Radioactive potassium dating

These techniques, unlike carbon dating, mostly use the relative concentrations of parent and daughter products in radioactive decay chains.

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