The Fossil Record...

I was reading a blog which belongs to a friend of mine yesterday (link) that refers to the volcanic island of Surtsey off the coast of Iceland, and that fossils have been found there. This island was created as a result of volcanic eruptions between 1963 and 1967, so logically thinking these fossils cannot be more than 50 years old!

I was intrigued when I read this and decided to learn more. It turns out that fossils were present on the seabed when the initial eruption occurred; chunks of rocks (called xenoliths) containing some of these fossils were "shaken" loose, carried up with the lava flow and deposited onto the still forming island. Go figure!

My friend's article yesterday went onto criticise the concept of radiometric dating. It seemed almost a throwaway comment, but again, got me thinking - are radiometric decay rates constant?

The truth is, I don't know. I'm not 4.6 billion years old and wasn't there during the big bang. What I do know can be inferred from evidence. For example:

Supernovae are known to produce a large quantity of radioactive isotopes (Nomoto et al. 1997a, 1997b; Thielemann et al. 1998). These isotopes produce gamma rays with frequencies and fading rates that are predictable according to present decay rates. These predictions hold for supernova SN1987A, which is 169,000 light-years away (Knödlseder 2000). Therefore, radioactive decay rates were not significantly different 169,000 years ago. Present decay rates are likewise consistent with observations of the gamma rays and fading rates of supernova SN1991T, which is sixty million light-years away (Prantzos 1999), and with fading rate observations of supernovae billions of light-years away (Perlmutter et al. 1998). link to source here

So, based on this (and other) evidence, it would seem that radiometric decay rates have not changed significantly over the last 169,000 years. So we have there proof of an old universe, rather than the 6000 odd years proposed by some Young Earth Creationists.

There is one model for radiometric dating which is consistent with Young Earth Creationism, that of Helium Diffusion (link), and from what brief research I have been able to conduct, this technique has been extensively debunked (link). Again, having read all this today, there are some holes in Radiometric dating, but it is the best method we've got. For less old samples, we've got Dendrochronology (tree-ring dating), and there exists a complete record for the last 11,000 years, with another set of data for the last 26,000 years. (link).

So, all in all, even if any type of radiometric dating is bogus, it doesn't really matter. Tree-ring dating and ice core sampling are used for a plethora of different purposes and their practical purpose is hinged on the fact that they are reliable for periods older than the last few thousand years.

Also let us not forget that these highly flawed and untestable techniques (Potassium-Argon, Uranium-Lead, Samarium-Neodymium, Rubidium-Strontium, Argon-Argon, Iodine-Xenon, Lead-Lead) cross confirm each other and arrive at the same dates for objects. Weird how they do that when they're so flawed.