Thursday, May 19, 2016

Breaking in a Baseball Glove...and a Little Physics

Given my quasi-rant from a couple of days ago, you would think I'd have minimal time to waste on baseball. That's simply not true. The game itself has an elegance to it and I see my son hustling and trying his best. He says practices are boring and it's hard, but that also means he's learning to handle himself somewhere besides on the couch.

One thing I noticed was the number of balls that bounced in and out of his glove. Essentially, he caught most of what was thrown to him only to have it fall out of his glove. I can imagine this being tiring and frustrating. Then the thought occurred to me that his glove was advertised as "pre-softened", but that it was only "half-fast" pre-softened. The softening makes the glove, well, softer. It allows the hand to squeeze the glove easier to catch, but also there's a little physics to something being softer as well.

When a ball strikes a hard surface, the collision could be considered elastic. That is, little energy is absorbed by the hard surface. In an "ideal" case the ball would recoil with the same energy as it hit the surface, or in this case a stiff glove. This is a similar principle to why aluminum bats hit further than wood. The stiffness allows more energy to stay with the ball (plus energy from the movement of the bat).

For a softer surface, more energy is transferred to the surface in order to compress the material. This results in a larger loss in kinetic energy for the ball. The most obvious example is trying to bounce a basketball on your driveway and then on your carpet, or bed.

In theory, this should lead to a more easily caught baseball as there is more energy absorption. There is another aspect too. Friction. The softness adds friction to the glove/ball interface. There's just a little more area in contact with the ball than on a hard surface. Thus, the edges contacting the ball of a softer mitt will help the ball stick.

Take the energy transfer, friction and add in that a softer glove is likely just easier to close around a ball; softening a glove should be a no-brainer.  There are a million ways to do this, but I keep it simple. This morning I used some store bought glove oil and gave it a good rubdown. You don't need much so I wet a cloth with the oil and applied it over the whole mitt, working it in good. The glove is currently sitting on my workbench with a ball in the pocket under a landscape stone.  Hopefully, this will result in a few fewer "in and outs" and add some enjoyment to playing the game.

I do find the rituals that develop with a sport to be quite interesting. Especially ones that seem to be actually useful. I don't envision writing a "physics of rally caps" article anytime soon.