(Copyright © 2000 Piero Scaruffi | Legal restrictions - Termini d'uso )
This is an impressive, colossal work of synthesis that tries to find a common
law for cosmological, biological and mental phenomena.
Layzer begins the book by observing that a human being belongs to two distinct worlds: i am both an object described by the laws of Physics and we are selves who act consciously. Layzer's aim is precisely to reconcile these two selves.
Layzer divides the sciences into two parallel projects. On the one hand there is the timeless Pythagorean project to discover the universal laws that apply to everything. On the other hand there is the timebound Heraclitean project to discover the order of evolving structures (astronomical and biological structures). Both projects need to figure out laws and initial conditions. Layzer thinks that initial conditions contain both a regular and a random component, and that the timebound order does not contain the latter (no randomness). The regular component is due to physical processes, so that physical processes working on initial conditions lead to a new set of initial conditions. Working backwards one reaches the initial state of the universe.
Initial conditions also depend on a random component. The evolution of the random component can be determined by Boltzmann's entropy equation. Boltzmann realized that the molecules of an isolated gas tend to scatter until they are as randomly distributed as they can be, and that's the state of thermodynamic equilibrium. This randomness turns out to correspond to Clausius' entropy, and this randomness can be expressed mathematically as the number of microstates that can create a macrostate. For example, a straight flush is the least random kind of poker hand because it can be generated by the smallest set of card distribution (it takes five sequential cards in the same suit).
Layzer points out that there are multiple definitions of "order", depending on which scientific discipline uses the term, whereas "disorder" is easier to define: absence of randomness. Disorder is governed by the second law of Thermodynamics, whereas different varieties of order are governed by different laws ("disorderly systems are all alike; every orderly system is orderly in its own way"). All varieties of order consist in the absence of the same kind of disorder.
He then defines information as the difference between maximum randomness and actual randomness, i.e. as the measure of how far a system is from maximum randomness (thermodynamic equilibrium). For a physicist this is the equivalent of potential energy, and therefore Layzer views information as "potential randomness".
The problem with this definitions is that information ends up being independent of its meaning. The information of a message broadcast by telecommunication equipment can be considered without any reference to its meaning, but biological information (the DNA) cannot be considered without any reference to its meaning. Hence, Layzer tries to elucidate the biological meaning of randomness. One way of doing this is to assign values of information to proteins proportional to their fitness so that biological order gets defined as contributing to an organism's chances of survival and reproduction, so that natural selection tends to generate biological order. Natural selection is not the only process that generates biological order: human culture too does it.
Astronomical and biological structures (the timebound order) are organized in a hierarchy of initial conditions and order-generating processes, with each process creating the initial conditions for the next one. (I find this postulate wildly arbitrary and confusing).
Objective randomness can only exist in a discrete universe like the one described by Quantum Mechanics. It turns out that Boltzmann's entropy formula was also based on the implicit assumption that a system can be approximated as being made of discrete cells.
Modern physics adheres to the Cosmological Principle that the average properties of the universe are the same everywhere and in every direction, the laws of nature are invariant under translations and rotations, i.e. the universe is "isotropic". Layzer turns it into the "Strong Cosmological Principle": there was nothing in the initial state that gives a position or a direction a preferred status. It follows from this principle that randomness is a property of the universe. "A complete description of the universe contains only statistical information", and the probabilities that figure in that "statistical information" simply reflect the absence of microscopic order (not our ignorance of the truth), and this absence of microscopic order is responsible for the decline of macroscopic order. Since all natural systems were formed with little or no microscopic order, macroscopic disorder must increase, as the second law of Thermodynamics states, but this is actually a historical consequence of the initial state.
All of this discussion follows from the assumption that the universe is discrete, not continuous (unlike what Newton and Einstein believed). Layzer shows that all the other "oddities" of Quantum Mechanics (e.g. Heisenberg's principle of uncertainty) are descendants of the discrete nature of its quantities.
At this point Layzer takes a detour into music, another discrete domain, and shows the relationship between musical harmony and Quantum Mechanics.
After a brief introduction to Quantum Mechanics, Layzer analyzes the consequences of his "Strong Cosmological Principle". First and foremost, it implies cosmological indeterminacy, i.e. that the more you know about the macrostate of the world the less you know about the microscopic states that cause it. Layzer shows that this indeterminacy is related to Heisenberg's principle of indeterminacy. In other words, knowledge of the macrostate does not include knowledge of its corresponding microstates. Einstein's interpretation of the probabilistic nature of Quantum Mechanics was similar: Quantum Mechanics is a statistical theory useful to describe sets of particles, but not individual objects. Likewise, Layzer believes that we can only describe statistical properties. Layzer, however, parts from Einstein in explaining the origin of this limitation: Einstein thought that it was simply due to our ignorance of the fundamental laws of nature, whereas Layzer thinks that it follows from the equivalence of all positions and all directions anywhere in the universe.
The immediate consequence is that macroscopic processes are irreversible despite the fact that microscopic processes are reversible (since the laws of Quantum Mechanics don't discriminate between the two directions of time).
In theory, as Clausius and Boltzmann realized, the universe should be doomed to decline towards states of decreasing order because natural processes generate more and more entropy. One would conclude that at the beginning the universe was more orderly than it is now. Layzer, however, points out that this is not necessarily true in an expanding universe: order is created by the cosmic expansion. If entropy in the environment increases more than the entropy of the system, then the system becomes more ordered in that environment. Entropy and order can both increase at the same time without violating the second law of thermodynamics. This phenomenon can be described as: if the expansion of a set of systems is so quick that a number of states which are occupied increases less rapidly than the number of states which are available (i.e., the phase space gets bigger), entropy and order can increase at the same time. Unlike Prigogine, Layzer does not need to assume that an energy flow from the environment of a system can cause a local decrease in entropy within the system. Entropy and order increase together because the realization of structure lags behind the expansion of phase space.
Layzer does not believe that the universe was born complex and hot. He believes that such a vision leads to blatant contradictions, whereas an initially structureless and cold state accounts for the features of the universe that we observe today, starting with gravitational clustering, as that kind of state inevitably leads to a hierarchy of self-gravitating clusters.
The alternative to Boltzmann's model (that the universe began in a highly ordered state) is a model in which the initial state had no order at all and order (the hierarchy of self-gravitating clusters) was created as it cooled down and density fluctuations got amplified, each self-gravitating assembly becoming a component to generate with other peers the next self-gravitating assembly. Order was created because a gravitating gas with negative internal energy in an expanding medium is inherently unstable.
Next Layzer abandons Astrophysics and delves into Genetics. He disagrees that living organisms can be explained with a reductionist approach, as mere chemical compounds. He believes that order must be given the same status as energy among the fundamental features of the world, and in that case living organisms have something that nonliving organisms don't have: a special kind of organization. Living matter is made of the same stuff as nonliving one, but they way it is organized is different. In his opinion this approach can help solve the mystery of why evolution tends to create more complexity. In theory there should be no average improvement or decline in complexity. In pratice there has been a vast improvement from the first living cell to today's life. He quotes Peter Medawar: "The inexplicable tendency of organisms to adopt ever more complicated solutions to the problem of remaining alive" ("A Biological Retrospect", 1982).
The fundamental property of living organisms is, to Layzer, "reproductive instability", a property that turns life into a kind of viral infection: "Just as a virus transforms its living host into a factory for producing more virus, so life transforms its inert host into a factory for producing more life". He traces this reproducting instability back to an inherent instability of genetic material, and this one back to a property of all molecules organized in a particular way.
Evolution is due to the cooperation of two processes: variation and selection. Genetic variation allows new forms of life to emerge and natural selections determines which ones survive and reproduce. In 1949 the Russian zoologist Ivan Schmalhausen proposed that evolution is a process of hierarchical construction leading to a functional hierarchy in which each functional unit is created by aggregation of preexisting functional units. Genetic variation is the consequence of this general process of hierarchical construction, and evolution shaped this hierarchical process. Therefore, Layzer argues that genetic variation, that indirectly shapes evolution, is not a random process but was shaped by evolution itself. Because it is not random, but driven by a hierarchical process, it ends up fostering complexity, and the apparent paradox is solved.
In detail, Layzer distinsuighes alpha and beta genes. Alpha genes are the genes of classical genetics and the regulatory genes that transcribe these genes into RNA. Beta genes are not directly involved and serve maintenance chores. Layzer's theory, originally devised in 1977, is that beta genes drive evolution by promoting mutations that are likely to increase fitness and suppressing mutations that are likely to decrease fitness. He then argues that hierarchical construction is the natural consequence of this system.
Homo Sapiens is an exception to the rule that the acquisition of new skills results in the formation of many new species: the acquisition of cultural skills did not create more Homo species but only one, us. Layzer thinks that culture and language made the genetic program redundant: a more efficient form of evolution was at work.
Biological order is not only created by evolution, it is also created by development. Biological order due to evolution is embodied in DNA. Biological order due to development is embodied in neural connections. Layzer adopts the stance of ecological realism, that perception is an active process during which we construct our cognitive life. That too is a hierarchical structure.
When it comes to language acquisition (another example of the growth of order), Layzer sides with the US psycholinguist Roger Brown, who refined the view of Jean Piaget's "constructivism" (that language acquisition follows the acquisition of cognitive skills). First the child's mind develops the representation of the world in terms of objects and actions, then the child learns to speak; and that initial speech (of one-word sentences) is "semantic", i.e. the initial relation between that representation of the world and sounds is purely semantic. As mental life evolves into more and more complex structures, so does language. Language acquisition is a process of hierarchical construction, and complexity of adult language is the result of that process. Chomsky's "universal grammar" is an illusion due to the fact that all children are programmed to develop through the same stages and achieve the same adult stage, and language simply reflects the outcome of that step-by-step hierarchical process.
Layzer argues that subjective reality (consciousness) cannot be reduced to objective reality (the external world). The latter is governed by physical laws, the former is not. Therefore consciousness has no functional role: it cannot interact with events in the external world.
Layzer thinks that knowledge of the functioning of the nervous system is not enough to explain consciousness, as there is no one-to-one correspondence between neural states and conscious states (we are unconscious of most neural events). At every level of the biological hierarchy a new kind of order emerges, and consciousness is one such emergent property of living organisms. Consciousness cannot be reduced to the physical. It belongs to a metaphysical realm. And to critics who could attack him as a "mystic", Layzer responds that the reason for the existence of energy and electrical charge is no less inscrutable.
Inside the brain he finds again a hierarchy, this time a hierarchy of neural circuits modeled after Luria's three functional units (a theory that dates back to 1942).
His "Strong Cosmological Principle" has made randomness a property of the universe: the universe began from a state of pure randomness (zero order). He uss that randomness to prove that creative processes such as biological evolution (and cultural evolution) inevitably generates order in an unpredictable way. The future (both of life and of human behavior) is not predetermined. Free will is real.
My problem with this all-encompassing study is the liberal use that Layzer makes of the concepts of entropy, randomness and disorder, frequently used as synonyms.