Timmy flew to China. He loved the little packets the airline gave us, the ones with a tiny toothbrush in two put-togetherable pieces and the tiny tube of toothpaste. He used that toothpaste for a month, squeezing it tight with his 6-year-old fingers, eking out the last minty smudge.
But his flying days were over, he told us. Only two years later, his understanding of physics had dangerously advanced.
“Planes are made of metal, and they’re heavy. And plus all the people on them. They should sink, not float. How do they stay in the air?” he asked us.
We didn’t know.
This was a matter of serious financial concern to us, as my wife and I had already plunked down almost $7,000 on nonrefundable tickets to Australia for the whole family. At that point, we didn’t know about Timmy’s new interest in aerodynamics.
My wife gamely suggested we look up the Bernoulli Principle on the Internet, and I Googled it right up, finding—talk about definitive—the NASA website. Those guys should know their “lift” from their “drag.”
Here is some of what NASA had to say:
Lift is the force that holds an aircraft in the air. Lift can be generated by any part of the airplane, but most of the lift is generated by the wings. Lift is an aerodynamic force produced by the motion of a fluid past an object.
How is lift generated? There are many explanations for the generation of lift found in encyclopedias, in physics textbooks, and on Web sites. Unfortunately, many are misleading and incorrect. Theories of lift have become a source of great controversy and heated arguments. To help you understand lift and its origins, a series of pages will describe how some of the popular theories fail.
I asked my wife to look over my shoulder.
“Dolly, when it says here that these ‘theories fail,’ what exactly does that mean?” Dolly is a true rationalist and knows about these things. She places a trust in science that I’ve never been able to muster.
“It means that the theories explaining ‘lift’ aren’t always correct. What do you mean, ‘What exactly does that mean?’ It means what it says.”
This is the kind of thing she said all the time, and you just didn’t know how to explain to her how unsettling it was.
“Dolly, I feel like NASA is basically telling me that even they don’t know why planes can fly. I really want NASA to understand this clearly. Not to mention United and Delta. Timmy needs to know that adults are on top of this stuff.”
“They’re on top of it, don’t worry. They just can’t explain it as easily as you want them to. Trust me. Don’t worry.”
But we did, Timmy and I.
* * *
Our teenage daughter came up with an idea. “Forget that website, Dad,” she said. “The Internet is run by a bunch of techie-nerds who don’t want regular people to understand stuff, anyway—that way they’re the masters of the universe. I think you and Timmy should build an airplane so he can see that it works. Get empirical, Dad.”
Emma knew I wanted her to be a teacher just like me, and she was always teasing me by flaunting her vocabulary. But this had promise. Timmy and I went to the hobby shop and bought an expensive glider kit—balsa wood, finely detailed plastic, decals, complex instructions and no debate about underlying theory. Applied science. Empirical data.
The weather was warm. Summer and Australia were quickly approaching. Timmy and I worked on a table we set up in the garage. X-ACTO knives and Duco Cement and sandpaper played prominent roles. Timmy was in charge of the decals, which leaned heavily in the direction of flames and eagle wings. While I fretted away a long Sunday morning decoding the meaning of the instructions, translated from Japanese, Timmy conquered whole worlds and sub-levels on his Super Mario Game Boy Advanced.
“Done yet?” he asked every 17 minutes.
“Hey,” I said, looking over his shoulder. “Those turtle thingies can fly.”
“They have wings.”
“So do planes,” I said.
“But not ones that flap.” And he put his arms out at his side and flapped for me.
We finished after a late lunch of Kraft mac ’n’ cheese that Dolly had delivered to the garage on plastic trays, along with sodas and canned pears. We let the decals dry while we went into the kitchen to sneak some Oreos.
