[PREV - SUPERCONDUCTING_STATE]    [TOP]

QUASICRYSTALS

                                             February 16, 2012

  There's a simple geometric
  proof that shows that you            And by simple, I mean
  can't have five-fold                 *really simple*, I could
  crystalline symmetry.                look it up and sketch it
                                       out here in a few paragraphs.
  In the 80s, then, when
  someone succeeded in                            no fives allowed
  producing a material
  that showed a five-fold
  symmetry in it's            Explanations for how this can
  diffraction pattern,        be are not quite as simple as
  that caused some            the proof for why it can't;
  consternation.              myself I would say that the
                              trouble was we were being
                              dogmatic about what we meant
     I often think of         by a "crystal" and nature
     quasi-crystals when I    doesn't particularly care
     start getting dogmatic   about that.
     about something like
     the lightspeed limit,        There are 5-fold
     or the second law of         symmetric penrose
     thermodynamics.              tilings that don't
                                  show the translational
     Violating those              uniformity we expect
     physical principles          from the classic
     is impossible...             definition of crystals.
     no, really, it is.
     Or so close to                  It would seem quasi-crystals
     impossible that the             are something like that.
     "they all laughed
     at Christopher                      CRYSTALLINE_DEFINITION
     Columbus" crowd
     might as well shut
     up about it.

         But might there be
         some little loophole          We already know about things
         we're missing, some           like quantum entanglement:
         odd case where there's        it's possible to
         a tiny (apparent)             instantaneously *find out
         exception?                    something* about a place
                                       arbitrarily far away from
                                       where you are... but that's
                                       different from instantaneously
                                       *transmitting information*.

                                           Given "quantum
                                           entanglement", we don't
                                           suddenly throw away
                                           relativity, but we
                                           *do* need to be more
                                           precise about our
                                           definitions in ways that
                                           never mattered before.



--------
[NEXT - CRYSTALLINE_DEFINITION]