(or 10): How does a vacuum work? Why does gaseous matter feel pressured (pardon pun) to occupy as much space in a vacuum as possible?

Question

Reading The Martian and thinking about things like depressurisation – why does air from a higher concentration feel the need to rush through a small leak with enough force to rip or blow things apart instead of staying put?

What calls it from the vacuum for it to be so obsessed in doing so?

In: Planetary Science

Answer 1

So gas is made up of these very tiny things called molecules. Scientists have found out that gas molecules love to dance, but don’t like bumping into each other because they are shy and like their personal space.

Now when there are a lot of gas molecules in an area, they like to spread out so that each and every molecule has about the same space to dance on the dance floor. If some of the gas molecules leave the dance floor there is now more personal space for the rest of the molecules to have for themselves.

So what happens is that as more molecules leave, each molecule that is still on the dance floor has more personal space. That is why gasses, like air, fill the space they are in.

If there are more gas’s molecules outside the dance floor than in, the gas molecules from outside will wiggle onto the dance floor since they will have more personal space to dance.