Nature's clocks : how scientists measure the age of almost everything /

Nature's Clocks is a well-written book about radiometric dating, the only method that gives scientists an accurate measure of geologic time. The work combines historiographic reviews of the important developments in the field of geochronology beginning with the discoveries of radioactivity in the 19th century. Macdougall (Scripps Institution of Oceanography, Univ. of California, San Diego) uses his expertise to add anecdotal details of the scientists who perfected dating techniques during the 20th century. Carbon-14 dating and the history of its development are covered in some depth. This is followed by chapters on dating the age of the Earth, the relation of absolute dating to the stratigraphic record, the rise of potassium-argon dating, and the dating of more recent events during glacial times. The book ends with detailed appendixes which provide some of the mathematics behind the science and a nice glossary. Macdougall is also the author of Frozen Earth (CH, Mar'05, 42-4038). Summing Up: Recommended. General readers and all undergraduate students. P. K. Strother Boston College

When most people read about dating an ancient artifact, we think of carbon-14 dating. But as earth scientist Macdougall (Frozen Earth) tells readers, carbon dating works only if the object contains carbon, and then it can't be more than about 50,000 years old. Many other elements are radioactive, allowing, for example, for a potassium-argon dating system of volcanic and Precambrian rocks, and other applications in studying archeology and human evolution. Macdougall says that scientists have used these various radiometric dating systems for research as far-flung as dating the age of the solar system, figuring out when humans immigrated to the North America and when the Neanderthals died out, determining that a huge tsunami was created by a massive earthquake off the Northwest Pacific Coast in 1700 and nailing down the age of the Shroud of Turin (it dates to the Middle Ages, though controversy persists). Science buffs from all fields along with general readers will find this a helpful handbook on how we are now able to travel to the distant past. B&w photos, line drawings, map. (June) (c) Copyright PWxyz, LLC. All rights reserved

Since the late 1800s, scientists have used "nature's clocks" to measure Earth's age, human beginnings, evolution, and extinctions. In one of the few overviews of geochronology, Macdougall (earth sciences, Univ. of California's Scripps Inst. of Oceanography) looks at fixed dating via decay rates of radioactive isotopes of carbon, uranium, and potassium. He examines relational dating via dendrochronology, ice cores, and stratigraphy. And he tells the stories of the scientists who teased out these techniques with excruciating patience. Although the prose is serviceable rather than soaring, and the opening and closing chapters are slightly unfocused, the heart of the book reveals ingenious science. From assessing zircon crystals in a clean room to measuring greenhouse gases in the ocean, scientists use nature's clocks to clarify the formation and composition of our world. Giving a sense of the scope of early discovery, Macdougall writes, "...in little more than a decade, the prevailing view about the Earth's age had shifted from Lord Kelvin's 20 million years to more than 1.5 billion years." Recommended for public and undergraduate libraries.--Michal Strutin, Santa Clara Univ. Lib., CA (c) Copyright 2010. Library Journals LLC, a wholly owned subsidiary of Media Source, Inc. No redistribution permitted.