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*waits for Stuart*
Quote from: DoctorBeaver on 21/07/2007 20:10:41*waits for Stuart*what are you trying to say [?]
Quote from: paul.fr on 21/07/2007 20:15:56Quote from: DoctorBeaver on 21/07/2007 20:10:41*waits for Stuart*what are you trying to say [?]Stuart works in forestry (cannot recollect his role right now, something to do with the European forestry commission, or something, if I recollect - it is somewhere mentioned on the site if you want to search for it).
You cannot carbon date a living organism because carbon dating merely dates an organism to the date when it was last alive, so an organism that is still living will have zero carbon date - you date the death of the organism, not its birth.
Quote from: another_someone on 22/07/2007 01:29:10You cannot carbon date a living organism because carbon dating merely dates an organism to the date when it was last alive, so an organism that is still living will have zero carbon date - you date the death of the organism, not its birth.I thought they had carbon dated a living Methuselah Tree !
Carbon Dating is a controversial dating technique. The method is based on the rate of decay of the radioactive carbon isotope, Carbon-14, which is formed in the upper atmosphere through the effect of cosmic ray neutrons upon Nitrogen-14. The Carbon-14 is rapidly oxidized and enters the earth's organic life through photosynthesis (plants) and the food chain (animals). Carbon-14 also enters the earth's oceans in an atmospheric exchange and as dissolved carbonate. Plants and animals, which utilize carbon in organic functions and food chains, absorb Carbon-14 during their lifetimes. The assumption is that the earth-bound carbon exists in equilibrium with the Carbon-14 in the atmosphere, which means that the number of Carbon-14 atoms and non-radioactive carbon atoms stays approximately the same over time. As soon as a plant or animal dies, it ceases its carbon intake. Thereafter, there is no replenishment of radioactive Carbon-14, only decay. In 1949, a team of scientists led by Willard Libby of the University of Chicago discovered that this decay occurs at a constant rate. They found that after 5,568 years, half the Carbon-14 in a dead sample will decay, and after another 5,568 years, half of that remaining Carbon-14 will decay, and so on. Thus, the "half-life" for Carbon-14 was measured by Libby and his team at 5,568?0 years. After ten half-lives, there is a miniscule amount of radioactive carbon left in a sample, which means that the limit of the Carbon Dating method is reached at between 50,000 and 60,000 years.