George Gamow was a leading scientist of the 20th century, a man who's name frequents the pages of modern-day science. One of the great services offered by Dover Books is the manner in which they have made timeless books by the world's great scientists available at a reasonable price. I consider it remarkable that, for a few dollars, I could sit at Gamow's feet by reading "Gravity."
This is a short book, barely 150 pages long. Written in the second half the 20th century (1960s) it doesn't have any new or particularly earth-shattering information, but information content isn't always the best way to measure a book; there's the delivery, too. And this book, this little gem, has one of the best deliveries I've seen. That's what I appreciated most about "Gravity," the nuances of Gamow's writing and explanatory style.
Several weeks before I found Gamow's book in the bookstore, I'd planned a solo kayak trip down the Columbia River, from the town of Saint Helens to the Pacific Ocean. I was looking for something to read during breaks, and in the evening. This is an ideal book for leisure reading, it's not too involved, has very little mathematics, and yet has enough intellectual content that it leaves you feeling accomplished after an hour or two of study. If you've ever picked up a copy of Scientific American magazine and read some of the articles, that'll give you a pretty good idea of what's in this book. In fact, some of the material in the book is based on articles written by Gamow for Scientific American. My copy, stained with river water, has bleached, tattered, dog-eared pages.
There's a short (6 pages) but interesting biography at the beginning of the book, followed by a preface to the Dover edition, followed in turn by Gamow's preface to the original edition. I enjoyed this introductory material for the light it shone on Gamow's life. I was humbled by the fact that, while I considered my trip down the Columbia River to be of some merit, Gamow had the nerve to attempt (unsuccessfully) escaping from the Soviet Union by paddling a kayak 170 miles across the Black Sea to Turkey.
The first four chapters of Gamow's book follow the same outline used by my high school physics teacher, Mr. Lewis. The first chapter, titled "How things fall" is a historical recounting of Galileo, the tower of Pizza, and balls rolling on ramps, along with some stinging insight into the history of human thought. I particularly liked this commentary from Gamow:
"For centuries Aristotelian philosophy and scholasticism dominated human thought. Scientific questions were answered by dialectic arguments (i.e. by just talking), and no attempt was made to check, by direct experiments, the correctness of the statements made."
Galileo, of course, dispatched the dialectic arguments by conducting experiments, and in the process helped to establish the core scientific ideas of experimentation and observation.
Following tradition Gamow explains gravity by tracing history, with key historical events relegated to various short chapters He begins with Galileo's experiments that showed how things fall at constant acceleration, independent of mass, and then moves to Newton's quantitative treatment and one of history's great insights: that the same force that makes apples fall to the ground also causes the moon to orbit the earth.
You can't study physics without speaking the language, and the language of physics is mathematics. With that admission Gamow takes a brief hiatus from the physical manifestation of gravity to describe the most significant dialect of mathematics, the calculus. Still, this book shouldn't be thought of as mathematically intense. If you've mastered algebra you'll have no difficulty following Gamow's arguments, and indeed the book will help you with some of the preliminary concepts in calculus.
With the basic physics and mathematics established as foundational material, Gamow uses these tools to explain planetary orbits, the motion of the spinning earth (the earth as a spinning top) tides, key concepts in celestial mechanics, and the notion of escape velocity. He ends his book with a short qualitative description of Einstein's General Theory of Relativity and then poses some unsolved problems associated with gravity.
Two remarkable things struck me when reading Gamow's book. First, I'm amazed at how far we've come in understanding gravity and predicting the behavior of gravitational bodies. Second, I'm struck by the fact that, in spite of our best efforts, none of the unsolved problems described in Gamow's final chapter have been resolved.
This isn't to say there haven't been wonderful discoveries since Gamow (black holes, for example), but we seem to be stuck when it comes to making the next great jump in our understanding of what, exactly, gravity is. Written in 1962, this clearly isn't a contemporary book in which you'll find the latest research. Read it for its historical value, and to understand key concepts in Newtonian physics, and for the love of science.