The Effective CIO

A Slide What? May 15, 2008

My son and I were driving home from an errand last night, engaged in a typical Guy Discussion: the mechanics of building a nuclear weapon.  My son observed, correctly, that building an atomic bomb was easy; it was getting it to explode that was really hard.  The trick, I pointed out, was getting the right material in the right shape at the right time.¹

My son asked how the first bomb designers did this.  I replied that while current designers use extensive computer simulation (which is why we design and build ever faster computers: bomb design and weather prediction), the original designers did it all by hand, with slide rules.

My son looked at me and asked, in all seriousness, “What’s that?”  I gave him an incredulous stare, completely at a loss for words.² “No, really.  What is that?”  My son, 13, is an outstanding student, way ahead of the curve in math and science and currently fascinated with computer-aided bridge design.  He was asking an honest question.

“Umm, well, it’s a computing device.  It has three wooden sticks with numbers, and you slide them back and forth to line them up so that you can multiply and divide.  Nicer ones have extra scales for trig functions.”  To help bring this detailed description to life, I used my fingers to simulate the mechanical action of a slide rule.

I may as well have tried to describe some medieval leather tanning contraption or a turn-of-the-century gadget that trimmed lamp wicks.  For a teenager with his own cell phone, laptop, iPod Touch, and game console, the idea of a wooden calculator is either pathetic or hilarious.  I half-believe he thought I was making it all up just to tease him.

Sigh. Another cultural touch point has been reached.  Slide rules are officially ancient and unknown to the current generation.  Close on its heels are tape in any form (cassette, 8-track, reel-to-reel), followed by analog video.  Phones with cords aren’t far behind, either.  Time marches on.  Does it matter?  Yes and no.

In terms of the actual device, it doesn’t matter.  I have my father’s K&E Log Log Decitrig slide rule, a beautiful device that was given to him when he graduated college with a degree in Mechanical Engineering.  It was his most important tool on a daily basis and no practicing engineer could work without one.  It still works, although the slide sticks a bit.  Still, it has been completely replaced by calculators of all stripes and for good reason: slides rules are only accurate to a few digits and are slower to use.

In terms of how it works, the loss of “slide rule awareness” is devastating.  General math abilities in the US are at an all-time low.  No one knows how logarithms work, or why this might be important.  No one understands precision, accuracy, or error ranges any more.  As a result, people cannot interpret numerical data, understand relationships, or make informed decisions.  Even worse, it has become apparent that most people cannot compute percentages or interest rates on a loan.  A disturbing number of cashiers cannot compute the change from $20 in their head.

Not everyone should be able to use a slide rule.  But maybe if we tried to teach everyone to use one, a pleasant side effect might be that everyone would at least learn percentages, and subtraction, and the ability to discern “bad” numbers from “good.”  Such an education will never happen; we’d wind up with lots of people who feel bad about themselves because they failed the slide rule test, and that’s just not acceptable these days.  Instead, we’re building a nation full of happy idiots, lacking the basic skills to survive in a modern world but certainly feeling very good about themselves.

¹How like life itself. See my next blog post for more on this.
²Those who know me can attest how shocking this situation is: I am never at a loss for words.