Science advances when people realize they are wrong

Science advances when people realize they are wrong

Naomi Oreskes

Many of the traits expected of scientists—calmness, detachment, extraordinary attention to detail, reservations about everything, and always hiding your lead—don’t lend themselves well to everyday life. For example, the contrast between scientific and everyday conversation is one reason why much scientific communication doesn’t resonate with a wide audience. (As one observer put it bluntly: “Scientific writing is often… bad writing.”) But one aspect of science, especially in times like these when many seem convinced they are right and their opponents are wrong, offers a good model for how we should behave: the ability to say, “Wait a minute. Maybe I was wrong.”

Of course, not all scientists live up to this ideal. But history offers great examples of scientists admitting their mistakes and changing their views in the face of new evidence or arguments. My favorite is the history of plate tectonics.

In the early 20th century, German geophysicist and meteorologist Alfred Wegener proposed the theory of continental drift, suggesting that the continents are not fixed on the Earth’s surface, but have moved widely throughout the Earth’s history. Wegener was no eccentric, but a well-known scientist who made important contributions to meteorology and polar studies. The idea that the now separate continents were once somehow connected was supported by extensive evidence from geology and paleontology, evidence that had already influenced other theories of continental drift. His proposal was not ignored, and was debated in Europe, North America, South Africa, and Australia in the 1920s and early 1930s. However, the majority of scientists, especially geologists in the United States, challenged the formulation of the theory, and geophysicists, clinging to models of the Earth that seemed incompatible with continental drift, rejected it.

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In the late 1950s and 1960s, a wealth of new evidence, especially from the ocean floor, reignited the debate. By the mid-1960s, several leading scientists, including Patrick MS Blackett of Imperial College London, Harry Hammond Hess of Princeton University, John Tuzo Wilson of the University of Toronto, and Edward Bullard of Cambridge University, supported continental drift. In 1967–1968, this revival began to coalesce as the theory of plate tectonics.

Not so at the Lamont Geological Laboratory, then part of Columbia University. Under the direction of geophysicist Maurice Ewing, Lamont was one of the world’s most respected marine geophysical research centers in the 1950s and 1960s. With financial and material support from the U.S. Navy, Lamont researchers accumulated vast amounts of data on ocean-floor heat flow, seismic activity, water depth, and structure. But under Ewing’s direction, Lamont was a bastion of resistance to new theories.

It is unclear why Ewing was so strongly opposed to continental drift; having studied electrical engineering, physics, and mathematics, he may not have had much interest in geological issues. Evidence suggests that Ewing was not involved in Wegener’s work at all; in a grant application written in 1947, Ewing confuses “Wegener” and “Wagner” and refers to the “Wagner hypothesis of continental drift.”

Ewing was not the only one at Lamont who was ignorant of geological debates. One scientist recalled that in 1965 he had “only a vague knowledge of the[continental drift]hypothesis,” and that most of his colleagues at Lamont who were familiar with the hypothesis “were skeptical and dismissive.” Ewing was also known as an authoritarian figure; one oceanographer called him “the General Patton of oceanography.” It was not an environment that encouraged dissent.

One scientist who changed his mind was Xavier Le Pichon. In the spring of 1966, Le Pichon had just finished his doctoral thesis, which rejected the possibility of regional tectonic shifts. After looking at some important data at Lamont Laboratory (data that had been presented that week at a meeting of the American Geophysical Union), he went home, had his wife pour him a drink, and told her, “The conclusions of my thesis are wrong.”

Lepichon had used the heat-flow data to “prove” that Hess’s sea-floor spreading hypothesis (that basaltic magma rose up from the mantle at mid-ocean ridges, and the pressure split the ocean floor, separating the two halves) was wrong. Now, new magnetic data has convinced him that his hypothesis is correct, and that there must have been an error in the heat-flow data or their interpretation.

Le Pichon described the event as “extremely painful,” explaining in an essay that “for twenty-four hours I had the impression that my whole world was falling apart. I tried desperately to deny this new evidence.” But he did what any good scientist should do: he put aside his bruised ego (presumably after drinking down that booze) and got back to work. Within two years, he had co-authored several key papers that helped establish plate tectonics. By 1982, he was one of the world’s most highly cited scientists, one of only two geophysicists to have earned that honor.

In the years that followed, Lamont’s scientists made many important contributions to plate tectonics, and Le Pichon became one of the leading geoscientists of his generation, winning numerous awards, honors, and medals, including, ironically, the Maurice Ewing Prize from the American Geophysical Union.In science, and in life, we benefit from being able to admit when we’re wrong and change our minds.

This is an opinion and analysis article and the views of the author are not necessarily those of Scientific American.