I read after 50,000 years carbon dating is inaccurate.
2006-09-17 02:49:38 · 6 answers · asked by Gingerbread Man 3 in Science & Mathematics ➔ Earth Sciences & Geology
If a certain telescope can't see an average size star
beyond 50,000 light years, does that mean it's no good?
2006-09-17 02:57:09 · answer #1 · answered by albert 5 · 0⤊ 3⤋
Carbon dating is a very good technique for setting the ages of certain kinds of materials that are as much as 50,000 years old. It does not work on older materials.
Carbon dating depends on the existence of two isotopes of Carbon - C12 and C14. The C14 carbon is formed in the atmosphere by radioactivity from space. It mixes with the C12 in the air and is absorbed by plants when they photosynthesize and animals when they eat plant food. Once a plant or animal dies, it stops taking in C14. The C14 is not stable, it decays slowly back into C12. So it gradually disappears until there is none left. That takes about 50,000 years. So, if you want to check the age of a body, or a piece of wood, etc. you can check the material and see what is the ratio of C12 to C14 in it. If it has about the same amount of C!4 as air, then it is recent, but if all the C14 has totally decayed, then it is over 50,000 years.
So, you can check the age of ancient houses, or a ice-age frozen mammoth, or a medieval piece of cloth. But you cant check a dinosaur bone!
2006-09-17 10:01:06 · answer #2 · answered by matt 7 · 4⤊ 0⤋
Carbon dating is no good, I went out on a date and she was very wooden. - :).
Seriously Carbon dating relies on the principal that radioactive C14 decays to Nitrogen at a fixed rate. When alive all organisms are in equilibrium with the environment on the ratio of C12 to C14. When it dies then the clock starts, the equilibrium is no longer maintained. After so many half lives the amount of C14 become too small to measure accurately.
2006-09-17 09:58:01 · answer #3 · answered by christopher N 4 · 0⤊ 1⤋
Carbon 14 half life is 5730 years, so 57300 years would mean about 10 half lives. 10 half lives mean that 1/2^10 of the original carbon 14 atoms are left in a sample (or one thousanth), and carbon 14 is not that abundant to start with (one part per trillion).
With the naturally occuring carbon 14, you get about 14 disintegration per minute per gram of carbon. Reduce that to 14 disintegration per 1000 minutes, or one every 71 minutes per gram of carbon -- and samples are usually not that big to start with, and you usually have to destroy them to measure the carbon 14 -- and you have about reached the limit of that method.
From that point, there are other techniques that have a greater range, but are less accurate, althoug accuracy may remain of the same ratio, the absolute numbers get bigger. (i.e. 6000 years +/- 100 years is just as good comparatively as 60 million years +/- 1 million year...)
2006-09-17 10:08:39 · answer #4 · answered by Vincent G 7 · 1⤊ 0⤋
People often seem to confuse "carbon dating" in particular with "radiometric dating" in general.
Carbon dating is indeed accurate to (about) 50,000 years; however, there are other radiometric methods accurate for much longer time frames.
2006-09-17 10:05:03 · answer #5 · answered by Zhimbo 4 · 3⤊ 0⤋
Well, I reckon this is strange but true because for years we've been guessing dates correctly. It's just that carbon dating is supposed to be easyer. :(
2006-09-17 10:11:19 · answer #6 · answered by babachoom3m3 1 · 0⤊ 1⤋