The Man Who Found Time: James Hutton and the Discovery of the Earth’s Antiquity by Jack Repcheck. Perseus, $26, 247 pages.

The Chapel Hill News

December 28, 2003

A Toast To Times Past

By Phillip Manning

A few days from now, boozy crowds will gather at midnight to sing “Auld Lang Syne,” Robert Burns’s poignant song about days gone by. Burns penned the song in 1788 during the intellectual flowering known as the Scottish Enlightenment. Burns was part of a convivial group in Edinburgh whose writing and thinking produced the Enlightenment. One of the most original thinkers in that group, the man whose work would stimulate Charles Darwin’s ideas about evolution, was a well-to-do gentleman farmer named James Hutton. He discovered the immensity of our past, the days gone by that Burns wrote about so eloquently.

Jack Repcheck tells Hutton’s story in “The Man Who Found Time” (Perseus, $26). Hutton was born in Edinburgh in 1726. He was fascinated by science from a young age, but he trained as a lawyer and graduated as a physician. For reasons not at all clear, the city-born, city-bred Hutton decided at age 26 to become a farmer. For 13 years, he farmed, studied mineralogy and chemistry, and made occasional geologic excursions into the country with friends.

He also thought about erosion, the comings and goings of the soil and rocks around him. Hutton observed the erosion under his feet as the Scottish rains washed the soil from his farmlands. He realized that erosion of rock is necessary to form soil, but erosion also removes soil by washing it into the sea. “Without a mechanism to restore [soil],” writes Repcheck, “the land would quickly become uninhabitable.”

What that mechanism was may have occurred to Hutton as he built rock walls around his farm. The rocks available to him were sedimentary rocks, formed from soil compressed by the sea into layers of sediments, which over long periods of time formed sedimentary rocks. Hutton speculated that subterranean events later lifted the rocks above sea level, where they would erode into soil once again. The land we live on today, he concluded, is no more than ancient eroded soil made solid by the pressure of the sea. But this never-ending cycle of loss and regeneration required time, lots of time. When Hutton presented his ideas to the Royal Society of Edinburgh in 1785, he stated his beliefs about the vastness of time explicitly, “[W]ith respect to human observation, this world has neither a beginning nor an end.”

These were fighting words to Christians. Numerous biblical chronologies had established the Earth’s age at about 6,000 years. The most famous of these was compiled by the Anglican bishop James Ussher, who counted the “begats” in the Bible and firmly established the date of creation as noon on October 23, 4004 B.C. So well accepted was this date that it was printed in the margin of Bibles.

Most geologists were equally convinced that the Earth was young. Only a few scientists had questioned Ussher’s young age for the Earth before Hutton dropped his bombshell. One of them, Georges Buffon, was pressured to recant his views because he implied that natural forces acting over a long time, not God, had created mountains and valleys. Because the young-Earth doctrine was so ingrained in the religious and scientific communities, Hutton’s ideas about an ancient Earth were either attacked or ignored. It would fall to a new generation of geologists to embrace and extend Hutton’s ideas.

Chief among the new breed was Charles Lyell. Lyell was a hands-on geologist, and during his extensive investigations he encountered lakes — clearly modern by geological standards — with limestone bottoms, which must have formed in the recent past. All geologic formations, Lyell concluded, were due to processes going on around us. And the same processes that operated today had operated in the deep past. This was Hutton’s idea repackaged as “uniformitarianism,” which became the foundation of modern geology. Lyell summarized his ideas in his book “Principles of Geology,” which became geology’s defining text for the next 100 years.

Charles Darwin took Lyell’s book with him on the H.M.S. Beagle. What he saw confirmed Lyell’s (and Hutton’s) view of the world as dynamic and ancient, constantly but slowly changing over an immense period of time. Darwin extended Lyell’s uniformitarianism to include the living world, which helped him develop his theory of the evolution of species by natural selection.

Determining that the Earth is an ancient, changing planet enormously increased our understanding of it. Today, radioactive dating tells us the Earth is 4.5 billion years old. And that brings us back to Robert Burns. When you lift your glass at midnight on New Year’s Eve, drink a toast to Bruce, who wrote the song you will sing, and one to his Scottish compatriot James Hutton, the man who discovered the vastness of the days gone by that Burns captured so beautifully in song.