Carbon-14, though, is continuously created through collisions of neutrons generated by cosmic rays with nitrogen in the upper atmosphere and thus remains at a near-constant level on Earth.
The level of bomb carbon was about 100% above normal levels between 19.
The level of bomb carbon in the northern hemisphere reached a peak in 1963, and in the southern hemisphere around 1965.
See this graph, and description below. Radiocarbon_bomb_One of the main methods used to date fossils is by the strata they are found in.
Some strata are dated absolutely via radiometric dating.
When these fossils exist, they can be used to determine the age of the strata, because the fossils show that the strata correspond to strata that have already been dated by other means.
For more information on radiometric dating, read Radiometric Dating and the Geological Time Scale, Circular Reasoning or Reliable Tools? Given that the half-life of carbon-14 is 5730 years, one can calculate that 4 billion C-14 atoms will produce 1 decay per minute on the average.These effects are corrected for by the calibration of the radiocarbon dating scale. Nuclear carbon dating is not the only test used to date fossils.Note that the position the "God made the Earth seem older." (also known as the Omphalos hypothesis) is unfalsifiable.Therefore, it isn't a scientific hypothesis, but a faith-based one, and off-topic.These methods are sufficient to determine a great deal of stratigraphy.