Physics

In the middle of the summer holidays, a number of high school students came to my hospital. They sat on either side of the doctor in the clinic, going around with the doctor who saw patients everywhere in the hospital. This could have been the first time they stayed in a public hospital.

I haven't thought much about the high school education before the students joined us. We talked about everything, and then I realized that high-school days are pretty far away in my life. For a moment I was puzzled how much high-school teaching I could still remember.

Not much. Let me think. How about Newton's three laws of motion? The first law states that every body perseveres in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impress'd thereon. Yes, of course, it's all about the kid's resistance to change. No, not changes. They don't like changes. They really don't. Kids react to changes with vehement opposition. My daughter - and many other children, I'm sure - doesn't want to go out after she has started drawing at home, and once in the playground, doesn't want to leave, and by night time, doesn't want to sleep.

Now think about Newton's second law. We're taught that motion doesn't require the action of a force, but a change in momentum does. That is proportional to the force causing it. That's easy to understand. To speed things up we need to push it. Beautiful, I know, but does it mean I have to push my three-year-old daughter? Wait. The third law states that we can't push something (or someone) without it pushing back.

Let me summarise. A force can cause change, and a harder one gives more drastic change, which can backfire because of another force - you guessed it: action and reaction (or rebellion). What an important rule that would be.