Critique of Bejan's "Design in Nature", Part III

The left photo is the Lena Delta, rotated and mirrored; image taken from Wikipedia.  The right photo is a resin casting of the human lung, distinctly showing the bifurcation of the air passages (off-white color) along with the arteries and veins (red and blue color); photo provided to Glenny and Robertson by Dr. Ewald Weibel, Institute of Anatomy, University of Berne.



The items in the above photo are used by Bejan in the Mechanical Engineering article to illustrate the similarities of a natural flow system and an engineered system, with the river and lung being a "flow" from a single point to an area, or a volume.  However, the fact that they are both flows from a single point to an area or volume is the only similarity.  The actual differences between the Lena Delta and a human lung are so vast and profound, I am astounded that Bejan would lump them together to try to illustrate his 'constructal law'.

Here is what Bejan says about his constructal law and river basins:

The constructal law tears down the walls that have separated the disciplines of science by providing a new understanding of what it means to be alive.  Life is movement and the constant morphing of the design of this movement.  To be alive is to keep on flowing and morphing.  When a system stops flowing and morphing, it is dead.  Thus river basins configure and reconfigure themselves to persist in time.  When they stop flowing and morphing they become dry riverbeds, that is, the fossilized remains of earlier “live” flow systems.

This to me this is an unholy amalgam of Darwinism and thermodynamics, and I would very much disagree with Bejan’s definition of ‘life’, and his assertion that living things must flow and morph to remain alive.  That’s not even true for rivers.  What if a river were completely channeled by solid rock from its source in the mountains all the way to the sea, and not allowed to morph?  How does this ‘kill’ the river?  Why would it need to morph to persist?  Obviously, it wouldn’t.  The only thing that matters is whether or not there is a constant inflow of new water into the river system, but that is the requirement for there to be any persistent flow of anything.  So if you omit morphing, to say that “to be alive is to keep on flowing” is like saying “to keep on flowing is to keep on flowing.”  What’s the point of saying that? 

And what about dormancy? 2000 year old seed found in Herod’s palace was able to be germinated.  Would that comport with anyone’s definition of ‘dead’?  Just because the flow of any energy or water or chemicals has completely stopped does not mean that something is dead.  For actual living things, what matters is its ability to receive an input (moisture) and execute its programming to give an output (growth and development).

It should also be said that the analogy of the dry riverbed being the fossilized remains of a river is erroneous.  If the flowing river is that which is alive, then the riverbed, or the channels carved out of the landscape, is the work being performed by the system, it is not the system itself.  So if you must equate riverbeds with fossils, the dry riverbed would be analogous to finding tetrapod tracks, not a trilobite or nautilus shell.  

With that said, whether or not life has evolved, or to what extent it has evolved, or the extent to which it is possible for it to evolve, is the question.  The whole debate between Darwin and Intelligent design is in regards to these very questions, so to hold up ‘constructal’ law as a unifying law of design in nature is begging the question.

But what about the differences between river deltas and lungs?

River deltas form due to the deposition of sediment. The sedimentation is what causes the delta to form by either diverting the original flow or by the formation of new channels during flooding.  Over time, the delta grows larger and can eventually completely relocate, as the Mississippi delta has done several times throughout its history.  But it must be noted that the branching associated with a river delta is simply the result of the sediment losing energy, falling out of the flow and building up to the point that the river is forced to branch.  This is due to pure physicality, and is contingent on whether or not the sediment blocks the flow.  All that is required for there to be a river is water + gravity + any landscape.  And even if the river becomes completely blocked, it still ‘flows up’ until it finds a spot to flow back down again.  The river is going to flow so long as there is a constant infeed of water, with or without the sediment. 

If a delta does form, it is true that the delta morphs over time, but so what? The sediment is not part of the flow per se; it only either travels with the flow, or redirects the flow after it has been deposited.  Further, the fact that there is a flow at all is not dependant on the sediment.  The formation of the delta is simply the work performed by the flow.  The channels are carved and the sediments are picked up and deposited by the flow.  The river will flow whether it carves out channels or not, and if it does carve channels, it will flow whether the channels morph or not.  And if the flow stops (or ‘dies’), it is because the water was turned off, which has nothing to do with anything other than the water having been turned off.

Now what about lungs? 

Lung formation is highly conserved, in that the branching of both the air passages and the blood passages are the same for all individuals, at least up to a point.  This includes number of branches, length of the branches, angle of branching, etc.  I am not a doctor, so I don’t know to what degree this branching is conserved (i.e. when does the branching become unique for each person, if ever), but even if the number of clusters of alveoli is not conserved, the lung must still maintain a certain shape, for the size, shape and number of lobes are conserved as well.  River deltas are not like this, for they are formed by the random deposition of silt, hence their random branching and shifting.  Lung formation is algorithmic, following a set of rules (e.g. grow until this long, then divide in two at these angles, grow until this long, then divide in two at these angles, do until this length or volume is achieved, terminate with alveoli).  Lung growth is algorithmic, not random like the formation of river deltas.

After the lung structures have been formed, the flow of the fluids can then ensue.  But it must be noted that the fluid flow begins only after the passages (i.e. channels: bronchi, arteries, etc.), are already formed. The passage formation is independent and prior to the fluid flow through the passages or channels.  Rivers form the channels in which the rivers flow, and the river basin or delta forms subsequent to the flow of water; but because the lungs form before the flow of air and blood even begins, something else entirely other than said flow has obviously caused the growth and development of the lungs.

So with the lungs we actually have two distinct flows.  The first is a flow of materials during the process of lung development, in that the air and blood passages must be manufactured, and are built on and bifurcate from the previously built bronchi and arteries. But it is only after these passage ways have been constructed that the secondary flow of air and blood can happen at all.  The first flow of materials is controlled by a set of instructions, and the second flow of fluids is controlled and directed by the structures built by the first flow.  Rivers and river deltas are not like this at all.

In light of this, it should be painfully obvious that Bejan has completely ignored the ways in which these structures are built, which are so fundamentally disparate that I don’t understand why he conflates the two, other than in an effort to sell his constructal theory to the uninitiated.

Critique of Bejan's "Design in Nature", Part II

So let’s get to it.  Bejan’s constructal law is this:

For a finite-size flow system to persist in time (to live), it’s configuration must evolve in such a way that provides easier access to the currents that flow through it.

He then elaborates a little:

…Everything that moves, whether animate or inanimate, is a flow system.  All flow systems generate shape and structure in time in order to facilitate this movement across a landscape filled with resistance (for example, friction).  The designs in nature are not the result of chance.  They arise naturally, spontaneously, because they enhance access to flow in time.

My initial concern here is his equivocation of the word “design”, which he uses for both inanimate phenomena like lightning, snowflakes and river deltas, and for actual engineered systems, such as airplanes, cars and modern infrastructure.  This is a common tactic used by the Darwin lobby.  Life is best described as  engineered systems, in that the appearance of design is breathtaking, especially as we learn more about it.  The similarities between life and systems engineered by humans is so striking, in fact, that Atheists and/or Naturalists must engage in wordplay in an effort to detract from the painfully obvious.  And it appears that this is exactly what Bejan is attempting to do.

But the basic premise is this: flow systems tend to find the path of least resistance.  When a river makes its way to the ocean and begins to branch, the water cuts its way through the landscape according to whatever dirt and rock gives way first, thereby forming channels in those areas, which forces continued removal of dirt and rock along those channels. Also, water tends to flow downhill, not uphill, so we can expect to see the water to also flow with gravity, which is also a way in which it finds the path of least resistance (duh).  It is the same with lightning and snowflake formation.

He then lumps life and engineered systems into the flow system category by saying that they, too, tend to find the path of least resistance.  And he points to the branching of trees, lungs, vascular systems and cooling fins.  He also points to animals and says that they have evolved to move mass across the landscape in a very efficient manner, i.e. their designs have been configured to minimize the work required to move them across the landscape.  He is correct that engineered systems and life are flow systems, but to say that they are no different than simple law-like physical phenomenon is way off the mark.  In fact, I would say that his theory is sophomoric.  So then what are the differences between unbridled energy flows and engineered systems? I can identify at least three dramatic differences off the top of my head: 

Engineered systems utilize energy flow, they are not a manifestation of such flows due to pure physicality.

The river flows downhill due to gravity alone, and the channels carved into the landscape are a result of the loosest materials giving way first, which, again, is a manifestation of pure physicality.  However, the hydroelectric dam harnesses this energy flow, or redirects it to serve a purpose.  The dam, or barrier, is put in place to maximize the potential, and the generator transforms the potential energy into electrical potential, and the power lines transmit that potential to the end user, thereby fulfilling the purpose of the dam itself.  Likewise, there exists a proton gradient across certain membranes in the cell.  ATP synthase is a protein complex that utilizes this potential to achieve an end, instead of just allowing the gradient to flow across the boundary without doing anything useful.  The membrane creates a barrier to maximize the potential, then the ATP synthase complex not only channels the flow, but transforms the potential across the membrane into chemical potential (ATP) which is then utilized to power most of the motorized goings-on in the cell.

There must be a choice contingent arrangement of matter that cannot be accounted for by pure physicality in order to accomplish this harnessing of available potential.

There is no physical law that can explain the composite concrete and steel arch needed to dam the river.  And there is no physical law that would cause the windings within the generators to be drawn out to a precise gage thickness, or to be coated with resin or plastic, or to be arranged into a specific number of loops and orientations about the armature.  These qualities are instantiated into the matter by a designing mind, which is what I mean by ‘choice contingent’. Likewise, the ATP synthase proteins are arranged in such a way as to have an actual generator, complete with ion channels, a rotor and a stator, configured and oriented in such a way to allow for one degree of freedom to rotate and capture the energy provided by the proton gradient.  

The best way to see the difference between natural phenomena and engineered systems is to picture a hurricane.  A hurricane is a heat engine that forms because of the heat energy flowing from the surface of warm tropical waters to the upper atmosphere.  A very predictive structure results, along with very destructive winds which perform ‘work’.  But it must be noted that the energy flow itself is what builds and maintains the structure.  If the energy is removed, the structure dissipates.  This is not so with engineered systems which only channel the energy and are not maintained by it.  When the energy flow is removed, the structure remains until the energy flow resumes.

Sophisticated engineered systems are algorithmic, whereas the behavior of natural phenomena is governed by pure physicality.

Hurricanes, rivers, stars, etc. are predictive because they are governed by laws, and can be expressed as a set of equations.  Projectiles trace a path through the air in accordance with an initial velocity vector and the pull of gravity.  Hurricanes rotate in accordance with the rotation of the Earth and their strength waxes and wanes in some proportion according to the magnitude of such variables as the heat gradient, pressure, humidity, etc.  So we can describe the behavior of natural phenomena with a set of equations with variables representing aspects of the environment.

But integrated engineered systems perform in accordance with a set of instructions, execute logic and looping, and calculate outputs based on inputs.  Consider an automated machining cell that produces widgets: a box a raw material is loaded onto a platform, which satisfies one or more on/off conditions, such as whether or not the box holds open a switch, or if the operator initiates a program by pressing the ‘go’ button.  If these conditions are satisfied, a robotic pick-and-place device begins execution of a program which picks up each individual raw widget from the box (which requires step-over looping), and places the raw widget into the first machine.  If another series of on/off conditions is satisfied after loading, such as a bank of sensors that detects whether or not the part is loaded against the datums, the first machining center initiates another program that turns on motors and pumps for spindles and hydraulic slides and such.  Once these programs have completed execution, and another series of on/off conditions is satisfied, such as sensors that detect the end position of the slides, a signal is sent back to the robot to unload the first machine, and then carry the load to the next machine.  The automated robot cell is executing a plan, and making ‘decisions’ based on inputs received from the environment or components of the system itself. It is not a set of equations that governs the system, it is a set of instructions, or an algorithm (fig 1).

fig 1

But to which of these does life compare?  Life is without question algorithmic.  Consider the assembly of the flagellum, which must be assembled according to a very exacting plan; a procedure which if not followed perfectly will result in the failure of the flagellum’s construction.  The plan executes when the cell senses a signal to start building a flagellum, which initiates a cascade of controls, starting with the manufacture of a protein that binds to and flags the section of the DNA that codes for the base of the flagellum, effectively turning it ‘on’.  So we start with an ‘on’ signal, which initiates a program that executes the construction of a marker that when bound to a particular section of the DNA acts as another ‘on’ signal, which initiates another program that starts production of the flagellum proteins that form the base of the structure.  Each stage of production is initiated in this way and will not begin until the previous phase is completed and sends an ‘on’ signal to initiate the next stage, just like the robot cell.

[D'Onofrio, Abel and Johnson have illustrated the algorithmic properties of protien synthesis in this article. And here is the flowchart.]

It should be noted that the algorithmic nature of engineered and living systems is only made possible because of the special arrangement of matter, not the governance of the laws of physics.  If the sensor in the robot cell is not positioned in just the right spot, it will not be able to detect whether or not the part is loaded correctly, and will not ever register an ‘on’ signal to initiate the next step in the process.  It is the laws of physics that makes the sensor work the way it does, but it is the choice contingent positioning of the sensor that enables the algorithmic quality of the system.  Likewise, the protein that binds to the DNA that codes for the first stage flagellum construction must bind in the right spot, or else the wrong portion of code will be switched ‘on’, or it will not switch on anything at all.  It is the laws of physics that causes the protein to bind to the DNA, but it is the special arrangement of amino acids that causes the protein to bind where it does.  But rivers and hurricanes and such are manifestations of pure physicality.  They do not execute a plan, they only behave according to a set of governing equations.  These phenomena will follow the equations regardless of any special arrangement of matter.  The arrangement of matter for natural phenomena serves as variables for the equations that describe its behavior, but the arrangement of matter for the algorithmic system only provides an ‘on’ or ‘off’ condition, and there is a very narrow range in which an ‘on’ signal can be realized, but only because it corresponds to another aspect of the system that is ‘looking’ for an ‘on’ signal at that precise arrangement.  Intelligent Design proponents would call this a ‘specification’.

In part three, I will use these distinctions to further critique Bejan’s concept.

Critique of Bejan's "Design in Nature", Part I

The June 2012 issue of Mechanical Engineering, the magazine of ASME, has an article called “Design in Nature” by Adrian Bejan and J. Peder Zane (Bejan is a Mechanical Engineering professor at Duke University, and Zane is an assistant professor of journalism at St. Augustine’s College). The subtitle of the article is “The law of physics that guides the development of organisms is the same for inanimate nature and engineered systems”.  But the big problem with this title is that there is no law of physics that guides the development of engineered systems.  Engineered systems are choice contingent arrangements of matter and energy which utilize the laws of physics to achieve an end – but their development and end arrangement is not determined by any law, let alone some obscure principle one of the authors invented, which he calls “the constructal law”.  But the article is packed with contradictions and problems [and assumptions stated as fact], which appears to be an advertisement for the authors’ book “Design in Nature”.  [Note: I have not read the book, but this series of posts is intended to serve as both a critique of the author's ideas as they appear in the article, and to give the reader an idea as to whether or not the book is worth buying] 

The article begins:

“This book is about design in nature as a scientific discipline, centered on a physics law of design and evolution: the constructal law.  This law sweeps the entire mosaic of nature from inanimate rivers to animate designs, such as vascular tissues, locomotion, and social organization”

Then Bejan describes his ‘epiphany’ that phenomena like river deltas, the air passages in our lungs, and lightning bolts are governed by a certain scientific principle, and are therefore predictable patterns.  He says:

“In a flash, I realized that the world was not formed by random accidents, chance and fate but that behind the dizzying diversity is a seamless stream of predictable patterns.”

This provided the first clue that something was fishy.  If these things are all governed by a law of physics called the constructal law, then ‘fate’ would be a very good word to use, because this law would determine the outcome of these phenomena, which would be why they are so predictable, if indeed they are.  So how can he discount fate?  Thus it appears that right off the bat the author is perhaps confused, or at least his definitions are not the same as mine.  But then it gets really fishy.  He goes on to say:

“…I have shown how a single law of physics shapes the design of all around us.  This insight would lead me to challenge many articles of faith held by my scientific colleagues, including the bedrock beliefs that biological creatures like you and me are governed by different principles from the inanimate world of winds and rivers, and the engineered world of airplanes, ships and automobiles. Over time, I would develop a new understanding of evolutionary phenomena and the oneness of nature that would reveal how design emerges without an intelligent designer.”

 That last part is a talking point if I ever saw one.  So “design emerges without an intelligent designer”, eh?  Yeah, I’ve heard that one before.  And at this point I became suspicious that ASME is getting into the business of evangelizing for the Darwin lobby, thereby putting me into full BS detection mode.

Let me just say that I am an Intelligent Design proponent.  I believe that life was designed, and that there are therefore ways in which this design can be rigorously detected and even measured, and that the probability of something having been designed or not can be clearly evident.  Therefore, I would say that life, or creatures like you and me, are in fact governed by the very same principle that governs the engineering world, that being the choice contingent arrangement of matter and energy to achieve an end, and that is most certainly a different principle that governs inanimate nature, which would be pure law-like physicality.

In part II, I hope to start to show Bejan's error in claiming that the inanimate world and the designed world are governed by some unifying law of nature.

Douglas Adams's Puddle - A Retort

“Imagine a puddle waking up one morning and thinking, ‘This is an interesting world I find myself in, an interesting hole I find myself in; fits me rather neatly, doesn’t it?  In fact it fits me staggeringly well!  It must have been made to have me in it!’” –Douglas Adams

Obviously the puddle would be wrong.  He fits so neatly into his hole because of physicodynamics alone.  No matter what the hole's shape was, the puddle would take on, and the appearance of the hole having been designed just for him would be an illusion.  This quote is used to try to answer the apparent fine tuning of our universe to accommodate life.

But the analogy is flawed, and is a rather lousy thing to mention when disputing the anthropic principle [or rather, I should say disputing fine tuning arguments]  because life’s processes are not the way they are because of physicodynamics.  Life cannot adjust its intricacies to accomodate the universe, nor can the way life works be adjusted to fit a multitude of universes of varying physical constants - instead, the universe must be exactly the way it is in order for life to exist at all.  To make the analogy correct, imagine if water could only take one particular three dimensional shape and size (with an accuracy down to the atom or better) in order for it to be water at all.  If this were the case, and the puddle woke up to find itself in an independent hole that fit its shape and size staggeringly well, then the puddle’s realization would not be an illusion.

Or, what about this scenario:

Imagine a puddle waking up at the bottom of a well in the Sahara, with the walls lined with hewn stone, and the top of the well had a bucket attached to a rope, which was wound around a shaft, which had a crank attached to it.  Would the puddle’s inference to design be somewhat more accurate in that case?  Yes, it would.