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Henning Genz - Nothingness: The Science of Empty Space

"The experiments at the LEP collider have shown us many times that all virtual particles need in order to become real is energy. Now, we might argue that the energy needed for the passage from virtual particles to real ones could become available by that very passage." (page 234)
Can there be space independent of things? How can something come from nothing? Why something rather than nothing? Genz poses these questions and dozens more. Overall--and especially during the first half of the book--the discussion is more philosophical than scientific. "The Philosophy and Science of Empty Space" would have been a more accurate subtitle.

The reader is taken through a near complete history of what people have thought about the nature of space and the nature of 'nothingness'. This includes pre-Platoian times, Plato, Aristotle, the Scholastic philosophers, Galileo, Newton, Leibniz, Descartes, and the modern scientists who have left us with experimental evidence that we are really dealing with a quantum mechanical vacuum filled with fluctuations. Although the history of these ideas is important and frequently interesting Genz can go beyond what many people are expecting or wanting to read. Chapter 2, for instance, rambles for much of its 64 pages.

The point Genz hammers home through this history lesson is that vacuums were once thought to be impossible, then thought to be probable, and are just now (during the past hundred years of experimentation and observation) known to be impossible. He states on page 207 that "there is no such thing as absolutely empty space. All space contains fluctuating fields and particles. Even in the emptiest space that the laws of nature permit, there are energy levels about which the energies of the fields and particles fluctuate; and these energy levels are never sharply defined." Essentially, as space is created it is given some properties of 'non-emptiness'.

Similar to the vacuum fluctuations the book describes, Genz's prose and topic choice oscillate between engrossing and dull, scientific and philosophical. Part of this 'dullness' may be due to the reader's background. I found the topics I was completely unfamiliar with to be more 'dull'.

Although the original German version of Nothingness (entitled Die Entdeckung des Nichts) was published in 1994, several more recent works and studies are cited. Usually, these are mentioned in passing as if they were thrown in before publication rather than adequately incorporated into the flow of the narrative. Two recent possible 'finds' regarding travel faster than the speed of light and neutrino mass were either missed or only brought to light after the final English version was completed. Both would have added substance to a few of the discussions (for instance the section on page 300 entitled "What Dominates The Universe").

Genz uses water and its various states as an analogy for the 'nothingness' and matter in the universe. When water freezes or vaporizes via a change in temperature, do the laws of nature change, or is it a change in the "ground state"? Obviously the latter is the correct response. Similarly, the changes in temperature, fields, pressure waves, currents, and reactions with other 'substances' can change the vacuums and matter in the universe (especially in the very early universe now simulated on computers and at particle accelerators). To do this he explains various topics including the inflationary universe, Higgs fields, zero-point energy, Einstein's famous E=mc2 equation, and Edward Tryon's scenario in which the universe is one gigantic vacuum fluctuation with total energy (and hence mass) equal to, or close to, zero.

"...there may be something that has less energy than nothing--charges or masses at close proximities can realize these conditions... quantum mechanical fluctuations have a lifetime that increases with diminishing energy... If [the universe's] total energy equals or approximates zero, it may have originated as a spontaneous vacuum fluctuation. We might imagine that there is an approximate cancellation between the negative potential energies of all the masses that attract each other in the universe and the motion (or kinetic) and mass energies of these configurations, keeping Einstein's E=mc2 in mind." -- page 261
There are a couple of other minor critiques I have of Nothingness. Several topics are not dealt with in enough detail for comprehension of subsequent statements made by Genz. If nothing else, his fairly superficial treatment of inflation (similar to that of Martin Rees) makes me want to read Alan Guth's The Inflationary Universe again. Likewise, his introduction, in the Epilogue no less and with only a page or two to go in the book, of baby universes and wormholes leaves the reader wondering if portions of the book were tossed together at the last moment.

Nothingness is not a light read by any means. But if you are interested in the subject and able to get through the first half of the book, the scientific aspects found in the later chapters are fascinating. Be careful not to meet up with your anti-you or the two of you may be sucked back into the nothingness that makes up this vacuum fluctuation known as our universe.

"...every particle has its antiparticle of opposite charge and that particle plus antiparticle are nothing but an excitation of the vacuum, accessible from the Dirac sea once there is enough energy for the transition. Conversely, every real particle-antiparticle pair can annihilate into a pure energy excitation of the vacuum. These are the results that count; and the uncertainty relation tells us that pair creation and pair annihilation happen in the vacuum at all times, in all places." -- page 205
From the publisher:
This is a wonderful book on one of the most puzzling problems of physics and philosophy: Does empty space have an existence independent of the matter within it? Is "empty space" really empty, or is it an ocean seething with the creation and destruction of virtual matter? With crystal-clear prose and over a hundred cleverly rendered illustrations, physicist Henning Genz takes the reader from the metaphysical speculations of the ancient Greek philosophers, through the theories of Newton and the early experiments of his contemporaries, right up to the latest theories of quantum physics and cosmology to give us the story of one of the most fundamental and puzzling areas of modern physics and philosophy.

Henning Genz is a professor of theoretical physics at the University of Karlsruhe, Germany. [an error occurred while processing this directive]