Billy Pettit real disappointment

Sean Conner spc at conman.org
Sun Jul 1 16:44:13 CDT 2007


It was thus said that the Great der Mouse once stated:
> >>> Can you make an icosahedron out of tetrahedra?
> >> No - at least not assuming you mean a solid regular icosahedron and
> >> regular tetrahedra.  [...]
> > No, I'm not sure I meant a solid icosahedron.  I was only thinking as
> > far as a tetrahedron has equilateral triangles as faces, and so does
> > an icosahedron.
> 
> Then yes, there's no reason you couldn't take 20 tetrahedra and
> position them so as to result in something that's basically a
> tetrahedron constructed, inward-pointing, on each face of an
> icosahedron.  (It might not be all that easy to realize physically, but
> that's a separate issue.)

  Won't work.  I tried doing that with a Magnetix kit, and the results
weren't encouraging:

	http://www.flummux.org/ico1.jpg
	http://www.flummux.org/ico2.jpg

  You can see the gaps there the struts aren't long enough due to the angles
involved.

  I have, however, made a regular icosahedron that's *very stable*, albeit
*very hollow*.  

  -spc (Magnetix are basically plastic struts with magnets at the end, and
	a bunch of metal balls, and very fun to play with)






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