This also has to be corrected for.[2] Second, the ratio of C in the atmosphere at that time to be estimated, and so partial calibration of the “clock” is possible.

Accordingly, carbon dating carefully applied to items from historical times can be useful.

Familiar to us as the black substance in charred wood, as diamonds, and the graphite in “lead” pencils, carbon comes in several forms, or isotopes.

One rare form has atoms that are 14 times as heavy as hydrogen atoms: carbon-14, or C ratio gets smaller.

So, we have a “clock” which starts ticking the moment something dies.

For example, potassium-40 decays to argon-40; uranium-238 decays to lead-206 via other elements like radium; uranium-235 decays to lead-207; rubidium-87 decays to strontium-87; etc.

However, even with such historical calibration, archaeologists do not regard C produced and therefore dating the system.

The amount of cosmic rays reaching the Earth varies with the sun's activity, and with the Earth's passage through magnetic clouds as the solar system travels around the Milky Way galaxy.

Unless this effect (which is additional to the magnetic field issue just discussed) were corrected for, carbon dating of fossils formed in the flood would give ages much older than the true ages.

Creationist researchers have suggested that dates of 35,000 - 45,000 years should be re-calibrated to the biblical date of the flood.[6] Such a re-calibration makes sense of anomalous data from carbon dating—for example, very discordant “dates” for different parts of a frozen musk ox carcass from Alaska and an inordinately slow rate of accumulation of ground sloth dung pellets in the older layers of a cave where the layers were carbon dated.[7] Also, volcanoes emit much COC.