Is it easy to create a vacuum in space?

Question

Say for example you have a closed, empty, and air-tight plastic bag, then you can't grip it from each side and pull the sides apart because for that to work a vacuum would need to be created inside the bag (and I'm not sure where I've heard this but - nature abhors a vacuum).

But then if the bag was in space (and for arguments sake wasn't harmed by the environment there) would it be possible to do the above? It seems likely because the emptiness created inside the bag would be the same as the emptiness in space, the wall of the bag would not be restricting anything, right?

It'd be pretty weird if this was the cause though.

Answer 1

Yes, in space this would be possible.

The reason that one cannot open up a space inside a plastic bag when it is empty and sealed is because of the air pressure surrounding the bag. A huge number of air molecules are constantly bombarding the plastic bag from all directions (a.k.a. air pressure), so it would take a large amount of evenly distributed force to open the bag despite the pressure. Pulling on it with your fingers doesn't cut it.

If you were in the near vacuum of space, that air pressure would be almost entirely gone, so I predict that you could indeed fairly easily open up a space inside a sealed, empty plastic bag (neglecting the fact that current space suits have very clumsy fingers that might not be up to the task).

Answer 2

Define 'empty' bag.

If the bag had legitimately nothing in it, then it would already be a vacuum, so no problem there you already have what you want.

If the bag had some air in it, if you send it to space it would explode outwards, because space is 'empty' like you say, so the air within the bag would push outwards, eventually tearing the bag apart. In this sense, it is 'easier' to create a vacuum within space, because any system will try and become a vacuum by itself with no outside intervention.

Unless your bag was really strong, like metal. But then it's not really a bag is it.