Re: [asa] Oklo as the graveyard of YEC

Kirk,

There are cases where isotopic ratios have a specific physical cause. There are quite a few cases where physical behavior (more so than chemical behavior which depends on the electron valence states) depends on the weight of the nucleus. Diffusion rates, as you mentioned, are a very good example. They depend on the isotopic mass. Another is the evaporation rate of water. A small percent of water is O-18 based instead of O-16. About 0.2% to be exact. The evaporation rate of O-18 based water has a slightly different temperature dependence than O-16 water. This leads to a different O-18/O-16 ratio in evaporated ocean water in summer than in winter. That leads to a slightly different ratio in the snowfall in Greenland which leads to differences in the annual layers of ice. Hence, ice cores have an elegant method of detecting annual layers using isotope ratios.

Examples of this kind are not uncommon.

Randy
  ----- Original Message -----
  From: Bertsche@aol.com
  To: gmurphy@raex.com ; asa@calvin.edu
  Sent: Monday, April 16, 2007 11:49 PM
  Subject: Re: [asa] Oklo as the graveyard of YEC

  In a message dated 4/15/07 1:52:38 PM, gmurphy@raex.com writes:

    Now there are some properties that a fully formed creation would have to
    have, though it's hard to see why a 325/238 ratio of 1/138 would be one of
    them. But let that pass.

  Though George doesn't pursue this, I think it's worth considering in a broader sense. Why would there need to be any specific isotopic ratio for a physical system? Other than slightly different diffusion rates, there is essentially no chemical difference between isotopes. Ruling out nuclear effects (natural reactors or radiation/heat produced by short half-lives), there seems to be no functional advantage for any specific isotopic ratio.

  To make the argument more concrete, why should a rock be created with any specific ratio of 39-K to 40-K, for example? There seems to be no functional advantage of any specific ratio. So why would God have given different ratios to different rock formations in a fully-formed creation? And why would He do so in a systematic fashion which is consistent with other indicators of age? Why create any 40-K at all?

  Other than being an indicator of true age, it seems to me that there is no reasonable explanation for the variation that we see in isotopic ratios. In fact, we could argue the other way: Why would God create such a well-behaved system as K-Ar, with a half-life well-matched to the age of the earth? Could it be that He wanted us to learn details about the antiquity of His creation?

  Kirk

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Received on Tue Apr 17 20:24:20 2007