How Things Work

January 3rd, 2010 by k8gu Leave a reply »

flying

As a part of my employment, I occasionally have the opportunity to talk to students in the local schools about my work.  I tend to treat these talks as a “choose-your-own-adventure” for the students, weaving some of my stories and demonstrations into the discourse along the way.  The students love it because they are participating; the host teacher and I don’t get bored hearing/saying the same thing over and over.  It’s a win-win for everybody.  Plus, I get to explore the creativity, imagination, and mental models of the students.  This is one of those stories.

About a month ago, I was talking to some 8th graders about electromagnetic radiation and radio.  When we were talking about the speed of light, I asked the class if anybody knew how GPS works.  One student raised his hand and I called on him.

“You type in the address of your destination.  Then, a satellite moves over that spot and it directs you in.”

These answers always surprise me.  “If there was a satellite for every GPS user, ” I asked, “how many GPS satellites do you suppose that there are?”  He speculated that there had to be quite a few.  Then, I asked, “How much do you suppose a satellite costs?  Do you think that would be cost-effective?”  The discussion continued for a minute or two until we converged on the time-of-arrival method.

Later, I was reminded of watching the movie Enemy of the State with my dissertation advisor when we were on a field installation trip.  We chuckled when a spy satellite was repositioned to track Will Smith’s character.  It’s a good movie, but it’s a bit fanciful at times.  The movies might be the most education the average person gets about satellites—a sobering thought.  On the other hand, there are dozens of things (such as biology, I tell my wife, who did her B.S. in biology) that I treat like black boxes.  There’s just too much to know about to have specialist understanding of it all.  How much is enough?

Since today is Epiphany Sunday (the day that celebrates the magi visiting the baby Jesus) in most Christian churches, I also add the following:  A week ago when we were home for Christmas, I was telling Dad how I always enjoy questioning students about how technologies they take for granted operate to cultivate their creativity and curiosity.  I mentioned the model of the GPS satellites hovering over destinations.  He quickly replied, “Well, that’s how the wise men found Jesus with the star, isn’t it?” These people keep me on my toes!

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