Backspin Basketball Flies Off Dam

Recently, some friends of mine went to the Gordon Dam in Tasmania, which is 126.5 meters (or 415 feet) high. Then they dropped a basketball over the edge. You can see that the basketball gets pushed around a bit by the breeze, but it lands basically right below where it was dropped.

Now watch what happens when they drop another basketball, but this time with a bit of backspin...

"Woah, look at that go!"

"That's incredible."

"This is Bret who just threw it."

I literally just dropped it, with a bit of spin, like I didn't even throw it, and it just took off, like we had no idea that was gonna do that.

And this is where I come in: the basketball was subject to the Magnus effect, which affects all rotating balls or cylinders as they fly through the air. And it works like this: as the basketball picks up speed, air on the front side of the ball is going in the same direction as its spin, and therefore it gets dragged along with the ball and deflected back. Air on the other side is moving opposite to the ball spin, so the flow separates from the ball instead of getting deflected.

The net result is the ball pushes air one way, so the air applies an equal force on the ball the other way. And this is known as the Magnus effect, named after Heinrich Gustav Magnus who described it in 1852. Of course, Isaac Newton beat him to it by nearly two hundred years, describing the flight of tennis balls at Cambridge College. But, you know, he's got enough stuff named after him....

This effect is very important in sports like tennis, soccer and golf, but could it have non-sport applications? Perhaps. This is a sailboat. I know it doesn't look like a sailboat, but those aren't chimneys. They are spinning cylinders called "Flettner rotors", and they take the place of the sails. They deflect crosswinds, using the Magnus effect, to propel the ship forwards.

And this is a plane with spinning cylinders instead of wings. Using the Magnus effect, the cylinders actually generate more lift than traditional wings. However they also generate way more drag, making them impractical. This place only flew once, and then it crashed.

But the Magnus effect is making a comeback. Here is an experimental rotor wing aircraft which generates all its lift from spinning cylinders. And this is the E-Ship 1 which uses four spinning cylinders (that's four Flettner rotors) to increase its efficiency and reduce the amount of diesel it burns.

So, in the future, the Magnus effect may help more than just basketballs fly.

"Woah, look at that go!"

Now the real reason my friends from "How Ridiculous" were at the dam was to set the world record for the highest basket ever scored. So go check out their channel and the video, and subscribe to them for more epic trickshots.