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From: Alpern.IBM-SJ%Rand-Relay@sri-unix.UUCP
Newsgroups: net.physics
Subject: Radioactive Dating
Message-ID: <12863@sri-arpa.UUCP>
Date: Fri, 21-Oct-83 11:49:10 EDT
Article-I.D.: sri-arpa.12863
Posted: Fri Oct 21 11:49:10 1983
Date-Received: Wed, 26-Oct-83 03:31:26 EDT
Lines: 23

From:  David M. Alpern <Alpern.IBM-SJ@Rand-Relay>

Max Ewell commented in his recent note on "Scientific Creationism"
that the best estimates of the earth's age come from measurements
made on the radiation from long-lived elements.
 
I've always wondered where the boundary knowledge for such
measurements comes from.  For example, I've been under the
impression that fossil dating assumes that the concentrations
of various isotopes in the human body has been reasonably constant
throughout the generations, and thus that the original radiation
was at a level equal to that of a modern human (on whom we can take
measurements).
 
But how does one gain reasonable information on the original
concentration of various radioactive isotopes on the planet?
How wrong is my understanding of the radioactive dating process?
 
Thanks for any enlightenment you can provide.
 
- Dave
 
p.s. Anybody need a name for a post WW-3 matchmaking service?