I’ve been reading on vacuum and it is super interesting, I have questions about it.
Vacuum is simply defined as a space that has zero matter in. Outer space isn’t even a true vacuum because of a few hydrogen atoms floating, and it’s very hard to create a true vacuum, and it was only created momentarily in labs. (Source: wiki)
Why is true vacuum so hard to create? What exactly makes the matter “want” to go into a empty space? What creates that pressure?
Can black holes be considered as permanent (or very long term) vacuum?
If we assume I have a small box filled with matter as usual. And I have the technology to filter out atoms/molecules one by one. At what point would it start showing vacuum properties?
I’m trying to wrap my head around why the lack of matter creates such a big difference and matter tries to fill it no matter what.
Thanks! Is it possible to have a non-pressured space that is not a vacuum?
The pressure of a non vacuum space would be generated by the gaseous molecules as they collide with the walls of their container.
My layman’s understanding is to get 0 pressure, you either need zero molecules, or the molecules can’t move. Which can only happen at 0K, theoretically.
This is true, in practical terms. The Ideal Gas Law gives us the equation PV=nRT, for gas pressure P, volume of container V, number of molecules n, R a constant that doesn’t matter here, and temperature T in Kelvin. The only other theoretical way to get 0 pressure would be to have infinite volume, but that’s hardly practical.
No, a vacuum is a lack of pressure. Anything that is at a lower pressure than the surrounding atmosphere will act the same as a vacuum.