Drawing a spiral

6/11/05, 3:06 AM #1

Keith Tompkins
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Drawing a spiral

Keith Tompkins

>In a previous post, I mentioned using a compass to draw a spiral. This one is based on a square, any rectangular shape will work as well, such as a "golden rectangle".

To draw, erect a perpendicular line to each side of the square....labeled a,b,c,d. Place the point of the compass at 2, draw an arc from 1, stopping at line A. Then, place the point at 3 on the square, open the compass to line up with the arc that ended at line A, and draw an arc to B. Continue the same pattern around the square until you run out of paper, or forever if you want.

By expanding on the idea, multiple spirals can be drawn. Does this have anything to do with turning? You bet it does.

Re: Drawing a spiral

6/11/05, 3:07 AM #2

Keith Tompkins
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Re: Drawing a spiral

Keith Tompkins

>A sketch may be nice....oops

Re: Drawing a spiral

6/11/05, 5:39 AM #3

John K Jordan
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Re: Drawing a spiral

John K Jordan

>>...using a compass to draw a spiral.

Keith,

I think you get an approximation.

Here's a good method for drawing a Fibonacci spiral based on the golden rectangle:

http://kjmaclean.com/Geometry/BuildPhiSpiral.html

I'd have to check the math, but if I remember correctly from 30 years ago this is still an approximation of a true logarthmic spiral (but a pretty good one).

Some other references:

http://www.mathematische-basteleien.de/spiral.htm

http://www.bath.ac.uk/~ma2mrm/logarithmicspiral.html

http://www.dougcraftfineart.com/SacredGeometry.htm

JKJ in East TN

Re: Drawing a spiral

6/11/05, 1:58 PM #4

Stuart Johnson
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Keep It Up

Stuart Johnson

>Keep it up guys and pretty soon you will be investing in commodity futures. What you are describing is one method used by futures and security traders to try and predict markets. It works very well. That is until it doesn't work and and the tradergoes broke. Then the reason it didn't work it was mis-read.

Drawing a spiral

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