Gilpin observer., 1913-06-05
The Physics of Baseball
By Hugh S. Fullerton
(oopyrisht, lslS, By W. G. Chapman


accomplished the aim of making ball
not too dead" and not too lively.
The shock of the bat against the ball
dispels the air gradually and at the
same time causes molecular change
In the rubber SO that ball, after be-
ing batted hard, loses much of its re-
silent power. The disarranging of
the molecular force causes a ball
which, to an outsider may seem as
firm and solid as ever, to become a
"mush," dead and lifeless, and likely
to slow the entire game If permitted
to remain in play. The bats used are
| almost all of second growth ash of the
finest and straightest grain, and
carefully dried. They are supposed to
retain their resilient qualities indef-
nitely, but after a month or two of
hard usage the bat no longer possesses
the drive" necessary for hard hit
ting. Yet bats that have lost life"
often will, when kept in storage few
months, recover their lost ring" and
be as good as ever, although the sec
ond time they die" more quickly.
This sense Of feeling and hearing
among players is wonderful thing.
The object of each batter is to "hit
| 1t on the trade mark" with that part
of his bat between four and six inches
| from the end. He does not express it
that way, but he aims to hit the CEN
| ter Of mass Of the ball with the CEN
ter of percussion of the bat-so he
| says, square on the nose" The cen
ter of percussion of the bat varies ac-
cording to the grip of the batter's
hands, and it is the object of the
pitcher to force the ball to revolve 80
as to avoid meeting the center OF per-
| cussion.
A ball weighing five and eight
ounces and with a circumference of
nine inches, pitched at an approx
mate velo :ity of $50 feet a second
over distance Of so feet, is struck
squarely upon the center Of percus-
sion Of bat weighing 40 ounces and
swinging at velocity of 1880 feet
per second, will travel how far? Per-
haps the professor of physics can
figure 1t out, but If he does he is
wrong. He would have to know more
than these statistics before he could
make the correct calculation. He
should know the forearm strength of
the batter, the muscle leverage, the
meeting angle Of ball and bat, the ro-
tary motion of the ball, the condition
of the atmosphere, direction of wind
and few other things. 1t is much
easier to have Vean Gregg shoot up
fast one, let Larry Lajoie hit 1t, and
measure the distance, than to take q
postgraduate course and calculate it.
Every ball that is pitched, or
thrown, or batted has some rotary or
oscillatory movement all its own fur
ther to complicate attempts to solve
problems in baseball physics. The
ball has a wonderful ability to abb
sorb and retain motion no matter how
impaired The spit ball, which was
SO fully and exhaustively treated in
the lectures of my friend the pro-
fessor that l expect to see about 12O
Washes graduate from his school in
the next two years, is the result of
skillful applying of an unnatural force
to counteract the natural rotation of
the ball. The professor disputes this.
Possibly he does not know that ball,
fingers, and thrown directly over
hand, has natural tendency to ro-
tate upward and hop" as the pitch
ers say. All good fast balls rotat-
ing this way take sudden jump In
the air. The spit ball pitcher vets
the surface of the ball, grips the low
er side tightly with his thumb, let's
the ball slide off the fingers. The eff
feet is that two conflicting forces
cause the ball to "wobble' for dis
tance, and then, yielding to the infiu-
ence of the thumb pressure and the
attraction of gravity, 1t darts down
ward. When ball thus pitched is
hit it still refuses to surrender its in
clinatioD to rotate. 1t starts toward
the infield with two forces still
struggling for mastery. Each time the
ball touches the earth it takes a diff
ferent English. The infielder scoops
the ball and throws. If he clutches
the ball hard enough to kill all mo-
ton, all is WELL If he seizes 1t light
ly and throws with the same motion
the ball takes fresh and renewed Eng
lish as 1t leaves his hand and is more
likely to shoot out of reach OF the
batsman toward whom he throws.
The pitched ball. manipulated so as
to revolve unnaturally, takes Eng
lish" in the air just as billiard ball
does against cloth and cushion. Many
persons have told me that the atmos-
phere on still day offers practically
a uniform resistance to projectile.
1t does not. We know now that the
air is filled with eddies, currents and
pockets, even on the calmest of days.
But admitting that 1t is uniform in
density, a ball does not follow the
physical law OF constant decrease in
speed in ratio to the resistance of the |
air. 1t even is capable of accelerated
motion, and of both In the same 80