The Mudcat Café TM
Thread #59418   Message #2243196
Posted By: Amos
23-Jan-08 - 06:53 PM
Thread Name: BS: The Mother of all BS threads
Subject: RE: BS: The Mother of all BS threads
Here. You may need this:

A NEW CALCULATION EXPLAINS THE MECHANISM BEHIND CARBON DATING in
terms of the way the mass of mesons changes as they travel through
an atomic nucleus. Mesons (particles such as pions, containing a
quark and an antiquark) are thought to mediate the nuclear force
between two nuclei.
Radiocarbon dating began in 1949 when Willard Libby said that the
amount of carbon-14 (the radioactive cousin of carbon-12) left in an
object (such as a fossil tree) could provide an estimate of how old
the object was. The thinking was that the organism, while it was
alive, would constantly ingest enough of the rare C-14 to replace
those nuclei that were decaying into -14 (the other products being
an electron and a neutrino). But as soon as the organism died, the
ratio of C-14/C-12 would begin to drop exponentially since the C-14
was no longer being replaced. Measuring the ratio in terms of
radioactive half-lifes would provide a good estimate of the fossil.
This method has been used by archeologists ever since to measure the
age of things, at least those things that had been alive.
A big questions presented itself: if the radioactive half-life of
C-11 is 20 minutes, and that of O-14 is 1 minute, and that of O-15
is 2 minutes, and that of N-13 is 10 minutes, why is the life-time
of C-14 some 3 billion minutes (5730 years)? This is what Jeremy
Holt and his colleagues at Stony Brook, TRIUMF (the accelerator
facility in Vancouver), and the University of Idaho have set out to
determine. Holt says that the anomalously long C-14 half-life has
been a mystery to theorists for half a century. An earlier theory,
called Brown-Rho scaling (named for Gerry Brown and Mannque Rho,
advanced in 1991), suggested that the masses of most mesons decrease
uniformly when (insofar as they carry the nuclear force operating
inside nuclei) they travel through dense nuclear material (see
figure at http://www.aip.org/png/2008/294.htm ). Holt
(jeholt@tonic.physics.sunysb.edu, 631-632-9843) and his fellow
authors bring things up to date by accounting, with fair accuracy,
for the observed long C-14 lifetime. (Holt et al., Physical Review
Letters, upcoming article; designated as an Editor*s Suggested
article)