Walter was a geologist specializing in paleomagnetism, Luis was a physicist and I was a nuclear chemist. And now here we were telling paleontologists that we had solved a problem that had eluded them for over a century. It's not terribly surprising that they didn't embrace it immediately." As Luis Alvarez joked: "We were caught practicing geology without a license."
But there was also something much deeper and more fundamentally abhorrent in the impact theory. The belief that terrestrial processes were gradual had been elemental in natural history since the time of Lyell. By the 1980s, catastrophism had been out of fashion for so long that it had become literally unthinkable. For most geologists the idea of a devastating impact was, as Eugene Shoemaker noted, "against their scientific religion."
Nor did it help that Luis Alvarez was openly contemptuous of paleontologists and their contributions to scientific knowledge. "They're really not very good scientists. They're more like stamp collectors," he wrote in the New York Times in an article that stings yet.
Opponents of the Alvarez theory produced any number of alternative explanations for the iridium deposits—for instance, that they were generated by prolonged volcanic eruptions in India called the Deccan Traps—and above all insisted that there was no proof that the dinosaurs disappeared abruptly from the fossil record at the iridium boundary. One of the most vigorous opponents was Charles Officer of Dartmouth College.