WORDS
Complexity, Order, Chaos
M. I. Katsnelson (Radboud University, Nijmegen, The Netherlands)
We, physicists, believe that nothing studied by other branches of science can contradict basic physical laws. Any electrons and quarks within our bodies, or within any other living beings should follow (as we believe) the same physical laws as any other electrons and quarks in the Universe. There is however an immediate problem. Fundamental physical laws are local in space and time. What happens with physical fields and particles at a given point of space-time continuum is dependent only on the situation in an infinitely close vicinity of this point. At the same time, to answer any, even simplest, question about our planet, or about our solar system, let alone about living organisms - we need to go far, far back into the past. Here evolution becomes crucially important, and not only in biological sense but also the evolution of the Universe as a whole, from homogeneous hot plasma at early stages to diversity of galaxies, stars and planets. To understand why the Earth has the Moon, a huge satellite, we need to understand processes
which have happened in the solar system billions of years ago. Even more complex problems arise when we try to understand the origin of cats and mice, and why cats catch mice. The roots are hidden in multibillion-year history of life at the Earth, and the origin of this life is still a mystery for us.
Thus, we live in the world which has a certain complexity and which has a memory. At the same time, it consists of microscopic particles obeying the basic laws of physics which are simple and instantaneous, prescribing the changes by infinitely dense step-by-step processes. How complexity can originate from simplicity and how billions of years of the evolution can agree with fundamental physical laws acting at femtoseconds or even much faster? This is one of the most ambitious unsolved scientific problems.
People who created our science as we know it in XVII-XVIII centuries were obsessed by the idea of order. Newton has paved the way showing how much can be understood based on just a few simple general rules. Engineers built mechanisms consisting of simple details but demonstrating more and more complicated behavior. This world of automata and clockworks can be also very frightening as it is expressed in many beautiful works of art and literature, from The Sandman by Hoffmann to contemporary Fellini’s Casanova. Dark mystique and horror of romanticism provided the opposite extreme. The tragic history of XX century has shown in the most terrible way what may be the consequences of two types of idolatry, a cult of unrestricted order and rationality, from one side, and a cult of wild biological instincts, blood and semen, on the other side. Misunderstanding of crucial concepts of the worldview can kill people, and contradictions of complexity and simplicity, memory and spontaneity, chaos and order, ratio and emotions are much more than merely subjects of arts or subtle scientific problems to be solved by the experts, they are true issues of life and death.
Coming back to physics we are just in the very beginning of the long way of scientific understanding of origin of complexity and long-term memory of physical systems. Most probably they arise as a result of competition of different interactions, weak and strong, short-range and long-range. Evolution is an optimization, Darwinian “survival of the fittest”, but the meaning of “fitness” can be dramatically different for different elements and parts of a complex system. Any complex system is pushed by numerous contradictory wishes and requirements acting simultaneously at different levels of its organization. Molecules tend to evolve into the minimum of free energy, genetic elements tend to unrestricted self-reproduction, individual cells tend to their immortality but this tendency, in the form of cancer, kills the whole organism once constrains are eliminated. Randomness and chaotic processes provide the material for selection and for the growth of complexity. Replication unavoidably leads to appearance of parasites but
parasite-host arms race results in the increase of biological diversity and thus in the progressive development, as we usually understand it. “You have to make the good out of the bad because that is all you have got to make it out of”, said a personage of “All the King’s Men” by R. P. Warren, and the biological evolution is the process of making good from evil, because in nature the evil, the growth of entropy, the competing requirements, constrains, controversies and frustrations are all you have got to make it out of.
Importantly, the properties of the whole system do not follow directly from the properties of the constituents, and with the same elemental base we can reach totally different results. The same transistors and electron beams in our TV sets can be used for enlightenment of people, via beautiful performances of Shakespearean plays and Mozart symphonies or telling people on the deepest mysteries of Universe, as well as for the darkening of our minds, via the worst forms of propaganda and manipulation. We are animals obeying all kind of biological instincts. Moreover, we are physical systems consisting of electrons and atomic nuclei and obeying the laws of quantum electrodynamics. Mozart and Einstein were consisting of almost the same chemical compounds as any rat or a skunk. They have shown us what can be reached with this, seemingly disappointing, background. We are what we are but we still can make the world more complicated, more interesting, and more beautiful. Or, at least, we should try.
M. I. Katsnelson (Radboud University, Nijmegen, The Netherlands)
We, physicists, believe that nothing studied by other branches of science can contradict basic physical laws. Any electrons and quarks within our bodies, or within any other living beings should follow (as we believe) the same physical laws as any other electrons and quarks in the Universe. There is however an immediate problem. Fundamental physical laws are local in space and time. What happens with physical fields and particles at a given point of space-time continuum is dependent only on the situation in an infinitely close vicinity of this point. At the same time, to answer any, even simplest, question about our planet, or about our solar system, let alone about living organisms - we need to go far, far back into the past. Here evolution becomes crucially important, and not only in biological sense but also the evolution of the Universe as a whole, from homogeneous hot plasma at early stages to diversity of galaxies, stars and planets. To understand why the Earth has the Moon, a huge satellite, we need to understand processes
which have happened in the solar system billions of years ago. Even more complex problems arise when we try to understand the origin of cats and mice, and why cats catch mice. The roots are hidden in multibillion-year history of life at the Earth, and the origin of this life is still a mystery for us.
Thus, we live in the world which has a certain complexity and which has a memory. At the same time, it consists of microscopic particles obeying the basic laws of physics which are simple and instantaneous, prescribing the changes by infinitely dense step-by-step processes. How complexity can originate from simplicity and how billions of years of the evolution can agree with fundamental physical laws acting at femtoseconds or even much faster? This is one of the most ambitious unsolved scientific problems.
People who created our science as we know it in XVII-XVIII centuries were obsessed by the idea of order. Newton has paved the way showing how much can be understood based on just a few simple general rules. Engineers built mechanisms consisting of simple details but demonstrating more and more complicated behavior. This world of automata and clockworks can be also very frightening as it is expressed in many beautiful works of art and literature, from The Sandman by Hoffmann to contemporary Fellini’s Casanova. Dark mystique and horror of romanticism provided the opposite extreme. The tragic history of XX century has shown in the most terrible way what may be the consequences of two types of idolatry, a cult of unrestricted order and rationality, from one side, and a cult of wild biological instincts, blood and semen, on the other side. Misunderstanding of crucial concepts of the worldview can kill people, and contradictions of complexity and simplicity, memory and spontaneity, chaos and order, ratio and emotions are much more than merely subjects of arts or subtle scientific problems to be solved by the experts, they are true issues of life and death.
Coming back to physics we are just in the very beginning of the long way of scientific understanding of origin of complexity and long-term memory of physical systems. Most probably they arise as a result of competition of different interactions, weak and strong, short-range and long-range. Evolution is an optimization, Darwinian “survival of the fittest”, but the meaning of “fitness” can be dramatically different for different elements and parts of a complex system. Any complex system is pushed by numerous contradictory wishes and requirements acting simultaneously at different levels of its organization. Molecules tend to evolve into the minimum of free energy, genetic elements tend to unrestricted self-reproduction, individual cells tend to their immortality but this tendency, in the form of cancer, kills the whole organism once constrains are eliminated. Randomness and chaotic processes provide the material for selection and for the growth of complexity. Replication unavoidably leads to appearance of parasites but
parasite-host arms race results in the increase of biological diversity and thus in the progressive development, as we usually understand it. “You have to make the good out of the bad because that is all you have got to make it out of”, said a personage of “All the King’s Men” by R. P. Warren, and the biological evolution is the process of making good from evil, because in nature the evil, the growth of entropy, the competing requirements, constrains, controversies and frustrations are all you have got to make it out of.
Importantly, the properties of the whole system do not follow directly from the properties of the constituents, and with the same elemental base we can reach totally different results. The same transistors and electron beams in our TV sets can be used for enlightenment of people, via beautiful performances of Shakespearean plays and Mozart symphonies or telling people on the deepest mysteries of Universe, as well as for the darkening of our minds, via the worst forms of propaganda and manipulation. We are animals obeying all kind of biological instincts. Moreover, we are physical systems consisting of electrons and atomic nuclei and obeying the laws of quantum electrodynamics. Mozart and Einstein were consisting of almost the same chemical compounds as any rat or a skunk. They have shown us what can be reached with this, seemingly disappointing, background. We are what we are but we still can make the world more complicated, more interesting, and more beautiful. Or, at least, we should try.
A second essay by M. I. Katsnelson is forthcoming.