Empty space cannot push
What Does Nothing Actually Do?
A vacuum has nothing in it, so it exerts no pressure and everything around it does the pushing.
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Step 1 of 5
Air is constantly pressing on everything.
Countless molecules strike every surface every instant, and the total is about a kilogram of force on every square centimetre.
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Step 2 of 5
We never notice because it presses evenly.
The push arrives from every direction at once, including from inside us, so all of it cancels out and we feel nothing at all.
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Step 3 of 5
Remove the air and the pushing stops.
A vacuum has no molecules, so it exerts no pressure whatsoever. It cannot pull, because pulling requires something to do the pulling.
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Step 4 of 5
The surrounding air causes everything.
Every dramatic vacuum demonstration is really the outside air pushing inward with nothing pushing back, which is why cans crumple.
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Step 5 of 5
A perfect vacuum does not really exist.
Even deep space holds a few stray atoms, and the best laboratory vacuums still contain far more particles than most people expect.
Two joined hemispheres emptied of air famously could not be pulled apart by sixteen horses, purely from outside air pressure.
The short version
A vacuum does nothing at all, because it has nothing to push with; every effect blamed on it is really the surrounding air pushing inward.
Try it yourself
Watch a plastic bottle crumple as it cools with the cap on. Nothing pulls it in; the outside air simply wins.
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