Scientific Progress Goes “Boink”

I was thwarted in my attempt to set up a a Foucault Pendulum here. It would have been very cool — the pendulum swings and the earth stays still under it, so it would appear to rotate relative to me and my station. But it turns out that a pendulum is a precision instrument, and likely doomed to failure. I was investigating work-arounds when, instead, I gave up. Others have been less timid.

As an alternative, my pal Simon suggested I just bring along a snazzy gyroscope. The effect could be roughly the same: The gyro wants its axis to stay the same, so while the earth spins in its course, the gyro would continue to point in the same direction, and so would appear to turn once in 24 hours. It’s a pretty cool toy — precision machined, with an external motor.

This still has issues, I expect. The forces on the gyro trying to keep it steady are probably pretty small. Is there a physicist in the house? Other forces are likely to be large by comparison, so really I would need to watch out for air circulation, biases in whatever support I was using, and biases in the gyroscope itself.

On batteries, the gyro only ran about two hours. That might be enough to detect a rotation, but it’d suck down batteries. On rechargeable it only ran about 20 minutes. Again, if I trust the measurements, that might be enough. An hour is 15 degrees of turning; 20 minutes would be 5 degrees. That’s not a lot, but should be visible

Simon suggested floating it in a bowl of water on a wood or styrofoam platform. I’d still need to anchor it near the middle, and keep it and its raft from touching the sides. I still might try that experiment, but it sounded messy, and could risk the electricity+water issues, or the really-fast-spinning-thing vs water on my bed issues.

As an alternative, I went for the “suspend it from the ceiling” option. This has issues as well. The string has a radial bias to it — it’s wound out of strands — so when any weight hangs from it it will have a tendency to uncoil. That property will probably also change with humidity, and humidity in my room changes a lot; I sleep with a humidifier. I also tried to defeat the battery problem by wiring the motor u with a power supply rather than batteries.

Boink! Bonk! Boink!

A once-precise gyroscope now all tanged with a string and some wires.

It ran fine — and may have even been showing the effect I was after — when after about 8 hours, in the early morning, it work me with a great noise, and was in this configuration. Experimental failure. The gyroscope now spins a bit roughly; I’m not sure it didn’t before, but it does now. I think what happened was that it overheated and seized up, made a little jump and tanged all the heck up in the cord and electric feed. At least that disconnected the electric feed, and the dingus stopped. Damaged? I don’t really know.

But I plan to soldier on. I’ll get a better grip on how long the rechargeable last, and see if that will do. I’ll look for some styrofoam for a float. I’ll figure out how to anchor it without putting any radial strain on it. I’ll figure if I can power it externally without introducing some radial bias. More pretend science coming up soon.


2 responses to “Scientific Progress Goes “Boink”

  1. Pingback: Spinning | barryontheice·

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