Piston in a vacuum

[aman]

I've been working on an idea that an empty universe needs energy to sustain itself. To have three infinite dimensions of empty space, eg. pre big bang, would take energy to keep from collapsing into a non-point. I need a device to make some measurements to prove it.

First a question. If I take a piston in a cylinder sleeve with perfect ring seals into the vacuum of space, can I pull the piston down in the cylinder creating a vacuum as large as I want and let go without the piston being pushed back because the pressures should be equal on top and bottom?

Just aman

[fafalone]

the pressure of a vacuum isn't exactly zero; there are still molecules floating around out there, but extremely few in deep space.

[aman]

The vacuum in the cylinder though should be absolute. Can we generate one this pure on Earth?

Just aman

[RAB]

It would be extremely difficult because atoms would escape off the vessal walls, unless walls could be made from something with a strong atomic structure (diamond) and be absolutly pure. We dont have technology to do this.

Seals of any kind are never absolutely leak free. And they also are part of the vessal walls.

If we could make a chunk of "ideal" material and stretch it so as to cause an internal rupture and then keep stretching it to form an internal void, that void would be a perfect absolute vacuum.

 

Then, what would you do with it?

[RAB]

Your perfect vacuum wouldnt have any atomic particles, no matter of any kind. But it would not be free of energy waves that would penetrate thru the walls. A stray high energy, sub-atomic particle or maybe a neutrino, could also spoil your experiment?

[NSX]

Originally posted by RAB

But it would not be free of energy waves that would penetrate thru the walls. A stray high energy, sub-atomic particle or maybe a neutrino, could also spoil your experiment?

 

What if the material has an extremely high ionization energy, so to allow particles to be basically reflected off...like ozone & UVs?

[aman]

It should still allow neutrinos to pass through. The experiment would not be practical in our relative space. Too much crap.

I guess my ideal device would be outside our universe in the void.

One cylinder would be sealed and the piston drawn back to create a perfect vacuum. The energy required would be measured.

An identical cylinder except for a small hole in the top open to the void would have its piston pulled back to the same point and have the energy required to do this measured.

Subtract one from the other and the energy left should be how much energy it takes to create a volume of empty space.

I'm betting that it is greater than zero.

Just aman

[RAB]

Which ofcourse would mean we couldnt call it emty space any more. But if you took your experiment outside our universe you wouldnt be measuring the space we are familiar with, and isnt our space what you're interested in?

 

Remember the "ether wind"?

[aman]

Thanks RAB, now I've got some ideas on what is the nature of the energy that maintains a space-time void but I have to start a new thread in psuedoscience to propose any thoughts. Soon.

Just aman