Re: Age dating question

B Richardson wrote:
[snip]
ISTM that radon being in the decay chain for Uranium is
inconvenient for a fast decay hypothesis. Its a mobile
gas with a half-life of 3.825 days. If the production
of it is increased by several orders of magnitude for
a short while, wouldn't it would leave a disproportionate
amount of decay product in fissures and other escape
routes for the gas during that time frame?

This is a good idea, but you need to work it out in detail
before it makes sense.

222Rn has a half life of 3.825 days. After a month or
so, there will be very little left. After a year you'd be
very hard pressed to detect any at all. Other isotopes
of Rn have shorter half lives. What that means is, if
you look some years after some kind of event, you
will be left with decay products. And which decay
products depends on the kind of event, what isotopes
it produced, and how they were retained.

The Oklo natural reactor has been mentioned in this
thread. Roughly 2 billion years ago it went critical
on its own, with natural ground water as a moderator.
We know it was a reactor because we find isotopes
in it that match exactly, all up and down the periodic
table, what we would calculate from a nuclear reactor.
Including 2 billion years of subsequent decay. Indeed,
we can see details so clearly that we can estimate
that it had a power cycle of roughly 1/2 hour on, then
2 or 3 hours off, and that it did this many millions of
times before exhausting its fuel.

The thing about Oklo is that it is not a single data point.
Nor even two or three. It is literally hundreds of different
isotopes, all right in line with what we would expect a
reactor to look like 2 billion years after it operated.
Not just a smoking gun, but an entire smoking arsenal.
Physics two billion years ago was highly similar to what
physics is today.

And the other thing about Oklo is, we know it's a reactor
because the fission products, or their decay products,
are right where they were generated. After several million
cycles of boiling the ground water out of the rock then
having it flow back in. Then two billion years of ground
water flowing through porous sandstone. The stuff in the
Oklo reactor is (except for a very few chemicals) exactly
where it was produced. This is a rather marvelous source
of validation data for geological disposal of nuclear waste.
Socks

.

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