08 March 2010

can of worms

Why are geologists so conservative about accepting new ideas?

This is a rhetorical question asked on the metafilter weblog by user russilwvong. It got me to thinking about three separate ideas I have encountered over the course of many years of studying earth science, and I believe they are similar, connected, and fascinating. And relevant to his question even if they do not completely answer it.

Idea one: continental drift and plate tectonics.

Continental drift as an idea dates back over a hundred years and the convexity of Brazil fitting perfectly into the concavity of the Gulf of Guinea off west Africa surely stimulated the imagination of the first geologically inclined thinkers who saw the first accurate maps. Alfred Wegener assembled data in the early 20th century correlating South American and African geological data but the smoking gun was the discovery in 1958 of magnetic striping on the sea floor of the Atlantic Ocean showing unambiguously that the ocean plates were spreading outward.

The data was first analyzed by a man named Morley and his papers were rejected as crack pottery and shortly after Vines and Matthews succeeded in getting the result into publication. When Peter Wyllie published The Way the Earth Works in 1971 he had a section titled "how Morley was screwed by the establishment" in his discussion of what was then described as the "Vines-Matthews hypothesis". I was surprised this morning when I loaded the wikipedia that their page as of now is entitled the Morley-Vines-Matthews hypothesis. The jargon changed when I was not looking at some point between 1985 (when I first read Wyllie's book) and 2009.

When I learned earth science my teachers were from the generation that grew up ignorant of plate tectonics and they had firsthand experience of reality shifting underneath them like the plates colliding along the San Andreas fault. Idea two and idea three in my little post here are more recent ideas, which appear to have become consensually accepted; however what interests me (not entirely accepting either) is the viewpoints of three men of that previous generation, which they shared with me in passing when we discussed them, as best as I recall.

Idea two: the Chicxulub anomaly meteor impact cretaceous extinction event.

I first heard about this in the 1980's, and I asked the smartest geologist I personally knew what he thought about it. At this point all the data we had was a circular potential field anomaly in Yucatan and an anomalous iridium rich stratum in one formation in the mountains in Italy. With this paltry amount of data geologists were talking to Scientific American and the New York Times and proclaiming we finally figured out what killed off the dinosaurs. My inside expert's opinion of the claims: maybe. His opinion of the publicity: grandstanding.

There has since been much work done on the Chicxulub structure and it really does look like a huge meteorite smacked into the Yucatan at around the time the dinosaurs died. Oh, and some other guys found some even larger circular anomalies they think have synchronous dating in the Indian Ocean. It is difficult to get clear cut answers when you are examining events that are from millions of years ago. The last time I spoke to a really smart geologist (of my generation) about the subject he stated: Chicxulub meteor impact structure equals Cretaceous extinction event, scientific fact.

Idea three: anthropogenic global warming.

This is the topic I was discussing on the metafilter weblog when russilwvong asked why are geologists so conservative? I first heard about this in the 1990's and read about it where and when I could. In 1999 I was at a summer school in Palo Alto and one of the teachers mapped ocean currents and computed ocean dynamic models. He seemed like he would have an expert opinion on anthropogenic global warming, so on a break and on a whim I asked him about it. He said we are warming up and carbon dioxide was increasing in the atmosphere and the claims about a direct causal relationship were not conclusive and the loudest claimants were not objective and not the best scientists.

At that time the most detailed models I had seen did not even account for cloud albedo so what he told me was in line with what I thought he might say. He has since been publicly embarrassed for criticizing the anthropogenic global warming research community and retracted all public criticisms. He has been corrected, or he has been silenced; I doubt he would tell me if it was the latter.

A couple of years later I had a short conversation with a man at the top of my own specialty on the subject. He had an interesting perspective. He told me when he first became aware of anthropogenic global warming, he went to the library and grabbed everything he could find and stacked it up on a table. He spent eight hours going through as much of the research as he could. After eight hours he decided he was not qualified to have an opinion on the subject.

He did not answer my question about anthropogenic global warming, but he taught me one of the most valuable lessons of all. The Socratic maneuver.

Agnosticism is irrefutable.

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About Craig

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Houston, Texas, United States
I have been living in the lovely neighborhood of Spring Branch in the great city of Houston since late in 2005. I started out with the idea of making this blog about my life in this neighborhood. That did not last long. Right now I am posting every five days on the alternating topics of literature, philosophy, psychology, and metaphysics. This project has been ongoing since July 27, 2010 and I believe it will continue for at least a few more months.