LA SCIENZA NN LA FA LA COMUNITÀ A MAGGIORANZA...NEANCHE QUELLA SCIENTIFICA
How will the public know when scientists have determined which scenario is right? It is tempting, but unreliable, to trust what appears to be the majority opinion. Adrian Currie, a philosopher of science at Cambridge University, worries that the feverish competition in academia coupled with the need to curry favor with colleagues—in order to get published, get tenure, or get grant money—rewards timid research at the expense of maverick undertakings
L ASTEROIDE ERA LA TEORIA STANDARD
impacters say they have come even closer to total certainty. “I would argue that the hypothesis has reached the level of the evolution hypothesis,” says Sean Gulick, a research professor at the University of Texas at Austin who studies the Chicxulub crater. “We have it nailed down, the case is closed,” Buck Sharpton, a geologist and scientist emeritus at the Lunar and Planetary Institute, has said.
MA C È CHI SI OPPONE
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
CAPIRE È IMPORTANTE X L UOMO
Vincent Courtillot writes in his book Evolutionary Catastrophes, “I believe the ancient catastrophes whose traces geologists are now exhuming are worthy of our attention, not just for the sake of our culture or our understanding of the zigzaggy path that led to the emergence of our own species, but quite practically to understand how to keep from becoming extinct ourselves.”
ILLUMINA ANCHE IL CAMMINO DELLA SCIENZA
This dispute illuminates the messy way that science progresses, and how this idealized process, ostensibly guided by objective reason and the search for truth, is shaped by ego, power, and politics. Keller has had to endure decades of ridicule to make scientists reconsider an idea they had confidently rejected.
GRADUALISTI VS CATASTROFISTI
Alvarez’s theory was a boon for the catastrophist school of thought, which maintains that the Earth is shaped by sudden, violent events—and can turn on its occupants in a heartbeat. The impacters contend that the fossils of both marine- and land-dwelling organisms show an abrupt and instantaneous die-off at virtually the same moment, geologically speaking, that the asteroid hit. “If you look at the extinction rate up to the event and you look at the recovery after, this is the most sudden of all the known extinctions,” Sean Gulick says. “This one is like a knife-sharp boundary in the geologic record”—consistent with the kind of destruction an asteroid could cause.
Alvarez’s theory initially faced strong opposition from the gradualists, who argue that enormous planetary changes tend to result from slower, less adrenaline-pumping forces. Among those who disagreed with him was Keller.
GUARDARE AI PRECEDENTI
She had a promising lead: The Earth’s four prior mass extinctions are each associated with enormous volcanic eruptions that lasted about 1 million years apiece. The fifth extinction, the one that doomed the dinosaurs, occurred just as one of the largest volcanoes in history seethed in the Deccan Traps.
DIFETTI DEL VULCANISMO
The planet’s species went extinct “almost overnight,” Smit insists, too quickly to be caused by Deccan volcanism. India’s volcanoes hiccuped for hundreds of thousands of years, too weakly and for too long to be deadly, Keller’s critics contend. They argue that there is no evidence that species suffered while Deccan simmered, and that the biggest volcanic eruptions occurred after the extinction, too late to have been the catalyst.
https://www.theatlantic.com/magazine/archive/2018/09/dinosaur-extinction-debate/565769/
