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October 26, 2009

Catastrophism and uniformitarianism

(My latest book God vs. Darwin: The War Between Evolution and Creationism in the Classroom has just been released and is now available through the usual outlets. You can order it from Amazon, Barnes and Noble, the publishers Rowman & Littlefield, and also through your local bookstores. For more on the book, see here.)

In the previous post, I examined some of the ways in which young Earth creationists try to deal with the scientific evidence arrayed against them. In this post, I will look at how they deal with geology, which poses the biggest challenge to their belief that the Earth is 6,000 years old.

For example, they know that they have to deal with vast amounts of scientific data that puts the age of the Earth and the universe in the billions of years. For example, the rings of trees, the slow rates of sedimentation and erosion, the layering of soils, radiometric techniques that depend on the many different half-lives of radioactive elements, the rate of mutations in DNA, rate of continental drift, the switching of the magnetic fields at the undersea geologic faults due to continental drift, and fossils are all used to build a network of clocks that can date even very old events. All these clocks are constructed by calibrating them using known events and other clocks, once again showing the interconnectedness of science.

It is with the age of the Earth that the young Earth creationists face their biggest challenge because apart from the true believers, nowadays everyone else takes an old Earth for granted. Even the media, always solicitous of the sensitivities of their religious viewers when it comes to evolution, do not bother putting on a phony balancing act by suggesting that some people disagree with the scientific consensus of an Earth that is billions of years old.

But the creationists try to provide their followers with at least some reason to defy science. When it comes to challenging the ages of things as established by science, what the creationists do is seek out anomalies here and there in the radiometric results (and these can always be found because there are often confounding factors that prevent clean analysis in some cases) and then argue that all the dates for things and events cannot be trusted. They are using the same bogus argumentation as 'Where is the missing link?', where they pick on something they think is a weakness (whether it is or not) and then argue for throwing out the entire theory. So be prepared when talking to a creationist for them to quote some obscure result where, for example, radiometric dating suggests that something whose age is known was found to be wildly off.

As for geologic evidence, in the early days people could see that things like the creation of mountains and valleys and gorges and cliffs required some explaining, unless one assumed that they always existed. The popular scientific view of that time was that they were due to a series of large scale catastrophic events such as earthquakes, volcanic eruptions and the like, that caused massive changes to occur rapidly. This model had the generic title of 'catastrophism'. People like paleontologist Georges Cuvier (1769-1832) who advocated this model were not necessarily religious and the age they arrived at for the Earth was in the millions of years, which was quite an achievement, given how inconceivable such large time scales must have been to them, and that religious beliefs of that time pinned the value in the thousands of years.

In the early nineteenth century, during the time just prior to Darwin going on his famous voyage of discovery, catastrophism went into decline and the idea of 'uniformitarianism' took hold, which held that most of the major geological features could be explained by the slow and steady accumulation of very small changes. Of course this meant that the Earth must be much older than previously thought and new estimates by people like Charles Lyell ranged in the hundreds of millions of years. This advance had a major impact on evolutionary thinking in general and Darwin's in particular. It helped him develop his idea that, just as major geological changes came about by incremental growth, small changes in organisms could, over a long time, also lead to major changes such as the creation of new species. And the much older Earth meant that there was enough time for those changes to have occurred. So again we see the interconnectedness of science, advances in geology leading to advances in biology, and the two needing to fit together.

To counteract this, what the young Earth creationists try to do is resurrect an extreme form of catastrophism, in which there was just one major event, Noah's flood, that was responsible for pretty much everything that we see in the Earth's features.

The creationists have been forced to concede some points. For example, they have been forced to accept that there was originally just one big land mass and that plate tectonics caused the break up and drifting apart of what we now call continents. (This raises the interesting question of why the Bible makes no mention of such a major event.) In order to make continental drift consistent with a 6,000 year old Earth, they have to argue that the speed of the moving continents reached orders of tens of miles per day or feet per second (i.e., at the rate of a brisk human walker), rather than the accepted range of 2-10 cm/year. Of course, this 'continental sprint' theory conveniently happened a long time ago, during Noah's flood, and the continents then slowed down to their present slow rate, which is why we (conveniently) cannot detect these high speeds now.

They also need to assert that the reversals of the Earth's magnetic field had to occur rapidly as well, flipping multiple times within the forty days. Though they are coy about how frequently it switched, a back-of-the-envelope calculation gives about once every hour! Of course sprinting continentals and magnetic fields run amok require that they try to construct a wholly different model of the Earth's core to try and deal with all these problems, resulting in them further losing contact with mainstream science (and reality).

For the acceptance of these alternative realities by their followers, they have to depend on two things: Their ability to create faux-scientific theories that look and sound impressive enough to fool the naïve, and the 'no one was around to see it then so how can we know for sure which theory is true' fallacious argument to cast doubt on accepted scientific theories.

Next: The worldwide distribution of species

POST SCRIPT: Cherry picking health care comparisons

The health industry and its supporters know that if comparisons are made on the basis of aggregated data, the US compares terribly with other countries in the developed world. So what they do is try and divert the discussion by picking on one or two items in which the US looks relatively good and fixate on it. It is like the tactics used by creationists in opposing evolution, with their "Where are the missing links?" red herrings.

When a health industry shill tries this tactic on Al Franken at a Senate hearing, he knows exactly how to respond.

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Comments

You comment "...the switching of the magnetic fields at the undersea geologic faults due to continental drift...."

The magnetic field of the earth does not switch due to continental drift. Rather, the switching of the magnetic field is recorded at the undersea geologic faults, where molten magma is solidifying as it is extruded. The solidifying material records the ambient magnetic field. As more magma is extruded, the older, solid rock is pushed away from the fault (causing continental drift). The polarity of the earth's magnetic field changes sporadically on a time scale consistent with sea-floor spreading. This leads to mirror image striping of the magnetic field reversals recorded in the rock of the ocean floor. The center of the mirror image is at the oceanic ridge, or spreading zone, where new material is solidifying. Magnetic striping was the data that clinched the previously discredited theory of continental drift.

And a tiny correction: "sprinting continentals" should read "sprinting continents."

Posted by Heidi Nemeth on October 26, 2009 11:31 PM

Heidi,

You are right and I did not write clearly. What I meant was what you said, that as the continents drift away from the fault, the magnetic fields at that time get recorded and fixed.

Posted by Mano on October 27, 2009 08:38 AM