In order to produce a "true vacuum", we would have to be able to not only remove all matter from the chamber, but insulate it against any and all forces - heat (we would technically have to insulate the inner layer of "hull" so it wouldn't radiate any heat transfer), electricity, magnetism, gravity...
Any hope of insulating against gravity is far beyond our reach at this point, and I suspect magnetic dampers are either beyond reach or impractical. But we can certainly insulate against some of the other things.
Is there any known way to confine a space, remove the matter (most if not all) and squelch the electromagnetic passthrough either completely or just to a significant degree?
A secondary question: Would this space have any unusual properties -other- than being a near-perfect vacuum?
2007-12-11 05:30:01 · 5 answers · asked by uncleclover 5 in Science & Mathematics ➔ Physics
I think you are asking for much more than a vacuum. A vacuum is zero pressure. What you want is zero everything.
You are in the realm of meta-physics now.
2007-12-11 05:36:26 · answer #1 · answered by Anonymous · 2⤊ 0⤋
We can pretty easily create a vacuum in which atoms and most electromagnetic waves are absent.
The way to do it is to make a sealed chamber, as you said and then lower the temperature to the point where ALL gas atoms stick to the walls. What is left in the volume is electromagnetic radiation due to temperature and Casimir effect.
And because that is QM, you can't get below that.
And yes, one can shield perfectly well against gravity, too. Just drop your experiment out the window. As long as it is in free fall, there will be no gravity in there, whatsoever. See Einstein's elevator Gedanken experiment.
This almost perfectly field free space would not show any interesting effects. It would be a waste of time and a good 3He fridge to make one (when the fridge hits the ground you will be sorry for your expensive equipment).
:-)
2007-12-11 14:46:24 · answer #2 · answered by Anonymous · 1⤊ 0⤋
Hi. The problem, as you note, is keeping the vacuum once you have it. Just about any material will sublimate in a hard vacuum but this can be slowed by keeping the chamber at as close to absolute zero as possible. If the chamber were to become super conductive this would prevent magnetism and electric fields from getting in. All you are left with is gravity. I do not think we can ever shield this. My opinion.
2007-12-11 13:35:33 · answer #3 · answered by Cirric 7 · 0⤊ 0⤋
Your basic assumption is flawed, any material you use for an inner layer would still be a black body radiator and would impart heat to the vacuum you wish to obtain.
If you were able to obtain absolute 0 Torr vacuum and no black body radiation you'd also create a vacuum that would achieve a temperature of Absolute zero and hence all matter would cease to exist. (zeroth law of temperature/thermodynamics).
Currently the best vacuums in laboratories are as hard as non interstellar space and equal to that found on the moon. at around 10 ^-11 Torr. Space in our solar system is between 10^-8 and 10^-11th Torr.
The hardest vaccum known to exist is interstellar space which is 10^-17 Torr.
Don't forget even in interstellar space the temperature is ever so slightly above absolute zero due to cosmic radiation and background radiation from big bang.
2007-12-11 14:05:01 · answer #4 · answered by Ian W 4 · 1⤊ 0⤋
ummz as far as i know, i dun know much, a true vacume is impossible to achieve. but there are ultra high vacumes 1x10to the power of -9. we use this types of vacumes on a regular basis for surface analysis procedures.
we use stuff like ion pumps, rotary vane pumps, tubomolecular pumps, sublimation pumps just to name a few.
cheers,
djohn
2007-12-11 14:04:04 · answer #5 · answered by djohn 2 · 0⤊ 0⤋