A few evenings ago, I had a particularly serene moment.

Today, our two-year old brat told me to go away, on two separate occasions.

First up was lunch time. Helping Eric get seated in his booster seat, strapping him in, I was apparently guilty of helping him too much. He said “want Frank walk”.

Second, at bed time. Having some fun with his nightly “hush little baby” serenade request, I messed with the lyrics. He said “Frank, want good night”, meaning that he wanted me to say good night and just go already. Juimiin then sang the tune properly, and was not dismissed.

He is starting to put together complex, sometimes grammatically correct, sentences now, which is cool But he’s using his newfound verbal know-how to tell me to get lost. How to balance pride and humiliation?

There is a canonical diagram in every student pilot’s text book: a free-body diagram of the major forces acting on an airplane. I have a problem with it.

Here is one version of the diagram:

My problem is the similarity of the sizes of the arrows. They are all around the same length. This creates screwed up intuition about the magic of aerodynamics.

The reality is that, for most aircraft, the weight/lift (up/down) forces are an order of magnitude stronger than the thrust/drag (forward/backward) forces. Here are some numbers for a few aircraft along a wide spectrum:

airplane	class	weight (lb)	thrust (lb)
Boeing 747-8	commercial jet	970000	66500
Piper Aztec	light twin	5000	500 (est.)
F-15E	fighter	81000	58000
Swift S-1	glider	1000	0

Notice that, except for very high-performance airplanes, the thrust is far weaker than gravity. This is the biggest miracle of aerodynamics. By using a wing to generate lift, the engine can be weak or even absent: it just needs to overcome mere drag. UPDATE: The effect is related to the much-greater-than-unity lift-to-drag ratio of most flying things.

Thusly informed, one’s intuition about flying ordinary airplanes forms differently. One no longer imagines that, for a landing going astray, if one just pulls the nose up a little higher, the engine will be able to contribute to a significant increase in lift. Instead, it is the wing lift that is paramount, which can be calculated as a function of airspeed and angle of attack. The engine plays only an indirect, gradual role.

By the time one becomes an experienced professional, good habits become second nature. But at the beginning, a misleading illustration can impede understanding.

This month’s issue of the University of Toronto’s alumni “send more money soon” magazine contains a deep (?) tidbit.

A full-page picture taken of a lovely young lady in a chapel, with the caption:

You can’t come to a rational conclusion that Christ was the son of God. But if you pray, and your prayers are answered, can you accept that as proof?” – Beatrice Sze

Well, Beatrice, no, I can’t. Some reasons:

• Let’s grant that “your prayers are answered” in arguendo. Unfortunately, this alternate explanation is just as consistent with the hypothetical observations as the Christ one: the true deity, the Flying Spaghetti Monster, listened to your prayer, and decided to taunt you by giving you your wish. Could you tell the difference? No? Well then, it’s not proof.

• Still, how exactly does one decide that a prayer was answered? A technical person such as Ms. Sze (an engineering student) is a practitioner of scientific disciplines. She’s surely aware of concepts such as placebo, empiricism, logic, falsifiability. As such, she would be aware that evidence for the extraordinary proposition that “prayer worked” would be very difficult to collect with sufficient quality and quantity to convince a neutral judge. (Though that would be worth one million dollars.) Anecdotes only convince those who already believe.

Such pseudo-logical claptrap reminds me of a rather terrifying event that happened in my very basement a few months ago. Superstitious acquaintances came over to visit, which was well and good. One was going through a rough patch in her personal life, which they attributed to a curse that was said to originate from another person. So, any article baby clothing that they donated to us some years ago, and which might have come in contact with this curse-originating suspect, was to be destroyed. There they sat for an hour, making two little piles. One apparently ended up burned.

In my defense, I was not aware of the purpose for partitioning the stuff: I was only bemused at taking back of gifts. When I later heard about the curse angle, and realized that the paranormal theoretician had in fact a Ph.D. and was a practicing medical scientist, let’s just say it shook my … er, faith … in the system. I sure hope dumb people like that are smart enough to keep their voodoo out of their professional lives. But really…

It seems that our brat Eric now has a little brother, Anonymous.
Naming rights are up for grabs. Submit your bid soon.

The full cast:
Frank Christopher Eigler
Juimiin Ailsa Hong
Eric Dreman Eigler
Stuart Dreman Eigler

Data point. If you would like to have & remember more nighttime dreams, consider regularly chomping down on multivitamins.
On the other hand, if you would like to have a sudden long-lasting bout of motion sickness, play or watch just a few minutes Gran Tourismo HD on the PS3 driving a big screen.