V & B FORUM
A Close Encounter with Physics
Book Review
by
Kaaren Strauch Brown
Seven Brief Lessons in Physics by Carlo Rovelli. (2014). Translated by Simon Carnell and Erica Segre. New York. Riverhead Books. 84 pp.
I have spent some of my retirement hours unlearning the misinformation fed to me in public school and in a variety of universities, having mainly to do with issues in history. Some other hours have been spent in learning things I didn’t learn about in previous lives. My only brush with physics was an attempt to complete an undergraduate science distribution requirement by taking Physics for Physical Education majors.
“These lessons were written for those who know little or nothing about modern science,” Rovelli announces in his preface. He really means, know little or nothing about modern physics. And let’s start with something really simple—Einstein’s Theory of Relativity, which takes only the same commitment and effort to understand as one would give to one of Beethoven’s late string quartets. This is the author speaking.
In nine pages, Rovelli describes how Einstein’s theory opened a new perspective on the nature of the universe. When I finished reading the lesson, several times (he is a dense although quite clear writer), I could say that although I now understand the revolutionary nature of the perspective—a simple and coherent vision of gravity, space, and time—the details may continue to elude me. I did learn that space is not empty; it’s filled with stuff.
Moving right along, Lesson Two shifts our attention from the workings of space and time to the nature of matter as defined by energy quanta: Quantum Mechanics. That reality seems to be constantly shifting:
I have spent some of my retirement hours unlearning the misinformation fed to me in public school and in a variety of universities, having mainly to do with issues in history. Some other hours have been spent in learning things I didn’t learn about in previous lives. My only brush with physics was an attempt to complete an undergraduate science distribution requirement by taking Physics for Physical Education majors.
“These lessons were written for those who know little or nothing about modern science,” Rovelli announces in his preface. He really means, know little or nothing about modern physics. And let’s start with something really simple—Einstein’s Theory of Relativity, which takes only the same commitment and effort to understand as one would give to one of Beethoven’s late string quartets. This is the author speaking.
In nine pages, Rovelli describes how Einstein’s theory opened a new perspective on the nature of the universe. When I finished reading the lesson, several times (he is a dense although quite clear writer), I could say that although I now understand the revolutionary nature of the perspective—a simple and coherent vision of gravity, space, and time—the details may continue to elude me. I did learn that space is not empty; it’s filled with stuff.
Moving right along, Lesson Two shifts our attention from the workings of space and time to the nature of matter as defined by energy quanta: Quantum Mechanics. That reality seems to be constantly shifting:
“In quantum mechanics, no object has a definite position except when colliding headlong with something else . . . . These interactive leaps with which each object passes from one place to another do not occur in a predictable way but largely at random.” (p.18)
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And so, quantum mechanics does not describe what happens in physical systems. That remains mysterious, even to physicists. The theory does describe how one physical system affects another physical system. The mathematical equations that describe quanta in midflight, between one interaction and another, underlie all of modern technology. Einstein did not approve of the theory. “God does not roll dice with the universe,” is his famous critique. Rovelli blithely suggests that one can accept both Einstein’s Theory of Relativity and Quantum Mechanics. It does require simultaneously holding two contradictory theories in one’s mind.
Lesson Three comes as relief to any follower of science fiction as it deals with the architecture of the cosmos. Simple drawings demonstrate our growing knowledge of our universe, and demonstrate the shrinking place of human beings in that universe.
Electrons, quarks, photons, and gluons (they glue quarks inside photons and neutrons) are the building blocks of our material reality. Lesson Four describes the nature of Particle Physics as an inelegant patchwork of ideas and concepts that work well in describing the world around us. Doesn’t account for dark matter, but then, you can’t have everything. This is what it does do:
Lesson Three comes as relief to any follower of science fiction as it deals with the architecture of the cosmos. Simple drawings demonstrate our growing knowledge of our universe, and demonstrate the shrinking place of human beings in that universe.
Electrons, quarks, photons, and gluons (they glue quarks inside photons and neutrons) are the building blocks of our material reality. Lesson Four describes the nature of Particle Physics as an inelegant patchwork of ideas and concepts that work well in describing the world around us. Doesn’t account for dark matter, but then, you can’t have everything. This is what it does do:
“A handful of elementary particles, which vibrate and fluctuate constantly between existence and non-existence and swarm in space even when it seems that there is nothing there, combine together to infinity like the letters of a cosmic alphabet to tell the immense histories of galaxies; of the innumerable stars; of sunlight; of mountains, woods, and fields of grain; of the smiling faces of the young at parties; and of the night sky studded with stars.” (p. 38)
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And that brings us to Loop Quantum Gravity, Lesson Five, which describes the end of ideas of time and the end of space as notions that have a fixed nature:
“. . . the dance of nature does not take place to the rhythm of the baton of a single orchestral conductor, at a single tempo: every process dances independently with its neighbors, to its own rhythm.” (p. 44)
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Black Holes, heat, and time (and perhaps time for me to throw up my hands and admit to complete non-comprehension) are the topics for Lesson Six. The author recasts this as, okay, we know what we don’t know but we hope that, someday, we will know the relationship between heat and time. What about Black Holes? Well, they are hot all the time. This lesson ends with the suggestion that Black Holes will be the Rosetta stone of physics, revealing the true nature of time once deciphered.
In the last lesson, Rovelli reveals himself to be a better communicator about physics than a philosopher as he discusses the difference between science and myth, as if science were not a series of stories searching for the nature of the real world, each story to be validated before the next can be constructed. The author is a pessimist, assuming that our lack of acceptance of the nature of reality, our preference for the stories of myth, and our distrust and fear of science will lead to the end of humanity.
This short book is Rovelli’s attempt to lead us to the wonders of nature. “Nature is our home and in nature we are at home.” Although the ideas can be difficult, they are clearly presented. The reader is amply rewarded by the acquisition of new perspectives on our physical universe, despite, perhaps, not understanding everything completely.
In the last lesson, Rovelli reveals himself to be a better communicator about physics than a philosopher as he discusses the difference between science and myth, as if science were not a series of stories searching for the nature of the real world, each story to be validated before the next can be constructed. The author is a pessimist, assuming that our lack of acceptance of the nature of reality, our preference for the stories of myth, and our distrust and fear of science will lead to the end of humanity.
This short book is Rovelli’s attempt to lead us to the wonders of nature. “Nature is our home and in nature we are at home.” Although the ideas can be difficult, they are clearly presented. The reader is amply rewarded by the acquisition of new perspectives on our physical universe, despite, perhaps, not understanding everything completely.
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