[rigney]

Is vacuum a physical thing, or a condition in which our universe began?

[Tres Juicy]

An absolute vacuum would be completely empty space, so not really a physicsl thing (more the total absence of physical things)

[doG]

A volume of space that is totally devoid of any matter would be an absolute vacuum, complete and totally empty space.

[rigney]

Tres Juicy, on 22 January 2012 - 10:17 PM, said:

An absolute vacuum would be completely empty space, so not really a physicsl thing (more the total absence of physical things)

If space has no physical attributes, why should it be there at all?

doG, on 22 January 2012 - 10:19 PM, said:

A volume of space that is totally devoid of any matter would be an absolute vacuum, complete and totally empty space.

Tell me, is space; even wihout having matter in it, not something?

[DrRocket]

Tres Juicy, on 22 January 2012 - 10:17 PM, said:

An absolute vacuum would be completely empty space, so not really a physicsl thing (more the total absence of physical things)

A useful idealization.

[Moontanman]

.

This post has been edited by Moontanman: 23 January 2012 - 02:53 PM

[doG]

rigney, on 22 January 2012 - 11:56 PM, said:

If space has no physical attributes, why should it be there at all?

It has physical attributes, it has volume.

rigney, on 22 January 2012 - 11:56 PM, said:

Tell me, is space; even wihout having matter in it, not something?

That depends on who you ask. Philosophers have long debated that question. For me, it is a volume of nothing.

That response kind of raises another question for me though. I'm wondering now, if I had a transparent, hollow sphere that had been totally evacuated of all matter I would have a container full of space at an absolute vacuum. Now, if I pass light, i.e. photons, through that sphere is it still an absolute vacuum inside?

[DrRocket]

rigney, on 22 January 2012 - 11:56 PM, said:

Tell me, is space; even wihout having matter in it, not something?

Define "something". "Something" is not a scientific term.

You are going down a path to philosophy, and you find no answers on that path.

[Tres Juicy]

rigney, on 22 January 2012 - 11:56 PM, said:

If space has no physical attributes, why should it be there at all?

Imagine a sealed box with a ball inside, you pump out every bit of matter apart from the ball

So you have a vacuum chamber with a ball inside. If you were to shake the box around you would see that the ball is able to move freely around the space.

So the space is still there - How could you possibly remove the space??


Although, an "absolute" vacuum as you've described would be very hard to create and would also be unstable.

That's where you get virtual particles messing up your nice tidy vacuum

[D H]

rigney, on 22 January 2012 - 11:56 PM, said:

Tell me, is space; even wihout having matter in it, not something?

Space is not matter. It is something else.

[Tres Juicy]

D H, on 23 January 2012 - 01:52 PM, said:

Space is not matter. It is something else.

Space is where you put your matter.

Without space there'd be nowhere to put anything...

[rigney]

Tres Juicy, on 23 January 2012 - 08:24 AM, said:

Imagine a sealed box with a ball inside, you pump out every bit of matter apart from the ball

So you have a vacuum chamber with a ball inside. If you were to shake the box around you would see that the ball is able to move freely around the space.

So the space is still there - How could you possibly remove the space??


Although, an "absolute" vacuum as you've described would be very hard to create and would also be unstable.

That's where you get virtual particles messing up your nice tidy vacuum

Even without virtual particles, space itself is physical. A vacuum pump powerful enough to evacuate all space from within a chamber will collapse the chamber. Same as for a paper bag or an entire universe. If a singularity was arguably responsible for the unfurling of this universe, there must have been a tremendous vacuum capable of drawing it all down to a size less than an atom??

[PeterJ]

DrRocket, on 23 January 2012 - 07:42 AM, said:

Define "something". "Something" is not a scientific term.

You are going down a path to philosophy, and you find no answers on that path.

Well, actually you do. The idea of 'Nothing' and 'Something' work no better in philosophy than in physics. That's why the Something-Nothing question of cosmogony is an intellectual dilemma. The brains of philosophers are no different to those of physicists, and to say that logic produces no answers is to throw away your reason. Yes. a lot of philosophy is pointless or badly done, but so is a lot of physics and many other things.

[rigney]

DrRocket, on 23 January 2012 - 07:42 AM, said:

Define "something". "Something" is not a scientific term.

You are going down a path to philosophy, and you find no answers on that path.

Quite right. Space is a specific entity just as are atoms and their sub-particles. Only difference is, we know quite a bit about the physical sciences, but little about this unphysical aspect of the universe; other than space is there. Believe me though, philosophy goes back much farther than the test tube or telescope.

This post has been edited by rigney: 23 January 2012 - 04:29 PM

[rigney]

DrRocket, on 23 January 2012 - 07:42 AM, said:

Define "something". "Something" is not a scientific term.

You are going down a path to philosophy, and you find no answers on that path.

After looking at a few essays I found that some scientists and physicists actually do rely on the word "something" from time to time. The following link about the dynamics of physical ether was interesting.
http://www.softcom.n...reebo/phys1.htm

[Tres Juicy]

rigney, on 23 January 2012 - 02:24 PM, said:

Even without virtual particles, space itself is physical. A vacuum pump powerful enough to evacuate all space from within a chamber will collapse the chamber. Same as for a paper bag or an entire universe. If a singularity was arguably responsible for the unfurling of this universe, there must have been a tremendous vacuum capable of drawing it all down to a size less than an atom??

You're confusing space with atmospheric pressure

[D H]

rigney, on 24 January 2012 - 01:48 PM, said:

After looking at a few essays I found that some scientists and physicists actually do rely on the word "something" from time to time. The following link about the dynamics of physical ether was interesting.
http://www.softcom.n...reebo/phys1.htm

That is crackpot, end to end. You need to watch what you read on the internet. Not taking care might steer you down the road to crackpotism. You really don't want to follow that road, do you?

[rigney]

D H, on 24 January 2012 - 02:17 PM, said:

That is crackpot, end to end. You need to watch what you read on the internet. Not taking care might steer you down the road to crackpotism. You really don't want to follow that road, do you?

Don't know! Please define crackpot, end to end? I read just about everything to be found on the internet. Not saying everything is truth. but some of these quotes are from papers written by very distinguished scientists and physicists. Should I disregard their years of research and dedication as "crackpottery"?

This post has been edited by rigney: 24 January 2012 - 02:41 PM

[JustinW]

A perfect vacuum would still be something. It would have pressure and potential energy. Some have talked about the possibility that the big bang was created from a perfect vacuum. But to say that space when void of matter, creating a perfect vacuum, is nothing would be incorrect. The fact is that there will never be a perfect vacuum since it is theoretically impossible to remove all matter from space.But to answer the OP, vacuum in itself is a physical thing in as much as gravity is. Invisible, yet the force can be felt and the effect can be measured.

This post has been edited by JustinW: 24 January 2012 - 03:07 PM

[rigney]

Tres Juicy, on 24 January 2012 - 02:02 PM, said:

You're confusing space with atmospheric pressure

No, I believe it's a matter of semantics. Pressure is pressure and vacuum is vacuum regardless of where the experiment is taking place. Atmospheric or barometric pressure is calculated to give you the varying degrees of vacuum or pressure we live in here on earth or in atmospheric flight. Outside that zone nothing changes, other than the scale used to calculate such change. I ask, would a container pressurized to 1 ccm here on earth, show the same reading when arriving on the moon?