Though there is no one age, a good rule is anything over 10,000 years old can be considered a fossil.
The oldest fossils ever discovered are more than 3.5 billion years old.
The iron pipes range in size, with some smaller than a toothpick.
The strangest part is that they may be about 150,000 years old.
This resemblance is used in chemical and biological research, in a technique called carbon labeling: carbon-14 atoms can be used to replace nonradioactive carbon, in order to trace chemical and biochemical reactions involving carbon atoms from any given organic compound.
These are relatively low energies; the maximum distance traveled is estimated to be 22 cm in air and 0.27 mm in body tissue.
In order for carbon dating to be accurate, we must know what the ratio of carbon-12 to carbon-14 was in the environment in which our specimen lived during its lifetime.
during the industrial revolution more carbon-12 was being produced offsetting the ratio a bit).
By taking a carboniferous specimen of known age (that is, a specimen which we are able to date with reasonable certainty through some archaeological means), scientists are able to determine what the ratio was during a specimen's lifetime.
Carbon-14 was discovered on February 27, 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, California.
Its existence had been suggested by Franz Kurie in 1934. The primary natural source of carbon-14 on Earth is cosmic ray action on nitrogen in the atmosphere, and it is therefore a cosmogenic nuclide.
They are then able to calibrate the carbon dating method to produce fairly accurate results.
Carbon dating is thus accurate within the timeframe set by other archaeological dating techniques.