X-Message-Number: 5022
Date: 20 Oct 95 20:07:57 EDT
From: "Steven B. Harris" <>
Subject: CRYONICS: Comments to Ettinger (pt. I)
Dr. Robert Ettinger writes:
>> Needless to say, enough observations of the right
kind by the right people under the right circumstances will
always carry the day and establish the facts. That is received
scientific truth. But it is also received truth that a well
established theory will steamroller a whole lot of alleged
contrary observations [discussion of the laws of thermodynamics
and perpetual motion machines omitted]. The turbulence formulas
may not have the standing of some others in physics, but they do
make a lot of sense--for example that high viscosity tends to
reduce the chance or amount of turbulent flow. And frozen or
freezing tissue undeniably has high viscosity.<<
Comment: yes, but there is a difference in argument here.
The laws of thermodynamics as formulated today, besides being of
great "standing" simply DO NOT PERMIT perpetual motion machines
under any circumstances, period. However, by analogy, it is NOT
true that the equations for viscous incompressable ideal
(Newtonian) fluid flow do not permit mixing. Rather, they simply
do not permit it by the mechanism of chaotic turbulence, under
certain conditions. Whether these conditions obtain under the
conditions we are looking at with freezing of tissues is not
clear, nor it is clear that we need chaotic turbulence to put us
into a region from where we cannot recover by mathematical
calculation. For one thing, vortices in fluids begin forming at
Reynolds numbers above 10 to 30 or so, which is 3 orders of
magnitude from those we've been talking about. Although these
vortices are not "chaotic," and thus theoretically calculable,
vortexes might still mix things well enough that back-calculation
may be impossible (the sensitive parameters of the equations
having been lost due to other effects, see below).
And how sure are we of the applicability of this equation to
biological fluids and systems? The pressures involved in osmotic
shock and in freezing are huge (many atmospheres), and the
openings though which fluids are forced, when membranes rupture,
are very small. Thus, I'd like to see something better than
hand-waving about the velocities involved. Additionally, the
solution for turbulence of fluid flow past a cell-sized sphere
used by Merkel surely does not apply even approximately to all
biological systems. Note for an example that the equation used
predicts no chaotic turbulence by six orders of magnitude at
fluid flows on the order of 10 m/second past a cell. However,
this cannot be used to imply that there cannot possibly exist
turbulence for cells in the human circulatory system (say) at any
reasonable blood velocity obtainable by any means. After all,
you can hear turbulent flow with a stethoscope and blood pressure
cuff, or even without the cuff in diseased or occasionally even
normal structures in the circulatory system (doctors call these
sounds "murmurs" and "bruits"). So there must be something badly
wrong with using the equation this way. One problem is that
Merkle mixes cgs and mks units, and should have used 10^-4 cm or
(better) 10-^3 cm for the characteristic dimensions of a cell
(this puts his figure off by 3 orders of magnitude), a second is
the fact that vortices occur at much lower Reynolds numbers
(noted above, again by another 3 orders of magnitude), and the
last is the problem that the structures producing the turbulence
may have linear dimensions considerably larger than a cell (this
is basically why there is turbulence in the circulatory system--
but note that you cannot get a number greater than 2000 out of
Merkle's equation using ANY applicable biological numbers and the
viscosity of blood). In a brain, the ice crystals forming
between cells may also be much larger than cells, and the cracks
and other structures causing damage and disruption may even be
macroscopic. At what scales do gross fluid flows occur, during
tissue freezing? It's not clear, at least not to me.
Secondly, even if we are satisfied that the laws of fluid
thermodynamics do not permit either chaotic-vortex or smooth-
vortex mixing under freezing conditions in tissues, these laws
STILL do not forbid physical mixing by other processes not
present in ideal fluids. For one thing, all discussants so far
seem to have forgotten Brownian motion (which you all would not
have if you had spent much time watching bacteria under a
microscope). Particles the size of organelles are kicked around
randomly (I mean this in the "truest" quantum mechanical sense of
randomness) a great deal in biological liquids; they move many
times their own diameters every second, typically (which is why,
inside cells, they are generally tacked down to some kind of
scaffolding if their positioning is important to the cell). Dr.
Ettinger may not believe that quantum processes are truly random
or that they cause loss of information via the Penrose mechanism,
but this is a philosophical point. There is nothing in physics
which suggests the opposite, so far as I know. In fact, the laws
of quantum mechanics as they presently stand do NOT suggest
persistance of all bits of information over time. On the
contrary, the direction of the progress of time is the one in
which phase-space information about particles is lost.
Finally, it has already been mentioned that biological
membranes are not tinker-toys, or solid unchanging aerodynamic
shapes in a wind-tunnel, but that they rather do things like
change shape, stick to each other, and form new structures--
more like soap bubbles or blobs of mercury. These processes,
once completed, do not present structures from which the original
things are inferable, again for basic quantum mechanical reasons.
(They are bulk behavior driven by London forces between lipid
molecules and by hydrogen bonding between water molecules; you
cannot tell from a big soap bubble anything about the small ones
that went into it, anymore than you can tell from a large
molecule anything about the starting reactants that were used to
make it. If you believe that molecules of the same structure are
truely identical, a fundamental premise of nanotechnology, you
are forced to come to terms with the logical consequences of this
view also. It's not fair invoking quantum physics when you like
it, and dismissing it when you don't).
Furthermore, these changing shapes, past which fluids flow,
present changing parameters to the basic hydrodynamic equations,
*without which* these equations become unsolvable, even if no
chaos is involved. These ideas are simply not addressed by Dr.
Ettinger.
The above merely argues that in the absence of good reasons,
the observational facts at this point can be taken at face value,
and it is perfectly reasonable to do this. Simply put, there is
a lot of random-looking damage in frozen tissue, and pace Merkle,
not all of this randomness is outlawed or forbidden by the
Bernouli-Stokes equations. It looks random, and I see nothing in
the laws of physics to say that it *isn't* random. I shall be
glad, of course, if it turns out to be calculable, but these
arguments about whether we know enough at this point to say it
isn't, are badly flawed.
<Steve Harris-- Continued Next message>
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