That balloon didn't just fly. It used the same science that launches rockets into space.

When you blow up the balloon, you're cramming millions of air molecules into a tight space. They're pushing outward in every direction — that's air pressure. The moment you let go, all that pressure has one way out. The air blasts backwards, and the balloon shoots forwards.

That's Newton's Third Law — for every action, there's an equal and opposite reaction. Air going that way means balloon going this way. Every single time, no exceptions. It's one of the most important rules in the entire universe.

Did you notice it slows down towards the end? That's not the balloon getting tired — it's running out of pushing power. Less air left inside means less pressure, less thrust, less speed.

Did you also notice it travels in a perfectly straight line? That's the string doing its job — channelling all that energy in one direction. Without it, the balloon would spiral and tumble all over the place.

A real rocket does exactly this — except instead of air, it burns fuel and blasts out hot gas at thousands of kilometres per hour.

You just held a rocket engine in your hands. 

But here's the question — how does a rocket steer in space when there's no string to guide it, and nothing to push against? 

Find out in The Crazy Scientist Lab!