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Evolutionary Theory Cosmic Evolution
Starting off with definitions, Chaisson defined cosmic evolution as "the study of the many varied developmental and generative changes among all radiation, matter, and life throughout the history of the universe." Although the rate of change varies throughout the history of the universe, the fact of change is constant—an observation noted as far back as the 6th century B.C. by the Greek philosopher Heraclitus. From Chaisson’s perspective as an astrophysicist, cosmic evolution is a larger rubric under which Darwinian evolution is but a smaller subset. Looking for a broader, more inclusive "selective force" at work in the universe, Chaisson thinks that we may soon discover the rules of "cosmic selection" which supercede the terrestrial rules of natural selection. And in this light, our budding planetary civilization—if it can develop a true set of planetary ethics—will be "selected for" by the universe to survive and thrive as a locus of life in the universe. But if we don’t develop such ethics, then we will, also by virtue of cosmic selection, be left behind in the grand scheme of cosmic evolution. A Cosmic Weltanschauung Chaisson argues that the fields of astrophysics and biochemistry are each part of a broader scientific enterprise that is building a truly grand narrative, a big bang to humankind story that can potentially serve as our larger heritage and an all- encompassing worldview, a Weltanschauung, to guide our planetary civilization. This worldview will be based in scientific philosophy and make use of the vast empirical, observational data that has been accumulated over the past four hundred years by the scientific enterprise. Irreversibility: The Arrow of Time Some astrophysicists earn their dollars by arguing over the age of the universe. Is it 15 billion years old or 12? Regardless of the exact age of our universe, Chaisson pointed out that what is not in dispute is the irreversible sequence of events that have occurred in that time span. In contrast to Newton’s time-symmetric worldview that dominates so much of physics, Chaisson maintains there is a direction to time and a way to measure it (see below "free energy rate density"). Summarizing the many years of work by observational physicists, Chaisson showed that sequentially there were particles first, then galaxies, then stars, then planets, then life. There is a continuous and irreversible thread of change in the universe. For example, so far as we can tell from our observations using the Hubble telescope, no more galaxies are forming today. There was a time in the universe’s early age when the seeds of galaxies, called quasars, were "planted" and none is observable in the present epoch. This indicates a clear trend over time. At one stage in the universe galaxy formation was possible, and then eventually, that window of opportunity closed. Reporting on research at the CERN particle physics laboratory in Switzerland, Chaisson noted that 1.3 million high-speed sub-atomic collisions events recently had been studied. The result of this research implies a slight asymmetry in the universe. According to these data, time is indeed irreversible, because for every anti-kayon elementary particle, there is a 1% probability that it will decay into a kayon, and thereby provide the constituent "stuff" needed to form matter. The Increase in Complexity Defining complexity as, "the state of intricacy, complication, variety or involvement among in the inter-connected parts in a system. The amount of information content in a system, the amount of energy density flowing through an open thermodynamic system," Chaisson indicated that when we plot the rise of complexity in the universe on a chart, we derive not just an exponential but a hyperbolic curve depicting its rise. Amazingly, this rise of complexity in the universe could not have happened by chance alone. Mathematicians have shown that by random events alone the universe would have taken upwards of 100 billion years to form the complexity we observe all around us. Thus, Chaisson emphasized that there is a creative balance at work in the universe between chance (fluctuations of the environment) and necessity (natural selection of systems) that drives the rise of complex structures. The Greatest Change of All Time What could this possibly be? According to Chaisson, it is nothing less than the shift from a universe dominated by radiation—raw seething energy in the early universe—to one dominated by matter, by structure, by "stuff." This epochal shift occurred when the universe was young—the best estimates are after the first three minutes and before 100,000 years after the Big Bang. During this window in time, the universe had expanded enough and cooled enough so that ubiquitous photons of light could decouple from electrons. This enabled electrons to bond with atomic nuclei to form the base constituents of matter, such as hydrogen and helium, which were the only two elements created before the birth of stars. All other elements on the periodic table had to wait until galaxies and stars formed. Showing a slide of one of the most famous pictures of all time, the Hubble Deep Field, Chaisson noted that before the Hubble telescope was launched, scientists estimated there are anywhere from 10 to 100 billion galaxies in the universe. Now that estimate has been narrowed to around 40 billion. (In each galaxy there are estimated to be 100,000,000,000 stars. It is also estimated that there are 1068 atoms in a galaxy. And there is estimated to be 10 79 particles in the observable universe.) Free Energy Rate Density What empirical evidence is there for cosmic evolution? What consistent quanitative changes occur in the history of our universe? Chaisson argues that he has found an appropriate measuring tool for this task in the "free energy rate density." Pointing out that many people confuse this term with total energy, Chaisson noted that a sun/star has a tremendous amount more total energy than a human brain, yet a brain has a much greater density of energy flowing through it than any portion of any known star. What does this mean? If we measure the energy density of something in the universe, we are measuring the amount of energy that flows through a given unit of space. The common measurement unit is ergs per second per cm3. Our sun has 4 ergs per second per cm3, while the human brain has a much larger density of 150,000 ergs per second per cm3. Using a chart, Chaisson showed that a hyperbolic curve—not just exponential—displays the rise of this energy density rate over the course of the universe’s age from stars to planets to plants to animals to the human brain. The curve has a clear direction upward in free energy rate density. The universe seems to be irreversibly evolving the ability for ordered systems to optimize the rate at which energy transits them. The Cause: Cosmic Expansion The question looms: what drives this relentless rise of complexity, the rise of greater densities of energy flow? Nothing less than the expansion of the universe itself is responsible for the rise of complexity. In 1914 Albert Einstein through his own brilliance at mathematics discovered with his General Theory of Relativity that the universe must be either expanding or contracting. Such a shock to his Newtonian belief in a static universe, Einstein doctored his own equations to obscure this seemingly startling fact of the universe’s expansion. Approximately 15 years later, the observational cosmologist, Edwin Hubble, came to the same conclusion by observing the recession of the galaxies through his telescope in Palomar, California. Today, cosmologists have confirmed Hubble’s discovery that the universe has been expanding since its birth billions of years ago. Yet, the twist that Chaisson has added to the story is to show how that very expansion is the cause for the rise of complexity in the universe. As it expands, the universe transforms its immense reservoirs of kinetic energy. That is, the expansion of the universe takes energy and makes it possible for structures to use it in their growth towards complexity. The very expansion of the universe unpacks its available energy. In accord with the 1st Law of Thermodynamics, the total energy of the universe never changes; it just becomes more readily available for use. Furthermore, it is the initial break in symmetry shortly after the Big Bang that enables the flow of energy in the first place. Drawing upon the non-equilibrium thermodynamics described by Ilya Prigogine, Chaisson noted that the complex structures of the universe, such as life on our planet, are open systems, which means that they take in and give off energy constantly. There is a constant flow in and out. For example, the rise of complexity on the planet earth is due to the fact that the earth takes in the energy of the sun every day, and this free energy flow is necessary for the rise of complexity. A Cosmic Framework for Life From the astrophysical perspective, Chaisson defined life as "an open, coherent, spacetime structure maintained far from thermodynamic equilibrium by a flow of energy through it—a carbon-based system operating in a water-based medium with higher forms metabolizing oxygen." Within the larger framework of cosmic evolution, Chaission reasons that we can understand life and human life, in particular, in a new light. With the "free energy rate density" that describes all ordered structures, we now have discovered a modern version of the Platonic Form that underlies the very warp and woof of the universe. Addressing the often asked question—How do we reconcile the rise of complexity with the 2nd Law of Thermodynamics?—Chaisson noted that we must always remember that islands of complexity, in which there are high rates of free energy rate density, exist within seas of disorder. The rise of complexity is not a contradiction to the 2nd Law but rather its complement. Who Started It All? Concluding with some speculative thoughts about the perennial "million dollar question," Chaisson offered that the zero-energy vacuum may have served as the origin of the universe. A slight quantum fluctuation led to the Big Bang, which 15 billion years later led to us. Ending with a cosmic joke, Chaisson said that the next time you meet someone and want to summarize the 15 billion year history of the universe in one line, you can say to them humorously: Hydrogen is a light odorless gas, which, when given enough time, changes into people!
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