Every year around Christmas, "analyses" go out over the net purporting
to show that Santa Claus cannot possibly exist, because of the
extremely high speeds (and accelerations) required for him to make his
rounds, absence of chimneys or other means of ingress, etc. These
analyses merely confirm the prevalence of the classical mechanical
mindset. Consider the following:
Santa is never directly observed, but indirect evidence of him
abounds.
If direct observation is attempted (say, by staying up all night
with the lights on), not only is Santa not observed, but the
indirect evidence of his presence does not appear either--only if no
attempt is made to observe Santa do the stockings get filled.
Evidence of Santa appears in multiple locations simultaneously
throughout the world. (The multiplicity of time zones does not
substantially alter this argument, and will therefore be ignored.)
Evidence of Santa appears even in rooms that are separated from the
rest of the universe by barriers (small or non-existent chimneys)
that Santa cannot classically pass through.
It is obvious, then, that Santa can best be described by a
quantum-mechanical wavefunction SC, which is nonzero at midnight on
Christmas eve throughout the world. Like other quantum-mechanical
wavefunctions, it is not confined to one spatial location, and can
"tunnel" through classical barriers (house walls and roof), producing
a potentially nonzero expectation value in (classically allowed)
living rooms and apartments. Children expect Santa to arrive; therefore,
in living spaces with the child operator (closely related to the
annihilation operator), the expectation value
<SC*|C|SC>
is small but
finite, and a small but finite fraction of Santa's presents are
deposited. However, if an attempt is made to observe Santa, the
observation finds the Santa wavefunction in either a "not-Santa"
(OC|SC> = |SC->) or "Santa"
(OC|SC> = |SC+>) eigenstate. Because of
the very small expectation value of the Santa function (approximately
the reciprocal of the number of houses Santa visits, adjusted by local
"naughty" and "nice" operators), the eigenstate is extremely likely to
be "not-Santa" (|SC->)--no presents appear. One cannot really blame
these intrepid experimentalists, however: if one of them did suceed in
finding Santa in the "Santa" (|SC+>) state, he or she would not only
have unprecendented direct evidence of Santa Claus, but would find
Santa's entire load of presents deposited in his or her living room.
