Let’s play with air!

Take an empty mineral water bottle or any other bottle made of

thin plastic. Drill a hole in the cap, insert a straw into it and seal it

with clay. Or seal the mouth of the bottle with clay and poke a

straw through. Now suck in the air through the straw. The bottle

crumples. Why? The air outside is pushing against it, and there

isn’t enough air inside the bottle to push it back with equal force.