Date: Fri 23-Oct-1998

Publication: Bee

Author: SHANNO

Quick Words:

sidebar-Bruce-Museum-Play

Full Text:

SIDEBAR FOR BRUCE MUSEUM: "It's Time To Play At The Bruce Museum"

Did You Know?...

When a professional pitcher throws a curve ball, the ball spins so fast that

the 108 red stitches merge to create a dark red spot in the middle of the

ball. Batters with acute eyesight can spot this as a clue to the behavior of

the ball. Ted Williams, for example, had 20/10 vision.

The highest vertical jumps in basketball are around four feet, with a hang

time of one second. Michael Jordan appears to stay in the air longer because

he does not let the ball go until he is on the way down. He also draws his

legs up, making the jump look higher than it really is.

A golf swing -- arm and club -- has an arc of 12 feet or more. The club head

goes from zero at the top of the back swing to 100 miles per hour when it hits

the ball. This acceleration of the club head is 100 times faster than the

acceleration of the fastest sports car.

Before nylon strings became popular, it took gut from the intestines of seven

sheep to string a tennis racket.

Tennis racket strings are like trampolines. When the ball hits the racket the

strings deform absorption energy from the ball. As the strings spring back

they return most of the energy to the ball, sending it off at speeds of up to

140 miles per hour. Slightly looser strings give more power than the tautest

ones but less control -- similar to jumping on a trampoline versus jumping on

hard ground.

From the 12th to the mid-18th Century, golf balls were made of leather stuffed

with feathers. It took a top hat full of feathers to make one ball.

Balls bounce differently depending on how they are made. Air-filled balls like

basketballs and tennis balls bounce better than solid balls like croquet balls

and baseballs. Golfers keep balls in their pockets on cold days because warm

balls bounce higher than cold balls.

With the exception of engine-powered machines, balls are the fastest moving

objects. The fastest is the jai alai pelota (ball) at 180 miles per hour,

followed closely by the golf ball at 170 mph. The slowest is the bowling ball

at 15 mph.

A slight change in the chemical composition of rubber balls can increase the

internal friction so much that the balls do not deform on hitting the ground

and do not bounce back. This is seen in the trick Happy/Unhappy balls. These

are two identical looking balls that when dropped together behave quite

differently -- one bounces and the other goes "thunk."

Spheres spin at different rates. For instance, golf balls move at 8,000

revolutions per minute, baseballs leave the bat at 2,000 rpm, a curve ball

pitch at 1,800 rpm and a knuckle ball pitch at 120 rpm.

From the exhibition catalogue for "Spinning Spheres and Whirling Wheels: The

Art of Play," courtesy Bruce Museum of Arts and Science.