Geoscience Reference
In-Depth Information
ing backward, he calculated that the earth could be no more than
20 million years old. His eminence caused this erroneously short
time scale to be accepted, delaying for decades recognition that the
true extent of geologic time is on the order of 4.5
billion
years.
(Kelvin also denounced X rays as a hoax.) G. K. Gilbert, chief geol-
ogist of the U.S. Geological Survey and the leading geologist of his
day, incorrectly concluded that Meteor Crater, Arizona, was not
formed by meteorite impact, leading to a dogma that was decades in
the unmaking. When the deans of American geology and the facul-
ties of research universities scoffed at the theory of continental drift,
budding geologists of the 1950s and early 1960s chose other topics.
The history of science is full of the undue influence of magisters—
authoritative masters—whose pronouncements receive an uncritical
acceptance.
WITHOUT
HELP
FROM
A
COMET
Walter Alvarez could have told his father that it is hard to find any
idea in the history of science more consistently and continuously
spurned by authorities than the notion that meteorite impact has in
any way affected the earth. The rejection stretches back to the dim
beginnings not only of geology but of science itself. In the 1680s,
William Whiston, mightily impressed by the great comet that had
opened that decade, wrote that God had directed the comet at the
earth and that its impact had produced both the tilt of the earth's
axis and its rotation, had cracked the surface, and had allowed the
waters to rise to create the biblical flood.
6
Even though Whiston con-
vinced no one, his idea so offended Charles Lyell, a founding father
of geology, that nearly 150 years later he went out of his way to
debunk Whiston's suggestion, writing that he had "retarded the pro-
gress of truth, diverting men from the investigation of the laws of
sublunary nature, and inducing them to waste time in speculations
on the power of comets to drag the waters of the ocean over the
land—on the condensation of the vapors of their tails into water, and
other matters equally edifying."
7
Lyell's disciple, Charles Darwin, was
equally convinced that catastrophes played no part in earthly events,
writing: "As we do not see the cause [of extinction], we invoke cata-
clysms to desolate the world, or invent laws on the duration of the
forms of life."
8
A century later, little had changed. E. H. Colbert of the American
Museum of Natural History, the dean of American dinosaur studies
