Baseball, Pianos, and Medicine

[Dan Squire]

Hello all,
I just got my ASME (American Society of Mechanical Engineers) News in the
mail today.  I thought an article in this paper would be of interest to some
on this delightful and exciting listserve, so I am going to quote a small
section of it for your reading enjoyment.  The title of the article is:
Fine-tuning construction of baseballs raises safety questions.  The author
is Benedict Bahner.

      "Last year, with the major league baseball strike  about to go into full
swing in the United States, Henry Scarton hit on another way to maintain his
interest in the game.
      Intrigued by the recent controversy over the rising number of
out-of-the-park home runs, Scarton began to wonder if the explanation could
be related to the baseball's dynamic hardness, a characteristic he believed
could be measured using a patented method that he had developed to test
piano hammers for the piano manufacturer Steinway & Sons...
      Baseballs are not currently measured by their hardness.  They are
categorized by their "liveliness." with a coefficient of restitution number
that represents the speed of a ball before and after it hits a wall.
      In the sports applications of Scarton's SDH testing method - which he
developed with student ASME members Peter Giacobbe and Yau-Shing Lee - a
baseball's hardness is measured by  the vibrations it emits on impact.
      Vibrational responses in pianos and baseballs are similar, Scarton said.
Piano strings that are hit with a felt-tipped hammer produce a richer sound
because the harmonics of the strings that are excited are reduced.
      That vibration principal can be applied to a moving baseball, Scarton said.
When a standard baseball hits the rib cage, the bones absorb the vibration
much like piano strings.  Because the frequencies emitted by a soft-center
baseball are lower, Scarton said, the rib cage does not absorb the
vibrations on impact.  If the rib cage doesn't dispel that extra energy, it
will be absorbed by the soft, vulnerable tissue underneath - principally the
heart.
      In slow speed testing of a variety of balls - regular baseballs,
softer-core baseballs, softballs, even Ping-Pong balls and bowling balls -
Scarton found that although the soft-center baseballs had a lower peak force
on impact, which could reduce the severity of injuries in players who were
hit in the head, Scarton suspected the lower impact vibrations they emitted
could interrupt the heart's regular rhythm and induce the potentially fatal
condition, heart arrhythmia."

It gives me a warm-fuzzy kinda feeling when I see a piano plastered on the
front page of my ASME newsletter.

Cheers,
Dan Squire