08 Oct '13 09:00>
If I read it correctly, even with 4×10^5 molecules per cubic centimetre a given molecule can travel 10,000km before colliding with another one. WOW!
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
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,
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?
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!
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 )
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.
If that can be done,
then why even worry about a pump?
The ANSWER - It can't.
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.
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
Originally posted by humyHe 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.
What are you talking about? You are talking total gibberish.
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.
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.
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.