What homeschool science looks like

This year I’m teaching my daughter physics, and though you might think it would be easy for a guy with a degree in physics to teach eighth-grade physics, it is not. It is undoubtedly easier than it would be if I didn’t have a degree in physics, but that’s not a high bar, you know? Much of physics beyond the most elementary observation is deeply mathematical; you need at least first-year algebra to make any sense of it, and at least a year of calculus to make a lot of sense. And to the extent that there are simple, practical, hands-on ways of exploring deep concepts, I didn’t learn them in college. So, for example, I did lots of fancy calculations of torque but never built a trebuchet, and I learned to analyze the role of a capacitor in a circuit but never built a Leyden jar. Teaching middle-school physics, then, has been an opportunity for me to fill in some rather distressing gaps in my own education, and to think about what I did learn in new ways.

To wit: In planning our unit on electricity and magnetism I stumbled across a book called Safe and Simple Electrical Experiments, by Rudolf F. Graf. Since it was published in 1960, “safe” assumes something slightly less than the helicopter parent’s standard of child care, and “simple” assumes a child whose brain has not been squeezed completely to mush by electronic devices: all the better! You have to think to do this stuff, and fiddle with things when they don’t work the first time, and there are delightful instructions on how you can give your friend an unpleasant but allegedly harmless shock. On the negative side, some of what were considered household objects in 1960, such as vinyl records, may not be as easily accessible in 2017. But there are nearly always substitutes if you hunt for them.

As our culminating project, we built a working telegraph. I will let Dear Daughter explain it herself. (Video after the jump.) Continue reading “What homeschool science looks like”

The devil of false precision

Eating lunch today I noticed on my bottle of soy sauce the words expiration date on label and, an inch away, a dot matrix stamp: 2019.03.28 14:48.

I expect that the stuff was bottled on March 28, 2016 at 2:48 pm and that it’s supposed to be good for three years from the date of bottling. But that’s not the same thing as saying it’s good until March 28, 2019 at 2:48 pm. Certainly a machine can record the exact time of bottling, but the idea that the soy sauce is good for exactly three years, for three years down to the minute, is absurd — as if, at twelve minutes to three on a particular March afternoon two years from now, the contents of the bottle will instantly develop a fuzzy blue mold and smell distinctly of gasoline. Obviously that’s absurd.

For one thing, it was bottled in Taiwan, so it would actually expire at 1:48 am EST and not in the middle of the afternoon.

“Three years from date of bottling” means three years, give or take. Give or take what? That’s the question. Six months, maybe? I would assume that they kept a bottle around for three years and it seemed to be okay. I doubt it’s very scientific at all. But it’s so easy just to take the present time, add three years, and stamp it on the bottle.

The expiration date on my soy sauce is not in itself a big deal. (I’ll use it within a few months anyway.) But this kind of arbitrary precision is everywhere — the practice of assigning a number to something, giving it as many decimal places as we can, and then slapping it on a label, noting it in a chart, entering it into a database — where it takes on a kind of magical invincibility, a rightness that can no longer be questioned or challenged. There are cases where this might have disastrous consequences, but more important is the impression of invincibility. Knowledge is power; false precision is an implication of knowledge; therefore false precision is an assumption of power. False precision is one way that science and industry and government claim power over us. But wallpapering the world with false precision builds false confidence in our own abilities, individually and collectively.

Every measurement is an estimate. If I were king of the world, I’d decree that every published measurement must be accompanied by a margin of error, e.g. “Expires on 2019.03.28 14:48 ± 6 mos.” It would be honest, it would be accurate, and it would remind everyone many times a day of the limits of human knowledge.

(And no, since you ask, I cannot think of anything better for a king to do than to demand accountability and humility from the powers of the world. Can you?)

Ouija boards and what we want to believe

It’s too late for Hallowe’en, but Linda Rodriguez McRobbie’s Smithsonian Magazine article on “The Strange and Mysterious History of the Ouija Board” is worth a read if you’re at all interested in nineteenth-century history, or in the occult, or if you’ve ever played with one. Or if, like me, you’re at all interested in the limitations of science and of scientific thinking and in the ways Americans today think about religion. (My thoughts follow the jump.) Continue reading “Ouija boards and what we want to believe”

The dangers of eating hot bread

One of the perks of baking bread at home — maybe half the point of baking bread at home — is the privilege of hacking off the crust while it’s still hot, slathering it with butter, and eating it messily over the sink. Cookbooks will tell you that bread only develops its full flavor after it cools, which may be true. They will also tell you that if you slice bread while it’s hot, you’ll crush it, which is definitely true. But I do it anyway. Damn the torpedoes and all that.

Thank God I didn’t live in the nineteenth century, though, because then, it would probably have killed me.

Back then, it was commonly believed that eating hot bread was unhealthful — dangerously unhealthful. The famous health reformer Sylvester Graham said bread shouldn’t be eaten until at least twelve hours old. Magazine articles about what ladies should eat for breakfast (of which I’m afraid there were lots) recommended day-old bread and warned sternly that hot buttered toast was “hostile to health and female delicacy.”

Tea, coffee, and milk, are the most wholesome beverages for the morning meal; which should be accompanied, if possible, by home-made bread, at least one day old. This seldom disagrees with any one; if it should, it may be toasted, and buttered cold and slightly; but warm buttered toast is by no means advisable: indeed, it is far preferable to use only hard biscuits, which require no butter, and are of easy digestion. 1

Even the high mortality rate of Indians living on reservations was blamed (by white observers, anyway) on severe indigestion caused by their diet of hot biscuits — not that white flour and cheap fat, which was all they had access to at that point, had no nutritional value, but specifically that the biscuits were eaten hot. Continue reading “The dangers of eating hot bread”

  1. From the Females’ Encyclopedia, mentioned below, but the advice was republished in Godey’s Lady’s Book, the most popular American women’s magazine, in 1835.

Scientifically sound? Maybe. But wise?

“Let’s start the new year on scientifically sound footing,” writes Jane Brody in the New York Times (“What You Think You Know (but Don’t) About Wise Eating,” December 31), and quotes “one of Canada’s brightest scientific minds” to the effect that “chemical” shouldn’t be a dirty word, because all food is made of chemicals and there’s chemistry going on everywhere. True enough. Sadly but predictably, she (and, one has to presume, Joe Schwarcz, the scientist she cites) jumps straight to the conclusion that food is nothing more than a bunch of chemicals, and uses it as an excuse to justify industrial food and fling barbs at the alternatives. Continue reading “Scientifically sound? Maybe. But wise?”

Of scientific misconceptions

I was looking today through the National Science Digital Library’s “science literacy maps,” which are a sort of graphic organizer for science concepts, showing what concepts are related to what other concepts. A valuable resource for teachers, certainly. Even more valuable, I thought, at first glance, are the lists of student misconceptions: the things students think they know about science and have trouble unlearning. But then I started wondering about the wisdom of framing that as “misconceptions” and, in fact, about the value of this idea of science “literacy” itself. Continue reading “Of scientific misconceptions”

What’s really in the molasses?

Sometimes the things that are ostensibly the simplest turn out to pose the most interesting problems. Molasses, for example, which I’ve been using by the gallon to bake all this gingerbread. In an age when practically everything Americans use in the kitchen is constructed to industrial specifications — unless, like farmers market produce, it’s specifically branded and marketed in opposition to that sort of standardization — it’s surprising to find that a packaged, branded product has enough variation to fundamentally changed the character of baked goods, but that’s exactly what I’ve found with molasses. Continue reading “What’s really in the molasses?”

Why I don’t like the metric system

For the benefit of Canadians, Jacobins, progressives, engineers, and stuck-up stickybeaks of all stripes, I herein explain why the metric system is inferior to traditional systems of measurement for those who work with their hands, think with their right brains, and prefer not to resort to a calculator for every little thing.

Metric vs. traditional systems

First, I don’t like the term “metric system.” Either it refers only to the meter and ignores all of the other units of measure (which is silly), or it implies that it’s the only system that is metered (which is also silly). What is commonly called the metric system is part of a much larger system of measurement known as the International System, or SI. (The abbreviation is backward because it comes from the French, and they do everything backwards.)

The SI is all decimal, and its units, which include familiar ones like the watt and the second and less-familiar ones like the joule, are all interrelated in a very nice way that I won’t trouble to explain here. (You can read about it here.) It’s a very nice system, for many purposes — but not for all purposes. (I’m unnecessarily familiar with it from having been, at some time late in the last century, a theoretical physicist in training.) Continue reading “Why I don’t like the metric system”