If I were doing it, I'd wrap a wire tightly around the circumference of the gear blank and mark the circumference on the wire. Then I would use a grid of N equally spaced parallel lines to put N equally spaced marks on the wire; rewrapping the wire would let me transfer the marks to the gear blank. I'm sure there are other equally practical contructions. On Fri, Nov 30, 2012 at 2:42 PM, Henry Baker <hbaker1@pipeline.com> wrote:
At 08:48 AM 11/25/2012, Robert Baillie wrote:
here is an interesting (58 minute) bbc documentary that explains in more detail how the device actually works, as far as we know today: http://www.youtube.com/watch?v=-rUsgL2VGeU
many of the gears had a prime number of teeth. this was very helpful in figuring out what the device was used for, and how it worked.
Fabulous video; highly recommended!!
Ok, all you algebra geeks: these gears with prime numbers of teeth had to be built, so which of the prime numbers in this device are "constructible" using a straight-edge and compass ?
For the non-constructible numbers, how did the Greeks construct them? Which additional operations were allowed to enable the construction of those gear wheels ?
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