It is possible that spokes are intended to be only tensile, in which case the equality in the constraint should be replaced by "less than or equal", and the answer is almost certainly different. On Mon, Oct 25, 2010 at 9:32 PM, Dan Asimov <dasimov@earthlink.net> wrote:
From various comments made, especially by Fred, I think the intended problem is something like this:
Given two finite cylinders C_r, C_R of radii r < R and equal heights in R^3, how many constraints of the form
||x_j - y_j|| = c_j, for x_j in C_r and y_j in C_R
in order to require C_r to be fixed in a uniqconcentric
I wrote:
<< In the biography of H.S.M. Coxeter "King of Infinite Space", one section describes his interaction with Buckminster Fuller.
It states that Fuller erroneously claimed that a bicycle wheel needs 12 spokes "to hold it rigid", whereas the correct number is 7. This seems to be stated as a fact of geometry, rather than one of structural engineering.
Anybody have any insight into this claim?
Those who sleep faster are sooner rested.
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun