TECHNOLOGY

Radiocarbon Dating

1949 CE

Phanerozoic · Cenozoic · Quaternary · Holocene · Meghalayan

Radiocarbon dating, established in 1949, is a method that gives the age of anything that once lived from the steady decay of the radioactive carbon that it stopped taking in at death.

Radiocarbon dating is a method that measures the age of the remains of living things. It rests on radiocarbon, a radioactive form of carbon that living things take in for as long as they are alive and cease to take in at death. The radiocarbon left in the tissue then decays, its atoms breaking down at a fixed rate, so the quantity that remains measures the time elapsed since death. Arnold and Libby (1949) first tested the method on wood whose age was already established by written history, including Egyptian material. A dating method is of no use until it has been checked against something independently known.

Why it matters

With radiocarbon dating, archaeologists ceased debating the order of sites and began supplying dates. Most of the ages on this timeline for the last fifty millennia come from this method. The limit belongs to the method itself: in older remains, too little radioactive carbon is left to be measured. Everything older on this timeline is therefore dated by other methods.

Dating & uncertainty

The date of this entry is the year in which the checks of the method were published. The method was tested against objects of known age, including Egyptian wood, before being applied to samples of unknown age. It can date remains up to about fifty thousand years old.

Earth history as one day

23:59:59.99851.5 ms before midnight

if Earth’s 4.54 billion years were compressed into a single day