Magdeburg Suction Cups
What Do You See?
Snap the suction cups onto each other. Have a friend grab one handle while you pull on the other handle. Pull as hard as you can. Can you pull them apart?
What Can You Try?
Try snapping one onto a table. Can you pull it off the table?
What is Going On?
When you snap on the handle, you push the air out between the two surfaces. The pressure of the air in the room pushes down on the cups and prevents you from pulling them off.