Science Smarts: The science of the knuckleball
By Patty Rooks on June 17, 2023.
The past month or so, I have spent a great deal of time at the baseball diamonds. Just when you think the pitch is coming in and it will be a home run, it is a strike. The ball seems to wiggle or dip, and then a miss…how does this happen? The coach says these are “knuckeballs.” Hmmmmm… I think we had better turn to science to help us figure this out. Let’s get started! Remember to ask an adult before doing this experiment. Materials – 2 L pop bottle (empty) – Marbles – Water – Sturdy work surface Procedure 1. Fill the pop bottle as full as you possibly can with water. 2. Place the bottle on a steady surface. 3. Bend down so the mouth of the bottle is at eye level 4. Holding one marble between your forefinger and thumb, position it just above the mouth of the water bottle – almost touching the water. 5. Keep observing and DROP the marble. 6. Observe what happens. 7. Repeat a few times so you can see any variations. What is going on? In this experiment we had to slow the baseball game down and simulate what is happening and make careful observations. The path the “knuckleball” takes in the air is similar to the path the marble took as it passed through the water. After a few tries, you should have observed that it did not take two paths the same. When a pitcher throws the baseball, it is often a curveball or fastball which pushes the air to one side. This results in a consistent amount of drag behind the baseball allowing it so slow down and behave a bit more consistently. As we seen with the marble, when there is no spin on the ball (knuckleball), there is no consistent force acting on the ball and the path it takes is inconsistent – bobbing and weaving all over the place. Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. We are located at: #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403.527.5365, email: praxis@praxismh.ca. 20-19
