Mysteries of Terra Firma: The Age and Evolution of the Earth

In James Powell book about the evolution of Earth and the dating techniques was interesting to read about. It is amazing how much we can find out about Earth just by studing certain things or by looking into space.

It often amazes me that most students get out of high school with no appreciation of how science is done or how difficult it is to extract information from nature. In James Powell's book, "Mysteries of Terra Firma: The Age and Evolution of the Earth" these themes are repeated again and again as we learn how difficult it was to get away from Lord Kelvin's 20-100 million year estimate of the earth's age, escape the idea that the continents were stable and did not move, and counter the view that asteroids could not have caused the moon to be ejected from the earth. A similar debate is now raging over global climate change, but eventually all of these arguments fall to the weight of evidence. Now (as Powell says) we know that Lord Kelvin was wrong and all of the modern estimates for the earth's age are concentrated around 4.5 billion years. We know that sea-floor spreading, continental motion, and volcanoes and earth quakes, are all tied together by convection in the earth's mantle. We also know that many asteroids and comets have struck the earth, other planets and our moon, and that several caused great disruptions, including separating materials from the planet struck as was the likely case with our own moon. This was brought closer to home by the spectacular impact of Comet Shoemaker-Levy's on the atmosphere of Jupiter, an event who's resulting marks on Jupiter's clouds could be observed (as I did) easily with a ten-inch telescope. On my cabinet I have a rock from South Africa dated at 3.5 billion years. The depth of that long corridor of time is truly difficult to even comprehend, but the secret of this little rock was one of those hard-won from nature. The history of that struggle is exactly the story we need to teach in order to make science understandable to young people. Powell's book is a good place to start.

James Powell has a rare talent for explaining the concepts of science while making the story fresh and exciting. As in his previous book, Night Comes to the Cretaceous, Powell explores the revolutions in our understanding of the Earth's history that took place during the 20th century. Here he selects the three really big discoveries that transformed our view of the world on which we live: dating the Earth (the discovery of deep time), developing the theory of plate tectonics, and recognizing the role of impacts by comets and asteroids that shape the surfaces of both the Earth and the other planets and satellities. I found this to be one of the best books about science that I have read in recent years -- factually accurate yet crafted with the skill of an adventure story.

Mysteries of Terra Firma: The Age and Evolution of the Earth written by James Lawrence Powell is a very well-written, cogent, lucid, and extremely lively book that is about the age of the Earth. Through discoveries in deep time, tectonics and extraterrestrial impacts, the mysteries of time, drift and change have established with admirable clarity how geologists came to discover the true nature of the Earth.This book is a story of three parts... time, drift and change these three profound stories have affected the Earth and life as we know it today. Without knowledge is these three disciplines the true nature of our Earth would still elude us. Have you ever asked yourself, "How old is the Earth, the Universe? How firm the the Earth? How do meterorites affect the Earth? Well, this book takes on these tough questions and gives us some startling answers.First, time... How can we understand the ground on which we walk, or how that ground holds the key to the greatest secerts of deep space time. Lord Kelvin and Ernst Rutherford helped set the stage for the calculations for the solution of the age of the Earth. When they were finished a number 4.5 billion years of geologic time was the answer... the universe is 13.5 billion years old, enough time for our solar system to die and another to be reborn. If this were all condensed to a 24 hour clock, man would only be found on the very last second.Second, drift... Without drift, life would no exist. What the author is talking about is plate tectonics or continential drift. Believe it or not this theory was not accepted when first proposed, by a German meteorologist and polaer explorer Alfred Wegener, espicially in the petroleum industry. So, how firm is Terra Firma... well that depends upon where your perspectives lay... but for all intents and purposes, yes the Earth moves.Third, chance... Throughout geologic time meteorites have been bombarding everything in the solar system. From a grain of sand to a mountain-sized meteorite have flown through space, struck the Earth, killed the dionsaurs and almost everything else on Earth, leaving a very small mammal the size of a hamster as our ancester. Powell says, "The chance of that happening again is essentially zero."Ernst Mayr says much same thing, "...highly intelligent life originated only 300,000 years ago, in a single one of the more than one billion species that had arisen on Earth. These are indeed long odds."If you are looking for a book about the study of the Earth, geology, and plate tetonics, this is a very good choice considering no more than the rocks beneth our feet.

Mysteries of Terra Firma by James Lawrence Powell, author of Night Comes to the Cretaceous, is an excellent introduction to what are arguably the science of geology's greatest contributions to humankind's knowledge of the universe. These great discoveries are the age of the Earth [4.55 billion years old], the theory of plate tectonics, and the knowledge that the impacts of comets and asteroids are an important force in our solar system, including here on Earth. In each of the three sections of the book, Powell takes the reader through the convoluted histories of each of these great discoveries, showing geology and the geologists, warts and all. These histories illustrate the fact that science can be slow and imperfect, but ultimately does a good job at pushing our knowledge of the universe forward. Mysteries of Terra Firma is an excellent read and should be enjoyed by anybody with an interest in geology, the Earth, or the history of science. I also recommend that college and high school earth science teachers append this title to their supplementary reading lists as soon as possible. I thoroughly enjoyed Mysteries of Terra Firma and I think you'll enjoy it, too.