deep time
Deep time is the concept of geologic time first recognized in the 1700s in the Western world by Scottish geologist James Hutton[1][2] and in 11th century China by the polymath Shen Kuo.
Science in succeeding centuries has established the age of the Earth as between four and five billion years, with an exceedingly long history of change and development.
Scientific concept
An understanding of geologic history and the concomitant history of life requires a comprehension of time which initially may be more than disconcerting. As mathematician John Playfair, one of Hutton's friends and colleagues in the Scottish Enlightenment, later remarked upon seeing the strata of the angular unconformity at Siccar Point with Hutton and James Hall in June 1788, "the mind seemed to grow giddy by looking so far into the abyss of time."[3]
Hutton's words, "we find no vestige of a beginning, no prospect of an end," are in stark contrast to most creation mythologies, which hold that the Earth has existed for only a few thousands of years. It was both professionally and personally extremely hazardous in Hutton's time to oppose the young Earth creationism doctrine which was then dominant.
Hutton's comprehension of deep time as a crucial scientific concept was developed further by Charles Lyell in his Principles of Geology (1830-33). Naturalist and evolutionary theorist Charles Darwin studied Lyell's book exhaustively during his expedition on the HMS Beagle in the 1830s.
Physicist Gregory Benford addresses the concept, in Deep Time: How Humanity Communicates Across Millennia, as does paleontologist and Nature editor Henry Gee,[4][5] in In Search of Deep Time.
Use of the term
One of the first uses of deep time in a general interest publication may have been by John McPhee in his 1981 book, Basin and Range, parts of which originally appeared in The New Yorker magazine. One of the metaphors McPhee used in explaining the concept of deep time, which was cited by Stephen Jay Gould in Time's Arrow, Time's Cycle (1987), was to
Consider the earth's history as the old measure of the English yard, the distance from the King's nose to the tip of his outstretched hand. One stroke of a nail file on his middle finger erases human history.
Basin and Range was republished, with four others and additional material, as Annals of the Former World: five books in one which won the 1999 Pulitzer Prize:
- Basin and Range (1981) - (see Basin and Range Province)
- In Suspect Terrain (1983) - (see Terrain)
- Rising From the Plains (1986) - (see Plain)
- Assembling California (1993) - (see Geography of California)
- Crossing the Craton (1998) - (see Craton)
McPhee's title Annals of the Former World is taken from James Hutton's own phrase about the geologist's preoccupation with the "annals of a former world," the stories figuratively told by layers of rock laid down over many millions of years.
References
- ^ A. R. Palmer and E-an Zen. The Context of Humanity: Understanding Deep Time (html). Critical Issues Committee, Geological Society of America.
- ^ Kenneth L. Taylor (September 2006). Ages in Chaos: James Hutton and the Discovery of Deep Time. The Historian (abstract). Book review of Stephen Baxter, ISBN 0-7653-1238-7.
- ^ John Playfair. Hutton's Unconformity (html). Transactions of the Royal Society of Edinburgh, vol. V, pt. III, 1805, quoted in Natural History, June 1999.
- ^ Gert Korthof (2000). A Revolution in Palaeontology: Review of Henry Gee's In Search of Deep Time (html).
- ^ Anthony Campbell (2001). Book review: In Search of Deep Time (html).
See also
External links
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