Thursday, 22 March 2012

Welcome!







Welcome to a blog on universal Darwinism. Universal Darwinism is an exciting new field which contains the numerous scientific theories, spanning much of scientific subject matter, which use a Darwinian process to explain the creation and evolution of their subjects. It also attempts to elucidate the principles which unite these theories.

I have hosted the Universal Darwinism website for many years where the work of a number of prominent researchers is featured and have also written scientific articles and a book on the subject.

The decision to start a blog was driven by my interest in writing a second book. I thought I might provide a series of previews as the book is written and hopefully receive some feed back before it is published and cast in stone.

Tentative titles for this book include 'The Darwinian Universe' and 'Darwin Does Physics'

Enough preamble; here is a first installment!


Introduction

In the first few years of the twentieth century physicists were feeling cocky. The Newtonian paradigm had proceeded from triumph to triumph over more than two hundred years. In 1814 Pierre-Simon Laplace, perhaps history’s greatest researcher in celestial mechanics, had made the bold claim that if given the position and momentum of every particle in the universe he could calculate the state of the universe at any future time. By the turn of the nineteenth century many physicist had convinced themselves that physics had explained everything that could be explained. Exposing themselves to historical ridicule some prominent physicists, including William Thompson, later elevated to Lord Kelvin and Albert Michelson both went public with claims there was little of interest left for physics to explain. In 1894 Michelson wrote ‘in physics there were no more fundamental discoveries to be made.’  Referring to Lord Kelvin, he continued, ‘An eminent physicist remarked that the future truths of physical science are to be looked for in the sixth place of decimals’ 

 
Figure 1
Lord Kelvin believed there remained nothing more for physics to understand.

Whilst many physicists were self satisfied with their all encompassing state of knowledge they could still heap scorn on other branches of science they considered not up to their standards. Ernest Rutherford, the Nobel winning physicists dubbed the ‘father’ of nuclear physics, summed up the somewhat arrogant but quite prevalent belief of many physicists at the turn of the century when he stated (1902):
All science is either physics or stamp collecting
He had a point. At that time physics had a deep mathematical structure and provided a level of predictive accuracy that was simply unrivaled by any other branch of science. However as it turned out this privileged position for physics was already slipping away. Biology was challenging for entrance to the top tier of science.

 
Figure 2
Ernest Rutherford described branches of science other than physics,  as mere 'stamp collecting'.

Rutherford’s slur on other branches of science was perhaps targeted especially at biology. Specimen collection was an essential aspect of biology at the time and it may even have been further targeted specifically at Charles Darwin. Darwin was a inveterate collector of beetles as a young man and from the Beagle voyage alone he shipped back to Britain an astonishing 5,436 preserved specimens.

Charles Darwin had published his On the Origins of Species in 1859 and its corrosive effect on both the scientific and religious establishments were already well under way. Darwin had developed a biological theory that united the innumerable species making up the collection of life on this planet. He showed how all of life was related through their common ancestors. However this landmark accomplishment went unheeded by the physics establishment. In fact when they did take notice it was mostly with disparagement and challenges to Darwin’s theory.

Conservative gentlemen physicists such as Rutherford and Thompson were unlikely to be sympathetic to Darwin with his revolutionary and somewhat anti-religious theory. In his survey of Rutherford’s life Nigel Costley reports that:
…you could tell when work was going well in Rutherford’s laboratory: he strode about singing a spirited rendition of "Onward Christian Soldiers." His character, full of hearty good humour interspersed with imperious commands, was more that of a boisterous colonial farmer than the world’s leading scholar.  

It is easy to imagine that a compulsive singer of ‘onward Christian soldiers’ might have had some motivation to sneer at an upstart biologist who claimed a closer human relationship to apes than to God.

Indeed a most serious scientific challenge to Darwinism was leveled by Lord Kelvin. Kelvin had calculated that the age of the sun could be no more than 20 million years. There was no known mechanism by which a fuel source having a volume as small as the sun’s could burn so hot for so long. He further calculated that the earth could be no more than 20 million years old as otherwise it would have cooled below its current surface temperature. Of course if true these objections would rule out Darwin’s theory as it required that the earth had been receiving light, heat and energy from the sun for at least hundreds of millions of years.

Darwin recognized this challenge from Kelvin as a grave one and addressed it carefully and with humility:
With respect to the lapse of time not having been sufficient since our planet was consolidated for the assumed amount of organic change, and this objection, as urged by Sir William Thompson, is probably one of the gravest as yet advanced, I can only say, firstly, that we do not know at what rate species change, as measured by years, and secondly, that many philosophers are not as yet willing to admit that we know enough of the constitution of the universe and of the interior of our globe to speculate with safety on its past duration.

As it turned out Darwin hit the nail on the head, physics did not know enough of the constitution of the universe and of the interior of our globe to speculate with safety on its past duration. Kelvin was wrong, the nature of the nuclear reactions powering the sun and warming earth’s interior were unknown to physics at that time and Darwin was able to successfully identify the flaw in the physical argument that Kelvin had missed. This may have been the first instance where Darwinism showed physicist the way in solving a physical problem, but it would not be the last!
The paths ahead for physics and biology turned out to be ones of divergent fortunes. The beginning of the twentieth century was the panicle of physical understanding within the theoretical structure of the Newtonian universe. This theory had served remarkably well for over two centuries. Many leading physicists thought it the last word in science. Kelvin for example reportedly claimed in 1900:

There is nothing new to be discovered in physics now. All that remains is more and more precise measurement.

The untroubled future which physicist foresaw for physics as well their condescending attitude towards biology could hardly have been more wrong or ironic. Already in 1865 James Clerk Maxwell published A Dynamical Theory of the Electromagnetic Field which gave a full theoretical description of electricity and magnetism. Unlike Newton’s theory of gravity Maxwell’s theory of the electromagnetic force was a field theory meaning that is posited a force field emanating from any magnetic or electric charges and permeating the space around them. This field interacted locally with other electric and magnetic charges and caused them to experience a force described by the theory.

Also buried in its equations was a constant c which signified the speed at which the electromagnetic field travelled. Contrary to the Newtonian paradigm it seemed to be a constant for all observers. When light itself was understood to be an electromagnetic field the implications were that the theory predicted that the speed of light would be a constant for all observers. Although most physicists were able to ignore these incompatibilities with Newtonian theory these issues were not missed by Albert Einstein, a patent clerk in Bern Switzerland and a physicist enjoying a status about as far removed from the physic’s establishment as is possible to imagine.

Figure 3
Albert Einstein created or helped to create two theories that revolutionized physics but that also pointed to problems at the foundations of physics.

Although complacency and smugness ruled in the physics establishment it was about to be shaken by two fundamental revolutions in understanding. On the other hand the framework which Darwin bequeathed biology has to this day not yet undergone fundamental revolutionary change but continues to be the essential organizing principle of biology (Dobzhansky 1973). The continuing huge advances in biology since Darwin have merely served to fill in the details and strengthen the theory (Coyne 2009):

Every day, hundreds of observations and experiments pour into the hopper of the scientific literature... and every fact that has something to do with evolution confirms its truth. Every fossil that we find, every DNA molecule that we sequence, every organ system that we dissect supports the idea that species evolved from common ancestors. Despite innumerable possible explanations that could prove evolution untrue, we don't have a single one. We don't find mammals in Precambrian rocks, humans in the same layers as dinosaurs, or any other fossils out of evolutionary order. DNA sequencing supports the evolutionary relationships of species originally deduced from the fossil record. And, as natural selection predicts, we find no species with adaptations that benefit only a different species. We do find dead genes and vestigial organs, incomprehensible under the idea of special creation. Despite a million chances to be wrong, evolution always comes up right. That is as close as we can get to a scientific fact.

Thing turned out quite different for physics. Einstein’s ‘miracle’ year came in 1905 and ushered in the revolutions of relativity and quantum theory that would shortly overwhelm the complacency of scientists such as Kelvin and Rutherford. Relativity and quantum theory replaced the long secure Newtonian framework. It is not that the Newtonian universe was shown to be wrong; it worked just as well as it always had. It was that the Newtonian paradigm was shown to be only part of broader theories which included the Newtonian theory as a special case. Further the new explanations pointed to a very different kind of universe than that portrayed by Newtonian theory.

Newton’s theory of universal gravitation was replaced with Einstein’s theory of general relativity. General relativity is a field theory meaning that the force of gravity is transmitted through a force field which contorts the geometry of space and thus determines the paths which matter will take through space which is always along a geodesic of the contorted space. Thus gravity was seen as more akin to the force of electro-magnetism as described by Maxwell than it was to Newton’s theory which portrayed gravity as a force acting instantaneously between pieces of matter.

Quantum theory was even more alien to Newtonian understanding. Mechanism was replaced by mathematical formalism. Whereas Newtonian dynamics is easily pictured as particles acting under the influence of forces there is no comprehensible picture available for quantum theory. Instead we have mathematical objects including infinite dimensional spaces and vectors within these spaces evolving by arcane mathematical laws. Quantum theory only coincides with the world as we experience it when a measurement is taken. But even here there is no comprehensible explanation of the measuring process. Instead an arbitrary mathematical operator is applied to the vector in high dimensional space and an answer is calculated. The only great beauty to quantum theory is that its answers form an exquisitely accurate prediction of what the measurement will actually be.

Some physicists including Einstein, who won his Nobel Prize for work in explaining the quantum nature of light, became disenchanted with both of these revolutions. Einstein objected to the growing consensus amongst quantum theorists that all we could know about quantum theory was the result of measurements. He believed that science is explanation and that the explanation offered by quantum theory was obviously incomplete. It is a travesty that Einstein, perhaps the greatest physicists who ever lived, came to be regarded in his own life time by his colleagues as something close to a crank due to his strenuous objections regarding the consensus interpretation of quantum theory.

Towards the end of his career, his concerns rejected and ridiculed by the establishment, he largely retreated from the community of physicists to pursue another problem he perceived with physics. He became convinced that the way forward in finding a proper interpretation of quantum theory would lie in uniting the two field theories of forces then known: general relativity and electro-magnetism.

Einstein died in 1955 without finding this unified field theory and without developing an appealing interpretation of quantum theory but interest in these central problems within physic and their associated research programs did not die with him. Shortly after his death and with the discovery of two more quantum field forces of nature his quest to discover a unified field theory explaining all forces morphed into the quest to discover a theory of quantum gravity. For the last fifty years this research program has been the largest theoretical effort ever undertaken by the community of physicists. The bulk of this effort has been focused on developing string theory. Despite a great deal of early promise it now appears that sting theory is unsuitable as a useful theory of quantum gravity; it has no predictive ability.

Meanwhile the problem of quantum interpretation has not gone untended. Although perhaps most physicists choose to ignore the controversy and are said to belong to the ‘shut up and calculate’ school of interpretation a substantial number have kept the search for a real explanation alive. Wojciech Zurek, of the Los Alamos National Laboratory, has recently developed the theory of quantum Darwinism which claims to have solved the quantum interpretation problem. It does this by showing quantum processes to be much in accord with those same Darwinian processes which guide the evolution of biological species.

 

Figure 4
Wojciech Zurek has solved the quantum measurement problem.

From the ashes of the project to develop a theory of quantum gravity from string theory a Phoenix may have arisen. A leading cosmologist, Lee Smolin of the Perimeter Institute, has argued that any theory that can serve as a solution to the quantum gravity problem must be a Darwinian theory and he has developed such a theory, cosmological natural selection, as a starting point.

 
Figure 5
Lee Smolin’s theory, cosmological natural selection, explains the fine tuning of the universe’s fundamental parameters.

Undoubtedly the idea that physics would look to biology for answers to its deepest problems is repugnant to many physicists. However physics is only the latest branch of science to have succumbed to the power of the Darwinian explanation. In fact the discovery that much of scientific subject matter can be understood in terms of Darwinian processes is a unifying revolution that has as yet gone little noticed.

Darwin himself in his On the Origin of Species speculated that human languages might evolve in a manner similar to natural selection. If one abstracts the algorithm used by natural selection one uncovers a process of copy with variation and selective retention that if followed by any type of process leads to evolution. This Darwinian algorithm for evolution has come to be known as the Darwinian process.
In the mid twentieth century some prominent philosophers of science including Donald Campbell and Karl Popper wrote that the practice of science could best be described as a Darwinian process (Campbell 1965, Campbell 1974, Popper 1972). Their writings founded the branch of philosophy called evolutionary epistemology. 

In 1972 Richard Dawkins’ ground breaking book The Selfish Gene described the Darwinian process in detail and suggested that human cultures might evolve via a Darwinian processes he coined ‘memetics’. Subsequently Susan Blackmore’s book The Meme Machine expanded Dawkins’ idea (1999).

 
Figure 6
Richard Dawkins unleashed the Darwinian paradigm on scientific subject matter outside of biology.

Today practically every branch of the social sciences includes a field of study with ‘evolutionary’ in its title: evolutionary psychology, evolutionary economics, evolutionary archeology and evolutionary anthropology to name a few.
With new theories involving Darwinian processes being developed to solve some of physics thorniest problems the casting of all scientific subject matter within the Darwinian paradigm is almost complete. We might list the main branches of science as:

·       Physics
·        Chemistry
·        Biology
·        Social Sciences

If we grant that chemistry is in essence a quantum based science in that chemical bonds are examples of quantum processes and that therefore the theory of quantum Darwinism is applicable to chemistry we must admit that theories utilizing Darwinian process to explain the creation and evolution of their subject matter span much of science.
Further if we accept Lee Smolin’s line of reasoning it is a logical necessity that advanced theories explaining many of universes most basic features can only take the form of the Darwinian paradigm (2012).

His argument recaps the view held by many of history’s most eminent physicists and philosophers of science including, Leibnitz, Pierce, Dirac and Wheeler that the laws and subject matter of science can only be understood within an historical context and that in many cases they can be seen to evolve.
Although this notion flies in the face of the dominant view within physics which holds scientific law to be eternal and unchanging it is almost obviously true in many cases. If we follow the history of the universe backwards in time it clearly becomes less complex. Shortly after the Big Bang the most complex matter was in the form of fundamental particles. The complexity of atoms, chemistry and life all evolved in the future. This additional subject matter and the laws which came to govern it have clearly evolved over time (J. Campbell 2009).

Smolin grapples with a key problem of historical explanations; we might suppose that each historical step to be explained was preceded by another that must also be explained. Wouldn’t a complete explanation involve an infinite regress?

Smolin also notes that many natural systems are extremely fine tuned to a state which allows their existence. All life forms are examples of such fine tuning. However this observation is true of other natural systems such as the cosmos as a whole. The best current cosmological theories contain thirty five basic parameters whose values appear finely tuned to produce the complex universe we observe. Any small difference in the value of many of these parameters would lead to a universe where very little complexity is possible (Smolin 2007).

Smolin suggests when such convergence to a design occurs it must be due to the existence of an ‘attractor’ (2012).

However, to explain the choice of laws there must be an attractor in the landscape. Otherwise the progression of laws through the epochs will just be random, and nothing about the present choice of laws will be explicable.

He identifies such attractors with the selection mechanism of Darwinian processes and has named his theory for the evolution of the cosmos cosmological natural selection.
Not all subject matters that are best explained within an historical context involve Darwinian processes. Geology was perhaps the first science to develop an explanation involving deep history but it does not involve a Darwinian process.
When Darwin embarked on the Beagle for his famous voyage of exploration he was fascinated with the study of Geology. Darwin may have first encountered academic geology during his studies at the University of Edinburgh in the lectures of Robert Jameson, a champion of the ‘Neptunist theory’ of geology. The Neptunist theory explained rocks having had a one-time creation as the crystallization of minerals in ancient seas. Darwin found these lectures extremely dull and concluded (Darwin 1958)

The sole effect they produced on me was the determination never as long as I lived to read a book on Geology or in any way to study the science. Yet I feel sure that I was prepared for a philosophical treatment of the subject”

Fortunately, disgusted with the study of medicine, Darwin left the University of Edinburgh and took up theological studies at Cambridge. Here he fell in with some of the great thinkers of his time and his interest in geology was rekindled.

Darwin spent much of the year before his Beagle voyage on a geological tour of Wales in the company of the great geologist Adam Sedgwick and learned to make geological field observations. The Beagle’s captain, Robert FitzRoy, presented Darwin with Charles Lyell’s Principles of Geology, as a welcoming gift. Darwin devoured this volume on the first leg of the voyage and had Lyell’s further two volumes sent to him when he reached South America.

Lyell’s great work popularized the theory of uniformatarianism, the idea that geological processes, similar to those operating today, had operated throughout the vast stretch of ‘geological time’ and slowly formed the earth to the state we see it in today.

This view that small incremental changes over long periods of time could produce dramatic results electrified Darwin. While still on the first leg of his voyage he wrote (Darwin 1985):

literally could hardly sleep at nights for thinking over my [geology].

En-route to South America the Beagle stopped in at the St. Iago in the Verdes Islands where Darwin immediately put Lyell’s principles to work (Darwin 1958, 101):

I am proud to remember, that the first place, namely St. Iago, [where] I geologized, convinced me of the infinite superiority of Lyell’s views over those advocated in any other work known to me

Using Lyell’s methods he was able to correctly reconstruct the island’s geological history and his findings were published some time after his return to Britain in 1844.
Volume 2 of Lyell’s great work awaited Darwin when he reached South America. In this volume Lyell gave a full accounting of the consensus view of biological evolution at the time: the Lamarckian theory of evolution. Although Lyell thoroughly discussed this theory he rejected it and offered some ideas of his own in its place. Doubtless Lyell’s treatment of the subject prodded Darwin to consider the general problem of biological evolution.



Since that time geology has gained a second great unifying theory; the theory of plate tectonics. Together with an updated version of uniformatarianism and borrowing from cosmology current geological theory provides our best explanation of the earth’s geological features; it is able to explain most of the mechanisms by which the earth was created and has evolved to its present state.

However geological theory does not invoke a Darwinian process. Using Smolin’s terms it does not involve an ‘attractor’ which selects specific designs. Darwinian processes selectively pass information forward in time. Geological processes on the other hand do not accumulate geological knowledge. The earth’s geology is well explained as the playing out of cosmological, physical, chemical and biological forces.

Darwin knew that biological characteristics of the parents are inherited by their offspring but he did not know the information processing mechanism that accomplished this transfer. In the hundred years following Darwin the details have been discovered. We now know that organism’s have a genome, information coded in DNA that mirrors the physical organism called the phenotype. Each organism, as an offspring, is constructed using inherited information in the form of the genome and it is this genome which is responsible for introducing new characteristics into the specie’s population when rare copying errors are made.
If the altered genome codes for biological characteristics which add to the organism’s reproductive success they may become spread throughout the population. 

Biological information, in the form of the genome, is central to biological understanding. The genome is a store of information that has accumulated over the evolutionary history of the organism’s ancestors back to the very first life form. Each generation is constructed from this information in a process that effectively recapitulates the specie’s evolutionary history. Biological organisms are the products of knowledge, knowledge of the construction and strategies which form the organism and that has slowly accumulated over a vast history. 

Geology does not appear to be a feature of reality that involves the accumulation of knowledge. Geological theories are different in that they do not specify Darwinian information processing mechanisms.

One might have expected that theories within physics would not utilize Darwinian processes either but would more closely resemble geology than biology in this respect. However in much of physics information appears to be central. In cosmology the laws and parameters by which our universe was constructed look as if they are a form of well honed knowledge; knowledge for the construction and operation of the particular universe we see around us. Smolin theory of cosmological natural selection argues that this knowledge has accumulated and that the laws and parameters of cosmology have evolved to their present state through the operation of a Darwinian process. 

Cosmology studies the universe on a grand scale but information is also central to quantum physics; our best understanding of the most micro aspects of reality. The quantum world contains a vast range of possibilities. Seemingly mutually exclusive states may occur at the same time; things can be both here and there or both alive and dead at the same time.

Most of these quantum possibilities are filtered out in our ‘classical’ world. The world we know and are a part of is effectively selected from the quantum possibilities. Wojciech Zurek’s theory of quantum Darwinism explains this selection processes as a Darwinian process and thus places the evolution of quantum systems such as atoms and chemistry within a Darwinian context. 

I will argue that for many aspects of reality beyond biology knowledge is essential for existence and that this knowledge has been built up over a long evolutionary history. Further I will argue that the only processes known to science capable of accumulating such knowledge is the Darwinian processes. These arguments are not original or even novel but the amazing scope of scientific theories which explain the creation and evolution of their subject matter as due to Darwinian processes seems to have gone largely unnoticed.
Given the inclusion of physical theories within the rapidly growing number of scientific theories employing the Darwinian paradigm we might ask: why do Darwinian processes seem to be the exclusive mechanism used by nature to build knowledge, the knowledge necessary for existence?

Lee Smolin has offered an explanation for this that is compelling. I will develop an alternative explanation. Mathematically there is only a single mechanism for developing knowledge and that is the process of inference. A Bayesian inference starts with the assignment of probabilities to a mutually exclusive family of hypothesises as to the outcome of some event. Each time the event occurs and a specific outcome becomes known these probabilities are updated according to Bayes’ rule in a manner which increases their future predictive accuracy. I define knowledge as this predictive accuracy and argue that Darwinian processes are the only known physical implementation of Bayesian inference.

A most important lesson we learn from Darwinian thinking is that things have to be designed for the purpose of existence; such designs contain knowledge and are rare, they do not happen by accident. Science often explains such purposeful design as the product of Darwinian processes.
Purposeful design found in nature has long been the central argument for the existence of God. Many have thought that a creation implies a creator that is vastly more sophisticated than its creation. Scientific understanding does not deny that the universe was created but it argues that much of this creation may be explained not by the operation of a God but by the operation of relatively simple Darwinian processes. Both common sense and the philosophy of science agree that given two equally powerful explanations the simpler is always to be preferred.


Figure 7
Daniel Dennett has  written extensively on 'Darwin's Dangerous Idea'.

Darwinism provides a mechanism for the realization of purpose.  We are reminded of Daniel Dennett’s insightful observation concerning the fundamental importance of Darwinian thinking:

if I could give  a prize to the single best idea anybody ever had, I’d give it to Darwin—ahead of Newton, ahead of Einstein, ahead of everybody else.  Why?  Because Darwin’s idea put together the two biggest worlds, the world of mechanism and material, and physical causes on the one hand (the lifeless world of matter) and the world of meaning, and purpose, and goals.  And those had seemed really just—an unbridgeable gap between them and he showed “no,” he showed how meaning and purposes could arise out of physical law, out of the workings of ultimately inanimate nature. And that’s just a stunning unification and opens up a tremendous vista for all inquiries, not just for biology, but for the relationship between the second law of thermodynamics and the existence of poetry.

This unifying view brings scientific credence to the inspiring view of humanity offered in the Desiderata (2012):

You are a child of the universe, no less than the trees and the stars; you have a right to be here.

We have the best scientific reasonss for believing that the trees and the stars are indeed our relatives and we like them naturally occupy a seamless place in the fabric of reality. Man is not an island; as we understand more about our cosmic relations we understand more about ourselves.



No comments:

Post a Comment