Science of Football – Spin

Science of Football – Spin

Ambience: Football Game
Ever wonder why a football is shaped the way it is? Stay tuned. I’m Jim Metzner and this is the Pulse of the Planet.

Engineer Ainissa Ramirez is the co-author of the book, Newton’s Football the Science Behind America’s Game. Here’s her spin on the aerodynamics of a prolate spheroid that’s science lingo for the geometric shape of a football.

Ramirez: When you throw a football, you don’t just push on it. You actually rotate it. You use your finger to kind of roll against the top of the ball, and that causes the ball to spin. And quarterbacks can make a ball rotate 600 RPMs revolutions per minute.

And just to give you a sense of how fast that is, your CD player spins about that fast, and the spin does a few things. It stabilizes the ball. You see, if you’re going to throw a ball into the air with that kind of shape without spin, it’s going to do belly flops. So the spin prevents the ball from flopping over, and the spin actually moves the ball laterally across the field slightly. So, if I were to throw a ball and I’m left-handed or if I were to throw a ball and I’m right-handed, the spin looks very different, and the ball will end up in a different place.

So when a right-handed quarterback throws a football, it’s going to tend to veer slightly to the right.

Ramirez: Receivers don’t talk about it. Except Jerry Rice did. He’s like, “The ball looked very different when Joe Montana threw it and when Steve Young threw it.” And it’s because one’s right-handed and one’s left-handed. This thing called gyroscopic torque it actually moves the ball in the direction that it’s spinning.
The advantage of the prolate spheroid, besides that the spin stabilizes it and the shape prevents less air resistance, is that it’s just easier to carrier. You can just tuck that in your arm and be able to move without defenders taking it away from you.

We’ll hear more on the science of football in future programs. Pulse of the Planet is made possible in part by Virginia Tech, inventing the future through a hands-on approach to education and research.

Science of Football - Spin

Ever wonder why a football is shaped the way it is?
Air Date:01/31/2014
Scientist:
Transcript:

Science of Football - Spin

Ambience: Football Game
Ever wonder why a football is shaped the way it is? Stay tuned. I'm Jim Metzner and this is the Pulse of the Planet.

Engineer Ainissa Ramirez is the co-author of the book, Newton's Football the Science Behind America's Game. Here's her spin on the aerodynamics of a prolate spheroid that's science lingo for the geometric shape of a football.

Ramirez: When you throw a football, you don't just push on it. You actually rotate it. You use your finger to kind of roll against the top of the ball, and that causes the ball to spin. And quarterbacks can make a ball rotate 600 RPMs revolutions per minute.

And just to give you a sense of how fast that is, your CD player spins about that fast, and the spin does a few things. It stabilizes the ball. You see, if you're going to throw a ball into the air with that kind of shape without spin, it's going to do belly flops. So the spin prevents the ball from flopping over, and the spin actually moves the ball laterally across the field slightly. So, if I were to throw a ball and I'm left-handed or if I were to throw a ball and I'm right-handed, the spin looks very different, and the ball will end up in a different place.

So when a right-handed quarterback throws a football, it's going to tend to veer slightly to the right.

Ramirez: Receivers don't talk about it. Except Jerry Rice did. He's like, "The ball looked very different when Joe Montana threw it and when Steve Young threw it." And it's because one's right-handed and one's left-handed. This thing called gyroscopic torque it actually moves the ball in the direction that it's spinning.
The advantage of the prolate spheroid, besides that the spin stabilizes it and the shape prevents less air resistance, is that it's just easier to carrier. You can just tuck that in your arm and be able to move without defenders taking it away from you.

We'll hear more on the science of football in future programs. Pulse of the Planet is made possible in part by Virginia Tech, inventing the future through a hands-on approach to education and research.