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View Full Version : When Did the Earth's Core Separate from its Shell?



Fraser
2005-Oct-27, 07:24 PM
SUMMARY: Geologists have come up with two measurements of radioactive decay to calculate when the Earth's core separated from its crust, but the problem is, these two numbers don't match. Researchers from the University of Bristol think that the giant collision that occurred early on in Earth's history - which went on to form the Moon - might have reset one of these "countdown clocks" and created the discrepancy.

View full article (http://www.universetoday.com/am/publish/earth_core_separate_shell.html)
What do you think about this story? post your comments below.

cran
2005-Oct-28, 01:35 AM
Well, it makes sense, and something had to register the 'giant impact/moon formation' if it happened ... I remain mindful of the overlapping margins of error in the two estimated dates, however ...

Greg
2005-Oct-28, 03:50 AM
There is a maxim that archaeologists use when contemplating the range of error for radioactive dating (at least with regards to radioactive carbon dating) When ranges were given for tests on well known and established items of antiquity and compared there was a strong tendency for the actual (known) value to fall in the earliest 10 pecent of the range given by testing for those same objects by radioactive dating. If the same thing applies to other elements with longer half lives, then it lends more credibility to the findings.
I was wondering when anyone would provide some sort of corroborative hard evidence to support the widely accepted theory of a Mars-sized impactor hitting the Earth and forming the moon. If this research holds up, then it is quite an exciting and important find, indeed.