You know like the kind that go on a window or bathroom mirror or on the wall or in the shower. They need the atmosphere pushing down on them to work, right?
You know like the kind that go on a window or bathroom mirror or on the wall or in the shower. They need the atmosphere pushing down on them to work, right?
It’s a good line of thinking for trying to be scientific (how do we replicate conditions better, and where might we be introducing errors that would make the experiment “bad”), so you didn’t deserve a down vote.
That being said, it won’t change the outcome too much. In a vacuum, it’s just pushing a bit of rubber against something, there’s no possibility for suction. It’ll just fall off.
If it starts outside a vacuum, the force of air pushing on the outside will keep the rubber from pushing away from the surface at first, but as the air pressure drops, the little bit of air under the cup will give it the tiniest oomph of extra push as it falls off in a way visually indistinguishable from the vacuum scenario.
That’s my prediction as well, but if the experiment is cheap to run, why not do so, and see of you learn something?
No reason at all not to. :)
That’s what I was thinking too, you would need to have the pressure outside the cup to be higher, that’s the force keeping the cup “sticking”.
My prediction is that if you were to stick the cup while under atmospheric pressure, it would have a small amount of air inside … making it unstick more easily after the outside gets depressurized, compared to the condition of having stuck the cup while in vacuum, although the difference would properly be negligible.