Re: Clarification on Earth's age


"Friar Broccoli" <EliasRK@xxxxxxxxx> wrote in message
news:1148730532.841235.122070@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Hello world;

At this site

http://www.talkorigins.org/faqs/faq-age-of-earth.html

I read:

"... figure of 4.55 billion years for the Earth's actual age.

The most direct means for calculating the Earth's age is a
Pb/Pb isochron age, derived from samples of the Earth and
meteorites. This involves measurement of three isotopes of lead
(Pb-206, Pb-207, and either Pb-208 or Pb-204). A plot is
constructed of Pb-206/Pb-204 versus Pb-207/Pb-204.

If the solar system formed from a common pool of matter,
which was uniformly distributed in terms of Pb isotope
ratios, then the initial plots for all objects from that pool
of matter would fall on a single point. ..."


My question concerns those Pb isotope ratios. According to my
fuzzy thinking the only time when they would have been
uniformly distributed would be shortly after the explosions of
the super-novas which produced the clouds from which our solar
system subsequently formed.

If this is correct, then the 4.55 billion year estimate is not
an estimate of Earth's age, but of the average time of the
explosions of the super-novas which contributed heavy elements
to our solar system.

Could someone tell me if I am to basically right or wrong
about this.

Cordially;

Friar Broccoli
Robert Keith Elias, Quebec, Canada Email: EliasRK (of) gmail * com
Best programmer's & all purpose text editor: http://www.semware.com

--------- I consider ALL arguments in support of my views ---------

When the earth was formed (some say during a collision with a mars-sized
body), it was mostly molten, so the lead clock would have reset at that
time.

George


.

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