What Is Memory that It May Have Hindsight and Foresight as well? - Understanding Understanding: Essays on Cybernetics and Cognition - page 125

tion for the two isomeric states of an hypothetical molecule Z 4 composed
of four 3-valence atoms Z. Simple considerations show that the tetrahedral
configuration is more stable than the quadratic form, hence some energy
must be supplied to the tetrahedron to transform it into the square.
However, it will not stay indefinitely in this configuration because of the
quantum mechanical “tunnel effect” which gives each state a “life-span” of

D E

kT

t= 0 e

where DE is the height of the energy “trough” which keeps the configura-
tion stable, k is Boltzmann's constant, T is the absolute temperature sur-
rounding this molecule and t 0 is an intrinsic oscillatory time constant
associated with orbital or lattice vibrations.
It is these spontaneous transitions from one configuration into another
one which tempt me to consider such a molecule as a basic computer
element, particularly if one contemplates the large number of configura-
tions which such macro-molecules can assume. Estimates of the lower and
upper bounds of the number of isomeres are 29

5
8

mn

ª◊

and

()

pV

nV
2p V

Ê
Ë

ˆ
¯

m ª

()

where p(N) is the number of unrestricted partitions of the positive integer
N, and V and n are again the number of valences and the number of atoms
respectively.
Since each different configuration of the same chemical compound Z n is
associated with a different potential energy, the fine-structure of this mol-
ecule may not only represent a single energy transaction that has taken
place in the past but may represent a segment of the history of events during
which this particular configuration evolved. This consideration brings me
right to my conjecture; namely to interpret the responses of such macro-
molecules to some energy transactions as those of a recursive function com-
puter element.
The idea to look upon various structural transformations which many of
the macro-molecules perpetually undergo as being outcomes of compu-
tations is not at all new. Pattee, for instance, has demonstrated in a de-
lightful paper 30 the isomorphism between the growth of some helical
macro-molecules with the operation of a finite, binary autonomous shift-
register. In his example the recursive relation is only between a present
state Y and an earlier one Y¢:

YF= ( .