My oval equation works in 3 dimensions with no change, giving an oval of rotation. With the right choice of k [as in d(A) +c*d(B) = 2b (string length), and a good choice for 2a (A,B separation)] it can probably be made to look just like a chicken egg. Think of the locus point X as having a small, frictionless ring that the string slides through. What would the locus of d(A) + c*d(B) + e*d(C) = constant look like in 3-D? An oval of nonrotation? A lumpy egg from a sick chicken? This can be implemented mechanically with a string that starts at A, goes through a ring at point X (the locus point), loops back to a ring at B, goes straight to a ring C, then back to X where the end is tied. It has to slide frictionlessly through the small rings at B, C, and X. If this is not clear, let me know and I will try to confuse it further. If it's not correct, it's someone else's fault. Steve Gray Steve Witham wrote:
Fred Lunnon sent me a picture of an oval based on Steve Gray's suggestion.
What about the locus of points such that d(A)+kd(B) is constant,
I pulled out a bunch of quotes from the list to put it in context:
http://www.tiac.net/~sw/2007/02/Steve_Gray_oval/index.html
--Steve
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