 Hundreds of years ago, James Watt decided that my friend Helga could lift 550 pounds, a foot in the air, in one second. And that's the definition of a horsepower. This lawnmower has 6 horsepower. This car has 130 horsepower. And this jet has 85,000 horsepower. All of these engines produce power by forcing a mixture of fuel and air into a tight space and then burning it. But they do it in different ways. A car uses a piston engine. This is a piston engine that's been cut into a half so you can look into it. A mixture of fuel and air enters through these valves into this metal cylinder. It's compressed when the piston pushes up onto it. And then this mixture is burned through a spark plug, causing the mixture to expand and the piston comes back down. And this happens over and over again. There are multiple pistons in a car, and they're connected through a series of linkages to the wheel causing them to turn. Here is the piston engine just like in the car. But instead of it being attached to the wheels, it's attached to the propeller. A small plane like this, Cessna, actually weighs about the same as most cars. And so it needs about the same amount of horsepower to roll down the runway and get off the ground. But a Boeing 777 with all its passengers, cargo and fuel is about 200 times the weight of the Cessna, so it needs a lot more horsepower. You could provide that horsepower by using a ton of pistons, but you'd need 67 of the most powerful piston engines ever built to fly a 777 at cruising speed. That won't work. What you really need is one engine that can produce enough horsepower to fly the plane. A turbine engine is capable of much more horsepower than a piston engine because of the way it uses giant fans to compress the air. At the front of the turbine engine is an intake fan, which spins and brings a huge amount of air into the front of the engine. As we move backwards through the engine, a series of compressor blades makes that air more and more compressed until we get here and here fuel is introduced and burned and that hot high pressure flow gets sent out the back of the engine and that makes the thrust of the engine. But at the same time that flow passes through a series of four or five turbine blades and those blades are connected directly to a shaft at the middle of the engine. That shaft runs all the way back to the front and spins the intake fan. That's what keeps the engine running. We've gone from one horsepower to 290,000 horsepower. So Helga, I guess we don't need you anymore. Run free. Join your herd. That's Brandon. He's domesticated.