Re: left/right symmetry, manifest or not

[Bernard Cleyet <anngeorg@PACBELL.NET>]

You can tell who's read this and who hasn't, by saying
"beware left-handed Martians" and seeing who smiles and
who doesn't.

Anyway:  Two answers:
1) The answer is _no_, provided you:
   -- use just words, i.e. no diagrams, just words you
      could speak over an ordinary telephone, and
   -- use just pre-1940 physics (no weak nuclear processes), and
   -- no outside references (such as the handedness of the Big
      Dipper, or the rotation of the earth on its axis).

2) The answer is _yes_ if you disregard any of the provisos
listed above.
   -- You can make a big chalk-mark on the floor, an arc with
      an arrowhead on one end, and say "it's going this-a-way".
   -- You can tell me to borrow Madame Wu's cobalt-60 decay
      apparatus and observe the handedness of the beta-decay.
   -- You can tell me it's rotating the same direction as the
      earth.

Icy,

no inside references and applies to not only the earth but the U.

bc


"John S. Denker" wrote:

> Bernard Cleyet wrote:
> > since all terrestrial ("natural") proteins are l- would this aid in the room
> > problem?
>
> It almost certainly does not help.
> Feynman discusses this in TCoPL.
> One of the rules of the "room" problem is to not use
> any shared artifact as a reference.
>
> As far as we know, the handedness of natural proteins is
> merely an artifact inherited from a common ancestor.
>
> So in particular if you were communicating with some
> extraterrestrial creatures who do not share a common
> ancestor with you, it seems perfectly possible that
> their proteins are differently-handed from yours.  This
> possibility means that in general, proteins are a
> non-solution to the "room problem".
>
> The only way it could become a solution is if you can
> be sure that in an ensemble of _independent_ planets,
> the laws of physics _require_ the evolutionary process to
> select one handedness over the other.  Alas all the known
> chiral physics involves weak nuclear interactions, which
> are very weak, presumably swamped by thermal fluctuations
> under reasonable biological conditions, so betting that
> this solves the "room problem" doesn't seem like a very
> good gamble.