My First Perpetual-Motion Machine

A totally random anecdote...last night I recalled building my first perpetual motion machine. I don't have a clear idea of how old I was, but old enough to have my electronics science kit, including a small solar cell. Ten, perhaps?

My dad is big on O-gauge model trains, and they were set up in the basement. There were some lampposts with grain-of-wheat lightbulbs to go with it. The lampposts were intended to be battery-driven, but I had a better idea: I'd run them with my solar cell. I realized that they would need to be "primed"; I'd have to start with the battery hooked up, but then assuming all went well, I could unplug the battery and the solar cell would take over. Light from the lampposts themselves would drive the solar cell, which would drive the lampposts. Viola! Lighting for the trains, without a battery!

Needless to say, every time I unplugged the battery, the lampposts went out. I was smart enough to figure out that the solar cell needed more light, so I tried adding reflectors that would send back a greater percentage of the light to the solar cell. No joy. I think (though this part of the recollection is fuzzy) that I wound up trying a less ambitious system, with just the lightbulb directly in front of the solar cell, which of course failed, too.

And there this particular memory vignette fades to black. I have no particular recollection of realizing that what I was trying was theoretically impossible, only that the practical considerations were insurmountable. There were, in all probability, mechanical perpetual motion machines from about the same time frame. Something for me to try to dig out of that unreliable and fast-fading bank...