BOSTON — For scientists who swing picks and shovels for clues to humanity's history, time is an enemy. Geological forces and encroaching development threaten existing sites as well as sites yet to be discovered.
But during the past 20 years, and especially since the early 1990s, the computer revolution has hit the field of archaeology, speeding the pace of discoveries and their dissemination in ways only dreamed of a decade ago.
From the initial search for sites to the presentation of finds to colleagues and the public, computers are improving nearly every aspect of archaeology.
"Our wildest dreams are being fulfilled," says an enthusiastic Vincent Pigott, associate director for new technologies at the University of Pennsylvania's Museum of Archaeology and Anthropology in Philadelphia.
In essence, researchers say, powerful computers at discount-store prices are allowing them to take greater advantage of technologies whose data once would have required room-sized computers to process.
As a result, laptops, portable satellite receivers, and laser-based surveying equipment have joined hand tools, sun block, and a pair of sturdy boots on archaeologists' supply lists.
Back in the office, computer programs designed for drafting 3-D architectural plans are allowing researchers to tease the subtlest details from such long-studied structures as the Parthenon, atop the Acropolis in Athens.
"In Greek architecture, we're coming to worry about the refinements," says Harrison Eiteljorg, director of the Center for the Study of Architecture at Bryn Mawr College in Bryn Mawr, Pa. "Walls lean in on purpose. The Parthenon's floor curves up from one corner to another. The superstructure on top of the columns shares the curve. We known this was no accident."
With design software, he adds, "we now have the systems that will allow us to record these in drawings and begin to answer the 'why' questions."
But before the "why" questions can be answered, the "wheres" need some attention. Thomas Carr, a PhD candidate at the University of Colorado at Boulder, has developed a computer program to pinpoint ancient quarries amid Montana's Pioneer Mountains. The quarries, mined by early Americans from 5,000 to 10,000 years ago, yielded a quartz-based mineral known as chert, which was often turned into tools and weapons.
BY studying the quarries, and especially by comparing the chert found there with chert objects found elsewhere, Mr. Carr and his colleagues hope to reconstruct the economic links among groups of people during that period.
Using a known quarry as a reference point, Carr included data ranging from satellite images to aerial photos and details from past geological surveys. Information was superimposed on maps of the terrain.
Combining and analyzing all the data, the computer identified 12 candidate sites, of which eight proved to be quarries.
Based on past field work and a back-of-the-envelope calculation, Carr estimates that it would have taken three people up to a month to traipse through an 800 square kilometer (309 sq. mi.) region trying to locate the quarry sites.
"I found these eight in just over a week," based on the computer's projections. "This allowed us to spend a second week for more specific studies."
Such efforts should improve, Carr says, with the next generation of remote-sensing satellites.
Harold Dibble, curator of the the University of Pennsylvania Museum's European archaeology section in France, has used computer technology to develop the archaeological equivalent of the popular computer game SimCity.
"Ours was one of the first paleolithic sites computerized from beginning to end," Dr. Dibble says of Combe-Capelle Bas, a middle Stone Age site in Southern France. He began his excavations there in 1987, he says. As digging progressed, he and his team used laser surveying equipment to mark the location of each artifact in three dimensions as well as define the extent of each soil layer. Digging ended in 1990, and the results were published last year.
Six years may seem like a long time to publish the results, he says. But for each year in the field, it typically takes from three to four years to analyze the finds. Computerization cut the analysis time by as much as a half.
In addition to the book, he and his colleagues developed a CD-ROM. It has so much more information than the book - including a thousand color images taken at the site - that other researchers can literally re-dig the site from the comfort of their office using their own research objectives.