How to inflate a balloon without touching it
Inflate a balloon inside a bottle!
Warning! Only under adult supervision.
- glass bottle;
- boiling water.
Pour some boiling water into a glass bottle and wait until the glass warms up. Pour out the water and put the balloon on the neck of the bottle. After a while, the balloon will be drawn into the bottle, and then it will inflate!
In putting the balloon on the neck of the bottle, you create a closed system. This system has a fixed amount of air and a temperature higher than the ambient temperature. When the glass cools down, the air inside the bottle cools as well. With it, the pressure decreases, becoming lower than atmospheric pressure. Atmospheric pressure “inflates” the balloon into the bottle.
A lot more cool experiments are waiting for you in the MEL Physics subscription!