Talk:Natural nuclear fission reactor

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Moved from Oklo during merge

"since there is no physical reason why it should be exactly constant" is not well phrased. It is expected that the fine-structure constant is, exactly that - constant. Controversy arises from the fact that certain measurements described in the fine-structure constant article indicate it may have shifted over time. I have changed it to ", as new evidence suggests is possible". --JoeMeyerowitz 1/2/06

This is misleading for two reasons. First there is a long tradition of theoretical physics speculation about models where the so-called "fine structure constant", and/or other parameters, actually change very slowly with time. Theoretical models date back to Dirac in the 1930's. The original statement that there is no reason why it must be exactly constant is quite correct: these are parameters which a priori are continuously variable. Second, what has happened recently is the appearance of claimed signals of nonzero variation in astrophysical spectra, which is an experimental result. The new evidence does not "suggest that change is possible" since that was known all along; it suggests that change may actually have occurred. --Tdent 12:00, 20 September 2006 (UTC)

"A key to the creation was that at the time, the abundance of fissionable U-235 was about 3%, which is comparable to the amount used in today's reactors. Due to U-235's shorter half life than U-238, the current abundance of U-235 in natural uranium is about 0.7%. Therefore a natural nuclear reactor is no longer possible on Earth."

3% of what? I assume the 3% in the first sentence means 3% of natural uranium, as in the second sentence. This is ambiguous. --Jsnow 03:20, 22 August 2005 (UTC)

What about James Lovelock's claims that the Uranium was concentrated by bacteria? See his book The Ages of Gaia (1988).

I removed the "nuclear skullduggery" or whatever it was. If anyone knowledgeable can replace it with something comprehensible, it would be greatly appreciated.

[edit] Question

Are there any other sites than Oklo? thx.

So far no other sites have been found --21:26, 28 March 2006 (UTC)

Then why not replace 'best known location' with 'only known location?' 'best known' implies that there are other, more obscure ones. 69.249.92.211 16:25, 30 June 2006 (UTC)

Pending any clarification from an expert, I'll make that edit myself. 69.249.92.211 14:50, 11 July 2006 (UTC)

[edit] Timing

At one point the article states that the reactions occurred 1.5 billion years ago, while at another point it says the reactions took place over 2 billion years ago. Can someone clarify and/or correct this? How long did the reactors operate? Paul D. Anderson 06:28, 1 September 2006 (UTC)