It is a cold, clear day in January. Brrrrrr. Tomorrow is your best friend's birthday and you are in a store buying a bouquet of helium-filled balloons to decorate your friend's locker. You pay the lady at the counter and laugh at the brightly colored balloons.

[ Do not inhale the helium, it is dangerous. We here at Aspire once knew a guy who inhaled some helium. His head popped off. ]

You begin the walk home in the crisp, cold air. Again, Brrrrrr. As you finish the last block before you are home you notice something wrong with the balloons! They have shrunk! That lousy store, they sold you defective balloons! Arrrgh!

Arrrgh!

[ Hey! Calm down... We here at Aspire are here to help. :) ]

But before you demand your money back, let's figure out why this happened.

If we think about it, we already know some things about the "Mystery of the Deflating balloons" :

1. The balloons were inflated inside a warm store.

2. The balloons are filled with Helium, a gas.

3. Outside the store it is a "crisp, cold" day.

4. The pressure of the gas inside the balloon doesn't change.

We'd better use an experiment that will help us to understand how pockets of gas behave when they are exposed to changes in temperature.

In the 1700's, scientist Jacques Charles', conducted experiments with gas that led to his redesign of hot-air balloons as well as his appointment to the Académie des Sciences (Science Academy).