BAN #153: Listen to Asimov: Forget it!

September 30, 2019   Issue #153

[Saturn image credit: NASA / JPL / Space Science Institute / Gordan Ugarkovic]


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Ooo, meta

Last week in BAN Issue #151, I wrote about the silliness of teaching our children how to do things that are obsolete. One example I gave was reading a sundial, another was learning Roman numerals. I accredited the latter to Isaac Asimov, based on an article he wrote that I read when I was in high school.

At least, that’s what I remembered. I wasn’t sure. To my rescue came two readers, Ted Jerome and Rick Kopp, who informed me I was correct and the essay (ironically) was called “Forget It!”, which was published in a couple of his collections.

The relevant quotation:

But why? Where's the need? To be sure, you will find Roman numerals on cornerstones and gravestones, on clockfaces and on some public buildings and documents, but it isn't used for any need at all. It is used for show, for status, for antique flavor, for a craving for some kind of phony classicism.

I dare say there are some sentimental fellows who feel that knowledge of the Roman numerals is a kind of gateway to history and culture; that scrapping them would be like knocking over what is left of the Parthenon, but I have no patience with such mawkishness. We might as well suggest that everyone who learns to drive a car be required to spend some time at the wheel of a Model-T Ford so he could get the flavor of early cardom.

Roman numerals? Forget it - And make room instead for new and valuable material.

You should read the whole essay, as he goes into some detail and his writing style is eminently readable.

I’ll note again that teaching such things isn’t terrible by itself. My problem is with attitudes about “kids these days” who can’t do things the previous generation did, like these are Holy Sacraments to be handed down, lo, unto our descendants.

In some cases it does make sense. For example, when I was working on my PhD, I had a lot of data I had to fit functions to (if you have a scatter plot of dots, for example, you can fit a line through them to get a trend). One I used a lot was a spline, which worked the best for what I was trying to do. A spline fit is a smooth curve that is forced to go through all the points. Here’s an example:

[Credit: Anton (rp) on Wikipedia]

Several fits are shown here: a straight line (purple), which clearly doesn’t capture the shape well; a smooth polynomial (black) that does a good job of fitting the points, but doesn’t actually go through very many of them; a connect-the-dots (red) which is just useless; and a spline (green), which as you can see hits all the points and is smooth.

I had a subroutine to perform this, and it had lots of settings I could use, including one called tension. If you increased the tension, those max and min parts of the curve would jump wildly, shooting up and down madly. In my head I figured this was like using a physical wire to fit the points, and if you increased the tension in it the wire would bend more wildly.

I was right. But I learned why that is around the same time. I took a class called “Math with Calculators”, a graduate-level course that taught you what all these kinds of functions actually do, but you couldn’t use a computer. You had to write down all the equations or methods step by step, using a calculator to do the actual math, but limited to adding, subtracting, etc. In other words, we were forced to see how all this works behind the scenes, so we’d understand it.

Splining was one of the things we learned. It was fascinating, and it actually did help me understand how better to fit my data. 

I wound up learning, too, that splining is a craftworking term, when you bend a piece of wood or metal to fit a bunch of pegs in a board (this illustration should make that clear). That’s exactly the analogy to what I was doing with my numbers from Hubble. It was like a light bulb went off in my head when I saw this.

My point is that sometimes it makes sense to learn the underlying math or reasoning or etymology of something, even if we have computers to do the real work for us now. If you want to make sure you’re doing something correctly, you should understand not just how it works, but why. I learned that lesson decades ago, and clearly it’s stuck with me.

… and wouldn’t you know it, Asimov wrote a short scifi story with this precise theme. I remember reading “A Feeling of Power” in high school as well, and it’s funny how that stuck with me as well. I’m sure he wrote it in part as a cautionary tale, and it still stands that way to me all these decades later.

Sometimes forgetting is OK, but sometimes it’s also important to remember. The real wisdom is in knowing when to do which.



Blog Jam

What I’ve recently written on the blog, ICYMI

[A boulder the size of a house dislodged from a cliff on the comet 67P/Churyumov-Gerasimenko and bounced across the landscape. From Wednesday’s post. Credit: Vincent et al.]

Monday September 24, 2019: Happy September equinox! So what exactly does that mean, anyway?

Tuesday September 24, 2019: 466 million years ago, a huge asteroid impact helped life on Earth be fruitful and multiply

Wednesday September 25, 2019: What's shakin', 67P? Cliff collapses and bouncing boulders on a comet

Thursday September 26, 2019: What does a black hole look like up close?

Friday September 27, 2019: Exoplanet-hunting observatory TESS sees a star torn apart by a black hole


Et alia

You can email me at thebadastronomer@gmail.com (though replies can take a while), and all my social media outlets are gathered together at about.me. Also, if you don’t already, please subscribe to this newsletter! And feel free to tell a friend or nine, too. Thanks!