Book reviewed: Just Six Numbers: The Deep Forces That Shape the Universe by Martin J. Rees (Paperback - May 2001)
Space, time and matter are principal components of the universe in which matter and energy are interconvertible given by the famous Einstein's energy-mass equation. The structure and functions of the universe are guided by the laws of physics and four principal forces. These forces operate on matter and energy in spacetime to provide structure. The cosmic structures include; the clusters of galaxies, galaxies, clusters of stars, stars, planetary systems and various sub-planetary objects and stellar debris that fill the interstellar and interplanetary space. The atomic and subatomic particles are controlled mainly by the electromagnetic force, the weak force, and the strong force; the gravitational force is very weak and insignificant at the atomic level but plays a dominant role in the structure and functions of large cosmic bodies in the heavens. The classical laws of physics that includes the Newtonian physics and Einstein's theory of relativity are satisfactory in explaining the behavior of macroscopic structures of matter and energy, but the laws of quantum physics are necessary to explain the behavior of microscopic structures. The physical laws are described by equations and mathematical formulas, and these formulas quantitatively describe an observed behavior of matter and energy, and it also predicts unobserved behavior of physical objects.
There are several universal constants that appear in physics equations and in this book the author discusses the fundamentals of cosmology in easy to understand language with a focus on six physical constants that help shape our universe. These constants are as follows: 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. Herman Weyl first observed this phenomenon and suggested that there may be a universal selection principle in operation. A small deviation from this would have produced a universe with no living beings. The structural constant which has a value of 1/137, determines how various atoms are formed from hydrogen, and what made our universe rich in carbon and oxygen that led to the evolution of living forms. A small deviation in this value would not have produced life forms, because enough life supporting carbon and oxygen wouldn't have been formed by the stars. The third constant is the cosmological constant that is very close to unity; if this constant was a little higher then the universe would have collapsed in big crunch, conversely if this constant was a little lower then the universe would have expanded at a tremendous pace without giving the matter the opportunity to undergo mass accretion to produce galaxies, stars and planetary systems. The fourth constant is the lambda - a cosmic antigravity force that controls the expansion of the universe and it has no discernable effect on scales less than a billion light years. This force is responsible for the expansion of our universe. The fifth constant, Q expresses how tightly clusters of galaxies bound together because this constant measures the ratio of the energy needed to break them apart to their rest energy. This value is small about 1/100,000. The sixth constant is the number of spatial dimensions of our universe which is three. In extra dimensions the life forms would have been too complex because the chemistry would have been different. The author sees that these fundamental constants made this universe unique because stars, planetary systems and life could be formed under these conditions.
There are many theories that explain why these constants are so finely tuned; some physicists argue that this is due to anthropic principle, which requires fine tuning of constants for the evolution of life. Others postulate that we are one universe in a multiverse where there are billions of universes, and all possible values for constants exists and ours is unique in that it has the desired values for the evolution of life.
There are several universal constants that appear in physics equations and in this book the author discusses the fundamentals of cosmology in easy to understand language with a focus on six physical constants that help shape our universe. These constants are as follows: 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. Herman Weyl first observed this phenomenon and suggested that there may be a universal selection principle in operation. A small deviation from this would have produced a universe with no living beings. The structural constant which has a value of 1/137, determines how various atoms are formed from hydrogen, and what made our universe rich in carbon and oxygen that led to the evolution of living forms. A small deviation in this value would not have produced life forms, because enough life supporting carbon and oxygen wouldn't have been formed by the stars. The third constant is the cosmological constant that is very close to unity; if this constant was a little higher then the universe would have collapsed in big crunch, conversely if this constant was a little lower then the universe would have expanded at a tremendous pace without giving the matter the opportunity to undergo mass accretion to produce galaxies, stars and planetary systems. The fourth constant is the lambda - a cosmic antigravity force that controls the expansion of the universe and it has no discernable effect on scales less than a billion light years. This force is responsible for the expansion of our universe. The fifth constant, Q expresses how tightly clusters of galaxies bound together because this constant measures the ratio of the energy needed to break them apart to their rest energy. This value is small about 1/100,000. The sixth constant is the number of spatial dimensions of our universe which is three. In extra dimensions the life forms would have been too complex because the chemistry would have been different. The author sees that these fundamental constants made this universe unique because stars, planetary systems and life could be formed under these conditions.
There are many theories that explain why these constants are so finely tuned; some physicists argue that this is due to anthropic principle, which requires fine tuning of constants for the evolution of life. Others postulate that we are one universe in a multiverse where there are billions of universes, and all possible values for constants exists and ours is unique in that it has the desired values for the evolution of life.
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