Monday, November 5, 2007

Paradigm shift

A short while back, I read James Lawrence Powell's Night Comes to the Cretaceous. It's a very interesting history of the proposal (by Luis Alvarez and his son Walter in 1980) of the theory that it was a meteor impact that caused both the iridium layer that forms the geological boundary between the Cretaceous and the Tertiary, and the extinction of the third age of dinosaurs.

Vehemently opposed by the geologists of that day, this theory is now (only 25 years later) universally accepted by scientists. The impact crater itself has been identified (it's known as Chicxulub, and is on the Yucatan Peninsula and adjacent Caribbean waters). Now, astronomers believe they have identified the particular family of asteroids (in the belt between Mars & Jupiter) from which that impact body broke loose.

To me, the most fascinating part of this book was its history of a major paradigm shift within science. And I think there are lessons for the paradigm shifts occurring today.

For example, almost without exception, those who opposed the Alvarez theory never did capitulate to the evidence for it; they died rejecting what everyone today accepts. I suspect the same will be true of those who today defend neo-Darwinism in the face of overwhelming and multiplying evidence.

To put it another way, only when a new generation of scientists has grown up aware of naturalism's evidential problems will more accurate understandings be accepted.

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