Time Detectives

The study of human history through the recovery of remains of the past, archaeology has evolved for more than two hundred years. Until comparatively recently, however, the field made little progress in the critical matter of dating its finds confidently. Assigning dates to archaeological sites required linking the sites with independently datable artifacts—such as documents, coins, or trade goods—and the careful application of a sound digging principle called stratigraphy, which establishes chronological sequences. In the matter of dating, archeology has advanced dramatically since World War II—thanks to technological advances in a wide range of other disciplines. These advances are the subject of Brian Fagan’s aptly titled TIME DETECTIVES.

Long the most interdisciplinary of the sciences, archaeology has become even more ecumenical as it has drawn on every scientific field that might conceivably lend a hand. The most far-reaching breakthrough came from the field of physics during the late 1940’s, when carbon-14 dating was developed (a technique that makes it possible to date virtually any once-living material, such as bone fragments, wood, or cloth). The impact of this technique on archaeology is merely the most dramatic of the many advances that Fagan discusses. While he also discusses such other space-age tools as sideways-looking airborne radar, ground-penetrating radar, and thermoluminescence dating, the real fascination of his book is to be found in some of the less flashy breakthroughs, such as vegetation histories and pollen studies. Even fifty years ago, what archaeologist could have imagined that one day scholars would rewrite human history by analyzing minute animal bone fragments and other materials that they themselves once routinely discarded?