The Physics of Baseball

Porter Johnson

Albert Belle Hitting the Baseball

"It is a haunted game in which every player is measured against the ghosts of all who have gone before."--- Ken Burns

Baseball is the national sport in the United States, but it has a significant international constituent, as well.  Besuboru has thrived for about a century in Japan, and the homu ran is as much a part of their national culture as sumo wrestling, kabuki, and sushi. Baseball is definitely the national sport of Cuba, and is thoroughly entrenched in the Caribbean basin, and quite popular in the Pacific Rim, as well.

The baseball, bat, and glove are still composed of natural materials that reflect an obsolete technology, to maintain the myth that the game is the same as that played over a hundred years ago.  However, baseball has continuously been altered (indirectly and sometimes directly) by the advance of technology.  Here are some significant milestones in the history of baseball:


Questions Concerning Baseball


The pitcher stands less than 20 meters from the batter, and throws the ball at speeds of around 40 meters/sec.  In that time the ball drops from its "straight line" path by about 1.2 meters.  Because of the stitches on the baseball there is considerable turbulence affecting its motion, and it may behave somewhat erratically.  The pitcher may put considerable spin on the baseball, corresponding to about 20 revolutions over its path.  A few pitchers have been able to perfect the knuckleball, which hardly spins at all, and which drifts somewhat arbitrarily in its motion.  The complications in the motion of the ball arise from the Prandtl Layer of air that moves with the baseball, and which has a dominating effect on the motion of the ball.

Ty Cobb's remembrance of his introduction to the legendary pitcher Walter Johnson:

"On August 2, 1907, I encountered the most threatening sight I ever saw in the ball field. He was only a rookie, and we licked our lips as we warmed up for the first game of a doubleheader in Washington. Evidently, manager Pongo Joe Cantillon of the Nats had picked a rube out of the cornfields of the deepest bushes to pitch against us....He was a tall, shambling galoot of about twenty with arms so long they hung far out of his sleeves and with a side arm delivery that looked unimpressive at first glance....One of the tigers imitated a cow mooing and we hollered at Cantillon: 'Get the pitchfork ready, Joe-your hayseed's on his way back to the barn.' ...The first time I faced him I watched him take that easy windup-and then something went past me that made me flinch. The thing just hissed with danger. We couldn't touch him...every one of us knew we'd met the most powerful arm ever  turned loose in a ball park."

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"Did they tell me how to pitch to Williams? Sure they did. It was great advice, very encouraging. They said he had no weakness, won't swing at a bad ball, has the best eyes in the business, and can kill you with one swing. He won't hit anything bad, but don't give him anything good." - Bobby Shantz 

The batter has about 0.5 seconds to gauge the path of a pitch, and the bat must be at the right place [within about 1 cm] at the right time [within 0.01 seconds] to make solid contact.  The bat-ball collision lasts typically for 0.001 seconds, and the average force on this ball is of order 10,000 Newtons, corresponding to a mass of about 1000 kg [or a ton].  The process of hitting is mysterious, but with God-given quick reflexes and many years of practice, a few players can learn to hit the ball regularly.  Ted Williams said "Hitting is fifty percent above the shoulders" and wrote a book entitled The Science of Hitting, in which he analyzed hitting with detail normally reserved for scientists and scholars.

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Base Running

Many players have run the bases aggressively, but Ty Cobb [above] best terrorized the base paths, routinely scoring from second base on an infield out and from first on a single.

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"After the game, Jackie Robinson came into our clubhouse and shook my hand. He said, 'You're a helluva ballplayer and you've got a great future.' I thought that was a classy gesture, one I wasn't then capable of making. I was a bad loser. What meant even more was what Jackie told the press, 'Mantle beat us. He was the difference between the two teams. They didn't miss DiMaggio.' I have to admit, I became a Jackie Robinson fan on the spot. And when I think of that world Series, his gesture is what comes to mind. Here was a player who had without doubt suffered more abuse and more taunts and more hatred than any player in the history of the game. And he had made a special effort to compliment and encourage a young white kid from Oklahoma." --- Mickey Mantle

The baseball bounces erratically when it hits the ground in the infield, since there is usually a great deal of spin on ground balls.  A good infielder must come up with the ball and get off a throw to get the runner(s) out.  

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"Willie Mays was never sick, he was never hurt, he never had a bellyache, he never had a toothache; never had a headache.  He came to the park every day to put on the uniform and play." --- Leo Durocher, manager.


Willie Mays

A solidly hit baseball may leave the bat with  speeds as great as 60 meters/sec, much larger than the speeds with which the pitcher typically throws the ball.  The path of a fly ball is strongly influenced by air resistance; in f act, air resistance is just as important as gravity for its motion.  The ball remains in the air for as long as 5 or 6 seconds, and the outfielder must decide quickly where they should go to catch the ball, if they can.  It is somewhat of a mystery as to how outfielders are able to gauge the flight of the ball, since it can vary greatly because of spin, wind conditions, and atmospheric drag.   

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"Why has our pitching been so great? Our catcher (Yogi Berra, above ) that's why. He looks cumbersome but he's quick as a cat." --- Casey Stengel

Like the conductor of a symphony, the catcher directs defensive play, calls the pitches, and keeps the team focused on getting the batter out.  Also, a good catcher can manage to block the umpire's view of a pitch on the outside corner, to keep the hitter psychologically on guard, and guide the  the pitcher to success.  The catcher gets more than his share of bumps, bruises, and sprained fingers from foul tips, bad pitches, bats, and aggressive base runners.  Catchers are frequently required to chase after pop-ups behind the plate.  These poorly hit pitches usually have a lot of spin, and move erratically, so that pop-ups may be very difficult to catch.  A great catcher makes catching them look easy, in spite of the perils of bats, other equipment, dugout steps, fences, screens, and railing.

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"Most ball games are lost, not won." --- Casey Stengel

The manager gets the credit when his players hit home runs and win games, and may be the first person to go when the team does not live up to expectations.

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Baseball Quotations Additional References: Go To Top of Page

Baseball Trivia.

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