Sunday, September 06, 2009

A Practical use for Geometry

A typical question that always comes up at least once a semester from my students is when will they ever use this stuff in real life. My standard response has become, "I don't know. What do you plan on doing with your life?" Their usual response is that they don't know. So I tell them "It's ok if you don't know. But whatever it is, you had better be prepared for it and that's what you're here for." They seem to think that is a good idea and let the conversation go.

There is a McGyver tip titled Estimate Distances with Your Arm and This Rule of Thumb posted at LifeHacker. I used something like this for range estimation when I was in the Marine Corps. It relies on the ratio of the distance between your eyes and the length of your arm (usually about 1:10). The phenomena is called parallax. Astronomers parallax to estimate the distance to stars.

The post also mentions The Old Farmer's Almanac. I used to read this over and over again when I was a kid, along with Webster's Dictionary and Collier's Encyclopedia.

I guess I didn't have much else to do when I couldn't go outside to play during those long Michigan winters.