John O. Campbell
This is an excerpt from the book: Einstein's Enlightenment.
John A. Wheeler, one the greatest American physicists of the twentieth century, reminisced that his career had unfolded through three fundamental paradigms
I
think of my lifetime in physics as divided into three periods. In the first
period, extending from the beginning of my career until the early 1950's, I was
in the grip of the idea that Everything Is Particles. I was looking for ways to
build all basic entities - neutrons, protons, mesons, and so on - out of the
lightest, most fundamental particles, electrons, and photons. …
I
call my second period Everything Is Fields. From the time I fell in love with
general relativity and gravitation in 1952 until late in my career, I pursued
the vision of a world made of fields, one in which the apparent particles are
really manifestations of electric and magnetic fields, gravitational fields,
and space-time itself.
Now
I am in the grip of a new vision, that Everything Is Information. The more I
have pondered the mystery of the quantum and our strange ability to comprehend
this world in which we live, the more I see possible fundamental roles for
logic and information as the bedrock of physical theory.
His experience may have been usual among physicist at the
time but now our biggest quibble might be with his repeated use of the word ‘Everything’.
Although it is almost universally conceded today that information has a
profound role in the workings of the world, few would insist on a uniquely
primary role. After-all the Large Hadron Collider (LHC), the premier
experimental apparatus of an era, is understood largely in terms of particles and
fields. These concepts have not been displaced from physics.
We might understand the ‘Everything’ as due to an excitement
with novelty and the focus it commands. However, the real challenge of the information
revolution is to develop a more prosaic understanding of the relationships among
information and the other important physical entities.
Unfortunately, Einstein missed out on the last of these
paradigms. The information revolution came upon us only since his death. He did however play a fundamental role in developing the first two paradigms. Atomic
theory was accepted by many physicists, due to a paper Einstein wrote in his
miracle year of 1905 on Brownian motion. He demonstrated that the precise microscopic
jiggling observed of pollen grains floating in water could be explained using
the atomic theory. This was sufficient to convince many of the existence of atoms
and other types of fundamental particles. He also used an understanding of
fields to assist in the construction of his general theory of relativity.
It is unfortunate that he missed out on information theory
because it is likely that he would have put his own stamp on it by creating
another elegant fundamental theory. One feature of information which would not
have escaped him is that it describes an aspect of nature which seems
non-materialistic. Many of history’s great thinkers have argued that there is
more to nature than material or substances. Foremost in this list may be Plato,
Spinoza, Peirce and Einstein. At last the introduction of information as a fundamental component of reality provides a means of framing some of
their ideas in scientific terms.
Einstein’s understanding that (2) :
the
sublimity and marvelous order which reveal themselves both in nature and in the
world of thought.
reveals that he sometimes considered nature to have properties
akin to mind. This notion fit well with his belief, along with Spinoza, that
God and nature are equivalent. In this view nature may more closely resemble God
then material. Einstein might well have been open to any addition to the
physicist’s conceptual toolkit which would support an alternative to strict
materialism.
The relationship between information and other aspects of
reality appears to be a deep one and one that is only beginning to be explored.
Although the information revolution has swept practically every scientific discipline,
no widespread agreement has emerged that they are even taking about the same
thing except at the most abstract level. For instance, few biologist or physicists have noted much similarity
between the genome and the wave function.
In this section I will build on the explanation discussed
earlier that information is only information if it informs something. That
something is a model and when a model is informed by information or evidence it
is updated so that its knowledge is increased. It is this knowledge which
supports the existence of complex entities; the more complex the entity the
more knowledge is necessary for its existence.
The mass of our solar system, including the sun, the planets
and their moons total 1.0014 solar
masses (3) .
In other words, the sun contains 99.9% of the of the matter in the solar
system. Although the sun and other stars are complex entities ultimately responsible
for forming all atoms more complex then helium, they are chemically quite
simple; they are composed only of atoms. Stars are so hot that their atoms are
ionized, they do not allow the binding of electrons to the atomic nucleus and they
are far too energetic for even more complex chemical forms such as molecules.
Only in interstellar space and on those bodies orbiting stars, where temperatures are much cooler, can the delicate bonds joining atoms into molecules form. Even then, naturally-occurring inorganic molecules seldom combine more than a hundred atoms. Only in exceptionally rare circumstances does even this level of chemical complexity exist. In the end the complexity of chemical forms is governed by quantum forces, chemical structures are constrained to those quantum possibilities which environmental circumstances allow.
Central to the evolution
of life was the invention of chemical forms orders of magnitude more complex. Indeed,
the essence of life is its ability to design and choreographer intricate chemistry.
Organisms are only chemistry, but an astonishingly complex chemistry, one which,
as far as we know, does not exist anywhere else in the universe. Organic
molecules may be composed of almost a million atoms. Life’s ability to achieve
this amazing leap in complexity does not violate chemistry’s quantum laws,
rather it achieves this complexity by placing chemistry in unique circumstances
or environments which resemble chemical factories. Many fundamental chemical
reactions carried out in these ‘factories’ employ organic catalysts known as
enzymes. These molecules, may for example, bind to one or more ‘substrate’
molecules and cause them to participate in chemical reactions that would not be
possible without the action of the enzyme. In this manner enzymes control much
of the specialized chemical pathways which take place in living things. As
Wikipedia describes this process (4) :
Enzymes accelerate, or catalyze, chemical reactions. The molecules at the beginning of the process are called substrates and the enzyme converts these into different molecules, called products. Almost all metabolic processes in the cell need enzymes in order to occur at rates fast enough to sustain life. The set of enzymes made in a cell determines which metabolic pathways occur in that cell. Enzymes are known to catalyze more than 5,000 biochemical reaction types
Even this wizardry of enzymes cannot defy physics, and in many biochemical reactions the products are more energetic than the substrate from which they were formed; physics requires an input of energy. The means of supplying this energy is the same in all types of life, and involves another enzyme: ATPase. This enzyme uses the energy rich molecule ATP as a substrate to inject energy into reactions involving other substrates
ATPases are a class of enzymes that catalyze
the decomposition of ATP into ADP and a free phosphate
ion. This dephosphorylation reaction
releases energy,
which the enzyme (in most cases) harnesses to drive other chemical
reactions that
would not otherwise occur. This process is widely used in all known forms of life.
Again the energy of ATP
must come from somewhere and that somewhere is a subcellular body called a
mitochondrion. Each biological cell contains hundreds or thousands of
mitochondria which function to convert the energy from food into the electro-chemical
energy of the ATP molecule. Mitochondria create an electric polarization by
pumping protons across an impermeable membrane, and use this to energize ATP
molecules which, in turn, may be used to perform biological work under the direction
of ATPase enzymes.
Our bodies process 50 to
75 kilograms of ATP a day; each molecule is recycled and reenergized over 500
times. The stunning magnitude of the process is made even starker if we
consider the rate at which our bodies must pump individual protons across
mitochondrial membranes. As the bio-chemist Nick Lane explains (6) :
Their job is to pump protons, and together
they pump more than 1021 of them – nearly as many as there are stars
in the known universe – every second.
I have attempted to hint
at the mind-boggling jump in complexity which biological processes have
achieved over inorganic chemical processes. This complexity is largely due to
genetic design which, in turn, has evolved continuously since the first life. It is this genetic knowledge which allows the complex chemistry which is life to exist.
Biological evolution is an
interplay involving genetically recorded knowledge and the environment in which
it finds itself. The knowledge is of
designs for individual organisms which may have an existence in that
environment. It is also knowledge for the execution of those designs and the
construction or development of individuals from that knowledge. The
differential success in maintaining an existence enjoyed by the individuals of
each generation is the information which updates the knowledge repository as to
what works and what doesn’t. This is a basic form of the evolution of evidence-based
knowledge.
The knowledge involved is
extremely specific. For example, each of the 5,000 enzymes which catalyze a
chemical reaction pathway may be composed of up to 2,500 amino-acid building
blocks and each of these building blocks is coded for by a 3-character sequence
of DNA. Over evolutionary time small variations, in the form of mutations, may
be introduced to this code and individuals with slightly unique enzymes are
given an experimental try-out in the environment. The successes are recorded and
live on within the species’ genome but the failures do not. In this manner
knowledge of successful designs form powerful models and accumulate in the
genome. Thus behind each of those vast number of enzymes is an informational
plan for its structure, construction and use. In this instance the information
is at least equally fundamental as is material in the form of the enzyme.
The entire realm of the
biosphere is formed from the interactions among a vast number of experimental
designs. Each of these individual organisms are mortal and have but a short
life span; it is the knowledge repository or model from which they spring that
is more nearly immortal. In this unusual perspective the vast system of
interacting organisms composing the biosphere appears less significant than the
timeless knowledge which forms them. As phenotypes, we strut and fret our hour upon the stage
but these experiments in living may signify only little to the repository of enduring
knowledge.
This view of a reality beyond materialism and the world of appearances is supported by a current scientific revolution in which information is understood as at least equally fundamental as mass and energy. It harkens back to Plato and his understanding that the world of appearances is but a shadow world, a mere reflection of an underlying realm of ‘ideas’.
The scientific duality of
matter and information is deeply entwined; all information is recorded in
material form and all matter is formed under the direction of information.
Their relationship in our understanding is not an exclusive one where either
matter of information will displace the centrality of the other, rather it is a
synergy. This synergy appears to be the only method which nature has found
capable of accumulating knowledge.
Science itself is a case
in point. Although we normally take it for granted, the rise of science was one
of the key moments in the history of both our species and of our planet. Agricultural
science transformed the planetary landscape as it developed processes capable
of feeding seven billion people. Geologists are about to name a new geological
epoch, as the Anthropocene, the geological era in which human activity is the
dominant force shaping our planet. As seen from space our planet is unique as
the only one to shine the light of its own internally-generated energy.
This transformation of the
planet by humans began long before the formal study of science but it may be
argued that even those early forms of human knowledge owe their power to a
vague similarity to refined science. For example, the transformation of the
earth’s surface through agriculture, which began in a so-called prescientific
era, undoubtedly occurred through a dynamic between human ideas of what might
work and the retention of experimental evidence of what did work.
Among all organisms,
humans are uniquely adapted to take nature’s ancient method of knowledge
accumulation to a new level. Perhaps the most unique of our biological
adaptations is our big brain. While much of our brain design is shared with
closely related animals, our prefrontal cortex is hugely outsized.
This is the section of the
brain which supports imaginative and sometimes even rational thinking (7) :
This
brain region has been implicated in planning complex cognitive behavior,
personality expression, decision making, and moderating social
behaviour. The
basic activity of this brain region is considered to be orchestration of
thoughts and actions in accordance with internal goals.
A striking feature of our
uniquely imaginative mind, despite its great power is its surprising lack of
accuracy. We can imagine practically anything; our imaginations know no bounds.
What use are such thoughts if they are likely wrong?
Fortunately, we have also
inherited a sensory cortex that is little changed from of our near animal
relatives. This part of the brain, which provides us with senses and
perceptions, is an ancient one and has been evolving for hundreds of millions
of years. Its purpose is to provide animals with accurate information about
what is actually going on in the world around them. Poor experimental designs of this
brain area are quickly erased from the evolutionary record and hence it now provides
us with highly detailed, reliable and accurate models of reality.
Humans and other animals
exploit a synergy between the abilities of the prefrontal and sensory cortexes.
The prefrontal cortex can provide hypothetical models of what is going on in
the world and these can be judged and selected using our accurate sensory
information. This synergy is used for the purpose of ‘orchestration of thoughts and actions in
accordance with internal goals’ but such resulting behaviours may be seen
in terms of experiments; behavioural actions are attempts to achieve goals but
are not always successful, hopefully we learn from the evidence of those
successes and failures.
This is essentially nature’s
ancient method of knowledge accumulation which has achieved new vistas with the
substantial increase in power of the human prefrontal cortex. It is most highly
refined in the practice of science. We learn scientific models from the
community of past and present scientists. No two people have exactly the same
models so there is some variation among them. These various models are tested
by experiments which collect sensory evidence and this evidence is used to calculate
the models’ relative plausibility in light of that evidence. The most plausible
models are selected. This is exactly the Darwinian paradigm of heredity,
variation and selection. Indeed, many philosophers of science describe science
as a Darwinian process (8; 9; 10) .
At the core of science is
reproducible evidence. A new variation to a scientific model will only gain
support if evidence, usually from experiments, is gathered, and it can be seen
that the sum of the evidence more clearly supports the new model rather than
the old. Scientific evidence must be reproducible by others to guard against
the possible bias, errors or delusions of a single researcher. Evidence which
may be freely reproduced can be considered a technology. For example, our cell
phones may be considered as providing reproducible evidence; each time we use
them and they work, we are adding support to the vast number of scientific
models used in their design.
In this light the vast
technological landscape we inhabit is similar to the biosphere; its members are
short-lived experiments and are but the temporal expression of a more timeless
process of knowledge accumulation.
While we might be willing
to view our cultural and perhaps even our biological selves as material or
substance orchestrated by an ancient knowledge, can we extend this paradigm to
the mind-bending possibility that it also applies to physical reality itself?
At the basis of a
scientific understanding of reality is the quantum/classical divide. Our best science
tells us that at bottom there is only quantum phenomena yet our experience of
the world is that it is almost exclusively classical. It turns out that quantum
reality is vast and contains many possibilities such as things being both here
and there at the same time which we never experience. We experience only a
classical reality where things are either here or there. Classical reality is
only an extremely small subset among the vast quantum possibilities. What makes
it special and how is it selected as the physical reality we inhabit?
A leading authority on the
nature of quantum interactions, Wojciech Zurek, has proposed an explanation he calls
quantum Darwinism (11) .
In this theory classical reality is selected from the quantum possibilities through
a Darwinian process.
To appreciate the significance of this theory,
we should first consider that at the basis of a scientific understanding of
reality is information exchange. The four fundamental forces of nature operate
through the exchange of information. With forces, such as electro-magnetism,
one entity provides information to another as to what it should experience, for
example, how it should move. Without such forces or information exchange the
most fundamental particles would be isolated and unable to bond to or have any effect on other
particles. There would be no reality at all, in the sense of containing complex
entities whose components have mutual information about one another, one which
could come to know itself. It is only through the process of information
exchange that reality exists, that any entity may experience a reality beyond itself.
In Zurek’s view the
quantum nature of reality is constrained to isolated particles but when these
particles pass information to entities in their environment it is only
classical information which can survive and reproduce. As the nature of reality
is dependent upon the information which is exchanged we experience only a
classical reality.
The nature of the
information which quantum system pass to their environments are in the form of
hard physical facts including force, position and momentum. Our understanding of
it may morph between considering it as information or as physical entity. Of
course the type of information which may survive is highly dependent upon the environment,
for example some environments may support information concerning position and
others information concerning momentum.
At the core of quantum
theory is the understanding that quantum reality is in the form of information.
The quantum wave function is a knowledge repository which fully describes
quantum entities and any information which may be received from it by any other
entity is contained within the wave function. Quantum Darwinism demonstrates
that the only type of information capable of surviving the rigors of transfer
is classical information.
When information transfer
occurs a remarkable transformation of the wave function takes place; it ‘jumps’
to a state that corresponds to the information it has transferred. Even though
the information which was transferred may have been selected from a vast array
of quantum possibilities, after the transfer the quantum possibilities are
reduced to only that information. For example, if the information transfer
takes the form of a measurement then quantum theory assigns a probability to
each possible outcome. The actual outcome may have been assigned only a low
probability. However, if another identical measurement is repeated immediately
following the first, the same result is predicted with probability 1. Thus the
updating of the quantum model keeps it in sync with the information transferred
to the environment.
Another way of looking
upon this is to view the information or physical entity which the quantum
system transfers to its environment as an experiment designed to gather
information concerning its environment and the forms which may survive there. This
evidence then updates the knowledge repository of the wave function. In the
light of quantum Darwinism those forms which can survive also do evolve, quarks
evolve into nucleons, nucleons into atoms and atoms into molecules. At each
step the quantum wave function is the knowledge repository which continuously
explores environmental possibilities through experimental probes.
Again we have the same paradigm,
this time portraying the fundamental physical constituents of the universe,
such as quarks, atoms and molecules, in terms of short lived experimental
probes which update a more timeless knowledge repository as to what can
exist.
Bibliography
1. Wheeler, John A. Geons,black holes
& quantum foam. [ed.] Kenneth Ford Norton. 1998.
2. Einstein,
Albert. Science and Religion. s.l. : New York Times magazine,
http://www.sacred-texts.com/aor/einstein/einsci.htm, 1930.
3. Wikipedia.
Solar System. Wikipedia. [Online]
https://en.wikipedia.org/wiki/Solar_System.
4. —. Enzyme. Wikipedia.
[Online] https://en.wikipedia.org/wiki/Enzyme.
5. —. ATPaes. Wikipedia.
[Online] https://en.wikipedia.org/wiki/ATPase.
6. Lane, Nick.
The Vital Question. s.l. : W. W. Norton & Company, 2015.
ASIN: B00OD8Z4JW.
7. Wikipedia.
Prefrontal cortex. Wikipedia. [Online]
https://en.wikipedia.org/wiki/Prefrontal_cortex.
8. Blind variation
and selective retension in creative thought as in other knowledge processes. Campbell,
Donald T. 1960, Psychological Review, Vol. 67, pp. 380 - 400.
9. Popper, Karl.
Objective Knowledge. s.l. : Claredon Press, 1972.
10. Hull, David L.
Science as a Process: An Evolutionary Account of the Social and Conceptual
Development of Science. Chicago and London : The University of
Chicago Press, 1988.
11. 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.
12. Ford, Kenneth.
John Archibald Wheeler: Doer and Visionary. s.l. : As viewed on
http://www.metanexus.net/magazine/ArticleDetail/tabid/68/id/5491/Default.aspx
September 24, 2010, 2010.
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