I got it into my head the other day to talk about gravity with my older daughter (whom I will refer to by the initial of her first name, “A”). After looking forward to it all day, I brought the subject up at the dinner table when we had finished eating.
“Have you ever wondered why things fall down instead of up?” I asked her.
She looked at me sideways with an intrigued smile. I could see she was trying to tell whether I was asking a legitimate question or just setting her up for a word-game trick.
She said no. I then asked her if she knew what gravity was, and she gave a good answer: it was the force that made us fall back down when we jumped up in the air.
“So why do we fall back down instead of falling up?”
“I don’t know,” she answered, still suspecting a trick.
“Well, sometimes things actually do fall up.”
“What?!! How?”
I started moving things around on the dining table to represent the earth and the moon and the planets and a rubber ball. I explained that if the rubber ball was very close to earth—like in our dining room—and you dropped it, it would fall down to the floor. But if you took it far enough away from earth out into space and close enough to the moon, for example, it would start falling away from earth—in other words, up—and toward the moon. I told her it would work the same way if you moved the ball close enough to Venus or Mars or the sun. If the ball got close enough to any of those bodies, it would fall toward it and away from the earth.
Then I did a few historical riffs, talking about how Isaac Newton figured all this out hundreds of years ago by studying the movements of the planets. (I left out the part about the apple bonking him on the head, since I understand there is little evidence to support that story.) I told her that Newton was one of the smartest people who ever lived and that she would be hearing more about him as she continued in school. I added that Newton had to invent a completely new branch of mathematics just to figure these things out (which didn’t mean much to her) and that he did it a long time ago before it was possible to even send rocket ships out into space to see if something would in fact start falling away from the earth and toward the moon if it got far enough away from earth (which did seem to catch her attention). And I closed with this moral: “Smart people don’t just try to answer difficult questions. Sometimes they start by thinking up entirely new questions that seem silly, like why things fall down instead of up, and then they try to answer those questions that other people might think are silly.” I was feeling pretty pleased with myself.
When I was originally planning my talk to “A” about gravity I imagined that I would be contributing to her education. But I think the truth is that I was just looking for a chance to show off by demonstrating that I knew things that my children haven’t learned yet. And I figure that my time for doing that is running out.
My father was a pretty smart man, and he could explain lots of things to me when I was a boy. Often, he would do it by drawing a diagram of some sort. He would take out his elegantly slim Paper Mate® mechanical pencil (the kind with the little raised white dot on the barrel near the top), give it a twist, send me to fetch a piece of paper, and then draw a picture. Sometimes, the picture would illustrate some concrete, physical thing (like some principle of mechanics) and at other times something abstract (like Roman numerals).
One day I came to him with a textbook opened to a page showing a simplified diagram of a rocket. There was something about the working of the rocket I didn’t understand. He looked at the picture only a few seconds and then handed the book back to me.
“Son, you’re asking me things now I don’t know anything about,” he said.
I don’t know if the sadness was in his voice or just in my hearing of it, but I was sorry I had asked the question about rocket science. I was in elementary school at the time.
So I figure my kids are going to catch up with me very soon. If I’m going to show off for them, I’d better hurry.
Here’s a list off the top of my head of things that I need to hurry up and teach my children before someone beats me to it:
1. How to use a map and compass.
2. How to use a watch (analog only) as a compass, based on the position of the sun. (Don’t forget to adjust for daylight savings time, because the sun doesn’t know anything about that.)
3. “GOP” stands for “Grand Old Party.”
4. In writing, use the passive voice as little as possible.
5. In writing, don’t use big words just to make yourself sound smart.
6. How electricity works (direct current only).
7. The moon rises approximately 55 minutes later each day.
8. “A quitter never wins.
A winner never quits.
When the going gets tough,
the tough get going.”
(From “Memo to My Son,” by Randy Newman, on his Sail Away CD.)
9. You don’t really have to change the oil in your car every 3000 miles. Most cars can go 7,500 miles or more between oil changes without harm, according to Consumer Reports.
10. Pay off your credit card bills each month.
11. The speaker implies; the listener infers.
12. “The Holy Roman Empire was neither holy, Roman nor an empire.”
But first things first:
13. How to ride a bike without training wheels.
