"A lucid and engaging account of the scientific revolution that changed the way we think about our planet and ourselves."—James Lawrence Powell, author of Grand Canyon and Mysteries of Terra Firma

"Radioactivity is like a clock that never needs adjusting," writes Doug Macdougall. "It would be hard to design a more reliable timekeeper." In Nature's Clocks, Macdougall tells how scientists who were seeking to understand the past arrived at the ingenious techniques they now use to determine the age of objects and organisms. By examining radiocarbon (C-14) dating—the best known of these methods—and several other techniques that geologists use to decode the distant past, Macdougall unwraps the last century's advances, explaining how they reveal the age of our fossil ancestors such as "Lucy," the timing of the dinosaurs' extinction, and the precise ages of tiny mineral grains that date from the beginning of the earth's history. In lively and accessible prose, he describes how the science of geochronology has developed and flourished. Relating these advances through the stories of the scientists themselves—James Hutton, William Smith, Arthur Holmes, Ernest Rutherford, Willard Libby, and Clair Patterson—Macdougall shows how they used ingenuity and inspiration to construct one of modern science's most significant accomplishments: a timescale for the earth's evolution and human prehistory.

Clear and accessible introduction to the concept of time examines measurement, historic timekeeping methods, uses of time information, role of time in science and technology, and much more. Over 300 illustrations.

Pulsars are rapidly spinning neutron stars, the collapsed cores of once massive stars that ended their lives as supernova explosions. In this book, Geoff McNamara explores the history, subsequent discovery and contemporary research into pulsar astronomy. The story of pulsars is brought right up to date with the announcement in 2006 of a new breed of pulsar, Rotating Radio Transients (RRATs), which emit short bursts of radio signals separated by long pauses. These may outnumber conventional radio pulsars by a ratio of four to one. Geoff McNamara ends by pointing out that, despite the enormous success of pulsar research in the second half of the twentieth century, the real discoveries are yet to be made including, perhaps, the detection of the hypothetical pulsar black hole binary system by the proposed Square Kilometre Array - the largest single radio telescope in the world.

Help children measure and tell time by the sun, the clock and the calendar; and learn why there are 24 hours in a day, 7 days in a week and 365 days in a year. Here's a cross-curriculum approach to time with learning activities that bring together history, science, language arts and math. A comprehensive look at time from the ancient civilizations who first tried to understand, arrange and measure it - to modern society where we organize our lives around the clock!

From the New York Times-bestselling author of The Secret World of Weather and The Lost Art of Reading Nature’s Signs, learn to notice nature’s hidden clues all around you “A captivating guide to finding one’s way in the wild.”—The Wall Street Journal Publisher's note: The Nature Instinct was published in the UK under the title Wild Signs and Star Paths. Master outdoorsman Tristan Gooley was just about to make camp when he sensed danger—but couldn’t say why. After sheltering elsewhere, Gooley returned to investigate: What had set off his subconscious alarm? Suddenly, he understood: All of the tree trunks were slightly bent. The ground had already shifted once and could easily become treacherous in a storm. The Nature Instinct shows how we, too, can unlock this intuitive understanding of our surroundings. Learn to sense the forest’s edge from deep in the woods, or whether a wild animal might pose danger—before you even know how you know.

Astronomy Methods is an introduction to the basic practical tools, methods and phenomena that underlie quantitative astronomy. Taking a technical approach, the author covers a rich diversity of topics across all branches of astronomy, from radio to gamma-ray wavelengths. Topics include the quantitative aspects of the electromagnetic spectrum, atmospheric and interstellar absorption, telescopes in all wavebands, interferometry, adaptive optics, the transport of radiation through matter to form spectral lines, and neutrino and gravitational-wave astronomy. Clear, systematic presentations of the topics are accompanied by diagrams and problem sets. Written for undergraduates and graduate students, this book contains a wealth of information that is required for the practice and study of quantitative and analytical astronomy and astrophysics.