Last time, we talked about how science’s biggest failures come not from shouting down heretical-but-correct ideas but from ignoring good ideas. I gave the example of Gregor Mendel, who was ignored for decades even though he’d made discoveries that, once recognized, revolutionized biology. We ended by noting that Mendel lived in the 1800s, and I promised to give a more recent example to show that science has not fully fixed its problem with ignoring good ideas.
So now it’s time for an example with a bit more punch: the asteroid impact that killed off the dinosaurs. In 1942, the astrophysicist Ralph Baldwin, professor of astronomy at the University of Michigan, first propounded the idea that earth was subject to perpetual, frequent, and cataclysmic asteroid bombardment.
As with Mendel’s ideas, this flew in the face of accepted theory, which held that large earthly craters were volcanic in origin. And again, his ideas weren’t vociferously rejected, just more-or-less ignored. When he first presented his theory, it “produced a mixture of apathy and disinterest, with no conversions and no encouragement.“
Looking back at his long career in 2000, the Meteoritical Society awarded him its top honor, the Barringer Medal. When awarding that “long overdue” recognition, the Society remarked that
[Baldwin] is special because he is one of the founders of two active fields of scientific discovery: lunar geology and terrestrial meteorite impact structure. His attempts to establish these fields half a century ago were greeted with disagreement—and much worse, with apathy and disinterest.
In fact, the response to his ideas was so apathetic that he could not find an academic publisher and had to resort to publishing in Popular Astronomy (somehow this failed to make his astronomy popular).
Unlike Mendel, at least Baldwin’s ideas weren’t entirely ignored. Several scientists eventually expressed at least tentative support for his theory, including a Nobel prize recipient (Harold Urey). But, crucially, the support was always of the form of saying his theories seemed right to them and that someone should really look into that—the support was never the sort that would get a real debate started or change the consensus view. (His theories about impact craters on the moon got a bit more traction, but still remained controversial.)
So, when a new team of scientists loudly proclaimed that asteroids do impact earth and that one was responsible for killing off the dinosaurs, their claims were a shock to the scientific establishment. In 1980.
This time, nearly four decades passed between the idea and the time when scientists took it seriously.
And, I need to point out, taking it seriously did not mean accepting it. This new team, Louis Alvarez, Walter Alvarez, and Frank Asaro presented overwhelming evidence that earth had been impacted by an extraterrestrial object. Using a new technique, neutron activation analysis, they analyzed a thin layer of clay that geologists knew marked the end of the age of the dinosaurs. Their analysis showed that the clay had three hundred times more iridium than expected. This was really weird.
You might know iridium as the metal Loki stole in The Avengers to help create the Chitauri portal to New York. As that movie explained, iridium is very rare on earth—at least anywhere near the surface. It’s one of the densest elements in existence, so the overwhelming majority of the iridium present on earth sank to the core when our planet was still molten,
So iridium is rare in earth’s crust—but relatively abundant on asteroids, which contain all the same elements that make up earth’s crust and core. (This is still science we all could have learned by paying attention in The Avengers. The exact quote is “Yeah, iridium. It’s found in meteorites.”)
So, detecting these excessive amounts of iridium was conclusive evidence that earth had been hit by meteorites. And how thin the clay layer proved that the iridium came from a single massive impact rather than a series of impacts spread out over time.
Despite all this evidence, they met fierce resistance. 1980 only began the ten year or so process that it seems to take for the scientific establishment to reorient to a new, paradigm-shifting theory. At first, their heretical research was roundly condemned, and even by 1988, about half of American paleontologists thought that the dinosaurs died off because of a sudden impact, and half thought the process was gradual.
(Though there’s an interesting flip side to this. These days, there’s a dissenting view put forward by Gerta Keller that the asteroid impact didn’t kill off the dinosaurs and that instead they died from a massive supervolcano in India. According to one supporter of Keller’s theory, “Her opponents have failed to adequately address the issues she has raised, and often choose to ignore her work.” And so the cycle of ignoring rather than engaging with ideas contenues.)
I want to focus on the “apathy and disinterest” that greeted Baldwin’s work for just a moment. This is exactly the phenomenon I worry about. The problem isn’t scientist who are “ridiculed by hidebound reactionaries.” That ridicule, however unfair, will draw attention to the issue and—if the new theory has facts on its side and the reactionaries are genuinely hidebound—the new theory will eventually carry the day. No, the problem is with scientists who present good ideas but who are nonetheless ignored. As Oscar Wilde put it: “there is only one thing in the world worse than being talked about, and that is not being talked about”; science’s problem is in what it doesn’t talk about.
And, even by 1980, science hadn’t solved this problem, and I doubt it has today. Next time, we’ll address a final example of science ignoring a good idea, this time an idea that non-scientists had not only known about but had been making money from for decades.