Re: [math-fun] new(?) equilateral dodecahedron
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.
Who is CNWH? Conway? -- Mike Stay - metaweta@gmail.com http://www.cs.auckland.ac.nz/~mike http://reperiendi.wordpress.com
Mike wrote:
Who is CNWH? Conway?
Yes, I believe the tetragrammaton is due to Gosper: http://en.wikipedia.org/wiki/Tetragrammaton http://www.argentum.freeserve.co.uk/lex_c.htm#CNWH
Agreed. Has the same fate befallen my pi calculator?
Fortunately, no, we showed him at G4G9.
Excellent! Presumably he was at Tom Rokicki's presentation, then?
His traveling biographer wanted *my* reaction to it.
Siobhan, per chance?
Also my mentioning BAMO while answering your IMO question was a non- sequitur--they're unconnected, but for O'Dorney's participation in both.
It appears he has beaten the UK's strongest contestant (James Aaronson, who has requested to join the list) by one mark. Aww... Sincerely, Adam P. Goucher
All right, I'll buy it --- who's BAMO, then? WOFL On 8/9/11, Adam P. Goucher <apgoucher@gmx.com> wrote:
Mike wrote:
Who is CNWH? Conway?
Yes, I believe the tetragrammaton is due to Gosper:
http://en.wikipedia.org/wiki/Tetragrammaton http://www.argentum.freeserve.co.uk/lex_c.htm#CNWH
Agreed. Has the same fate befallen my pi calculator?
Fortunately, no, we showed him at G4G9.
Excellent! Presumably he was at Tom Rokicki's presentation, then?
His traveling biographer wanted *my* reaction to it.
Siobhan, per chance?
Also my mentioning BAMO while answering your IMO question was a non- sequitur--they're unconnected, but for O'Dorney's participation in both.
It appears he has beaten the UK's strongest contestant (James Aaronson, who has requested to join the list) by one mark. Aww...
Sincerely,
Adam P. Goucher
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Fred wrote:
All right, I'll buy it --- who's BAMO, then?
WOFL
Not 'who', but 'what'. Like many abbreviations ending 'MO', it is a mathematical olympiad.
In Knuth's "Surreal numbers" the universe is created by "JHWC", who of course is also Conway. I suppose CNWH and JHWC are two separate Divine Substances, despite being the same person; a nice reversal of theological tradition.
I wonder whether Conway is the only two deities with an Erdos number of 1... Sincerely, Adam P. Goucher
On Tuesday 09 August 2011 18:46:37 Adam P. Goucher wrote:
Mike wrote:
Who is CNWH? Conway?
Yes, I believe the tetragrammaton is due to Gosper:
http://en.wikipedia.org/wiki/Tetragrammaton http://www.argentum.freeserve.co.uk/lex_c.htm#CNWH
In Knuth's "Surreal numbers" the universe is created by "JHWC", who of course is also Conway. I suppose CNWH and JHWC are two separate Divine Substances, despite being the same person; a nice reversal of theological tradition. -- g
participants (5)
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Adam P. Goucher -
Bill Gosper -
Fred lunnon -
Gareth McCaughan -
Mike Stay