas from the earth. A water wheel, or tapping a geothermal source is harnessing a natural source of energy so its inefficiency isn't an issue. Think about this, we can pressurize gas here on the surface of the earth and yet we do not use this as a source of energy.

HOWEVER, there is one way in which we do harness this source of energy in space craft. It is used as a source of thrust in course adjustment and for motive thrust by a man in a spacesuit doing EVA.