"Jeff Hecht - Extinction Theory" - читать интересную книгу автора (Hecht Jeff)

mass extinction without the bomb. Who do you think got the mastadons and other
Pleistocene megafauna? What do you think is happening now in the rainforests?"
I tried to convince him that he was just bolstering my argument, but he
would have none of it. The best estimate, he insisted, was that nothing at the
end of the Cretaceous had more brainpower than an opossum. That left a long
way on the IQ scale to match people, even in his cynical view.
The closest he could come to my idea was a catastrophic population
explosion of some hitherto obscure creature. It might have eaten everything in
sight, causing catastrophic population crashes of other species. It might have
excreted something that had dire effects on other living things. One factor in
the greenhouse effect that was heating up the globe, he said, was the rapid
increase in quantities of methane being farted by cows and rice paddies. Then
he reminded me of the iridium anomaly, and dared me to explain it. I said I'd
have to think about it.
We went out to lunch, and I kept trying to convince him. Wasserman just
kept sipping his beer and smiling. Midway through the third mug, he smiled and
looked up at me. "Tell you what," he said. "You sit down and make some
predictions of isotope ratios. Then I'll get you some fresh samples to try.
That should get this out of your system."
Two days remained before he left for the field again. I turned the
laser over to my postdoc and pored through the references in the university
library, making a little list. Depleted uranium was on it, with the U-235
removed by some prior inhabitants of the planet to make bombs. The decay of
cesium-137 might enrich barium-137 levels, but I doubted we could detect that.
I added lead to the list; it got the Romans, so why not somebody long before
Rome? But that was about all. No likely products or garbage were likely to
last 65 million years. Steel would have rusted away. No matter what the Sierra
Club thinks, aluminum and plastics don't last that long. Nor would they leave
any obvious signs behind, unless Wasserman hit something he could recognize as
a garbage dump rather than an ore deposit. Gold was the only thing that might
last that long, but it was so rare there was no sense in looking.
I gave Wasserman a copy of the list. To say he was not impressed would
be an understatement. He was cold sober and he scoffed as he read it. "Look,"
he said, "didn't I tell you where the sediments we find were deposited?
Underwater! Most of them come from the ocean bottom. Some come from places
near to the shore or even from lakes and rivers, but most that we find were in
the oceans. All the stuff you're looking for is deposited on land, and we
don't have many land sediments to look at. I'll look, but I'll tell you right
now the stuff you're looking for just plain isn't there!"
By the time he was finished, I was ready to give up. I didn't bother to
tell him my explanation for the iridium anomaly. I blamed it on beer cans --
steel beer cans, made with nickel refined from ores from which the iridium
hadn't been removed. I had been all set to get one of the grad students to run
steel-can samples through the laser spectrometer. I didn't bother. I laid the
notebook full of my crackpot ideas on a pile of trade magazines I wasn't ready
to throw out yet. There were other things to do. I started working on my own
proposal for trace-element detection to the Department of Energy. I got a new
batch of Karelski's samples and went to work. One of my doctoral students had
a crisis with his thesis; my postdoc quit to double her salary in industry.
I would have forgotten all about it if it hadn't been for Wasserman. It