A New Perspective
July 9, 2017 § 2 Comments
I recently read Astrophysics for People in a Hurry, by Neil deGrasse Tyson. It was not merely a pleasure, it was, for me, a rare and valued event: It changed my mind in some significant ways. At my age, most things I read simply entertain me or elaborate ideas I long ago incorporated as part of my belief and understanding. The exceptions I regard with surprise and appreciation. The last comparable event occurred when I read Capital in the Twenty-First Century by Thomas Picketty.
Professor Tyson has impressive credentials as an astrophysicist. In addition he is a deft writer capable of writing crisp prose packed with information in language easily understood by someone like me: a person with only a dabbler’s acquaintance with physics. His occasional interjection of humor made reading his book a pleasure.
In The Beginning
The book begins with a sentence I classify as an all-time winner as a “grabber”: “In the beginning , nearly fourteen billion years ago, all the space and all the matter and all the energy of the known universe was contained in a volume less than one-trillionth the size of the period that ends this sentence.” You have to be really jaded not to respond with “WOW!” when that sentence sinks in.
The Professor proceeds to describe, in near infinitessimal time segments, the process of the univers’s creation following the “Big Bang”, a gigantic explosion releasing all of the contents packed into the tiny dot described in his opening sentence. A nonosecond is a billionth of a second. A picosecond is a trillionth of a second. Some of time sequences pertinent to the development of the universe occurred in fractions of these terms.
For the first 380,000 years, the expanding universe was too hot and the vlocity of its component parts was too great to be visible to human eyes and instruments. Thereafter, the swirling sea of energy and precursors of atoms slowed to reach temperatures low enough for some components, affected by gravity according to Einstein’s General Theory of Relativity (E=mc²), to form connections and begin the process of creating atoms and the process of creating matter that ultimately became our universe and its inhabitants, including us.
The Secret Life of the Cosmos
I was fascinated by two aspects of the material in this book: The description of the spatial environment in which we live. And the creative genius of the scientists who have probed its secrets and made possible our appreciation of its mysterious majestic reality.
The universe consists of matter and energy, but both of these components come in two flavors: ordinary and dark. There is six times as much dark matter in the universe as ordinary, everyday, the-kind-you-see matter. Dark matter is essential because, although we can’t see it and nobody knows much about it, gravity reacts to it and it provides a vital component which makes the system understandable as an orderly complex.
Dark energy emerged as the solution for another problem. No one knows what it cosists of but its effect has been discovered and calculated. There are two ways of measuring the distance from Earth to galaxies in far distant parts of the universe: One way measures the progressive changes in their luminosity as they recede. The second way calculates their velocity as they recede by measuring their movement relative to known points in their path.
A problem arose because the results of these two methods resulted in differing distances. The solution was finally achieved by discovering that what was hitherto regarded as empty space was, in fact, not empty. It was rife with particles of energy and matter which appeared and were destroyed too quickly to be measurable but which caused a kind of energy opposed to the gravitational force driving the expansion of the universe.
Einstein had earlier postulated the existence of this phenomenon but had become convinced that his calculations were in error. He described the episode as his greatest “blunder”. Years later, those who were wrestliing with the enigma of the two conflicting measurement techniques, returned to Einstein’s hypothesis he had named Lambda. They found that if they added Lamba to the comparison of the two measuring techniques, it neatly served as a perfect and predictable constant to resolve the conflict. You really must be a genius if your “blunders”, years after you die, become trusted useful tools.
So, to summarize, while we don’t yet know what dark energy and dark matter are, we can measure them, we know they exist and they enable us to predict the future of the expanding universe in which we live.
This book is full of references to very smart creative men and women who have begun to unravel and understand the nature of the universe. The most extraordinary member of this pantheon is, of course, Albert Einstein. The book describes him as a young man living in Germany when the Nazis rose to power.
The managers of the Third Reich drafted all scientists into service for their military and social aims. Based on their doctrinaire anti-semitism, they segregated the Gentiles from the Jews. They assigned the Gentiles to the tasks considered more prestigious: working in laboratories. They put the Jews in offices to engage in mental speculation and the production of written reports.
The outcome of this hateful decision turned out to be the kind of mistake illustrated by Uncle Remus in his tale of an enemy throwing Brer Rabbit into the briar patch, oblivious of the fact that the briar patch was BR’s natural habitat.
Rather than rephrase Professor Tyson’s homage to Professo Einstein, I offer it is his own words because I can’t improve on it:
“Albert Einstein hardly ever set foot in the laboratory; he didn’t test phenomena or use elaborate equipment. He was a theorist who perfected the ‘thought experiment,’ in which you engage nature through your imagination, by inventing a situation or model and then working out the consequences of some physical principle.
In Germany before World War II, laboratory-based physics far outranked theoretical physics in the minds of most Aryan scientists. Jewish physicists were all relegated to the lowly theorists’ sandbox and left to fend for themselves. And what a sandbox that would become.
As was the case for Einstein, if a physicist’s model intends to represent the entire universe, then manipulating the model should be tantamount to manipulating the universe itself. Observers and experimentalists can then go out and look for the phenomena predicted by that model. If the model is flawed, or if the theorists make a mistake in their calculations, the observers will uncover a mismatch between the model’s predictions and the way things happen in the real universe. That’s the first cue for a theorist to return to the proverbial drawing board, by either adjusting the old model or creating a new one.
One of the most powerful and far-reaching theoretical models ever devised, already introduced in these pages, is Einstein’s general theory of relativity—but you can call it GR after you get to know it better. Published in 1916, GR outlines the relevant mathematical details of how everything in the universe moves under the influence of gravity. Every few years, lab scientists devise ever more precise experiments to test the theory, only to further extend the envelope of the theory’s accuracy. A modern example of this stunning knowledge of nature that Einstein has gifted us, comes from 2016, when gravitational waves were discovered by a specially designed observatory tuned for just this purpose.
These waves, predicted by Einstein, are ripples moving at the speed of light across the fabric of space-time, and are generated by severe gravitational disturbances, such as the collision of two black holes. And that’s exactly what was observed. The gravitational waves of the first detection were generated by a collision of black holes in a galaxy 1.3 billion light-years away, and at a time when Earth was teeming with simple, single-celled organisms.
While the ripple moved through space in all directions, Earth would, after another 800 million years, evolve complex life, including flowers and dinosaurs and flying creatures, as well as a branch of vertebrates called mammals. Among the mammals, a sub-branch would evolve frontal lobes and complex thought to accompany them. We call them primates. A single branch of these primates would develop a genetic mutation that allowed speech, and that branch—Homo sapiens—would invent agriculture and civilization and philosophy and art and science. All in the last ten thousand years.
Ultimately, one of its twentieth-century scientists would invent relativity out of his head, and predict the existence of gravitational waves. A century later, technology capable of seeing these waves would finally catch up with the prediction, just days before that gravity wave, which had been traveling for 1.3 billion years, washed over Earth and was detected. Yes, Einstein was a badass.”
Reading this book and wrting about it has been a pleasant relief from angrily following Donald Trump’s antics at the G-20 meeting. He has surely removed all doubt about his reckless ignorance and his disgusting admiration and fawning attraction to brutal bullies like Vladimir Putin and the present president of Egypt. It will take generations to restore the reputation of America as an admired leader of the western world. We can only hope that process will begin before this idiot involves us in a nuclear war.
If you have any curiosity about the cosmos I heartily recommend Professor Thomas’ book. I have hardly scratched he surface of he information he has packed into about 200 pages of well written prose.
When I read this book and realized it had changed my way of thinking about the past and the future, I was reminded of one of my favorite movies. Inherit the Wind. It is based on the “Monkey Trial” in which Clarence Darrow defended a science teacher in Tennessee who was charged with a criminal offense for violating a state law prohibiting the teaching of evolution. William Jennings Bryan represented the prosecution. The movie features two of Hollywood’s finest actors, Spencer Tracy as Darrow and Frederic March as Bryan.
The movie and the real life event illustrated how science and information compel intellectual changes. Here is a clip portraying Tracy’s devastating cross examination of March:
It begins with an ad. You can skip it after 10 seconds. Enjoy.