The anthropic coincidences are connections between physical constants that seem to be necessary for the existence of life in the universe and the physical reality we observe. Physical reality defined from the physical and scientific data is limited because it is not only limited by the narrow focus of our instrument and the boundaries of physical laws but also by the observer/experimenter's input in data collection process (observation selection effect.) The anthropic reasoning seeks to explain this physical reality from a philosophical standpoint. There are over 30 anthropic principles and they are tautological (circular reasoning), and hence indisputable, which makes many scientists skeptical about this idea. However, in multiverse concept, where space and time are infinite, then it is possible that fundamental physical constants may have a broad distribution in billions of universes, and in a selected universe it is quite likely that these constant may be fine tuned so that carbon based life (intelligent observers) may evolve. Such an idea avoids the universal selection of constants.
The authors bring a unique combination of skills from their specialized field of study and make every effort to discuss every aspect of anthropic principle, the best thoughts of past and present to make a comprehensive discussion in a meticulous manner. Examples include; does nature limit itself to three spatial and one time dimension at the most fundamental level (chapter 4); the anthropic relationship with cosmological factors (chapter 6); quantum physics and anthropic principle (chapter 7); and chapter 8 on the discussion of biological and statistical considerations in anthropic reasoning. This is also a good book to read about an introduction to quantum physics and cosmology.
The book may be summarized as follows: The idea of anthropic reasoning became apparent when the values of physical constants were considered. For example, the ratio of electromagnetic force to the gravitational force between two electrons is of the order of 10e(39). This is puzzling since pure numbers not associated with any measuring units must be close to unity when describing physical properties. Physicist Herman Weyl first observed this phenomenon and suggested that there may be a universal selection principle in operation. This large disparity is essential for life because if they were of comparable strengths, then the stars would collapse long before life had time to evolve.
The Brandon carter's weak anthropic principle (WAP) states that our location in universe is privileged to the extent of being compatible with our existence as observers, and strong anthropic principle (SAP) states that the universe (and its fundamental constants) must be such that it creates observers. Most constants such as gravitational constants, the speed of light (may be derived form Maxwell's equations), the electric charge, the mass of the electron, and Planck's constants are arbitrary, but the values of these constants make a great deal of difference between the selection of carbon based life (observers) and a universe with no life. For example, the gravitational constant must have the "correct" value to balance the repulsive and attractive forces in the interior of a star so that planetary system could evolve followed by carbon based life. The strong force coupling constants must have the "correct" value so that it holds together the nucleus of an atom together in a relatively stable form. The electromagnetic coupling constants with its "correct" value also hold the electrons and the nucleus in a stable form so that atoms, molecules and complex structures can evolve. If these constants deviate by a narrow range of 1 to 5 percent, atomic configurations wouldn't have existed, and intelligent life would be impossible.
The quantum reality interpreted by the many worlds hypothesis where every possible realization of position and energy of every particle exists. This interpretation resolves the problem of anthropic principle since we live in one of the many universes which support life. The anthropic coincidences are not coincidences after all, they are just one possibility of billions of possibilities that exists parallel to our universe. The cosmic inflationary theory also resolves the problem of anthropic principle in a similar fashion. The inflation at the symmetry breaking point of Grand Unified Theory resulted in enormous amount of energy that expanded spacetime at enormous heights of the order of 10e(54), but the matter moved by the limitations of special relativity. Thus our universe is like a bubble in an infinite number of universes that were formed. Our universe had the appropriate physical constants that lead to the evolution of intelligent life and this was not predetermined or required. Another early subscriber to an ensemble picture of multiverse was physicist Fred Hoyle. His interest in the many possible worlds of the anthropic principle was provoked by his discovery of a remarkable series of coincidences concerning the nuclear resonance levels of biological elements. Just as the electrons of an atom can be considered to reside in a variety of states according to their energy levels so it is with nucleons. Neutrons and protons have analogous spectrum of nuclear energy levels. If nucleons undergo a transition from a high to a low energy state then energy is emitted; conversely, the addition of radiant energy can effect an upward translation between nuclear levels. This nuclear chemistry is a crucial factor in the chain of nuclear reactions that power the stars. In chapter 4 the authors discuss how the resonance energy levels of carbon, beryllium and oxygen are located at the "correct" energy states so that carbon and oxygen (building blocks of life) are formed in nuclear reactions in significant proportions inside the stars.
In conclusion, the constructs of the key features of the natural world is deduced from the knowledge of a few constants of nature. The sizes of atoms, people, and planets are not accidental nor are they the inevitable result of natural selection. Rather, they are consequences of inevitable equilibrium states between competing natural forces of attraction and repulsion.
The authors bring a unique combination of skills from their specialized field of study and make every effort to discuss every aspect of anthropic principle, the best thoughts of past and present to make a comprehensive discussion in a meticulous manner. Examples include; does nature limit itself to three spatial and one time dimension at the most fundamental level (chapter 4); the anthropic relationship with cosmological factors (chapter 6); quantum physics and anthropic principle (chapter 7); and chapter 8 on the discussion of biological and statistical considerations in anthropic reasoning. This is also a good book to read about an introduction to quantum physics and cosmology.
The book may be summarized as follows: The idea of anthropic reasoning became apparent when the values of physical constants were considered. For example, the ratio of electromagnetic force to the gravitational force between two electrons is of the order of 10e(39). This is puzzling since pure numbers not associated with any measuring units must be close to unity when describing physical properties. Physicist Herman Weyl first observed this phenomenon and suggested that there may be a universal selection principle in operation. This large disparity is essential for life because if they were of comparable strengths, then the stars would collapse long before life had time to evolve.
The Brandon carter's weak anthropic principle (WAP) states that our location in universe is privileged to the extent of being compatible with our existence as observers, and strong anthropic principle (SAP) states that the universe (and its fundamental constants) must be such that it creates observers. Most constants such as gravitational constants, the speed of light (may be derived form Maxwell's equations), the electric charge, the mass of the electron, and Planck's constants are arbitrary, but the values of these constants make a great deal of difference between the selection of carbon based life (observers) and a universe with no life. For example, the gravitational constant must have the "correct" value to balance the repulsive and attractive forces in the interior of a star so that planetary system could evolve followed by carbon based life. The strong force coupling constants must have the "correct" value so that it holds together the nucleus of an atom together in a relatively stable form. The electromagnetic coupling constants with its "correct" value also hold the electrons and the nucleus in a stable form so that atoms, molecules and complex structures can evolve. If these constants deviate by a narrow range of 1 to 5 percent, atomic configurations wouldn't have existed, and intelligent life would be impossible.
The quantum reality interpreted by the many worlds hypothesis where every possible realization of position and energy of every particle exists. This interpretation resolves the problem of anthropic principle since we live in one of the many universes which support life. The anthropic coincidences are not coincidences after all, they are just one possibility of billions of possibilities that exists parallel to our universe. The cosmic inflationary theory also resolves the problem of anthropic principle in a similar fashion. The inflation at the symmetry breaking point of Grand Unified Theory resulted in enormous amount of energy that expanded spacetime at enormous heights of the order of 10e(54), but the matter moved by the limitations of special relativity. Thus our universe is like a bubble in an infinite number of universes that were formed. Our universe had the appropriate physical constants that lead to the evolution of intelligent life and this was not predetermined or required. Another early subscriber to an ensemble picture of multiverse was physicist Fred Hoyle. His interest in the many possible worlds of the anthropic principle was provoked by his discovery of a remarkable series of coincidences concerning the nuclear resonance levels of biological elements. Just as the electrons of an atom can be considered to reside in a variety of states according to their energy levels so it is with nucleons. Neutrons and protons have analogous spectrum of nuclear energy levels. If nucleons undergo a transition from a high to a low energy state then energy is emitted; conversely, the addition of radiant energy can effect an upward translation between nuclear levels. This nuclear chemistry is a crucial factor in the chain of nuclear reactions that power the stars. In chapter 4 the authors discuss how the resonance energy levels of carbon, beryllium and oxygen are located at the "correct" energy states so that carbon and oxygen (building blocks of life) are formed in nuclear reactions in significant proportions inside the stars.
In conclusion, the constructs of the key features of the natural world is deduced from the knowledge of a few constants of nature. The sizes of atoms, people, and planets are not accidental nor are they the inevitable result of natural selection. Rather, they are consequences of inevitable equilibrium states between competing natural forces of attraction and repulsion.
Reference: The Anthropic Cosmological Principle by John D. Barrow
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