Pop Top

Pop Top

Can you get a bottle to talk to you?

We can.  Here’s how:

We filled a bottle with very cold water and then emptied out the water.  The bottle looked empty, but we knew it was full of cold air.  Now when we warm the air in the bottle by gently putting our hands around the bottle, the lid begins to jump (and it looks like the bottle is talking!)  Teacher was the best at speaking bottle language, but we all enjoyed trying to guess what the bottle was saying.

In actual fact, what is happening is that warm air takes up more space than cold air, and so it needs to escape from the bottle, pushing up the top on its way out of the bottle.  When the warm air has escaped the lid stays on the bottle, until the next time the air inside the bottle heats up enough to need to escape.