It’s 9:00 on a Friday night, I’ve been up since before 6 a.m., and it’s been a doozy of a week. I’m tired. But there’s an Arduino on the couch next to me, and I’m still riding high on my earlier success this week: When I finally got my Arduino hooked up and figured out that a previous version of the IDE works on my computer even if the current one doesn’t, I didn’t just make the light on my Arduino blink. Heavens, no. Nothing would do until I made the light on my Arduino blink in Morse code! The Mysterious Benedict Society would be proud.
The next project in the Arduino Projects Book is “Get to know your tools,” which is not inspiring a great deal of excitement in me. It is surprisingly hard to remind myself that you can’t just jump in and expect mind-controlled robots on your first day/week/month. Also, it doesn’t help that there are a lot of words that my tongue trips over. Sensors and activators are types of transducers, for instance. Not part of my typical vocabulary!
Also, anodes and cathodes–these are words I recognize, but never before learned to define. Anodes are longer than cathodes, which is going to be terrible to remember because c-a-t-h-o-d-e is seven letters and a-n-o-d-e is only five. Anodes connect to the power and get a plus sign; cathodes connect to the ground and get a minus sign. Again, this is going to be terrible to remember. I don’t remember a *whole* lot of high school chemistry, but cations are + and anions are -, and all my mnemonics and mental connections are failing me!
This calls for my beloved Oxford English Dictionary! (Yes, Internet, I WAS an English major once.) And sure enough, there is a reason for these prefixes: A cation is “An ion carrying a positive charge which moves towards the cathode (negative electrode) during electrolysis.” An anion is the opposite. So… I’m going with opposites attract, here. Yes?
The reason I love the OED is that I get to feed my love of etymology, and this word lookup is no exception. According to the OED, the “ion” part of cation and anion apparently has a root that means “to go.” “Cat” has a root meaning down, and “an” comes less obviously from a root meaning “up.”
Given that the Arduino Projects Book was just comparing circuits to rolling rocks down a hill where the power source was at the top and the ground was at the bottom, I can tie in my newfound etymological geekery and say that anodes are uphill of cathodes. Thus they’re closer to the power source. Etymology and half-remembered chemistry for the win!
I’m feeling a bit better about this, now. Anything that ties into etymology can’t be too far from my existing skill set, right? Maybe by the next time I write, I’ll actually have made it far enough to put pieces together and build something!
Image Credit: “Arduino Kit” by Flickr user Bernard Goldbach
