Geoscience Reference
In-Depth Information
Alfred Wegener in the early twentieth century. Wegener defied the conventional geological thinking of
his day, arguing that Earth's continents slowly move relative to each other to yield the dramatic
changes observed in the distribution of continents over geologic time. The theory was not accepted
until the 1960s, by which time enough evidence had amassed—in particular, geological measurements
indicating the slow spreading of the seafloor—to support a break with the old paradigm, giving way
to the modern theory of plate tectonics.
Another example still closer to the field of climate research is what is known as chaos theory or,
in more common parlance, the proverbial “butterfly effect”—the idea that the behavior of certain
systems is so sensitive to small perturbations that an effect as small as the flapping of a butterfly's
wings in one part of the world can affect what transpires on the other side of the world. That natural
systems could, in principle, exhibit a dramatic sensitivity to the tiniest changes in their initial state
was first suggested by the French mathematician Henri Poincaré in the late nineteenth century.
It was not until the discovery in the early 1960s that such behavior could be seen in real-world
systems such as the weather, however, that chaos theory became viewed as a revolution in science.
We now know that it applies to diverse physical phenomena ranging from certain types of chemical
reactions to the behavior of pendulums. Chaos theory even applies to the way pinball machines and
amusement park Tilt A Whirl rides behave. It also applies to the climate oscillations associated with
the El Niño phenomenon. The influence of chaos, of course, has its limits. Just because certain
aspects of the weather and climate are chaotic in character, for example, does not mean that climate
changes are unpredictable, as anyone familiar with the rather easily forecasted climate phenomena
known as
winter
and
summer
is no doubt aware.
This scientific advance is generally attributed to Edward Lorenz, an atmospheric scientist at
MIT. It was nonetheless a 1963 paper on the problem of thermal convection published by my Ph.D.
adviser at Yale University, Barry Saltzman, that—as acknowledged by Lorenz in his original
publication
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—led to Lorenz's identification of chaos in real-world behavior. Barry had noticed that
the solutions to this atmospheric physics problem displayed unstable behavior. The behavior wasn't
simply some run-of-the-mill numerical instability, however. Though Barry didn't realize it at the time,
he had stumbled onto the next major scientific revolution.
The Galileo Gambit
A favorite tactic of contrarians is to attempt to usurp the mantle of the great paradigm breakers of
scientific history such as Wegener or even that patron saint of paradigm breakers, Galileo himself.
Galileo, or Copernicus, there are a thousand charlatans, pretenders, and false prophets. Almost
invariably, the culture of science allows them a chance to make their case. For example, at the fall
2008 meeting of the American Geophysical Union (AGU), the largest scientific society in America in
the field of Earth sciences, most scientists were discussing incremental advances in, say, our
understanding of the dynamics of ice sheets or the physics of auroras. One individual, however,
presented what he termed a “new cosmological concept called Accreation,” which he asserted would
overthrow the conventional understanding of how our solar system was formed, and which he
represented as “a paradigm shift equal to that wrought by Copernicus.”
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There was, as it turned out,
