I love physics. Conceptually, it has more fun ideas than Alice in Wonderland. Although some of the beginning-of-the-universe cosmological physics stuff goes a little too far on the Six Impossible Things Before Breakfast scale. The other difficulty I have with physics is the math. (I know; I’m supposed to be a modern, strong, girls-can-do-anything person. If I have to, I can do math. I just don’t love it and it is a struggle for me. I don’t often agree with Barbie, but for me, math is hard.) My interest, therefore, is entirely recreational, since the idea of integrals, the sines and cosines, and even the more elaborate algebra makes me nervous about running out of erasers.
Given all of that, The Manga Guide to Physics seemed to be a book designed with me in mind. Comics! Cute smiling big-eyed people and muscular guys with tennis rackets for heads! It was a good read and a good introduction to my buddy Newton. I admit I skimmed the parts that were labeled “Calculus Ahead!” since I forgot all the calculus I ever knew immediately following the AP exam, but I think that’s fine.
Here’s the thing, though. Some of the simplest concepts throw me. I get it that our heroine the tennis player exerts force on the tennis ball equal to the force of gravity when she’s holding out the ball on her palm. But then our hero the physics nerd said that when the ball is resting on a desk, the desk is exerting force equal and opposite to the force of gravity. Huh? The desk is just sitting there, same as the ball. I don’t think the desk exerts itself to hold up the ball. (Yes, I did read the part about how holding up a tennis ball is not work even if it is tiring eventually. And I know desks don’t get tired, or do work of any kind, more’s the pity.) So how, exactly, is the desk exerting force?
Please explain, my smart and talented friends.