John O. Campbell
Physicist and Philosopher Lee Smolin and Philosopher Roberto
Mangabeira Unger have teamed up to produce their long awaited book The
Singular Universe and the Reality of Time: A proposal in natural Philosophy
Throughout his career Smolin has injected novel ideas and
principals into scientific descriptions of the universe. His 1992 paper (1), Does
the universe evolve?, for the first time, offered a Darwinian process as an
explanation in a fundamental physical theory. This paper was followed in 1998 by
his book, Life of the Cosmos (2), which further
develops and describes his Darwinian theory. He calls it Cosmological Natural
Selection (CNS) and uses it to explain why our universe is a ‘Goldilocks
universe’, just right for the existence of complex structures like galaxies,
stars and chemistry.
Figure 1: Lee Smolin
He uses an analogy to natural selection in explaining that our
universe is one in a long line of universes which evolved over cosmological
time. What appears as the formation of a black hole in a parent universe is
actually a disconnected child universe starting off in its own Big Bang. With the bounce of a black hole into a child
universe the laws and parameters of the parent universe are inherited by the
child with slight variations. Over evolutionary time this Darwinian process has
selected universes with ‘just right’ laws and parameters for fecundity in their
production of black holes. Black hole fecundity relies on the existence of
galaxies, stars and complex chemistry. Therefore our universe has evolved to
its ‘Goldilocks’ state in order to achieve reproductive success in the
production of black holes.
This theory does not provide much centrality for Homo sapiens.
Our existence, and the existence of life, is merely made more plausible. It is not
a full explanation of life, it only explains the existence of a cosmological context
necessary for the evolution of life. Smolin
is content to leave life’s fuller explanation to Darwin’s theory of natural
selection.
It is perhaps of even greater importance that CNS marked a
milestone in the largely unnoticed scientific revolution of universal Darwinism.
Since Darwin’s time his theory had become ever more central to biology as its
molecular details came into focus. Philosophers of science such as Donald
Campbell and Karl Popper had since the 1970s described science itself as a
Darwinian process which accumulates knowledge. In 1976 Richard Dawkins, in his
book The Selfish Gene, speculated that there was a cultural replicator he
coined the ‘meme’ which might be at the basis of all forms of cultural evolution.
Today practically every field of the social science has a school bearing the ‘evolutionary’
prefix in its title: evolutionary psychology, evolutionary linguistics,
evolutionary economics etc. In 1987 the Nobel Laureate Gerald Edelman
introduced the Darwinian process to neuroscience where it rapidly spawned a
large number of variations.
Only the physical sciences remained unexplained by Darwinian Theory
but with CNS this last gap was beginning to be filled. For those of us with our
eye on this particular ball the next obvious question was why; why does nature
repeatedly use this single mechanism to create and evolve so much of reality? Answering
this question could possibly provide a unified view of reality which has so far
eluded science.
Finding the answer would take a fine scientific mind with great
mathematical expertise and a grand vision; it would take someone like Smolin.
Surely, now that he had introduced the Darwinian processes to physics, he would
take an interest in this larger question.
Since first developing CNS Smolin has spent much of his time at
the forefront of the development of Loop Quantum Gravity, a leading contender
in the race to find the theory of Quantum Gravity, the holy grail of modern physics. However one part of Smolin’s creative mind has
continued to think about the evolution of the Cosmos. In a number of follow-up
papers (3; 4; 5; 6) he summarized the
current scientific evidence pro and con his theory and argues for its many
advantages over string theory.
Smolin, like Newton and Einstein before him, gives a lot of
weight to philosophical guidance. He champions a relational view of physics as
pioneered by Gottfried Wilhelm von Leibniz and Charles Sanders Peirce where the
physical properties of entities can only be understood in relation to other
entities. This view is also central to the epic research program conducted by Julian
Barbour on the nature of time (7).
Much of Smolin’s recent writing features philosophical
criticisms of widely held views within the physics community such as the
Newtonian paradigm, string theory and the anthropic principle. He believes that
physics and cosmology have lost their way and hopes to lead it back to the true
path through development of guiding philosophical principles.
Smolin has accepted a faculty position in the philosophy
department at the University of Toronto. Since 2006 he has collaborated with
the Brazilian philosopher Roberto Mangabeira Unger on a project to develop
philosophical principles capable of guiding research in physics and cosmology.
Unger is a polymath who has made important contributions to
the law, philosophy, economics, natural philosophy and political science. His
influence is practical as well as academic; he was a leader of the movement
which brought progressive government to Brazil and was appointed minister of
strategic affairs in 2007 and 2015.
His radical political and philosophical outlook are somewhat reminiscent
of the counter-culture ideals many of us entertained at one time. He views the
present tense of our lives as a creative interface between past and future
where the individual’s potential has the capacity to transcend social roles and
institutions.
This notion of the present as the focus of reality also
permeates his understanding of natural history where again it is the present
which is the forum for the creative unfolding of reality. Philosophically he
understands the universe to evolve through the inventive action of the present
and thus finds greater explanatory value in becoming than in being.
It is perhaps his view of time which Smolin has found most
stimulating. Unger’s view of the universe as an historical process resonates
particularly well with Smolin’s CNS. In any case their relationship seems to
have greatly energised Smolin.
Figure 2: Roberto Mangabeira Unger
Smolin’s February 2012 paper (5) A perspective on the landscape problem examines
the current crisis in physics from a philosophical perspective. He considers
Leibniz’s principle of sufficient reason, that there must be a reason that explains
why each property of nature is what it is, as a bedrock principle for
understanding physics. These reasons are often historical; everything is what
it is because it got that way. Smolin’s theory of cosmological natural
selection is proposed as a scientific theory that respects the principle of
sufficient reason. Smolin also notes that this paper is partially based on his
collaboration with Unger concerning the evolving laws of nature.
This joint project drives much of Smolin’s subsequent
research. He describes his 2013 book Time Reborn as an introduction to
the book he is writing with Unger. He describes his 2013 paper (8) Temporal Naturalism as
outlining a project:
This essay is part of a larger project whose aim is to radically reconfigure the practice of science on a cosmological scale to admit three theses: 1) the reality of time, 2) the evolution of laws with respect to that time and 3) the uniqueness of the single causally closed universe that unfolds in time.
This project was conceived with Unger and its main fruit is their book being reviewed here. For almost three years prior to its publication this project was central to Smolin’s creative output while little was heard from Unger on the subject.
The book is an unusual version of shared authorship as it is actually two books, the first by Unger and the second by Smolin. Each author gives a full account of their individual take on three central ideas: the singularity of the universe, the reality of time and the limited power of mathematics in cosmology. A long concluding chapter lists the many issues on which they disagree and records each of their divergent views on those issues.
The topic of most heartfelt agreement seems to be the reality
of time. They share the belief that all of reality changes with the passage of
time in a manner that is not fully predictable. For those familiar with
Smolin’s body of work there is really very little new here. A natural
philosophy which views the universe from an historical perspective has been
central to Smolin’s research for over twenty years. CNS is only described in
this book as an example of a theory which may fit within their natural
philosophy.
Obviously his relationship with Unger has greatly stimulated
Smolin and lends support to his view of a historical universe. However I cannot
escape concluding that Unger’s philosophy is relatively sterile and serves to
blunt Smolin’s great insight that the universe may evolve through Darwinian
processes. Unger’s philosophy forms a defensive structure around his notion of
the true nature of things; nothing is allowed admittance which does not
conform.
In a section of the book debating their differences Unger goes
so far as to reject CNS on the grounds that time changes everything and that
there can be no process which itself remains unchanged as he imagines is the
case with CNS.
It is clear, at least within the forum of the cosmos, that Unger
is not a great fan of Darwinian explanations. One cannot help but imagine the
outcome if Smolin had collaborated instead with a philosopher having greater
understanding and sympathy for the Darwinian perspective. I can, for example,
imagine Smolin teaming up with Daniel Dennett and the fruitful exploration
which may have ensued.
Dennett understands the explanatory power of Darwinian
processes. Probably his most quoted observation is that Darwin had the best
idea ever (9), ‘ahead of Newton, ahead of Einstein, ahead of
everybody else’. Certainly ahead of Roberto Mangabeira Unger. In his
breakthrough 1995 book Darwin’s Dangerous Idea, Dennett outlines the
notion of ‘design space’, a type of mathematical space containing all possible
designs: physical, biological and cultural. For example we might conceive of
the biological design space as composed of all possible sequences of DNA base
pairs. He understands Darwinian processes to be active mechanisms which search
through this design space and select those designs which are solutions to the
challenges of existence.
Figure 3: Daniel Dennett
This great book was a milestone on the path to Universal
Darwinism, the understanding that all complex entities may be created and
evolve through the action of Darwinian processes. Dennett understood that both
biology and culture could be put under this theoretical umbrella. He even
discussed Smolin’s theory of cosmological natural selection as an example of how
physical reality may also be included within this paradigm. Dennett has a deep
understanding of Darwinian processes and runs with it. Here is someone who
might have provided fruitful philosophical mentoring.
A scientific treatment of a design space might consider it in
terms of a vast probability distribution where a probability is assigned to the
existence of each possibility. The vast majority of designs must have a
probability arbitrarily close to zero; most possible designs are not viable solutions
to the challenges of existence. Darwinian processes work their way through the
space of all possible designs trying out each in turn. Those that can have an
existence do have an existence; knowledge of how existence may be achieved is
selected and accumulates through an evidence based process.
Evidence based probabilistic models operate according to the
mathematics of Bayesian inference which describes how probabilities are
reassigned on the reception of new evidence or information. In this view
Darwinian processes are physical implementations of the mathematics of Bayesian
inference (10; 11; 12).
If Smolin had arrived at this paradigm via the philosophical
stepping stone of Dennett’s insights he would be much better positioned to
answer the many conundrums presented by the natural philosophy he has developed
with Unger.
First, their idea that all things change in a creative and
unpredictable manner within the present moment of time, may solve the conundrum
of the second law of thermodynamics at least when stated in terms of
information entropy. In the universal Darwinism paradigm all of the many
probabilistic models over design space, including physical reality, biology,
culture and even science itself accumulate knowledge through Darwinian
processes. This knowledge is an expectation of how to achieve an existence in
the entity’s particular environment. New stuff popping into existence in the
present moment is unforeseen by these probabilistic models and thus the passage
of time tends to increase the ignorance or entropy of all models.
In this context the second law is obvious: any model becomes
less certain as time goes on because there is more new stuff to know. The
continued existence of complex entities depends upon gaining knowledge of the current
conditions which is the function of Darwinian processes.
In the last part of the book Unger lists his disagreements
with Smolin’s published work and Smolin offers a rebuttal. Unger does not shy
away from criticizing Smolin’s theory of CNS. He sees it as violating his
principle that laws are not constant but change and evolve with their subject
matter over time:
the idea of cosmological natural selection would give a central and permanent role, in the history of the universe, to one mode of change: the one described by Darwin.
In his rebuttal Smolin points out that Darwinian processes are
not laws but rather a form of logic and thus share in the timeless nature of
mathematics. He is reduced to defending his most brilliant theoretical
contribution to his collaborator. If his natural philosophy had evolved instead,
under Dennett’s influence, to that of universal Darwinism he could have made
much more powerful arguments defending CNS.
A litmus test for Smolin and Unger is that a good scientific
theory must explain its laws. This is in contrast and forms a criticism of
theories in the Newtonian paradigm which include just about all existing
physical and cosmological theories. Theories in the Newtonian paradigm take as
given a set of initial conditions and a set of dynamical laws that drive the
evolution of those initial conditions through time. The question ‘why these
laws?’ is not answerable within this paradigm which cannot therefore provide a
complete explanation.
Amongst the most powerful possible explanations of ‘why these
laws?’ is a demonstration that the laws are unique in their ability to explain
the phenomena in question. Dennett describes such steps in reasoning as
‘forced moves’ such as in a chess game when there is only one move that will
stave off defeat. For example, an early hope for string theory, was that a version
would be found that was the only mathematically consistent theory of quantum
gravity. Unfortunately this did not turn out to be the case with string theory
as it has been shown that there are about 10500 consistent versions (5).
However it was proved by Richard Cox in 1946 that Bayesian
inference is the uniquely consistent mathematics of probability (13). Any other theory of
reasoning from uncertain knowledge must either be inconsistent or wrong. It has
further been demonstrated that a reasonable definition of knowledge is contained
within Bayesian inference (12). If we view
Darwinian processes as physical implementations of Bayesian inference then it
is clear that they are the unique method for accumulating this type of
knowledge. If we take one further step along the path of universal Darwinism
and accept that knowledge is required for the existence of complex entities and
is in fact their essence then we are led to conclude that Darwinian processes
are the unique method by which complex entities evolve. The last step in this
argument is that all entities we know of, even down to quarks and gluons, are
vast compared to the fundamental Planck scale and are therefore should also be considered complex
entities.
Without the accumulation of knowledge to constrain local
entropy production any complex entity will gain entropy and eventually lose its
complexity and its integrity as an entity. Thus the question ‘why this law of
Darwinian processes?’ can be answered: there is no other possible process by
which complex entities can maintain their existence. Accepting this law is a
forced move.
Unger’s view of the historical universe includes the
observation that ‘laws evolve with the
systems they describe’. This minority view has a long history reaching back
to Leibniz and Peirce. It is easily demonstrated by considering that the
historical universe consisted, at an early stage, of only a quark/gluon plasma.
At this stage there was no atomic physics, biology, cosmology or culture. All
of these subject matters as well as the laws describing them came into being as
the universe evolved. Smolin shares this
view with Unger’s but adds the insight that Darwinian processes are ‘the general logic making such evolution
possible’.
Universal Darwinism might have provided him with a deeper explanation
of the evolution of laws. In Dennett’s view Darwinian systems constantly probe
design space searching for the good solutions. When good solutions are found
they tend to spread and become essential to a wide range of phenomena. These
commonly shared design details may be understood as laws (11). In this view scientific laws are merely
the design details used in a wide range of solutions. Thus laws evolve with
design.
For example with the evolution of sexual reproduction came the
mechanism of dominant and recessive genes and the design details that form the
law of Mendelian Inheritance. This law is not a timeless principle, it is a
good solution discovered by natural selection and came to be used by a large
class of organisms. The process is highly contingent and if life is found
throughout the cosmos we may expect there will be many instances where this law
does not apply. In these cases the Darwinian process which govern the life
forms’ evolution may have found other, perhaps better, solutions to the
challenges of existence.
Unger appears riled by Smolin’s seemingly innocuous
observation that science is our most reliable guide to nature (8):
naturalists also hold that science is the most reliable route to knowledge about nature.
This quote is taken from the paper Temporal Naturalism which
Smolin describes as part of his joint project with Unger although Smolin is the
sole author of the paper. It may have slipped his mind that Unger is not a
scientist and has an ego unlikely to let this kind of imagined slight go by. Unger
does not let it go by but writes:
The claim that science is either the sole or even the most reliable source of insight into nature should exercise no influence on the temporal naturalism that we here espouse. There is no hierarchy of forms of inquiry that could entitle one to say that one such form trumps the others.
and
To assert, on behalf of science, a privilege over other sources of insight and experience does science no favor.
Is he having us on here? When he gets sick does he go to
someone who has studied medical science for many years or does he go to someone
who hasn’t?
These comments smack of post-modernist intellectual relativism
where anyone’s views concerning nature are equally as correct as anyone else’s.
Yet he presumes to be developing ‘methods
and principles adequate to a science of cosmology that is not simply a
scaled-up version of contemporary physics’. Why not develop methods and
principles for a new astrology, after all cosmological science holds no privilege over astrology? Geez Lee, how could you have teamed up with
this?
The superior knowledge of science is proven by its power. For
instance scientific knowledge has been used to create the only known instance
of atomic fusion outside of a star. From the beginning humans have dreamt of
such power to deliver themselves from their enemies. For better or worse, after
a history filled with sacrificial rituals, prayer and philosophizing, of all the schemes we humans have devised to bend nature to our will, only
science has accumulated the knowledge to deliver on this and so many other dreams.
In my opinion Smolin makes only a lame rebuttal, to the effect that
scientists tend to form dedicated communities of truth seekers. Universal
Darwinism would provide him with a crushing counter.
Models can only accumulate knowledge if they follow the mathematical
principles of Bayesian inference. This is an evidence based process where the
model assigns probabilities to a family of competing hypothesis and these
probabilities are updated to reflect the implications of any new evidence. In
this manner the model gains knowledge and moves closer to certainty. All of
human knowledge is based, at least loosely, on this process; we learn from
experience. However some processes follow the mathematics more closely than
others and are therefore more efficient. Science is clearly at the top of this
hierarchy as Bayesian principles are the heart of the scientific method. Indeed
E.T. Jaynes’ great textbook (14) on Bayesian
inference is titled: Probability Theory: the logic of science.
As a demonstration of this claim I would point to moon rockets,
cell phones and even steam engines as examples of the wondrous entities which
may be produced from the knowledge which science has accumulated about nature. Please
show me comparable entities which may be produced from the accumulated
knowledge of, let’s say, astrology or even philosophy. I believe this proves that science has a privileged
understanding of nature in that its knowledge of natural processes may be used
to construct novel natural entities having great complexity and power.
Unger also rejects the principle of sufficient reason which
Smolin endorses so fervently. His argument seems to be that the universe must
be free to do its own thing and cannot be hemmed in by reasons. In his view the
principle of sufficient reason is rejected because:
It expresses a refusal to accept the factitiousness of the universe: that it just happens to be one way rather than another.
Sorry, but I cannot leave this quote without noting Unger’s fondness
for impressive sounding words which hardly anyone has in their vocabulary. Actually,
it seems, they are not in his vocabulary either but like Humpty Dumpty he assumes
they can mean whatever he wants them to mean. Surely he does not mean
factitiousness, a noun specifying a thing made from a human or artificial design
rather than from a natural design. A Kindle search of his section of the book returns
twenty-four instances of this word and along with many of those repetitions he
insists, contrary to any dictionary I can find, that it means ‘a thing that is
what it is’. Perhaps he conceives of himself as above the realm of dictionaries
and like Shakespeare is free to give old words new meanings. ‘A thing that is
what it is’; perhaps he meant ‘uncaused’ or ‘unexplainable’? Nope. He doesn’t
like uncaused because everything is caused and he doesn’t like unexplainable
because that paves the road to explanatory nihilism. Better to use factitiousness
and then claim that it means ‘a thing that is what it is’. I dunno, there may be something very deep going on here which I do not have the wit to understand.
Smolin makes an important observation concerning the
equivalence of computation and physical processes:
There have been a number of suggestions that physical processes are computations.
He uses this observation to speculate that the universality of
computation may resemble the universality of physical theory. Given the
perspective of universal Darwinism he might understand the universality of computation
as providing an explanation for his notion of creativity within the present moment
of time.
Both MIT’s Seth Lloyd and the Nobel laureate Gerard ‘t Hooft have
suggested that quantum interactions are quantum computations; what is computed
is the outcome of the interaction (15; 16). In this view what
takes place in the present is a vast array of quantum computations,
computations whose outcome is the future.
As ‘t Hooft explains, the outcomes of these deterministic computations
are creatively unpredictable:
'Deterministic' cannot imply that the
outcome of the evolution process can be foreseen. No human, nor even any other
imaginable intelligent being, will be able to compute faster than Nature itself.
The reason for this is obvious: our intelligent being would also have to employ
Nature's laws, and we have no reason to expect that Nature can duplicate its
own actions more efficiently than itself.
We might wonder at the nature of quantum computation. In what
sense are quantum interactions equivalent to quantum computations? It has been
shown that quantum computation is homologous with quantum interactions as
described within Wojciech Zurek’s theory of quantum Darwinism (17). Quantum Darwinism describe quantum
interaction as the transfer of quantum information where only a very small
subset of the information describing one entity can survive the transfer to
another entity (18). The information
that does survive is selected by a Darwinian process which Zurek has named
quantum Darwinism. Thus the present moment is composed of a plethora of quantum
interactions where the future is being instantiated through the probing,
searching and testing of a Darwinian process.
Smolin’s greatest legacy to science may be his introduction of
the Darwinian process as an explanatory mechanism within fundamental physics. At
one point in his career he gave thought to intriguing questions such as: what
do physics and biology have in common? His answers were very good, for instance (6):
There is only one mode of explanation I know of, developed by science, to explain why a system has parameters that lead to much more complexity than typical values of those parameters. This is natural selection.
This statement is tantalizingly close to a claim that
Darwinian processes serve as an explanation for all complex systems. Disappointingly,
at the current stage in his career, rather than evolving his brilliant insights
this book stunts them by teaming up with a less fertile and at times antagonistic
philosophy.
Note: One really great thing about Physics is the website www.arxiv.org. It is an electronic archive of
physics papers hosted by Cornell University. Wikipedia reports that (19) ‘In many fields of mathematics and physics,
almost all scientific papers are self-archived on the arXiv’. I have
certainly found this to be true and marvel, for example, that most of Lee
Smolin’s papers may be found here and read for free. His are surprisingly
clearly written and I believe that any interested person will find them quite
accessible.
Bibliography
1. Did the
universe evolve? Smolin, Lee. s.l. :
http://www.universaldarwinism.com/documents/smolin-did-the-universe-evolve.pdf,
1992, Classical and quantum gravity, pp. 173-191.
2. Smolin, Lee. The life of the cosmos. s.l. :
Oxford University Press, 1998.
3. —. The status of cosmological natural selection. [book
auth.] R. Vaas. Beyond the Big Bang: Competing Scenarios for an Eternal
Universe. http://arxiv.org/abs/hep-th/0612185 : Springer, 2013.
4. —. Scientific Alternatives to the Anthropic Principle.
[book auth.] Bernard Carr. Universe or Multiverse. s.l. :
http://arxiv.org/abs/hep-th/0407213, 2007.
5. A perspective on the landscape problem. Smolin,
Lee. s.l. : http://arxiv.org/abs/1202.3373, 2012, Preprint:
Foundations of Physics.
6. The case for background independece. Smolin,
Lee. s.l. : http://arxiv.org/abs/hep-th/0507235, 2005,
arXiv:hep-th/0507235v1.
7. The Solution to the Problem of Time in Shape
Dynamics. Barbour, Julian, Koslowski, Tim and Merc, Flavio .
s.l. : http://arxiv.org/abs/1310.5167, 2013, arXiv preprint.
8. Temporal Naturalism. Smolin, Lee.
s.l. : http://arxiv.org/abs/1310.8539, 2013, Preprint.
9. Dennett, Daniel C. Darwin's Dangerous Idea. New
York : Touchstone Publishing, 1995.
10. Bayesian Methods and Universal Darwinism. Campbell,
John O. s.l. : http://arxiv.org/abs/1001.0068, 2009. AIP Conf. Proc.
1193, 40 (2009), DOI:10.1063/1.3275642. pp. 40-47.
11. Campbell, John O. Universal Darwinism: The
path of knowledge. s.l. : CreateSpace, 2011.
12. —. Darwin does physics. s.l. : CreateSpace,
2015.
13. Probability, Frequency, and Reasonable Expectation. Cox,
R.T. s.l. :
http://jimbeck.caltech.edu/summerlectures/references/ProbabilityFrequencyReasonableExpectation.pdf,
1946, Am. Jour. Phys. 14,.
14. Jaynes, Edwin T. Probability Theory: The Logic
of Science. s.l. : University of Cambridge Press, 2003.
15. Lloyd, Seth. Programming the Universe. s.l. :
Vintage; Reprint edition, 2007.
16. The Cellular Automaton Interpretation of Quantum
Mechanics. 't Hooft, Garard. s.l. : Arxiv preprint, 2014,
Vol. http://arxiv.org/abs/1405.1548.
17. Characterizing the Structure of Preserved
Information in Quantum Processes. Blume-Kohout, Robin, et al.
s.l. : http://arxiv.org/abs/1006.1358, 2008, Physical Review Letters,
100 (3). Art. No. 030501. ISSN 0031-9007.
18. Quantum Darwinism. Zurek, Wojciech H.
s.l. : http://www.nature.com/nphys/journal/v5/n3/abs/nphys1202.html,
2009, Nature Physics, vol. 5, pp. 181-188.
19. Wikipedia. arXiv. Wikipedia. [Online]
[Cited: 2 28, 2015.] http://en.wikipedia.org/wiki/ArXiv.
