Puzzles of the Microworld
This is a preliminary draft of one chapter of a book-in-progress
tentatively entitled, “Evolution As It Was Meant To Be — And the Living Narratives That Tell Its Story”.
You will find
a fairly lengthy article serving as a kind of extended abstract of major
parts of the book. This material is part of the
Biology Worthy of Life
Project. Copyright 2017-2021
The Nature Institute.
All rights reserved. Original publication: April 15, 2021.
Last revision: April 15, 2021.
A mouse and an elephant live in fundamentally different physical worlds so
far as their own spatial dimensions and their relation to the force of
gravity are concerned — a fact evident enough in the way mice scurry
around, darting this way and what, while the elephant carries its weight
more slowly and deliberately. Or, to approach the matter from a very
different direction: if you dropped a mouse from seven meters
(twenty-three feet) above a meadow, it would likely right itself after
landing and scamper away. If you dropped an elephant from that height, it
would die from massive internal trauma. And if you simply left a beached
blue whale where it lay, it might die from any of several different
causes, one of which is being crushed under its own weight. All this has
to do with the changing relation between the weight of an animal and the
surface area of its body as its overall size
So when we talk about the diverse environments in which organisms live,
one aspect of the diversity has to do with their varying experiences of
the force of gravity in relation to the dimensional aspects of their
lives. To be a different size is already to live in a different world.
Einstein, so it is said, was led to his theory of special relativity due
in part to his having imagined what it would be like to “ride on a light
beam”. Might we possibly discover equally strange things if we tried to
imagine what it would be like to dwell within an individual living cell?
Unlike Einstein with his task, ours would be much simpler. It would not
require bold new understandings in physics, but simply a willingness to
imagine the changing play, at different dimensions, of well understood
physical laws. And, fortunately, we have at least one scientific paper,
written thirty years ago, that has already done much of the work of
imagining the startlingly different conditions of life at the scale of the
That 1990 paper was written by Guenter Albrecht-Buehler of the
Northwestern University Medical School in Chicago. He began his
professional life as a physicist before moving into cell biology.
However, unlike what you might expect of a physicist, one of his larger
concerns was rooted in the conviction that we cannot build up an
understanding of organisms by starting from the molecular level. His
paper, titled “In Defense of ‘Nonmolecular’ Cell Biology”, has not, in my
judgment, received the attention it deserves. The present chapter
represents my effort to summarize only that part of the paper dealing with
the wildly unexpected consequences of differences of scale, and then to
offer a few additional comments of my own.
Unless otherwise indicated, quotes in the following section are drawn from
Warning: This chapter is a bundle of contradictions. In fact, that
is more or less its point. The ways we think and speak about the
submicroscopic world are almost guaranteed to be impossibly off the mark,
and yet anyone who would point this out has no choice but to use the
established, off-the-mark language, which is the only language we
currently have available. So if you begin to notice a jarring dissonance
between the intended meaning and the actual language of particular
statements — and I hope you will — you can take it as a sure sign that you
are getting the point of the chapter.
For example, you will hear me saying that “If you considered two isolated
electrons to be point masses and placed them 1 meter apart …” You
will likewise hear me talking about the “collisions” of “particles”, and
you will listen to a prominent cell biologist remarking how the 5 billion
proteins in a cell are “jammed shoulder to shoulder, [while] also charging
past one another at insanely high speeds”. These references to “isolated
electrons”, “point masses”, “collisions”, and “proteins charging past one
another” all seem to demand that we imagine particular things
acting in the manner of the familiar objects of our experience.
But, as I hope you will realize by the end of the piece, there are no
things of that sort “down there”. What is down there is a
very good question. And if you are asking it by the time you finish
reading this, then the chapter will have accomplished its purpose.
From here to there — or,
down the rabbit hole?
Albrecht-Buehler begins his main discussion by remarking that the size of
cells “is so dramatically much smaller than the macroscopic objects we are
accustomed to judging, that it is fair to say they live in an utterly
alien world”. The surface-to-volume ratio of a cell — a
underlying the mouse–elephant comparison above — is 100,000 times greater
for a typical cell-sized sphere than for an everyday-sized sphere with a
diameter of 50 centimeters (about 20 inches). But the “alien” character
we discover by imagining the life of a cell at its own dimensions goes far
beyond the principle we learn by dropping mice and elephants to the
ground. Nevertheless, that principle isn’t a bad place to start.
From wine to jelly.
Suppose we shrink a wine bottle to one-tenth its normal size, reducing the
2-centimeter diameter of its neck to 2 millimeters. If we now turn the
bottle upside down, nothing pours out. This is, again, due to the
changing surface-to-volume ratio as the size of an object (wine bottle)
decreases. Given the shrinkage of the bottle, the volume (and therefore
the weight) of the wine has decreased much more than the surface area of
the air-wine boundary in the bottle’s neck. The shaping
that hold the wine together in one compact mass at that boundary are now
too strong for the reduced gravitational weight of wine in the bottle to
Figure 15.1. A dew droplet on a leaf. The droplet is about one
We see the natural tendency of such shaping forces in water when we
observe tiny droplets of dew on a waxy leaf. Instead of spreading out
over the leaf, the water draws itself into a roughly spherical shape. But
if we instead had a ball of water 10 centimeters (4 inches) in diameter
and could manage to place it on a flat surface, the water’s much greater
weight would overwhelm its shaping forces, so that the liquid would flow
out in all directions. Only in the tiny droplets that might remain here
and there would we again see the spherical, dew-drop shape we are familiar
with on leaves, grass blades, and so on.
The point to attend to, then, is that change of size can result in
dramatic differences in the play of forces. Of course, our wine bottle’s
reduction in size was not very great. Reflect now upon the fact that the
volume of water in a typical cell is not 10 times, but rather 28,000 times
smaller than the volume of a wine bottle. Albrecht-Buehler remarks of the
non-flowing wine in the neck of the shrunken wine bottle that it appears
to have become rigid, “like jelly”. Indeed, “wine can turn into jelly
just by existing in smaller amounts”. Try to imagine the implications of
that statement in light of a scale reduction by a factor of 28,000!
A fluid’s viscosity
is a measure of its “thickness”, or its
internal, frictional resistance to free flow. Molasses is more viscous
than water. And the more viscous the fluid, the greater the drag
or resistance, it presents to an object moving through it.
Albrecht-Buehler compares the effects of viscous drag upon two objects
moving through water — a spherical cell, and a sphere with a 50-centimeter
diameter. Both spheres are assumed to consist of the same protein matrix.
He asks: if an initial movement of one diameter per second is imparted to
both of them, how quickly would they come to a stop due to the resistance
of the water? It turns out that the larger sphere will travel long enough
to traverse many diameters. By contrast, the cell-sized sphere will stop
within about a millionth of a second, during which it will have traveled
about a millionth of a diameter — which is more or less to say that it
stops immediately and doesn’t travel at all.
This might seem to suggest that if you or I lived at the size of a cell —
or, worse, a molecule within a cell — and if we wanted to take a swim, we
might just as well try swimming inside a large block of concrete. But
this can’t really be the case, and only illustrates the difficulty of
transporting ourselves in imagination to a different scale of existence.
Objects like you and I — or pebbles and flowers, or the gears and levers
of a machine — could not be scaled down to a sub-cellular level and still
remain what they were in any meaningful sense. They would become objects
of an entirely different character.
Further, molecules “live” at a radically reduced scale compared to the
cell, so in moving from the whole cell to the molecular level (what I will
call the “microworld”), we see the various lawful relations changing yet
again. In reality, molecules move through their cellular environs (as we
will see below) with remarkable speed. Moreover, despite the example
above, even cells move quite well in their viscous environment. So still
other factors must come into play.
In 1827 the Scottish botanist, Robert Brown, used a microscope to observe
tiny pollen granules, about 5 microns (5 millionths of a meter) long,
suspended in water. (For comparison, the diameter of a typical human cell
nucleus is about 10 microns.) He observed a continuing series of
movements — a “rapid oscillatory motion” — in what appeared to be random
directions. Such movements, apparently coming from nowhere, were a
considerable mystery at the time.
The motion, which gained the name “Brownian”, was further characterized by
later investigators. Their work confirmed three features of the
movements: they were indeed random in the sense that all directions were
“equally likely”; “further motion seemed totally unrelated to past
motion”; and “the motion never stopped”. In addition, “small particle
size and low viscosity of the surrounding fluid resulted in faster motion”
(Encyclopedia Britannica editors).
In the early twentieth century the French physicist, Jean Baptiste Perrin,
recorded the positions of three particles in water at 30-second intervals,
as viewed through the microscope. His representation is shown in
Figure 15.2. Tracings of the motions in water of three colloidal
particles of radius 0.53 microns, as seen under the microscope. Successive
positions every 30 seconds are joined by straight line segments. The grid
lines are 3.2 microns apart. Note that the straight lines are artifacts
of the fact that positions were recorded at 30-second intervals. More
frequent measurements would have yielded smoother curves (but the overall
movement, with its directional changes, might still be termed
Today Brownian movement is commonly visualized, however
as being due to random collisions (“random thermal fluctuations”) of a
liquid’s molecules with a very small suspended object. In this sense,
writes Albrecht-Buehler, the contents both within a cell and in its
external, watery environment are “jerking violently”. Moreover, these
effects outweigh those of gravity to such an extent that collisions with
just two to three molecules in a cell’s environment are enough to
counterbalance the gravitational weight of the cell, keeping it from
sinking in water. Given the countless trillions of such impacts coming
from all sides, “another way of formulating this result is to say that
gravity is an entirely irrelevant force in the violently chaotic world of
A cell, turbulent as it may seem from some standpoints, is actually far
from being an “out-of-control” world. One good reason for this has to do
with the chemical bonds between atoms and molecules. Even the weakest
(hydrogen) bonds are strong enough to remain stable in the presence of
Brownian fluctuations. So the making and breaking of these bonds involves
the ordered direction and redirection of vast amounts of energy.
Here is one example of the use of chemical energy. A single muscle cell
contains hundreds of subunits (“sarcomeres”) whose dimensions are less
than 3 millionths of a meter. They contract by converting chemical energy
into mechanical energy. The force delivered by one sarcomere, as
Albrecht-Buehler remarks, is such that “it can lift 60 entire cells! In
other words, the cells submersed in violently jerking molasses of their
surrounding aqueous media have literally gigantic forces at their
If gravitational forces tend toward complete insignificance at the
cellular level, the same can hardly be said of electrical forces. The
first thing to realize is how much more powerful than gravity is the
electrical force. Here is one way to think about it. If you considered
two isolated electrons to be point masses and placed them 1 meter apart,
there would be a certain force of gravitational attraction between them.
Suppose, then, that you wanted to know where you should place them in
order for the magnitude of the electrical force between them (a force of
repulsion rather than attraction in this case) to be of the same magnitude
as the gravitational force at 1 meter.
The answer is that you would have to separate the electrons by
approximately 200,000 light
This amounts to more than 34 billion times 34 billion miles. This is too
much to get one’s head around, so the take-home point is simply that the
electrical force is inconceivably stronger than the gravitational force.
The remarkable thing is that, in most of our routine experience of the
world around us, we would hardly suspect the ubiquitous presence of such
monstrous forces relative to our experience of gravity. This has to do
with the fact that, in the world we normally experience, the bearers of
negative electrical forces, such as electrons, are more or less
counterbalanced by bearers of positive electrical forces, such as protons.
The way in which charged particles naturally tend to distribute themselves
gets very complex, but the upshot of it all is the following: while the
electrical forces between cellular constituents are unthinkably more
powerful than the gravitational forces, they don’t simply rip the cell to
smithereens. Here, too, negative and positive charges tend to balance
each other out, but the operative word is “tend”. The imbalances that do
exist are enough to help account for a lot of what goes on.
Albrecht-Buehler puts the matter this way: in the molecular collectives of
cells, “[charged] molecules do not notice each other until they come
closer than about one-third of their diameter. Once they are that close,
however, they are attracted or repelled with almost irresistible
electrical forces”. And again: a single electron charge within the
typical electric field spanning a nerve membrane “can balance the weight
of an entire cell”. He goes on to mention that “cell surfaces contain
thousands of electron charges”.
We might also consider, not just static electrical forces, but electrical
currents. Michael Persinger, the late Laurentian University (Canada)
neuroscientist who investigated bioelectric phenomena in both the brain
and the earth’s atmosphere, was looking, not for great differences, but
for close parallels between the two widely varying scales. And he found
them. But even here the parallels show how differently we must think, for
example, of the brain compared to our routine picturing of physiological
For example, the electrical impulse traveling along the axon of a neuron,
is driven by what might seem to be a trivial action potential of 0.09
volts. But this voltage applies across a 10 nanometer neuronal membrane,
which means that it amounts to millions of volts per meter. This is on
the order of the action potential of an atmospheric lightning bolt. And
the density (amperes per square meter) of the current traveling along the
neuronal path is, according to Persinger, “remarkably similar” to the
density of the electric current flowing in a lightning bolt.
So the reality looks rather as if our brains are continually “lit up” by
countless cascading, lightning-like discharges — perhaps on the order of a
billion discharges per second
“One of the strangest forces that we can encounter in the world of cells
that has no counterpart in our world are the forces of polymerization”.
We came up against polymerization in
(“The Sensitive, Muscular Cell”), where we talked about the various thin
filaments forming the cellular cytoskeleton. The filaments are polymers,
composed of repeating protein subunits that can be added or removed at the
ends of filaments in a dynamic fashion. The process of adding subunits to
a polymer is called “polymerization”. When a cell is migrating, some of
these filaments are being extended forward (by means of polymerization) in
the direction of the migration, thereby facilitating the cell’s movement.
This can happen because the chemical addition of another subunit to a
polymer of the cytoskeleton is an energetic process. “The force of the
addition of only one [protein] subunit is ten times larger than the weight
of a cell!” In theory, therefore, “adding one subunit to a polymer could
lift ten cells by the thickness of the subunit”. This tells us a good
deal about how cells can move. At the normal scale of our lives we see
nothing like this ability of a tiny unit of matter to be chemically joined
to others of its kind and thereby to shift material objects (cells) that
happen to be billions of times more massive than that tiny unit. (A
typical human cell has been estimated to contain several billion protein
molecules, in addition to water, lipids, carbohydrates, and all its other
Figure 15.3. Colorized scanning electron micrograph of a T
lymphocyte (a kind of immune
Figure 15.4. Scanning electron microscopy image of mouse
fibroblasts cultured on artificial filamentous
You will recall from our earlier discussion that a dew drop on a leaf is
“pulled” into a sphere by its shaping forces. (See
Further, we heard that these forces, relative to the gravitational force
that might break the droplet’s form and cause it to flow over the flat
surface of the leaf, become vastly greater at very small scales. At the
level of a cell, one of these shaping forces (surface tension) is “several
thousand times larger than the weight of the cell, and we should expect
the surface force to shape the cell as a perfect sphere”.
The question, therefore, is why a cell is not held rigidly in the shape of
a sphere (Figures
Cells often have all sorts of non-spherical protrusions, and some kinds of
cell readily flatten themselves against a surface and slide over it. In
doing so, they are overcoming the hugely powerful shaping forces just
mentioned. Part of the answer to this particular puzzle is, in Albrecht-
Buehler’s words, that “the surface forces are no match for the strong
polymerization forces”. Bundles of cytoskeletal filaments extending in a
common direction have no difficulty re-shaping a cell and helping to bring
it into movement.
A world hard to
get a grip on
How all these unfamiliar elements of the cellular world add up is not easy
to picture. And it becomes even less easy when we look at some of the
apparent dynamics of cellular life. “Imagine packing all the people in
the world into the Great Salt Lake in Utah — all of us jammed shoulder to
shoulder, yet also charging past one another at insanely high speeds. That
gives you some idea of how densely crowded the 5 billion proteins in a
Those “insanely high speeds” in crowded places are thought to explain how,
as a standard textbook puts it, “a typical enzyme will catalyze the
reaction of about a thousand substrate molecules every second” — meaning
that the enzyme must bind to a new substrate in a fraction of a
millisecond. This happens despite the fact that there tend to be
relatively few substrate molecules per cell. If, for example, there is
only 1 substrate molecule for every 100,000 water molecules,
“nevertheless, the active site [the place where catalysis occurs] on an
enzyme molecule that binds this substrate will be bombarded by about
500,000 random collisions with the substrate molecule per second”. At the
same time, “a large globular protein [like many enzymes] is constantly
tumbling, rotating about its axis about a million times per second”
(Alberts et al. 2002, pp. 77-8).
As if everything we have heard so far is not difficult enough to
comprehend, the problem of imagining microworlds truthfully is greatly
magnified by emerging technologies that generate seductive images. When
biologists speak so casually of atoms and molecules as things, and
when engineers then present us with “pictures” of them, we can hardly help
taking the pictures as images of actual phenomena. And yet, the phenomena
we are dealing with are not “down there”. They are “up here”, where we
are experiencing our instruments.
Figure 15.5. An image produced by the interaction of a non-contact atomic
force microscope with graphene (a lattice of carbon atoms), in an IBM
laboratory. The bright green lines forming approximate hexagons are taken
to represent the molecular bonds between carbon
What we derive from “down there” (at the atomic and molecular levels) is
mostly mountains of data produced by our instruments. The pictures we
look at are representations of that data. If we take these pictures at
face value — if we unthinkingly accept them in the same way we
accept the terms of our visual engagement with the familiar world — then
we are projecting into the microworld phenomena that are not actually
This is a problem. If images like the one in Figure 15.5 truly
represented anything like the physical objects around us, merely reduced
to very small dimensions, and if billions of such objects (commonly, if
nonsensically, referred to as “molecular machines”) were racing around
inside the cell at “insanely high speeds”, tumbling around while rotating
a million times per second, they would presumably achieve nothing but
rampant destruction within the cell.
Figure 15.5, which is said to represent carbon atoms, is not in any normal
sense a photograph of atoms, as the scientists and engineers who produce
such images well know. There is no “thing” anywhere in the world that
looks like this, except the picture itself. Responsible physicists do not
talk about things at this level of observation at all. In this
particular case we are looking at a kind of colored graph of a data set
produced by an atomic force microscope. The spatial distribution of the
artificial colors represents the relations between the highly refined
measuring instrument, on one hand, and forces at an extremely small
(atomic) scale, on the other. It is a picture of a distribution of
forces. Forces are not things.
So what do we make of all the foregoing? It’s hard to say — and maybe
that itself is the important point. It is clear enough that when we
imagine the world of atoms and molecules in terms of our familiar
experience, we are far from truth. If we want some sort of picture, it
will hardly do to conjure images of nanorobots or sewing machines or
pliers, merely reduced in size and spinning around a million times per
second, or a brick beneath a skyscraper receiving an electrical charge and
thereby raising the building off the ground, or molecules consisting of
brightly colored baubles.
The one thing we can be sure of is that the cellular realm is not composed
of anything like our familiar objects, just made smaller. The really
foundational question is whether, and at what scale of observation, we are
justified in talking about “things” at all, as opposed to forces or
This question certainly bears on the common appeal by molecular biologists
to machine and computer models. As Albrecht-Buehler has written:
To my knowledge, there is not even a clue as to how to build a liquid
miniature computer that would function despite thermal fluctuations and
other turbulences in the liquid that would disrupt the circuitry.
There is, quite simply, nothing there that could remotely qualify as
“circuitry” in the sense of “machine parts”.
One might have thought that the puzzling revelations from our indirect,
instrument-mediated encounters with the microworld would have opened up a
space for free inquiry as we considered the nature of perceptible,
material appearance. (On this, see
“All Science Must Be Rooted in Experience”.) One might indeed have
expected that — given a realm considered fundamental to our understanding,
yet inaccessible to the direct activity of our senses — we might have
warned ourselves about the temptation to project falsely imagined
perceptual contents into what is in fact an experiential blank for us.
And, given the scientific commitment to empirical (experience-based)
evidence, what are we to make of a microworld characterized almost
solely in terms of thought-models, mathematical formulae, and theoretical
constructs, with no sense experience to ground us? Such grounding —
together with a desire to get beyond the unfettered flights of medieval
cerebration — was a good part of the resolve of the pioneers of the
Perhaps we should pick up again from where they started.
As the size of an animal decreases, its volume (and
therefore its weight) decreases much more rapidly than its surface area.
In other words, as any given object is reduced in size, its
surface-to-volume (surface-to-weight) ratio rises. The increased
surface-to-weight ratio of the mouse is why its rate of fall is reduced
by air resistance more than the elephant’s rate of fall.
More significantly for the fate of the mouse and the elephant in our
rather twisted thought experiment, the different surface-to-weight ratios
mean that the weight of the mouse per square centimeter of its body
surface striking the ground is minuscule compared to the weight overlying
the elephant’s area of contact with the ground. So the crushing effect of
the impact is much greater for the larger animal.
Among the interrelated shaping forces of a liquid such as water are
internal cohesion and surface tension.
Figure 15.1 credit:
cc by-sa 3.0,
via Wikimedia Commons
Figure 15.2 credit:
Original observations made by Jean Baptiste Perrin. Digital rendering by
MiraiWarren, Public domain, via Wikimedia Commons.
The word “collisions” suggests an activity of particles conceived
in the manner of our everyday experience of tiny bits of
matter. Thinking of water molecules in this way is not something any
physicist today would want to defend.
It is worth remembering that the lives of large, multicellular organisms —
ourselves, for example — are not centered upon the cellular and
molecular level. As we walk, run, and otherwise pursue our lives on
earth, our bodies
must work against the pull of gravity. If we do not sufficiently perform
that work — if we are bedridden or live a sedentary life-style — our
bodies suffer ill effects.
We know further that the weightlessness endured by astronauts on long
missions results in significant loss of bone mass, density, and strength
Likewise, lions raised in zoos, apart from the rigors and stresses of
hunting and the need to patrol large territories, have a bone structure
differing from lions raised in the wild
So Albrecht-Buehler’s assertion that “gravity is an entirely irrelevant
force in the violently chaotic world of cells”, while it may be true when
we are looking at the interplay of forces in the decontextualized cell,
can hardly be true for cells in the context of our bodies. If someone
experiences changes in bone mass and muscle strength while living in a
gravity-free environment, this implies radical changes in cells, including
the loss (death) of cells. The fact that, when a person stands upright on
earth, the weight of a 150-pound body comes to bear upon the small surface
area of two feet certainly makes gravity a “relevant force” for the
tissues and cells on the bottoms of our feet. And much the same can be
said about the distribution of weight and weight-bearing surfaces
throughout our bodies.
Actually, the importance of a larger context was very much part of
Albrecht-Buehler’s argument in his paper. He was claiming, quite rightly,
that we cannot explain either cellular or organismic behavior by trying to
ground our picture upon molecular-level analyses.
I have this answer courtesy of the physicist, George Burnett-Stuart.
Figure 15.3 credit:
cc by 2.0, via
Figure 15.4 credit:
by-sa 4.0, via Wikimedia Commons
citing a comparison offered by Anthony Hyman, a British cell biologist and
a director of the Max
Planck Institute of Molecular Cell Biology and Genetics in Dresden.
Figure 15.5 credit: IBM Research–Zurich.
Some experimental techniques do give us a form of sense-perceptible
the microworld. For example, the relatively small “green fluorescent
protein” (GFP) can be fused to particular molecules of interest in a cell.
When the cell is irradiated with blue or ultraviolet light, the protein
fluoresces, revealing under a light microscope the distribution of the
target molecules in a cellular location.
Again, however, blobs of fluorescent light, while informative
of location, do not give us pictures of molecular “objects” residing
at that location.
When a student collects a quantity of DNA on a glass rod, she is not
looking at DNA molecules, but rather at a white, sticky substance.
Similarly, a prospector may be looking at a chunk of iron ore, but he is
not examining iron atoms. To say that our instruments, by eliciting
responses at an atomic scale, can trace significant structure at that
scale, is not to answer in any meaningful experiential sense, “structure
of what?” — not if by “what” we refer to objects possessing
sense-perceptible, material descriptions.
As a hypothetical question: what would we “see” if, through some sort of
inner work, we should develop in the future a cognitive (clairvoyant?)
capacity to experience — bring to appearance — whatever can be found, say,
at the quantum level? This is, of course, pure speculation. But my
surmise is that we would discover an intricately structured play of
“forces” of will. We would discover, that is, a field of potential that,
when probed in appropriate ways, can be brought to manifestation as
materially engaged force. The fact that our own wills (in a manner of
which we are completely ignorant and unaware) can take form in the
enfleshed mechanical forces of our bodies, while a very different matter,
may nevertheless be suggestive in this regard.
Alberts, Bruce, Alexander Johnson, Julian Lewis et al. (2002).
Molecular Biology of the Cell, 4th edition, pp. 75-6. New York:
Albrecht-Buehler, Guenter (1985). “Is Cytoplasm Intelligent Too?”,
chapter 1 in Cell and Muscle Motility, edited by Jerry W. Shay, pp.
1-21. Boston: Springer.
Albrecht-Buehler, Guenter (1990). “In Defense of ‘Nonmolecular’ Cell
Biology”, International Review of Cytology vol. 120, pp. 191-241.
Callier, Viviane (2021). “A Newfound Source of Cellular Order in the
Chemistry of Life”, Quanta Magazine (January 7).
Encyclopedia Britannica editors, “Brownian Motion”.
Downloaded January 27, 2021.
Holdrege, Craig (1998). “Seeing the Animal Whole: The Example of the
Horse and Lion.” In Goethe’s Way of Science, edited by David
Seamon and Arthur Zajonc. Albany: SUNY Press, pp. 213-232.
Keyak, J. H., A. K. Koyama, A. LeBlanc, Y. Lu and T. F.Lang (2009).
“Reduction in Proximal Femoral Strength Due to Long-Duration Spaceflight,”
Bone vol. 44, no. 3, pp. 449-53.
Persinger, Michael A. (2012a). “Brain Electromagnetic Activity and
Lightning: Potentially Congruent Scale-Invariant Quantitative Properties”,
Frontiers in Integrative Neuroscience vol. 6, article 19 (May).
Steve Talbott :: Puzzles of the Microworld