EXPERIENCED baseball fielders can tell how far a ball is going to travel just
by listening to the crack of the bat. If they didn鈥檛, they wouldn鈥檛 stand a
chance of catching it, claims a physicist in New York.
鈥淲hen a baseball is hit straight at an outfielder, he cannot quickly judge
the angle of the ascent and the distance the ball will travel,鈥� says Robert
Adair, a physicist at Yale University. If he relied purely upon visual
information, the fielder would have to wait for about one-and-a-half seconds
before he could tell accurately if the pitcher hit the ball long or short. By
this time the ball may have travelled too far for him to reach it in time.
To stand a fighting chance of catching it, according to Adair, fielders must
listen to the sound of the ball hitting the bat to judge how far it will travel.
There is anecdotal evidence to support this, he says. A former centre fielder
told Adair: 鈥淚f I heard a crack I ran out, if I heard a clunk, I ran in.鈥�
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To test his hypothesis, Adair calculated how quickly a fielder could change
direction if he had misjudged whether the ball was going long or short. The
difference between the 鈥渃rack鈥� and 鈥渃lunk鈥� can be explained by how well the
batter has hit the ball, and could mean a difference in running distance of as
much as 30 metres, he told delegates at a meeting of the Acoustical Society of
America in Chicago last week.
快猫短视频s already knew that to hit a ball long the batter must strike it
somewhere near the vibrational node of the bat, known as the sweet spot. Balls
hit on the sweet spot generate fewer energy-sapping vibrations in the bat,
allowing greater energy transfer to the ball. Conversely, mishit balls make the
bat vibrate strongly and so do not travel as far.
Adair is quick to point out that this only applies to wooden bats, which are
used in major league baseball. Aluminium bats, on the other hand, tend to
produce a fairly uniform 鈥減ing鈥� sound regardless of where you hit them.
Even so, Dan Russell, an applied physicist at Kettering University in Flint,
Michigan, is not so convinced by Adair鈥檚 theory. 鈥淎 good hit is supposed to have
a higher-frequency content and a bad hit has a low-frequency content. I鈥檓
not sure I believe that,鈥� he says.
Russell conducted a five-minute experiment for 快猫短视频. After
hitting a few balls he found that the frequency of the sound continued to
increase the further up the bat contact was made. 鈥淲here you hit the bat does
make a difference to the frequency,鈥� he says. But he is not convinced that the
sound of the strike has anything to do with how close it is to the bat鈥檚
fundamental node.
鈥淗e is dealing specifically with balls hit straight at the catcher,鈥� says
Russell. But the majority of balls aren鈥檛 hit like this. The big test would be
to fire balls at fielders with some sort of cannon. 鈥淚f you remove sound can he
catch the balls?鈥� If not, then sound must be extremely important for fielding,
he says.