With the advent of the space elevator (or other {relatively} cheap means to transport large canisters into space) it seems feasable to send large tanks (simmilar to large propane tanks) which are capable of withstanding immense pressures up into space and then release their contents (air) and then close the valve again, thus trapping a vacuum. these tanks would then return to earth for use in various power generating areas. I know they have compressed air cars, this seems like it would be safer as no explosion would occur in a wreck.-- bleh, Jul 31 2006 vacuum polarization http://en.wikipedia...Vacuum_polarization [bleh, Aug 02 2006] 1. You gotta at least spell the title right. 2. This is a pretty cumbersome way to get a vacuum. It is not like it is plutonium or something that must be mined. Why not just pump the gas out of them?-- bungston, Jul 31 2006 Vacuum is a very poor energy source.-- jhomrighaus, Jul 31 2006 You'd be able to extract about the same amount of energy from a vacuum bottle as you would from the same bottle pressurized to 14.7 psig. That is to say, you'll get much less energy out than what it would take to carry the bottle up the elevator.-- Freefall, Jul 31 2006 if you build the base of the elevator out of hollow shells, you'd be sending it up there anyway. I cant remeber the exact quote (ill add it tonight) but a physicist once said a smart gov't would pay a billion dollars for one cubic inch of "pure" vaccum because of the energy contained within.
Pumping the gas out of them would require energy on the front end. the idea is to use the vacuum of space to do the work. I'm not really sure the implications of pumping large ammounts of our atmosphere into space though.-- bleh, Jul 31 2006 //I cant remeber the exact quote//Well, I'll pay you $5 to know what idiot said that.There was a story written 40 or 50 years ago where the protagonist caps an accidentally created wormhole that leads to deep space, hooks a long pipeline to it, and sells the hard vacuum to laboratories across the country. The problem is once you dump anything into such a pipeline, you've ruined the hard vacuum.-- ldischler, Jul 31 2006 //pay a billion dollars for one cubic inch of "pure" vaccum because of the energy contained within//
That is just bizarre. Any vacuum tube out of an old radio contains a cubic inch of purest possible vacuum, and isn't worth a nickel. There may be some confusion here with "zero point energy", which is way out in the fringes of theory, and has nothing to do with vacuum and pressure.
As was said above, a container of vacuum is just about as useful as a container with 14.7 psi of air pressure in it. Which is much less than the air pressure found in the softest of fat tires--try running your car off the air in your spare tire and see how far you get. It's all about pressure differential, and 14.7 psi isn't much.
//safer as no explosion would occur //
Ow! A vacuum container is heavier than a pressure container, and quite catastrophic when it fails. Take an old TV picture tube out of the set and whack it with a hammer--hint: call the ambulance first--and see what I mean.
Finally, the method proposed isn't gaining any energy saving over a vacuum pump on the surface of the planet. The elevator lifts a tankful of air to the top of the atmosphere, which requires a certain amount of work. An air pump evacuating an air tank is doing exactly the same thing--the air removed from the tank has to push other air out of the way, and the only way for that air to go is up--moving an equivalent tankful of air to the top of the atmosphere, indirectly but with the same effort.
Details: pure vacuum is a long way up, and friction losses are hell. This will not make a profit.
This idea isn't a good one, but it is slightly creative. Still, it shows a lack of thought. I'm fishboning.-- baconbrain, Jul 31 2006 Well its not really pure vacuum which is, in reality an impossible achievement. But the difference between a vacuum tube and a "pure" vacuum is negligable.-- jhomrighaus, Jul 31 2006 //This idea isn't a good one, but it is slightly creative.//-
Ill take that as a compliment regardless of how it was intended... this one was maybe 1/8th baked at best.
afterthinking about it, it may have been a mathmatician who said it, which would account for the unphysicallity of the inplications. it was said bysomeone in the early stages of the los alamos project in WWII. i'll post the real quote by tomorrow. i expect payment by next tuesday.-- bleh, Jul 31 2006 //A vacuum container is heavier than a pressure container, and quite catastrophic when it fails.//
what happens when a metal container with negative pressure fails? is it that catastpophic?-- bleh, Jul 31 2006 Why not do the reverse? Send air bags up to space and use the air pressure to generate energy. For surely, energy generated in space is worth more than on the ground. (Of course, you still lose big time since the energy cost of transporting bags of air up the elevator will greatly exceed the energy derived from them.)-- ldischler, Jul 31 2006 Combine this with that idea about compressing air in the depths of the ocean and you have a space elevator that runs to the bottom of the ocean to compress the air then lift it to outerspace to use it.-- jhomrighaus, Jul 31 2006 //Ill take that as a compliment regardless of how it was intended//
That was intended as a compliment. I look for odd side effects and uses, but hadn't realized that a space elevator could be used as a vacuum pump. Very insightful, I thought. Bravo.
Unfortunately, the uses and advantages of this idea weren't good. Pumping atmosphere into space isn't really all that bad, though--a lot of it will fall back towards Earth.-- baconbrain, Aug 01 2006 ok heres the quote as promised, though a day late. it is from a book called / Adventures of a Mathematician/ by Stanislaw M. Ulam, a member of the manhattan project in WWII. he is indeed a mathematician, but read further for physicist validation.
"Jokingly I told Feynman, 'One day people will discover that a cubic centimeter of vacuum is really worth ten thousand dollars-- it is equivalent to so much energy.' He immedately agreed and added, 'Yes, but of course it will have to be a *Pure* vaccum!' Indeed, people now know about the polarization of a vacuum. The force between 2 electrons or 2 protons is not (e^2)/(r^2), but an infinite series of which this is the forst term. It works on itself, like two almost parallel mirrors, which show a reflection of a reflection of a reflection ad infintuim."
I suppose the energy they are refering to is some sort of mathematical anamoly, as this idea is obvoisly flawed, but i wouldnt go around calling feynman an idiot....-- bleh, Aug 02 2006 Yeah --- people shouldnt call other people names...
Anyway perhaps a vacuum cannister cann bee fabbricatred ouut of thinn airr -- uusing the sunns ennergy off couurse...-- madness, Aug 02 2006 see link on vacuum polarization. anyone out there smart enough to know what these guys are talking about? Im not. obviously.-- bleh, Aug 02 2006 [bleh] it appears written in the style of a Martin Scorsese film; the very first sentence mentions 'Fock Vacuums'....-- monojohnny, Aug 02 2006 what?-- bleh, Aug 02 2006 [bleh] Just a weak juvenile joke; because the serious physics link you posted looks like its full of rude words.-- monojohnny, Aug 02 2006 I see.... makes sense now. sorry. I'm kind of a focking moron.-- bleh, Aug 02 2006 anno noted and filed, thank you [Freefall]
also, see above anno for correct quote with source. apparently the quote got sent through the exadgeration<sp?> machine in my head.-- bleh, Aug 02 2006 FOCK! accidentally deleted [freefall]'s most informative anno... damnit. please repost if you have time, sorry.-- bleh, Aug 03 2006 Sp: exaggeration.
The Fock vacuum business is new to me, but it sounds close to the Zero Point Energy that I mentioned above, way out in some hypothetical possibility. It isn't likely to be useful anytime soon, and it has nothing to do with vacuum-powered cars. If it requires PURE vacuum, it won't work on anything likely to be found in a freshly-emptied airtank a few miles above the Earth.
BTW, there are some vacuum-powered instruments in older airplanes, mostly because a venturi in the airstream was a good source of reduced pressure. The power was mostly used to spin gyroscopes, and wasn't much of a vacuum. (I've also heard of vacuum-powered windshield wipers, and of course, the FlowBee hair trimmer.)-- baconbrain, Aug 03 2006 random, halfbakery