Re: Orange stacks

On Tue, 15 Jul 2025 11:28:23 -0000 (UTC), Richard Tobin wrote:

This wikipedia page makes it explicit:
 
https://en.wikipedia.org/wiki/Close-packing_of_equal_spheres

Thanks. Also of particular interest is:

https://en.wikipedia.org/wiki/Kissing_number

Regarding the packing of twelve equally sized spheres in three dimensional
space, it includes the following comment: "In fact, there is so much extra
space that any two of the 12 outer spheres can exchange places through a
continuous movement without any of the outer spheres losing contact with
the center one." That is something I had failed to appreciate and my go
some way to explain my confusion. My vision of a similarity to the
tetrahedral carbon lattice, you may have seen at school during physics and
chemistry lessons, is wrong. Or, at least, incomplete.

I now have this Conway, Sloane book on order:

<https://books.google.co.uk/books/about/
Sphere_Packings_Lattices_and_Groups.html?id=hoTjBwAAQBAJ&redir_esc=y>

--
David Entwistle