APGoucher>Bill Gosper,>>>Another example, where all faces are identical, is the endo-dodecahedron.>>(The Symmetries of Things, p. 328)>> Is this four tetrahedra clumped around one <http://gosper.org/endodo.png>?

No, it has five non-convex equilateral pentagonal faces and pyritohedral symmetry. Specifically, it is the shape of the 'holes' left behind when regular dodecahedra are packed together in a FCC lattice. This reminds me of something only moderately well-known: Regular dodecahedra can lock together in an infinite airtight sheet.

There's always the rhombic dodecahedron, no?

Again, not pentagonal. Although I was reading somewhere about the regular dodecahedron as being the limit of a set of pyritohedral dodecahedra with vertices in Q^3, where the points are determined by ratios of successive Fibonacci numbers. The rhombic dodecahedron is indeed the degenerate case when this ratio is zero.

...

Which maths camp was this?>> http://www.mathcamp.org/currentstudents/visitingspeakers.php,> whereat Julian failed to show CNWH S. Silver's marvelous> 1x1013783 > breeder<http://pentadecathlon.com/lifeNews/2011/05/quadratic_population_growth_fr.html>> because it was "just a stunt". Grr, I bet CNWH would have loved it.

Agreed. Has the same fate befallen my pi calculator? Fortunately, no, we showed him at G4G9. His traveling biographer wanted *my* reaction to it.

Sincerely,

Adam P. Goucher

Also my mentioning BAMO while answering your IMO question was a non-sequitur-- they're unconnected, but for O'Dorney's participation in both.