Carbon Dating

Coal is a naturally abundant element in the atmosphere, land, sea and every living creature. C-12 is by far the most common isotope, but only one in a bilion carbon atoms C-14. C-14 formed in the upper atmosphere, where nitrogen-14 (N-14) is modified by the influence of the bombardment of cosmic radiation (neutron-proton effective alternative nitrogen atom of an isotope of carbon). The new isotope is called "carbon footprint" because it is radioactive, but is not dangerous. It is naturally unstable and disintegrate spontaneously Back to N-14 for some time. It takes about 5730 years for half of a sample of carbon decay of nitrogen. We need 5730 more than half of the rest, and then another 5730 for half of what was then left to rot and so on. The time it takes for half of a sample to decay is called "Half-Life."

The carbon is oxidized (which is combined with oxygen) to the biosphere by natural processes such as breathing and eating. Plants and animals contain naturally rich C-12 isotope, and much less carbon isotopes in their tissues at approximately the same proportion as they are present in the atmosphere during its lifetime. When an animal dies, it ceases to consume more carbon, while C-14 is already in the body continues to decline in the nitrogen. So if there are remains of a dead animal on C-12 C-14 ratio is half of what should be (for example, a C-14 atom per trillion atoms of C-12 instead of one on one billion) may think that the animal has been dead for over 5730 years (since half of the carbon is absent, it takes about 5730 years for half of the decay back into nitrogen). If the ratio is one fourth of what should be (one of four billion dollars), we assume that the animal has been dead for 11,460 years (two half-lives). After about 10 half-lives, is the amount of carbon is too small to measure, and this technique is not useful in six units, which it has killed more than 60,000 years. Another limitation is that this method can be used in organic materials such as bones, meat or wood. Can not be used to date rocks directly.
Radiocarbon Dating - The starting point

Radiocarbon Dating is a dating technique based on three things:
• The rate of C radioactive decay of unstable isotopes to stable 14 non-N-14 radioactive isotope,
• The relationship between C-12 to C-14 is in a given sample,
• The relationship between C-12 to C-14 into the atmosphere when the sample is dead.
Radiocarbon Dating - controversies
Carbon dating is controversial for two reasons. First, is based on a series of questionable assumptions. We have, for example, the percentage of reduction (which is a half-life of 5730 years) has remained constant over the past hidden. However, there are strong indications that radioactive decay could have been much faster in places hidden past.1 We also assume that the relationship between C-12 C-14 in the atmosphere has remained constant over the last hidden (from so we know what the ratio was at the time the sample is dead). And yet we know that "carbon is 28-37% faster than it is rotten," 2 which means it has not yet reached equilibrium, which means that the proportion is higher aujourd 'Today it was hidden in history. We also know that the proportion had fallen to the industrial revolution due to the drastic increase of CO2 emissions from factories. This artificial fluctuation was not a natural phenomenon but it shows that variations are possible, and a period of turbulence in natural lands will significantly affect the relationship. Volcanoes spew CO2, which could effectively reduce the quota. The factors that have lived and died during a period of intense volcanic activity appear older than they really are, if they were dated using this technique. The relationship can still be influenced by the rate of 14 C-production in the atmosphere, which in turn influenced by the amount of cosmic radiation penetrates the Earth's atmosphere. The quantity of cosmic radiation penetrates the Earth's atmosphere is influenced by things like the Earth's magnetic field deflects the cosmic rays. Precise measurements during the last 140 years have shown a decrease in the intensity of the magnetic field. This means that there has been a steady increase in radiocarbon production (which would increase the quota).

And finally the dates, the dating system is controversial because it is derived from the game are often inconsistent. For example, a portion "of Dima [a famous baby mammoth was discovered in 1977] was 40,000 RCY [Radiocarbon years] has been a second 26,000 RCY and" wood found immediately around the body was 9,000-10,000 RCY.