Here's a new story from the New York Times, "Rocks May Be the Oldest on Earth". Originally reported in the most recent issue of Science, this makes for fascinating reading (you can also find the original article here, behind the paywall). UPDATE: You can also find the BBC reporting of the story here. The précis is this: an area of bedrock has been discovered in northern Quebec, some portions of which appear to be some 4.28 billion years old. If further validated, this represents one of perhaps three sites where rocks well over four billion years old have been identified.
Of course, a number of people have already gotten to this (damn you, PZ Myers, damn you!), but I just find it fascinating and want to talk for a moment about the age of the Earth.
It's a source of endless fascination to me that our understanding of the age of the planet has evolved so radically in the last century. In the book On the Trail of Ancient Man, written by Roy Chapman Andrews and published in 1926, an old version of a geological column appears. I reproduce it here for you:
When I gave a presentation on Andrews back in June, I showed this slide and asked if anyone in the crowd could see the problem with it. To my chagrin, not even any of the parents noticed the problem, but each time I pointed it out gently and went on to explain why the difference was interesting. Readers of this blog, expecting science of some sort, no doubt see the problems,but here's a quick pointer: the Cretaceous didn't end ten million years ago. The current estimate is 65.5 million years ago. Here's what a modern view of the geologic column looks like, according to the Encyclopaedia Britannica:
So why is it interesting - or is just that way to me?
Unfortunately, there's is still a "bastion of religious conservatism", as Richard Dawkins puts it in 'The Root of All Evil?' which demands attention. It is unfortunate that the number one result in a Google or a Yahoo search for the term "geologic column" returns this entry: The Geologic Column: Does It Exist? (loving that "nofollow" tag, by the bye). When I saw this, my heart sank just a bit. Well, a lot. The foisting of evident falsehoods upon the gullible, in an effort to support bronze age myths (again, to paraphrase Professor Dawkins), is all too prevalent, even in the wilds of the digital frontier. A real geologic column, as represented in the colour image, gives a more appropriate view of the history of the Earth, as we understand it with increasing precision.
What young earth creationist types don't want to talk about is the actual evidence, and the people who spend their careers making very careful, precise measurements of rocks from various strata around the world, gradually building up a picture of their true age. This has been going on for more than a hundred years, and as we see from our two different versions of the geologic column, our knowledge has been expanded and refined quite a bit.
Major cultural shifts may well take longer than a century. But it is still worth hoping that, with more evidence such as the recent Quebec find, people will begin, finally, to opt for the better information, for the explanation that is actually supported by evidence, and not merely held to be true because they say that it is true. That is a fallacy of circular reasoning, and not one with which we really need to bother, except to point out, as often as necessary, that it is wrong.