The Elegant Universe

Brian Greene, “The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory”  Vintage Books, 1999, Paperback Edition  (387 pps.)

This book has been made into a three-part Nova special: a very intriguing journey through the mysteries of space, time, and matter.  I read about fifteen pages at a time and then read something else in the interims.  It requires a lot of thought for the layman.  Brian Greene is one of the world’s leading string theorists.  Although string theory, so far, cannot be tested, it may well be the route to the Unified theory (the search for a theory of everything) Einstein spent the latter part of his life searching for.  But, as it cannot be tested, it may better fit in to philosophy than science. 

The first 134 pages of this book I found very interesting.  However, at page 196 I finally quit as I was a bit in over my head; someday I may return. 

My Notes:  Read to pg. 196

Pg. x:  Superstring theory unifies the laws of the large and of the small, laws that govern physics out to the farthest reaches of the cosmos and down to the smallest speck of matter.  The author focuses on our evolving understanding of space and time. 

Pg. 3:  As they are currently formulated, general relativity and quantum mechanics cannot both be right.  The two theories underlying the tremendous progress of physics during the last hundred years—progress that has explained the expansion of the heavens and the fundamental structure of matter—are mutually incompatible.

Pg. 7:  In 1968 experimenters found that protons and neutrons (which make up atoms) are not fundamental.  Instead they consist of three smaller particles, called quarks.  Quarks themselves come in two varieties, which were named up and down.  A proton consists of two up-quarks and a down-quark; a neutron consists of two down-quarks and an up-quark.

Pg. 10:  During the past hundred years physicists have accumulated mounting evidence that all interactions between various objects and materials, as well as any of the millions upon millions of others encountered daily, can be reduced to combination of four fundamental forces.  One of these is the gravitational force (the weakeast of the four).  The other three are the electromagnetic force, the weak force, and the strong force.

Pg. 24:  Maxwell’s theory showed that all electromagnetic waves—visible light among them—never stop.  They never slow down.  Light always travels at light speed (670 million miles per hour and this is regardless of a benchmark for comparison: i.e., if you could travel toward the light at 100 million miles per hour, the light would still approach you at 670 million miles per hour; likewise for light coming from behind you).

Pg. 47:  The constancy of the speed of light has resulted in a replacement of the traditional view of space and time as rigid and objective structures with a new conception in which they depend intimately on the relative motion between observer and observed.

Pg. 51:  Einstein’s work showed that concepts such as space and time, which had previously seemed to be separate and absolute, are actually interwoven and relative.  He went on to show that Energy (E) of an object and its mass (m) are not independent concepts; we can determine the energy from knowledge of the mass (by multiplying the latter twice by the speed of light, c²) or we can determine the mass from knowledge of the energy (by dividing the later twice by the speed of light). 

Pg. 80: To make a black hole out of the earth we would need to crush it into a sphere whose radius is less than half an inch.  Mounting evidence indicates that there is a very massive black hole, some two and a half million times as massive as the sun, sitting in the center of our own Milky Way galaxy.  And even this seemingly gargantuan black hole pales in comparison to what astronomers believe to reside in the core of the luminous quasars that are scattered throughout the cosmos: black holes whose masses may well be billions of times that of the sun.

Pg. 86:  Quantum mechanics is a conceptual framework for understanding the microscopic properties of the universe.  And just as special relativity and general relativity require dramatic changes in our worldview when things are moving very quickly or when they are very massive, quantum mechanics reveals that the universe has equally if not more startling properties when examined on atomic and subatomic distance scales.

Pg. 107:  According to quantum mechanics, the universe evolves according to a rigorous and precise mathematical formalism, but this framework determines only the probability that any particular future will happen—not which future actually ensues. 

Pg. 130:  The incompatibility between general relativity and quantum mechanics becomes apparent only at the minute size of particles at what has been termed the Planck length: this is at a scale of a millionth of a billionth of a billionth of a billionth of a centimeter (10^-33 centimeter).  To get a sense of scale, if we were to magnify an atom to the size of the known universe, the Planck length would barely expand to the height of an average tree.   Physicists have made numerous attempts at modifying either general relativity or quantum mechanics in some manner so as to avoid the conflict, but with no success.  That is, until the discovery of superstring theory.

Pg. 139:  From 1984 to 1986 more than a thousand research papers on string theory were written by physicists from around the world. 

Pg. 175:  One of the puzzling features of nature’s four forces is the huge range in their intrinsic strengths.  The electromagnetic force has less than 1 percent of the strength of the strong force, the weak force is some thousand times feebler than that, and the gravitational force is some hundred million billion billion billion (10^-35) times weaker still.