Telling Time Volume 54 Number 2, March/April 2001 by Tom Gidwitz

By reading the rings of pines as old as the earliest pharaohs, Henry Michael has changed the way we look at the past.

On a rounded ridge in the Inyo National Forest, east of the Sierra Nevada and west of Nevada's parched deserts, are high-altitude slopes where the thin air makes your head spin and the trees seem to live forever. This is the home of the oldest bristlecone pine trees in the White Mountains of east-central California. Before Giza and the ziggurat of Ur, the trees in this grove were stubborn, thriving seedlings. Here, where the growing season is 45 days long and it rains barely ten inches a year, there are 200 trees more than 3,000 years old, and two dozen more than 4,000 years old. Here reigns Methuselah, the world's oldest living tree, which sprouted around 2700 B.C.

Discreetly out of sight, behind branches and on fallen trunks, are shiny metal tags with numbers and dates, foil strips attached to the trees by the scientists who study them. Most numerous are those with an "H." These are the tags of Henry Michael of the University of Pennsylvania's Museum Applied Science Center for Archaeology.

Almost every summer for more than 30 years, in a square-mile swath of forest, Michael dug out long-buried logs and took cores from standing trunks, taking home samples thousands of years old. With these bits of aged wood he helped build a tree-ring chronicle of Earth's ever-changing environment and a yardstick by which radiocarbon dating, then in its infancy, could be calibrated, with results that forced archaeologists to rethink their theories about the spread of civilization.

A self-effacing man with a dry sense of humor, Michael has a high forehead, bright blue eyes, and a wide, square face. Although his step has slowed and he has a slight stoop, there's little else in his appearance to suggest he's nearing 90. He has the sturdy build of someone who has spent decades hiking in the mountains and hefting logs, and when he speaks it is with the methodical pace of a man who makes meticulous measurements. True, he wears broad glasses and sometimes a hearing aid, but if names of old colleagues occasionally elude him, he retains the tenacity of spirit that helped rewrite the history of prehistoric Europe.

Tom Gidwitz is a freelance writer currently working on a book about volcanoes.