OK, now this is cool:

[originalpckelly]

http://en.wikipedia.org/wiki/Sigma_bond
http://en.wikipedia.org/wiki/Symmetry_group

:P

Specifically:


:P

Double cool...

"Maud, get my gun we's gots urselves wun dem syancy tiiiipes."

[originalpckelly]

1. And this:

[Occam Bandage]

2. Yep. You can rotate a tetrahedron so each face-up side is facing you (three possibilities), and can

complete a full rotation of unique orientations for each of the four possible sides that may be face-down on the table. Four times three is twelve. That graph is a neat way of representing an orderly way of going through each of those twelve orientations.