It's like something from a dream and seems impossible in real life. How does a hot air balloon actually fly?

It’s science. If our science teachers would have told us we could learn to fly, we would have perked up a bit!

We can't wait to speak with a balloonist at the Spirit of Boise Balloon Classic - until then, we've consulted with How Stuff Works to get our answer. Simply put: Hot air is lighter than cool air. In fact, you can actually make air lose weight!

Here is where math comes into play: If you take a cubic foot of air which weighs around 28 grams (almost an ounce) and heat it by 100 degrees, it will actually decrease in weight to about 21 grams. The difference in “air weight” is what can be lifted.

Pretty fascinating, isn’t it?

Hot air balloons use approximately 65,000 cubic feet of hot air to be able to lift 1,000 pounds. After all, it’s not just little ol’ you flying in the sky. All things have to be accounted for including the balloon and basket.

That’s not all. You have to keep that air hot.

The hot air balloons we see today use propane to heat the air and are controlled by the balloonist. Whenever the balloonist notices the air cooling, it’s time to turn up the heat and keep things afloat. The propane “tanks” aren’t heavy like we have under our grills at home, it’s in liquid form stored in lightweight cylinders within the balloon basket. Hoses are attached to the cylinders and release the propane quickly. The propane flows through the hoses to the heating coil (steel tube around a burner). The balloonist starts the burner, liquid propane flows out and a pilot light is ignited as a result. The flame heats up the metal coil eventually making the propane so hot it turns into a gas.

Wow, this sparks so many questions!

The best person to ask these questions to is a balloonist. There will be several at the Spirit of Boise Balloon Classic. Please comment with any information you learn. We can’t wait to hear about it!

Meanwhile, like us on Facebook to stay up to date on event details and how you can experience this one-of-a-kind event with your family!

Will you be at this year's Spirit of Boise Balloon Classic?