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Old Dec 5, 2003 | 11:19 AM
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From: NoVA
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Originally posted by Nightshade
How are they sure that it is accurate though...I mean they are judging this based on items much more recent than what they are using it for...so what if it is only accurate to say 100 years than the degradation process is sped up?

Science has been wrong many times before so what if this "accepted and accurate" dating system is wrong too.

Way too many questions for it to convince me.
now that i've had a few minutes to research, i doubt that they used carbon dating to date this particular specimen, since carbon-14 has a halflife of 5700 years, carbon dating is only reliable up to 50,000 years. most likely they used potassium-40 dating which has a half life of 1.3 billion years.

here's a brief explanation fo how carbon dating works...

Cosmic rays enter the earth's atmosphere in large numbers every day. For example, every person is hit by about half a million cosmic rays every hour. It is not uncommon for a cosmic ray to collide with an atom in the atmosphere, creating a secondary cosmic ray in the form of an energetic neutron, and for these energetic neutrons to collide with nitrogen atoms. When the neutron collides, a nitrogen-14 (seven protons, seven neutrons) atom turns into a carbon-14 atom (six protons, eight neutrons) and a hydrogen atom (one proton, zero neutrons). Carbon-14 is radioactive, with a half-life of about 5,700 years.

The carbon-14 atoms that cosmic rays create combine with oxygen to form carbon dioxide, which plants absorb naturally and incorporate into plant fibers by photosynthesis. Animals and people eat plants and take in carbon-14 as well. The ratio of normal carbon (carbon-12) to carbon-14 in the air and in all living things at any given time is nearly constant. Maybe one in a trillion carbon atoms are carbon-14. The carbon-14 atoms are always decaying, but they are being replaced by new carbon-14 atoms at a constant rate. At this moment, your body has a certain percentage of carbon-14 atoms in it, and all living plants and animals have the same percentage.
(from www.howstuffworks.com)

potassium-40 is created in a similar way and is found naturally in all organisms. since it's halflife is so long, potassium-40 dating is used for dating fossils that are over 50,000 years old.
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