How is the age of earth determined?
A) Radiometric dating of the "oldest" known zircon crystals from the Jack Hills of Western Australia. More specifically measuring the decay of uranium trapped in the mineral zircon. At the time of formation of the zircon crystal, Zirconium can be replaced by Uranium atoms because the ions of both elements have the same charge (+4) and roughly the same size. The radioactive uranium locked up in the zircon decays to lead at a fixed rate. By measuring the relative abundance of those two elements in the zircon today, one can determine how long ago it formed.
Problems with the method:
1) When zircon is heated during burial, some of the lead that had accumulated from radioactive decay can diffuse out of the crystal. The loss of that lead changes the ratio of lead to uranium, and so the new ratio, if measured, would give a spurious age.
2) Distinguishing isotope ratios as a result of zircon overgrowth and from the core (originally formed).
Assumptions:
1) Above mentioned problems are solved.
2) Radiometric decay is constant.
3) Ratio between mother and daughter isotopes a true reflection of the Zircon at the time of its creation.
B ) Radiometric dating of meteorites
Assumptions:
1) Radiometric decay is constant.
2) Ratio between mother and daughter isotopes a true reflection of the Zircon at the time of its creation.
3) Method is accurate.
Both methods employ radiometric dating and the most important assumption is that radiometric decay is constant regardless of the conditions the element resides in.
Textbooks will say that there is nothing you can do speed up radioactive decay.
Claus Rolfs from the Ruhr University of Bochum believes otherwise. A series of experiments where conducted (data yet to be published) whereby samples of metals with known radioactive decay time where implanted inside metals Paladium and Vanadium and cooled to just above absolute zero. What he found was quite interesting.
Eg: Sodium-22, which undergoes beta-plus decay with a normal half-life of 2.6 years, had a 1.2% increase in half-life.
Radioactive gold-198, which undergoes beta-plus decay with a normal half-life of 2.7 days had an increase in 5hours (predicted derease to be 1.2 hours).
Various other metals showed an increase in decay rate. According t the model, Radium-226 half-life time can be cut by a factor of 1000.
All this is good news for radioactive waste disposal, but will reopen the debate of the age of the universe. Interesting research and i do hope some data will be published soon.
http://www.newscientist.com/channel/fundam...tive-decay.html
Full Version: 4.5 billion year old earth
Interesting stuff
Perfect logic based off an incorrect first premise results in perfectly logical fallacy.
Perfect logic based off an incorrect first premise results in perfectly logical fallacy.
Looking at the data in the article, the more neutron rich the element, the faster the decay is in his model. Uranium has a relatively high amount of neutrons; higher than Radium which he predicts slashing the half-life by a factor of 1000.
And:
The dating of the age of the universe (and earth) based on radiometric dating might be grossly overestimated according to this model.... Interesting stuff indeed.
And:
QUOTE
Some of the heat produced on our planet's interior comes from from the radioactive decay of uranium and thorium. Yet there is more heat anyone can account for (New Scientist , 7 August 2004, p26). Rolfs suggests that in the molten metallic environment of the Earth's core, uranium and thorium could be contributing to the excess heat by decaying faster than we imagined.
The dating of the age of the universe (and earth) based on radiometric dating might be grossly overestimated according to this model.... Interesting stuff indeed.
QUOTE(Hehe @ Apr 8 2007, 07:36 PM) [snapback]1619017[/snapback]
Looking at the data in the article, the more neutron rich the element, the faster the decay is in his model. Uranium has a relatively high amount of neutrons; higher than Radium which he predicts slashing the half-life by a factor of 1000.
And:
The dating of the age of the universe (and earth) based on radiometric dating might be grossly overestimated according to this model.... Interesting stuff indeed.
And:
The dating of the age of the universe (and earth) based on radiometric dating might be grossly overestimated according to this model.... Interesting stuff indeed.
The Earth is only 131,383,296 years old. The Sun is 4,561,920,000 years old.
QUOTE(sirfiroth @ Apr 11 2007, 03:53 AM) [snapback]1623138[/snapback]
The Earth is only 131,383,296 years old. The Sun is 4,561,920,000 years old.
I didnt say the earth is 4.5Billionyears old, it is only a large proportion of geologic scientists that believe so. Feel free to discuss why you think the earth is 130million years old. QUOTE
THE AGE OF THE EARTH
United States Department of the Interior
GEOLOGICAL SURVEY
Branch of Isotope Geology Menlo Park, California
The Earth is a constantly changing planet. Its crust is continually being created, modified,
and destroyed. As a result, rocks that record its earliest history have not been found and
probably no longer exist. Nevertheless, there is substantial evidence that the Earth and the
other bodies of the Solar System are 4.5-4.6 billion years old, and that the Milky Way
Galaxy and the Universe are older still. The principal evidence for the antiquity of Earth and
its cosmic surroundings is:
1. The oldest rocks on Earth, found in western Greenland, have been dated by four
independent radiometric dating methods at 3.7-3.8 billion years. Rocks 3.4-3.6 billion years
in age have been found in southern Africa, western Australia, and the Great Lakes region of
North America. These oldest rocks are metamorphic rocks but they originated as lava flows
and sedimentary rocks. The debris from which the sedimentary rocks formed must have
come from even older crustal rocks. The oldest dated minerals (4.0-4.2 billion years) are
tiny zircon crystals found in sedimentary rocks in western Australia.
The rest of the article
United States Department of the Interior
GEOLOGICAL SURVEY
Branch of Isotope Geology Menlo Park, California
The Earth is a constantly changing planet. Its crust is continually being created, modified,
and destroyed. As a result, rocks that record its earliest history have not been found and
probably no longer exist. Nevertheless, there is substantial evidence that the Earth and the
other bodies of the Solar System are 4.5-4.6 billion years old, and that the Milky Way
Galaxy and the Universe are older still. The principal evidence for the antiquity of Earth and
its cosmic surroundings is:
1. The oldest rocks on Earth, found in western Greenland, have been dated by four
independent radiometric dating methods at 3.7-3.8 billion years. Rocks 3.4-3.6 billion years
in age have been found in southern Africa, western Australia, and the Great Lakes region of
North America. These oldest rocks are metamorphic rocks but they originated as lava flows
and sedimentary rocks. The debris from which the sedimentary rocks formed must have
come from even older crustal rocks. The oldest dated minerals (4.0-4.2 billion years) are
tiny zircon crystals found in sedimentary rocks in western Australia.
The rest of the article
Mother earth is a very old lady indeed, of course a gentleman never asks a lady's age. LOL
I must say that the minerals can decay at varying rates according to pressure and temperature changes. Similar to carbon dating it can be flawed.
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