Peter Rowe, the moderator of the rec.crafts.jewelry news group posted the following today. It clearly is some amazing feat of precision metalworking.
"Seems the folks on the mars rover project wanted watches that read in local mars time. The mars day is 39 minutes longer than earth's day, which apparently presents a problem in this day and age of quartz controlled watches that accuratly give us exactly 24 hour days... . I found this story on the NASA web site. Kinda fun..
BS! There's 1479 earth minutes in a mars day which means that 1440/1479 which is about .9736 ratio so you take the 32768Hz of the standard digital clock to
3190.3935Hz and you have the same time accuracy. Ask any crystal maker to make a crystal to that value and replace the crystal in the watch with that one and you're in. As to mechanical watches, you add some weight to the balance wheel and check the time to see what you have. Going at 97 percent is calculatable without problems and the combination of the coarse mass with the weight and the fine adjustment of the spring amount should give the results without any real problems. The process for a mechanical watch does take time as the timing checks can't be done in seconds like a crystal calibration takes but it isn't rocket science.
-- Bob May Losing weight is easy! If you ever want to lose weight, eat and drink less. Works every time it is tried!
It's also interesting to give ourselves a refresher course about the earth's rotation.
It doesn't make one revolution around its own axis in 24 hours, it does it in
23.93446965 hours, or about 3 minutes and 56 seconds less than 24 hours. That amount of time is called a "sidereal" day.
That's why, if the sun is overhead where in your town at noon today, about half a year later (182 days as our clocks count them), when the earth has traveled through half its orbit around the sun, the sun is still overhead at noon. If the earth took a full 24 hours to make one revolution around it's own axis, the "other side" of the earth would be facing the sun then and it'd be right around midnight at your location.
There was an article in the current issue of the JIR* "proving" that the earth wasn't really orbiting the sun. The proof was based on confusing sidereal days with
24 hour solar days.
Jeff
JIR The Journal of Irreproducible Results:
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Jeff Wisnia (W1BSV + Brass Rat '57 EE)
"If you can keep smiling when things go wrong, you've thought of someone to place the blame on."
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