topics: |  math | puzzle | brain

   Samuel W Golomb, mathematician: it is impossible to get only one corner
   turned by 1/3d of a full turn.  Given that quark is a particle with 1/3d
   charge (antiparticle w -1/3d), Golomb calls a CW 1/3d twist quark, and a
   -1/3d twist an antiquark.

   possible to give two corner cubies 1/3d / -1/3d twists (quark-antiquark
   pair = meson); or three cubies = twists in the same direction, qqq or
   baryon (e.g. proton, charge = +1).  Only quark combinations with integral
   amounts of charge (twist) can exist in the world (rubiks c).