ULTIMATE COMPUTING - Quantum Consciousness Studies

20 Toward Ultimate Computing
spatial structure whose geometry favors coupling among subunits. Coherent
oscillations in an appropriate medium like the cytoskeleton can lead to collective
phenomena such as long range cooperativity, communication, and holography.
Another model can help explain long range cooperativity in biomolecules. Soviet
biophysicist A. S. Davydov has considered almost lossless energy transfer in
biomolecular chains or lattices as wave-like propagations of coupled conformational
and electronic disturbances: “solitons.” Davydov used the soliton concept to explain
molecular level events in muscle contraction, however solitons in the cytoskeleton
may do what electrons do in computers.
The Fröhlich and Davydov approaches may be seen as complementary
(Tuszynski, Paul, Chatterjee, and Sreenivasan, 1984). Fröhlich’s coherency model
focuses on time-independent effects (stable states) leading to order whereas
Davydov’s model looks at time-dependent effects which propagate order through the
system. These and other theories of collective effects applied to information
processing in cytoskeletal lattices will be described in Chapters 6 and 8.
1.4 Molecular Computing
To approach the cognitive capabilities of the human brain, Al must emulate
brain structure at the nanoscale. Computer hardware is indeed evolving to smaller
switching components, and advantages of proteins themselves are being
considered. The smallward evolution of technological computing elements
embraces a number of concepts and material collectively known as “molecular
computing.”
The potential advantages of molecular computers have been described by D.
Waltz (1982) of Thinking Machines Corporation. 1) Current “planar” computer
design is limited in overall density and use of three dimensional space. 2) Further
miniaturization is limited with silicon and gallium arsenide technologies. Chips
and wires cannot be made much smaller without becoming vulnerable to stray
cosmic radiation or semiconductor impurities. 3) Biomolecular based devices may
offer possibilities for self-repair or self-regeneration. 4) Certain types of analog,
patterned computation may be particularly suited to molecular computers.
Forrest L. Carter (1984) of the Naval Research Laboratory has catalyzed the
molecular computing movement through his own contributions and by sponsoring
a series of meetings on Molecular Electronic Devices (in 1981, 1983, 1986).
Strategies described by Carter and others at his meetings have been aimed at
implementing nanoscale computing through switching in material arrays of
polyacetylenes, Langmuir-Blodgett films, electro-optical molecules, proteins and
a number of other materials. Interfacing between nanoscale devices and
macroscale technologies is an obstacle with several possible solutions: 1)
engineering upward, self assembling components, 2) optical communication, 3)
molecular wires, 4) don’t interface; build systems that are totally nanoscale
(though they’d have to be somehow developed and tested), and 5) a sensitive
bridge between macroscale and nanoscale. Technologies which may fulfill this
latter possibility include ion beam nanolithography, molecular spectroscopy,
quantum well devices, and scanning tunneling microscopy (STM). In STM,
piezoceramic positioners control an ultra sharp conductor with a monoatomic tip
which can probe and image material surfaces with atomic level resolution. STM
related nanotools may soon be capable of ultraminiature fabrication and
interfacing: “nanotechnology” (Chapter 10).
The medium of information flow in conventional computers is electronic
current flow, but electron transfer may be too energetically expensive and
unnecessary at the molecular nanoscale. Many of the projected modes of
molecular computing rely on propagation of nonlinear coupling waves called
“solitons” similar to what Davydov proposed for linear biomolecules. Carter