What’s in a Golf Ball?

My son asked us, this past summer, what’s inside a golf ball.

This experiment is extra fun because you can tie it into your golf game (I don’t play golf, so I did not), geology (I am a geologist, so I did), and good mechanical/shop skills.

Purpose:

Find out what’s in the middle of a golf ball.

Background Research:

Analyze the golf ball. Does it float or sink in water? Does it bounce? What does the surface appear to be made of? Can you think of other tests to perform on the golf ball?

Hypothesis:

The hypothesis simply states what your child thinks she will find in the center of the golf ball, based on her background research.

Materials:

• golf ball
• vise
• hack saw with new blade (you may need two-three blades)
• safety goggles

Procedure:

1. Wear goggles. Your child has her hypothesis, but she can’t be sure what’s inside the ball. YOU should have some idea*, but she won’t. This is part of the fun.
2. Clamp the golf ball into the vise (if possible, let your child do this herself).  Ideally, it shouldn’t be too tight because that will make it more difficult to cut. However, it needs to be tight enough that it won’t wiggle around.  Fiddle with it a bit. Kids love playing with vises so let her take her time.
3. Show your child how to change a blade in the hack saw. One side is sharp. You know this, make sure she knows this. The properties of a hack saw are not enhanced, to any appreciable degree, by the addition of blood.
4. At this point your child may be feeling quite mechanically accomplished. If this is her first foray into your shop/garage, you may be feeling quite parentally accomplished. Give each other a high five.
5. Start cutting. I started the cut for my son, just because the hacksaw can slide around before the first ridge was cut.  Your child’s fingers shouldn’t be anywhere near the ball or saw blade (please see above photo), so it’s up to you, but be sure to stay nearby.
6. Adjust the position of the ball as necessary to get entirely through the ball.

*There are two probable golf-ball gut scenarios.

1. 1. 1. solid core
      2. liquid (non-toxic) core

Results:

After your child finishes cutting the golf ball open, have her analyze it again. What does she see?

Conclusion:

Your child based his hypothesis by analyzing exterior properties of the ball (density, bounciness, etc.). Have her restate her hypothesis now that she has seen the interior of the ball. Was her reasoning sound? Was her hypothesis correct? If it wasn’t, that’s okay!

Science-y Parallel/Parable of the Day: Geologists can’t cut the earth in half to learn about about the earth. Just as your child couldn’t scratch very deeply into the plastic shell of the golf ball, a geologist can’t “scratch” much of the Earth’s surface and must gather information from the surface.

A small junior hacksaw and extra blades can be picked up very cheaply from Walmart or Harbor Freight.  Since hacksaws are good for other noble pursuits, such as building PVC Marshmallow Shooters, you should persuade yourself that they are a good addition to your child’s Young Inventor’s Kit.

Visiting from Skip to my Lou? Be sure to let me know what you think!