baz.com - Brett Thomas' Blog

Copyright (C) 2008 Julian Matz; Licensed under GNU Free Documentation License

While aimlessly pointing an infrared heat sensor gun (with helpful laser sight!) around a few months ago, I discovered that Buttercup will, just like a cat, chase a laser pointer. This cemented our relationship - I'll often sit in the kitchen, working on my laptop, and she's just behind me. I figured out about eighteen months ago that she could see me, and was aware of me. If I touched her tank, she'd initially retreat, then come investigate my finger. I've wondered if she were hunting the laser dot, or chasing it - cichilds are very territorial, which is why Betsy gave her a tank to herself.

I did a little touch-up exterior painting, today. Part of that included painting the part of the back door frame I'd replaced years ago and never gotten around to coloring. Deciding that the door sticking closed would be bad, I wedged it in a half-open position for most of the afternoon. In that interim, a very large housefly got in.

This evening, after everyone else had gone to bed, the fly was buzzing up along the kitchen ceiling, noticeably loud and annoying. About fifteen minutes later, I heard odd noises coming from Buttercup's tank. I looked over to see her lunging at bubbles on the surface. "Poor fish!" I thought. "She's so bored she's pretending there's food floating on the water!"

Almost as soon as I started paying attention, she swam back down, with a fly in her mouth practically as big as she was! Seems likely she's hunting the laser dot...

Our dinner conversations often track across history, or science, or engineering, or all kinds of other interesting topics. I'd been telling the kids about Liberty Ships, and giving a description of the engine room I'd received from a friend who is very much into naval history.

Dad: "They had this massive one-cylinder engine for the whole ship."

This is not actually correct - it was me misremembering my friend talking about how big just one of the pistons was. The engine was also steam-powered, thus rendering a lot of the following conversation irrelevant as to Liberty Ships.

Blake, 9: "Was it two-stroke?" Dad: "Could've been four-stroke."
Blake: "Maybe it had a flywheel."

I tried again to explain to him that they had been designed to be very simple, and that they probably wouldn't have built an engine that required a flywheel. His return implied that it must have, then, been two-stroke, and after switching from thinking about Liberty Ships to thinking about engines, I got his point.

Dad: "Oh! You're saying it couldn't be a four-stroke engine, since you'd need a second cylinder to run the non-firing part of the cycle."
Blake, patiently: "...Or, a second-cylinder analogue. Like a flywheel."

This, it turns out, is not strictly true - the Wright Brothers' first airplane had a four-stroke, one-cylinder engine (in fact, a lightweight, powerful engine was one of their key developments). I was so pleased with the phrase "a second-cylinder analogue" being casually tossed about, though, I had to write about it. In some sense, the engine itself could be considered a "flywheel analogue" in that design, in that it stores the momentum from the firing cycle and uses it to push the piston through the other three cycles.