Rifkin – Why is there a universe of matter and stars, and why do the laws of nature allow energy to organize matter into staggering complexity, including life and mind?
Crawford – The energy and matter are ALREADY organized! The total organization (negentropy) of the universe was maximal at the instant of the Big Bang and has been declining ever since. In the case of life on earth, humongous quantities of organization in the sun-generated lots of organized sunlight, a tiny fraction of which struck the earth, scattering large amounts of organization over its surface, a tiny fraction of which was manifested in the rise of living systems. The staggering organization of life and mind is but a microscopic fraction of the immense organization transmitted by the sun to the earth.
At this point, I will digress to preach about the meaning of entropy, negentropy, and the Second Law of Thermodynamics. Very few people grasp these concepts. Even after earning my master’s degree, I still had to spend years wrestling with the concepts to develop a firm understanding of what they meant. The physics community has been applying these concepts to cosmology with much success, and we’re seeing some interesting ideas here. Part of the problem that the non-science community has lies in the confusing terminology. The quick translation of “entropy” is “chaos” or “disorganization”, although these terms have an absolutist connotation that doesn’t fit well with the arithmetic nature of entropy. That is, any given system can be characterized as having more or less entropy, and the amount of entropy in any given system can change with time. We seldom think of “chaos” as existing in different degrees.
Even worse is the confusion arising from the term “complexity”. If all the people in a room crowd together in one corner, the spatial distribution of the crowd has LOW entropy, whereas if the people are milling about randomly throughout the room, then the spatial distribution of the crowd has HIGH entropy, even though we would characterize the latter situation as being more complex than the former situation. We think of complexity as demanding lots of information to specify, and that a situation requiring little information to specify as simple. Yet, we also think of complexity as entailing large amounts of order (negentropy). These two interpretations of complexity are contradictory.
For example, consider two bodies of text. One is, say, an encyclopedia; the other is an equally large amount of utterly random characters. The encyclopedia is clearly more organized than the random text — it has more negentropy. But it takes more information to specify the random text than the encyclopedia. If we compress both files, the compressed random text will be much larger than the compressed encyclopedia. I therefore suggest that you refrain from using the word “complexity” in your considerations of life — it will only lead to confusion. Better to think in terms of information content: negentropy.
Therefore, there’s nothing surprising about the rise of life on earth. Suppose that you were to fly an airplane over random locations on the earth, releasing huge quantities of hundred-dollar bills at these random locations. 70% of the bills would fall into the ocean and be lost; others would fall into Antarctica, the Sahara Desert, and other unpopulated locations where the money would have no effect. But in some places, the money would fall onto lots of poor people, and they in turn would use it to greatly increase their standard of living. So it is with negentropy. The sun blasts out huge quantities of negentropy, most of which falls on infertile soil (empty space). But some of it is lucky enough to hit a location with potential: earth. It is no more a surprise that life arises on the earth from the sun’s negentropy than that the people who get lots of money get rich.
Natural selection and genetics are part of the mechanism of the development of life, but the underlying driving force is the negentropy of sunlight. Turn off that sunlight and life on earth withers and dies.
Rifkin – My advocacy for cosmological natural selection was to further stimulate the idea that CNS is a powerful and logical scientific hypothesis to explain the existence of complexity and life in the universe as we know it.
Crawford – I have explained that the concept of negentropy explains the existence of life more clearly and more rigorously than CNS. The CNS hypothesis is not necessary to explain life; we have had that answer for a long time. Moreover, neither Mr. Smolin nor Mr. Susskind use CNS to explain the origin of life — at least, not in the discussion I read.
Rifkin – Black hole-generated variant universes (each its own Big Bang) is Smolin’s proposed mechanism for how CNS may occur. But the mechanism itself is not what I am advocating. (There are other speculative mechanisms, including a Big Crunch cyclic oscillating universe where each bang is a phase transition from a metastable state into another more stable state accompanied by a release of energy, with the laws of nature varying slightly in each round, the ones more conducive to star formation more likely to reproduce variants of those laws). My argument was not for any particular mechanism. It was for the underlying process of cosmological natural selection as a logical naturalistic explanatory foundation. So often in science, the mechanistic explanation and supportive evidence come long after the hypothesis. So arguing against the mechanism does not, to me, make one throw out the underlying idea itself. Will it forever be physically impossible to get contributory empirical evidence for or against CNS? Have we reached a physical limit of what can be known here? We’ve heard that before in the history of ideas. As I wrote, “it will come down to evidence. Our minds expand, while the God of the gaps gasps.”
Crawford – I have difficulty with that assertion; I cannot think of a single major scientific hypothesis that was NOT presented as a mechanism. Copernicus presented a detailed geometric mechanism. Darwin presented a detailed mechanism supported by a surfeit of examples. Special relativity began with the statement that the speed of light is constant for all observers regardless of their relative velocities; that seems a mechanism to me. General relativity was based on the observation that an observer in a box could not tell the difference between being accelerated and being in a gravitational field; that strikes me as a mechanism. I suspect that your definition of “mechanism” differs from mine. I’ll ask you to expand on the concept as you understand it.
As to the second statement regarding the lack of empirical evidence for CNS, I suggest that we base our conclusions on what we actually have, not on what we might (or might not) have in the future. The rational approach would conclude that the CNS hypothesis is untenable at present, and should be rejected at present. If at some future time, supporting evidence appears, we can reconsider the hypothesis at that time. To simply assume that the evidence will appear in the fullness of time is not rational.
Rifkin – Modern physics shows that black holes and the Big Bang have common physical attributes. In both, the curvature of space-time approaches the infinite. Our current scientific understanding is that our universe is felt to have emerged from a singularity (the Big Bang) and then formed singularities (black holes). If the singularity that was the Big Bang could create our universe, the hypothesis that the singularities that are black holes produce their own big bangs is certainly intriguing. But, again, the point in my original article and subsequently was to explore the explanatory power and logic of CNS, not any particular mechanism.
Crawford – Your point here relies on the equation of the two kinds of singularities — an assumption that has some appeal but remains quite a stretch. The fact that black holes create singularities and the Big Bang began with a singularity does not imply that the two singularities are of the same nature. The singularity that produced the Big Bang lasted an instant; the singularity produced by a black hole lasts almost forever. This raises the obvious question: does a newly created black hole continue to spew forth new universes every second? Every microsecond? Whenever it gains or loses mass? Or does a black hole generate a single universe upon its first formation, and then retain everything it had without observable change? Recall that black holes do not appear to lose anything (other than the slow loss of mass to the surrounding space) during their existence. If they’re spawning new universes, those universes aren’t coming from anything inside the black hole.
You have repeatedly declared that you are unconcerned with such mechanical objections to CNS, arguing that what is interesting and valuable is the notion of new universes being created with somewhat altered fundamental constants. I would argue that a phenomenon without a plausible mechanism is unworthy of consideration. Sure, it would be great fun to discuss a hypothesis in which the sun will slightly cool in the next few decades, exactly countering global warming so that humanity doesn’t have to suffer the consequences of its foolishness. But without any plausible mechanism for this to happen, the speculation is a waste of time.
Rifkin – If, as Mr. Crawford suggests, a good scientific hypothesis must be “simple” and “clear,” I suppose quantum mechanics and general relativity were not good hypotheses? In any event, the underlying mind-blowing powerful algorithm of biological natural selection is simple, clear, and elegant! It is the genetic mechanisms, the non-genetic influences, and ecological environments that are complicated. The logic of CNS, right or wrong, is also simple, clear, and elegant. The proposed mechanisms are not.
Crawford – Larry, you should learn what quantum mechanics and general relativity are. They are both based on simple, clear, and elegant notions. General relativity is particularly simple: Einstein asked whether a person inside an isolated box would be able to tell the difference between being in a gravitational field and being accelerated. The obvious answer — no — leads to all manner of complicated calculations that in turn reveal a great deal about the universe. Yes, the math is complicated. The hypothesis is not.
Similarly, quantum mechanics is based on the simple hypothesis (actually a conclusion from a variety of experiments), that it is not possible to measure both the position and momentum of a particle with arbitrary precision. That is Heisenberg’s Uncertainty Principle, which itself turned out to be of little computational value, but when the concept was re-expressed in the form of wave mechanics, we had an extremely powerful computational device. You are certainly correct that the mathematical expressions that are consequential to the initiating formulations are horridly complex. However, the initiating formulations are indeed clear, simple, and elegant.
Rifkin – I agree about the pervasive and fundamental explanatory power of “negentropy” (the idea goes by many names, and involves energy flows, non-equilibrium systems, etc.). I believe Kauffman phrased it something like this: A universe that maximizes entropy at the fastest rate possible will evolve toward a state that is increasingly complex, organized, alive, and intelligent.” The general idea is that complex life optimizes its ability to extract energy efficiently, and therefore facilitates overall entropy production. Disorder is the selection pressure for self-organized systems. All this is hugely fundamental and powerful. A book I highly recommend that explores these ideas is “The Romance of Reality” by Bobby Azarian.
Actually, living systems optimize their ability to extract negentropy, not energy. The energy carries the negentropy. Think in terms of money. A dollar bill is not intrinsically valuable. It carries or represents value. Value is what we work to obtain. Whether that value is represented by a dollar bill, four quarters, a number in a checking account, or an identification number on a smartphone is irrelevant. What is relevant is the value, not its representation. Negentropy, not energy, is the source of life.
Rifkin – What I believe Mr. Crawford misses is that while “negentropy” likely explains the formation of autocatalytic sets and simple peptides, current evidence suggests that no matter how much or what type of energy is then added, including sunlight, it does not create anything more complex. Simple molecules and nucleic acids are a far cry from the mind-boggling complexity of cells, to say nothing of bodies and minds. The explanation for the formation (not the continuation) of this next level of increasing complexity needs to go beyond an underlying non-equilibrium free-energy explanation. So far, only natural selection (differential replication based on variation and fitness) can explain the coming into being of that more complex scale, phase, and level of non-designed organized complexity.
Crawford – Wow! That’s quite a statement! I must ask, if sunlight is not fundamentally necessary to the development of complex systems, then why is it that depriving the Earth of sunlight would result in the termination of almost all life on Earth? If I understand you correctly, your argument is that natural selection, not negentropy from the sun, drives the development of all life on earth. I certainly agree that natural selection is the higher-order mechanism for evolution, but natural selection is itself fueled by negentropy from the sun. All living systems derive the CAPACITY to engage in the behaviors necessary to drive natural selection from the negentropy they absorb that initially came from the sun.
Rifkin – The existence of the complex laws of nature themselves allow for the creation of matter and allow for the ability for high-level complex material phenomena to form in the first place, and the apparent exquisite fine-tuning of the parameters of nature that are necessary for these laws and their effects to occur, need a naturalistic explanation beyond the underlying dissipative entropy flow that sustains them.
Crawford – The flow of negentropy from the sun is entirely adequate to explain everything about the development of life on Earth. The peahen is capable of sexually selecting the peacock with the most flamboyant tail because the peahen expends negentropy in the brain processes that evaluate the beauty of peacock tails. The peahen has a brain capable of making such evaluations because it has absorbed enough negentropy from the food it has consumed to assemble the chemicals necessary to construct that brain.
One other thing: there is no need to invoke magical explanations for the particular combination of values of fundamental physical constants that permit life to develop in this universe. Let us imagine another universe in which the strong force is weaker than in our universe. In such a universe, large nuclei would not be able to form, and so the periodic table would be smaller. Indeed, we could go so far as to imagine a universe in which the only atoms that could form were hydrogen atoms. In such a universe, life as we know it could not exist. But who is to say that life could not form in some other fashion?
Indeed, imagine a scholar in some alternate universe possessed of different fundamental physical constants. Suppose we present that scholar with the values of fundamental physical constants in our own universe, and challenge that scholar to determine from those numbers the kind of life that might evolve in such a universe. Do you really think that our alien-universe scholar would be able to predict kangaroos? Pterodactyls? Crabs? Venus fly traps? I very much doubt that such predictions would be possible. So if we turn the tables around, and challenge our best scholars to predict the nature of life in a universe in which the fine structure constant is 10% smaller, or the speed of light is 100 meters per second, we should expect them to throw up their hands and declare the task impossible.
The fact that we cannot imagine the nature of life in other circumstances does not imply that such life cannot exist.
Lastly, I’d like to offer a general observation that might be wildly off the mark. A number of times you have made comments suggesting to me that you rather like the idea of alternate universes with their own life forms. I have complained that you have offered no evidence to support a belief in such alternate universes, and you have parried my plaints with arguments to the effect that, even if unprovable, it’s still such a nice idea that it deserves our respect. This answer strikes me as similar to the arguments for theism. Most people are uncomfortable with the notion that our universe is a soulless mechanism with no sense of purpose. They therefore postulate the existence of some sort of supernatural force or agency that provides a higher purpose to life. While I do not share such beliefs, I have come to respect the propriety of individuals to cushion themselves from the icy harshness of physical reality with religious beliefs. They are, after all, Pleistocene hunter-gatherers equipped with brains optimized for survival in the savannah of Eastern Africa, not for understanding the universe.