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Golf is one of those things that, at first blush, can sound simple and easy. You swing a club; you hit a ball, you put it in the hole. Do that 18 times, then go have a sandwich. It might take a while, but how hard could it be?
As anyone who has ever tried serious golfing could probably tell you, it can actually be very hard. There are so many things you have to think about! Which way is the wind blowing and how hard? What’s the humidity like? Where are the sand traps? What club should you use? How much spin should I put on the ball? Will my friends notice if I write a four on this hole even though it took me six swings to finish? And on top of all of that, you still have to have a really good swing to make the ball go where you want it to go!
Crafting the perfect swing can be a lifetime endeavor for some people. You have to worry about your legs, your wrists, your elbows, your shoulders, your balance, the placement of the club, etc. etc. etc. And then you have to make all those moving parts work together. It’s not easy! Today we’re going to talk about the science behind just one aspect of a golf swing: your center of mass. We’ve talked about the center of mass on Saturday Science before, so you may want to go read that. Done? Okay, let’s experiment with golf.
Materials:
- A golf club
- A ping pong ball
- A lot of room to swing
- Seriously, outside is best here
Process:
- You may not already be familiar with the basics of a good golf swing. If you aren’t, go watch this video a time or two and take some practice swings without a ball involved. Cool? Cool.
- Once you’re pretty comfortable with the basic swinging motion, take your equipment outside and find a nice level spot to stand and do the experiment.
- Place your ping pong ball on the ground in front of you as if it were a golf ball.
- Get ready by taking a few normal practice swings without hitting your ball. Then step up to the ball and take a real one.
- How far did it go? Probably not far, since it’s hollow plastic. That’s okay. The distance here isn’t really the point. Go a few more times to get a feel for where in your swing the ball hits the club.
- Now it’s time for the experimental portion: close your eyes and take a swing. With your eyes closed, pay attention to your balance, and where that balance is taking you as you swing. You should feel your hips and shoulders shifting from back to front over the course of the swing.
- While your weight is shifting from back to front, there is a point when it’s directly below the center of your body. Take a few more swings at the ball and pay attention to this point. Is that centered moment right when you hit the ball? Is it before you hit the ball, or after? Believe it or not, just that one small thing can make a big difference in your golf game. Can you think of why?
Summary
Okay, I’ll tell you. You twisted my leg. It all has to do with energy, and where you’re putting that energy, and when it’s being put there. Unsurprisingly, to maximize the distance you send the ball, you want to hit it with the maximum amount of energy.
Now keep in mind that not every swing is intended to hit the ball as far as possible. Sometimes you want a low, short shot; sometimes you want a high, short shot. But then sometimes you really want to just whack the thing towards the putting green. And it turns out that to really whack it the best, your center of mass has to be right in the center of your body exactly at the moment your club hits the ball.
It sounds weird, but it makes sense if you think about it. As you swing the club, moving your body from front to back, energy from your entire body is being transferred into the head of the club, and when the club hits the ball, the energy is transferring into the ball, moving it across the sky and (hopefully) onto the fairway.
Think of that body motion like a pendulum in an old grandfather clock. When it’s high up on the left, it starts moving down, getting faster until it’s directly under the center of the clock. After that, it has enough inertia (the tendency of a moving object to keep moving) to get it up to its highest point on the left side, but it’s slowing down the whole way until it stops. Basically, the pendulum (and your body) has the highest velocity (and thus its maximum force) when it’s at the exact bottom of its swing.
If you hit the ball before your center of mass is dead center on your body, you still have a split second of acceleration left, and that energy won’t make it to the ball. If you hit the ball after your center of mass has passed dead center on your body, it’s a split second slower than it was a dead center, and you’ve wasted that split second of energy. Either way, the ball won’t go as far as if you hit it at the exact bottom of your swing. But don’t take my word for it, because here’s a Fabulous Golf Bonus Experiment:
Materials:
- A foot or so of string
- A few metal washers
- A ping pong ball
- A ruler or measuring tape
Process:
- Tie one end of the string around your metal washers to create a pendulum.
- Set the ping pong ball on level ground.
- Hold the other end of your pendulum, so the heavy washer side is directly above the ball. Now, prime it to drop by lifting it in one direction, string taut and at a 90-degree angle.
- Lower your pendulum-holding hands an inch or so, so that the pendulum will strike the ball instead of whiffing above it.
- Let it go!
- Measure how far the ball went, then repeat this a few times to establish a pattern.
- Now, hold the pendulum so that it’s about even with the ball but a bit behind it. Repeat the same process and measure the distance.
- Finally, hold the pendulum so that it’s even with the ball but a bit in front of it, and repeat.
Summary
See? I told you!
We're sure you want to spend more time on the green after these experiments! Swing on over to the Pete and Alice Dy Golf Experience at the Riley Children's Health Sports Legends Experience to try four 9-hole courses.
Want more Saturday Science? See all of our at-home activities on the blog or on Pinterest.
