08 Oct 13
1 edit
Originally posted by twhiteheadBut, logically, it MUST be possible, even if only with great difficulty, to make a total vacuum in the lab!
I got the impression from sonhouse that no, it is not possible.
According to Wikipedia, the pressure on the Moon (which I believe sonhouse says we cannot achieve) still contains 4×10^5 molecules per cubic centimetre.
http://en.wikipedia.org/wiki/Vacuum#Examples
Think about it;
if, say, we reduce the number of particles (excluding photons, neutrinos, virtual particles etc ) in a very large vacuum chamber to, say, just one particle per cubic meter, then put a smaller one-litre vacuum chamber within that larger vacuum chamber and allow the 'pressure' (if that is the right word) to equalize with it, and then close off that smaller one litre vacuum chamber form the large one, what you would have made is a small one-litre vacuum chamber with a probability of there being a particle in it being about one in one thousand (because there are a thousand litres in a cubic meter ) thus there would be a 99.9% probability that there are no particles in it and that you have made a total vacuum in that small vacuum chamber!
So, logically, not only MUST it be possible to make a total vacuum, it must be possible to make a vacuum that has an arbitrarily 'high' probability of being a total vacuum.
08 Oct 13
Originally posted by humyWe can't seem to get it below billions per cubic centimetre, and you can multiply by 1,000,000 to see how many are in a cubic metre.
if, say, we reduce the number of particles (excluding photons, neutrinos, virtual particles etc ) in a very large vacuum chamber to, say, just one particle per cubic meter,
The obvious way to get rid of air is to have a piston which you first close completely leaving no gap, then pull open, leaving a vacuum. But how do you close it completely ie how do you let the air out as you are closing it. And how do you create a perfect seal as you pull it out? And how do you deal with air molecules hiding in the surface of the materials that sonhouse mentioned?
Probably the best way to obtain a near vacuum is to have two flexible sheets pressed against each other then seal the edges and pull the centres away from each other. But then how do you get your instruments inside to do whatever you wanted to do?
08 Oct 13
4 edits
Originally posted by twhitehead
We can't seem to get it below billions per cubic centimetre, and you can multiply by 1,000,000 to see how many are in a cubic metre.
The obvious way to get rid of air is to have a piston which you first close completely leaving no gap, then pull open, leaving a vacuum. But how do you close it completely ie how do you let the air out as you are closing ...[text shortened]... rom each other. But then how do you get your instruments inside to do whatever you wanted to do?
But how do you close it completely ie how do you let the air out as you are closing it. And how do you create a perfect seal as you pull it out? And how do you deal with air molecules hiding in the surface of the materials that sonhouse mentioned?
didn't he already answer that? “cryopump” plus “THEN you can zap the rest with UV, and BTW, the UV gets the molecules hidden in the somewhat porous nature of the stainless steel walls”.
Using that plus my idea combined, I don't see any impossible barriers to cross to make a total vacuum, just difficult ones.
Actually, I would guess there are total vacuums existing in nature! -I am specifically thinking here of the vacuum that sometimes exists in tiny nano-cavities in space rock that have been sealed off from the external environment i.e. they are fully surrounded enclosed in solid rock with no route in or out -surely out of the trillions of them that must exist throughout the whole universe, there must be at least ONE that just by chance has currently not got a single gas molecules loose in it! After all, there is nothing in the laws of physics that says nor implies you cannot have a total vacuum somewhere!
08 Oct 13
Originally posted by humyTheory can not always be carried out in practice.But how do you close it completely ie how do you let the air out as you are closing it. And how do you create a perfect seal as you pull it out? And how do you deal with air molecules hiding in the surface of the materials that sonhouse mentioned?
didn't he already answer that? “cryopump” plus “THEN you can zap the rest with UV, and BTW ...[text shortened]... ng in the laws of physics that says nor implies you cannot have a total vacuum somewhere!
The Instructor
08 Oct 13
Originally posted by humyI was referring to your zapping theory. If that can be done, then why even worry about a pump? The ANSWER - It can't.
A theory can never be 'carried out' but a plan, action or method can (note the distinction between a theory about a plan/action/method and the plan/action/method )
The Instructor
08 Oct 13
Originally posted by RJHinds
I was referring to your zapping theory. If that can be done, then why even worry about a pump? The ANSWER - It can't.
The Instructor
I was referring to your zapping theory.
It isn't a “theory”. It is a fact since it has often been done and there is no physical reason why it can't be done.
If that can be done,
what are you talking about? It IS done! It is a routine laboratory procedure that has been done many times in the past and works just fine.
then why even worry about a pump?
Because zapping the gas with UV want work unless the pressure is first reduced by a pump enough so to make it practical to ionize all the gas molecules else there would be far too many gas molecules to ionize requiring an unrealistic amount of UV to ionize them all and, without ionizing them all, applying a voltage wouldn't effectively move all that gas to a side chamber where they could then be removed from the main vacuum chamber.
The ANSWER - It can't.
false. It can and HAS already been done.
08 Oct 13
Originally posted by humyThere is no such thing as a Zapping Air Law that removes air. I was being generous by calling it a theory. Well, at least you admit it is not practical.I was referring to your zapping theory.
It isn't a “theory”. It is a fact since it has often been done and there is no physical reason why it can't be done.If that can be done,
what are you talking about? It IS done! It is a routine laboratory procedure that has been done many times in the past and works just fine ...[text shortened]... amber.The ANSWER - It can't.
false. It can and HAS already been done.
The Instructor
09 Oct 13
1 edit
Originally posted by RJHindsWhat are you talking about? You are talking total gibberish. I said nothing about “Zapping Air Law”
There is no such thing as a Zapping Air Law that removes air. I was being generous by calling it a theory. Well, at least you admit it is not practical.
The Idiot
09 Oct 13
1 edit
Originally posted by twhiteheadI guess in his mind, making a total vacuum somehow indirectly contradicts some part of his religion. Strange religion.
He has been told off for spouting religion in the science forum, so he has instead resorted to talking total gibberish at any science that he thinks contradicts his religion.
Better just to ignore him.
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09 Oct 13
"Personal message to RJHinds:" You are a attention-seeking attention-whore. Very very annying. Please stop adding "The Instructor". They clame you to be "an instructor in the military". I understand that the military can attract strange persons... so that would make you a strange person. My attention is to post this message again and again. Until you stop. I am not a bad person.
Really. I can't skim through posts since all I can see is this.
The Instructor
The Instructor
The Instructor
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09 Oct 13
1 edit
Originally posted by humyYou are forgetting one unavoidable problem with that: the outgassing of material from whatever case you are holding the vacuum in. The walls of the container will outgass SOMETHING and will add to the problem of achieving your ultimate vacuum.
But, logically, it MUST be possible, even if only with great difficulty, to make a total vacuum in the lab!
Think about it;
if, say, we reduce the number of particles (excluding photons, neutrinos, virtual particles etc ) in a very large vacuum chamber to, say, just one particle per cubic meter, then put a smaller one-litre vacuum chamber within th ...[text shortened]... be possible to make a vacuum that has an arbitrarily 'high' probability of being a total vacuum.
You can't get around that. The uncertainty principle takes care of that, since there will always be atoms that are bouncing around higher than the escape energy of the surface no matter what material you use, even at zero degrees Kelvin.
09 Oct 13
Originally posted by bikingviking
[b]"Personal message to RJHinds:" You are a attention-seeking attention-whore. Very very annying. Please stop adding "The Instructor". They clame you to be "an instructor in the military". I understand that the military can attract strange persons... so that would make you a strange person. My attention is to post this message again and again. Until ...[text shortened]...
The Instructor
The Instructor
The Instructor
The Instructor
The Instructor
The Instructor[/b]
Very very annoying.
it sure is. You may have already noticed this but I have recently made it a lot less annoying to myself when I reply to his posts by editing out the words “The Instructor” from the Quoted-Post-box and replacing those words with “The idiot” -far more appropriate and quite pleasing I think. You might want to do the same.