Rangers, World Series, And Baseball Physics | KERA News

Rangers, World Series, And Baseball Physics

Oct 20, 2011

The Rangers bring the World Series home to Arlington Saturday for Game Three with the St. Louis Cardinals. Rangers fans are eager for a "home" win. But, as KERA's BJ Austin reports it'll take more than cheering in the stands. It'll take "physics" on the field.

Brandt: Physicists like to think about things where forces are involved. So, you've got a bat hitting a ball.

Dr. Andrew Brandt says the crack of the bat hitting the ball is exciting physics - which is defined as the science of matter and energy and the relationships between them. Dr. Brandt is a particle physicist at the University of Texas at Arlington and a big baseball fan. Put those two together, and you have a unique perspective on the game - starting with the physics of hitting a 90 mile an hour fastball, and just how hard that really is.

Brandt: You know, the pitcher throws it, it reaches your bat in about four tenths of a second. So the first half of that is just saying is that a ball I want to hit? And only the other half of the time for your swing. And if you're off by 7 thousandths of a second, it's a foul ball.

Off by another few milliseconds and it could be strike three. Dr. Brandt says fans should give the batter who strikes out a break every now and then. He says each batter has to make those split second assessments and back them up with a lot of force. To hit a 400 foot home run over the centerfield wall, the ball must come off the bat at 110 miles an hour or more. To get that speed, most of the energy from the bat must be transferred to the ball. And Dr. Brandt says that only happens when the ball is hit with the part of the bat physicists call the "center of percussion". On the baseball field, it's called the "sweet spot." 

Brandt: I don't know if you've ever hit a golf ball or a baseball on a cold day, if you hit it wrong it stings your hands. And that's the vibration of the bat where you're hitting it on the wrong place. If you hit a ball well, even a monster home run, you don't feel it very much, I'm told, because the bat doesn't vibrate because you're transferring all your bat speed into exit speed of the balls. 

Dr. Brandt says the second part of the physics of a home run is the ball itself, and its flight.

Brandt: The baseball actually decreases to half of its size when it's hitting the bat. It gets so compressed. It only takes a thousandth of a second in contact with the bat, so you don't normally see a squashed baseball as it flies off the bat.

How far the ball goes depends on its speed and air resistance. Dr. Brandt says the raised red stitches on the baseball actually help cut through the air, reducing resistance. He says a golf ball's dimples do the same thing - even better than a baseball.

And there's another physics principle that can send the ball faster and farther. Put some "backspin" on it. 

Brandt: You chop down on it, like a karate chop and that gives some backspin. The backspin makes a sort of thin layer of air around the ball that helps it go through the air with less resistance. So it can make it go further. That's something that Nellie does apparently better than just about anyone in the major leagues.

Nellie is Nelson Cruz, Texas Rangers power hitter whose grand slam in the playoff series against the Detroit Tigers sent Ranger fans into a frenzy.

Dr. Brandt says Cruz is a physics genius at the backspin. Brandt has his tickets for the World Series Games at the Ballpark and hopes to see a few "Einstein" moments when the Rangers take the field.