Monday, January 7, 2019

Maybe it wasn't an asteroid impact that killed off the dinosaurs

Bianca Bosker, The Nastiest Feud in Science, The Atlantic, September 2018:
But [Prof. Gerta] Keller doesn’t buy any of it. “It’s like a fairy tale: ‘Big rock from sky hits the dinosaurs, and boom they go.’ And it has all the aspects of a really nice story,” she said. “It’s just not true.”

While the majority of her peers embraced the Chicxulub asteroid as the cause of the extinction, Keller remained a maligned and, until recently, lonely voice contesting it. She argues that the mass extinction was caused not by a wrong-place-wrong-time asteroid collision but by a series of colossal volcanic eruptions in a part of western India known as the Deccan Traps—a theory that was first proposed in 1978 and then abandoned by all but a small number of scientists. Her research, undertaken with specialists around the world and featured in leading scientific journals, has forced other scientists to take a second look at their data. “Gerta uncovered many things through the years that just don’t sit with the nice, simple impact story that Alvarez put together,” Andrew Kerr, a geochemist at Cardiff University, told me. “She’s made people think about a previously near-uniformly accepted model.”

Keller’s resistance has put her at the core of one of the most rancorous and longest-running controversies in science. “It’s like the Thirty Years’ War,” says Kirk Johnson, the director of the Smithsonian’s National Museum of Natural History. Impacters’ case-closed confidence belies decades of vicious infighting, with the two sides trading accusations of slander, sabotage, threats, discrimination, spurious data, and attempts to torpedo careers. “I’ve never come across anything that’s been so acrimonious,” Kerr says. “I’m almost speechless because of it.” Keller keeps a running list of insults that other scientists have hurled at her, either behind her back or to her face. She says she’s been called a “bitch” and “the most dangerous woman in the world,” who “should be stoned and burned at the stake.”
The now more or less standard account of the the extinction, an asteroid impacting the Yucatan Peninsular 65 million years ago, was proposed by a "rock star" physicist, Luis Alvarez:
His numerous scientific exploits—winning the Nobel Prize in Physics, flying alongside the crew that bombed Hiroshima, “X-raying” Egypt’s pyramids in search of secret chambers—had earned him renown far beyond academia, and he had wielded his star power to mock, malign, and discredit opponents who dared to contradict him. In The New York Times, Alvarez branded one skeptic “not a very good scientist,” chided dissenters for “publishing scientific nonsense,” suggested ignoring another scientist’s work because of his “general incompetence,” and wrote off the entire discipline of paleontology when specialists protested that the fossil record contradicted his theory. “I don’t like to say bad things about paleontologists, but they’re really not very good scientists,” Alvarez told The Times. “They’re more like stamp collectors.”
Do we have a case of physicists cashing on their general intellectual prestige (see my recent post, The rise of condensed matter physics [Is particle physics over?]:
That the dinosaur wars drew in scientists from multiple disciplines only added to the bad blood. Paleontologists resented arriviste physicists, like Alvarez, for ignoring their data; physicists figured the stamp collectors were just bitter because they hadn’t cracked the mystery themselves. Differing methods and standards of proof failed to translate across fields. Where the physicists trusted models, for example, geologists demanded observations from fieldwork.
Hmmm... There is certainly an interesting history of researchers trained as physicists doing important work in other fields – Francis Crick in biology, Christof Koch in neuroscience, and, in another direction, any number of 'quants' in finance. But this is a digression from the main flow of the article.

A grim lesson?
The asteroid theory has ingrained in the public’s imagination the idea that mass extinction will be quick and sensational—that we will go out in a great, momentous ball of fire. Big rock from sky hits the humans, and boom they go. But Keller’s vision of the sixth extinction, given what she sees as its parallels with Deccan volcanism, suggests that the end will be drawn out and difficult to recognize as such within humans’ brief conception of time. “We are living in the middle of a mass extinction today,” Keller told me. “But none of us feel that urgency, or that it really is so.”

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