Decoherence and Orch OR: No black holes

Date: Thu, 12 Sep 1996 03:30:13 -0700 (PDT)
From: Stuart Hameroff <srh@ccit.arizona.edu>
To: quantum-d list <quantum-d@teleport.com>
Subject: Decoherence and Orch OR: No black holes


Lawrence B. Crowell:
A central issue for quantum biology is decoherence.  In order for a
wave function to play a real role in biological systems there must be a
mechanism that prevents the phase space volume of the quantum system from
being absorbed into the environment.  At issue is what the mechanism of
decoherence and the process that prevents decoherence, or "recoheres" the
system.

The Penrose-Hameroff approach invokes the role of quantum black holes
as the source of wave function collapse.

SH: It does? Where did we say that?

LBC: Below we briefly discuss these approaches.

[text and equations omitted]

....So here we have two models of decoherence.  One that involves black
holes and the thermodynamics of quantum fields in their environment, and
an approach that involves the breakdown of recurrence by coupling a
system to an external environment with an infinite dimensional Hilbert
space.

SH: The latter would be interaction with the environment. Penrose denotes
this as R, or SR (subjective reduction). Penrose's objective reduction (OR)
is something else again. In OR, environmental decoherence is avoided but
the system inevitably self-collapses when it's coherence (as measured by a
product of its gravitational self-energy and coherence time) reaches a
certain value related to quantum gravity (E=h/T).

LBC:  Before passing judgement on which process is the most relevant to
the issue of quantum biology, assuming experiments bear fruit on this
matter, I will first indicate that the two processes are in some way
related.

SH: That's swell, but you are ignoring Penrose's OR. It has nothing to do
with black holes.

In OR, fundamental spacetime underlying the superposed, separated mass
itself separates - there is a bifurcation, or separation of spacetime
(as illustrated on page 338 of Shadows of the Mind. This separation is
an instability which "decays" back to one or the other spacetime
configuration. It is not a black hole. Quantum gravity is relevant to
spacetime itself.

LBC: A model that involves decoherence according to the existence
of virtual black holes requires the tie in between physics at the scale
of 10^-33cm to that of macromolecules of a cell 10^-7 cm.

SH: There you go again. But, yes, the spacetime separation in OR *is* in
the Planck scale of 10^-33 cm (no black holes up our sleeves). This is
discussed in Hameroff and Penrose, 1996b:

"It should be made clear that this measure of separation is only very
schematically illustrated as  the "distance" between the two [separated
spacetime] sheets in the lower diagram in Figure 1. As remarked above,
there is no physically existing "ambient higher dimensional space" inside
which the two sheets reside. The degree of separation between the space-
time sheets is a more abstract mathematical thing; it would be more
appropriately described in terms of a symplectic measure on the space of
4-dimensional metrics (cf. Penrose, 1993) - but the details (and
difficulties) of this will not be important for us here. It may be noted,
however, that this separation is a space-time separation, not just a
spatial one. Thus the time of separation contributes as well as the
spatial displacement. Roughly speaking, it is the product of the temporal
separation T with the spatial separation S that measures the overall
degree of separation, and OR takes place when this overall separation
reaches the critical amount. [This critical amount would be of the order
of unity, in absolute units, for which the Planck-Dirac constant h bar
(=h/2pi), the gravitational constant G, and the velocity of light c all
take the value unity (cf. Penrose, 1994 - pp. 337-339).] Thus for small S,
the lifetime T of the superposed state will be large; on the other hand,
if S is large, then T will be small.

To calculate S, we compute (in the Newtonian limit of weak gravitational
fields) the gravitational self-energy E of the difference between the mass
distributions of the two superposed states.

(That is, one mass distribution counts positively and the other, negatively;
see Penrose, 1994; 1995.)

The quantity S is then given by:

S= E h^-1

Thus

T=h E^-1

Schematically, since S represents three dimensions of displacement rather
than the one dimension  involved in T, we can imagine that this dis-
placement is shared equally between each of these three  dimensions of
space - and this is what has been depicted in Figure 3. However, it should
be emphasized that this is for pictorial purposes only, the appropriate rule
being the one given above. These 2 equations relate the mass distribution,
time of coherence, and space-time separation for a given OR event. If, as
some philosophers contend, experience is contained in space-time, OR
events are self-organizing processes in that experiential medium, and a
candidate for consciousness."

LBC: Yet it is at least still reasonable to assume that things on
the Planck scale have little to do with biochemistry, molecular biology,
and the processes involved communication between cells.

SH: Except when it comes to consciousness.

LBC: The issue is which approach is the most fruitful for problem that
involve nonrelativistic wave propagation in a molecular wave guide.

SH: Don't forget Matti Pitkanen's infra-red micortubule quantum antenna
model...

LBC: To be honest I think the open systems approach is the most
reasonable.  Further, I am sufficiently familiar with people in the
molecular biology field to know that there is little interest in
some marriage of quantum black holes to molecular biology.

SH: It's probably not legal in Arizona anyway

LBC: Just getting basic quantum mechanics, Schrodinger equation, density
matrices, etc, married into molecular biology is going to be tough enough,
without straining things to include black holes, strings, or unification
of gauge fields.

SH: It's hard to throw out spacetime

LBC: I think that methods of quantum trajectories, master equations, and
the rest are much more likely to bear real fruit.  There is nobody in
quantum optics that is invoking quantum gravity to understand the problems
of decoherence in cavity QED, chaos and measurement.

SH: Maybe they should.

LBC: The alpha and beta tubulins linked together in microtubules and
centrosomes are subjected to an environment with thermal noise...

SH: Not necessarily. They may be intermittently isolated by actin gels
(Hameroff, 1996; Hameroff and Penrose, 1996c)

LBC: A microtubule is composed of alpha and beta tubulin that can carry
phonons and exhibit polarizations.  Microtubule associated proteins
(MAPs) bind to microtubules (MT's) to mediate the interaction of MT's
with the rest of the cellular structures.  As such the MAPs act to pump
energy into the MTs.

SH: Sometimes. But MTs also have intrinsic energy from GTP hydrolysis.
MAPs can also behave as environment and cause decoherence, thus acting
as orchestrating nodes.

LBC: Now let us assert the hypothesis that this energy that is pumped
into the MT drives the polarization of the tubulin molecules.  These
polarizations can be expanded into cylindrical Bessel functions with a
mode expansion.

[text and equations omitted]

...Physically this means that the fields within the tube are self focusing
for n_2 > 0.  For a few number of photons the interactions between the
photons are nonlinear.  The "gas" of photons forms a quantum wave packet
through this self-focusing process.

SH: Which is pretty much what del Giudice et al said in 1983 (del Giudice
E, Doglia S, Milani M 1983. Self-focusing and ponderomotive forces of
coherent electric waves: a mechanism for cytoskeleton formation and
dynamics. In Coherent Excitations in Biological Systems. Edited by H
Frohlich and F Kremer. Berlin, Springer-Verlag)

LBC: This makes MT's a possible quantum transmission line that utilizes
the infinite number of symmetries of a soliton as the fundamental bit, or
q-bit, carrier.  This part of the problem appears to be in hand, except
for the issue of decoherence.  This is an issue that I am currently
working on.

SH: I'll bet on cycles of actin gelation with ordered water (Hameroff,
1996; Hameroff and Penrose, 1996c)

LBC: MT's are the communication channels within a cell. They organize
the cellular environment by acting as motors and information conveyances.
If they are communication channels of quantum information they might
provide the "wholeness" that maintains cellular integrity.

SH: Right on!

LBC: There is still the issue of how these q-bits are process by the
macromolecular machinery at the send and receive end of the MT's.  It is
at the ends of the MT's that the problem becomes actually quite difficult.
It is here that J. Sarfatti's back-action should rear it head, if this
hypothesis is correct.

SH: It depends on which end of the microtubule you mean. The proximal
(beta tubulin/plus) ends are capped by gamma tubulin and embedded in
electron dense matrix surrounding the centrioles. The distal (alpha
tubulin/minus) ends may be capped by a variety of proteins acting as a
node. Jack's "back action" is just a non-biological imitation of our
Orch OR orchestration. Biological signals phosphorylate the MAPs which
convey the information to the MTs by (among other means) tuning the
quantum coherent oscillations.

LBC: ....back-action implies some degree of emergent complexity or
emergent behavior that occurs with chaotic or nearly chaotic systems.

SH: So does Orch OR. Even classical MT dynamics exhibits highly
nonlinear behavior (Rasmussen et al, 1989; Tuszynski et al, 1995)

LBC:...Molecular biology and genetics is the largest fundamental
science that fits into this emerging political reality.  Unfortunately
I do not [see] quantum gravity fitting into this, but other aspects
of physics might fit in quite well.

SH: If you take the hard problem of consciousness seriously, you are
forced to embrace some form of pan-psychism. If you embrace some form
of pan-psychism, you must look at fundamental spacetime geometry. If
you look at fundamental spacetime geometry, you see Penrose's quantum
spin networks based on quantum gravity.

In closing I'd like to steer back to Caroline Lewis's original post
regarding experimental work. I've been struggling with R. Omnes' excellent
book "The Interpretation of Quantum Mechanics" (Princeton Press, 1994)
particularly about decoherence. There is an interesting section on SQUID
experiments proposed by Leggett. Has anyone read it?

Stuart Hameroff
srh@ccit.arizona.edu
http://www.u.arizona.edu/~hameroff.html

Dayhoff, J.E., Hameroff, S., Lahoz-Beltra, R., and Swenberg, C.E.
(1994) Cytoskeletal involvement in neuronal learning: a review. Eur.
Biophys. J. 23:79-93.

Hameroff, S.R. (1994) Quantum coherence in microtubules: a neural
basis for emergent consciousness. Journal of Consciousness Studies
1(1):91-118

Hameroff, S.R. (1987) Ultimate Computing: Biomolecular
Consciousness and Nanotechnology, North-Holland, Amsterdam.

Hameroff, S.R., Dayhoff, J.E., Lahoz-Beltra, R., Samsonovich, A., and
Rasmussen, S. (1992) Conformational automata in the cytoskeleton:
models for molecular computation. IEEE Computer (October Special Issue
on Molecular Computing) 30-39.

Hameroff, S.R., Smith, S.A., and Watt, R.C. (1984) Nonlinear
electrodynamics in cytoskeletal protein lattices. In Nonlinear
Electrodynamics in Biological Systems, W.R. Adey and A.F. Lawrence
(eds.), Plenum Press, New York.

Hameroff, S.R., and Watt, R.C. (1982) Information processing in
microtubules. J. Theor. Biol. 98:549-561.

Hameroff, S.R., Dayhoff, J.E., Lahoz-Beltra, R., Samsonovich, A., and
Rasmussen, S. (1992) Conformational automata in the cytoskeleton:
models for molecular computation. IEEE Computer (October Special Issue
on Molecular Computing) 30-39.

Hameroff, S.R., and Penrose, R., (1996) Orchestrated reduction of
quantum coherence in brain microtubules: A model for consciousness. In:
Toward a Science of Consciousness - The First Tucson Discussions and
Debates, S.R. Hameroff, A. Kaszniak and A.C. Scott (eds.), MIT Press,
Cambridge, MA. pp 507-540
(also published in)
Mathematics and Computers in Simulation (1996) 480
http://www.u.arizona.edu/~hameroff/penrose1

Hameroff, S.R., and Penrose, R., (1996) Conscious events as
orchestrated spacetime selections
Journal of Consciousness Studies 3(1):36-53
http://www.u.arizona.edu/~hameroff/penrose2

Hameroff SR, Penrose R (1996) Testable predictions of the Orch OR
model of consciousness (in preparation)

Hameroff SR (1996c) Quantum Brain Dynamics: An Introduction M Jibu
and K yasue. Book Review. Trends in Neuroscience, in press

Hameroff SR (1996d) Cytoplasmic gels and ordered water: Possible
implications for biological quantum coherence. Proceedings of the
Advanced water Symposium, dallas texas, October 5 and 6,  1996, in press

Jibu, M., Hagan, S., Hameroff, S.R., Pribram, K.H., and Yasue, K.
(1994) Quantum optical coherence in cytoskeletal microtubules:
implications for brain function. BioSystems 32:195-209.

Penrose R (1994) Shadows of the Mind. Oxford Press

Penrose R (1989) Emperor's New Mind, Oxfrod Press

Penrose R (1996) On gravity's role in quantum state reduction.
General Relativity and Gravitation 28(5):581-600)

Penrose, R., and Hameroff, S.R., What gaps? Reply to Grush and
Churchland. Journal of Consciousness Studies 2(2):99-112.

Rasmussen, S., Karampurwala, H., Vaidyanath, R., Jensen, K.S., and
Hameroff, S. (1990) Computational connectionism within neurons: A
model of cytoskeletal automata subserving neural networks. Physica D
42:428-449.

Tuszynski J, Hameroff S, Sataric MV, Trpisova B, Nip MLA (1995)
Ferroelectric behavior in microtubule dipole lattices. Journal of Theoretical
Biology 174:371-380