Start Radiocarbon dating dates back

Radiocarbon dating dates back

CATEGORY: technique DEFINITION: Absolute pollen counting is the determination of the number of grains of each pollen type per unit weight (grains/gram) or unit volume (grains/cm3) of sample.

in which the proportion of carbon isotopes is counted directly (as contrasted with the indirect Geiger counter method) using an accelerator mass spectrometer.

The method drastically reduces the quantity of datable material required.. Libby showed the essential uniformity of carbon-14 in living material and went on to measure the radiocarbon level in organic samples dated historically -- materials as old as 5,000 years from sources such as Egyptian tombs.

Libby's conclusion, with allowance for SYNONYMS OR RELATED TERMS: radiocarbon dating CATEGORY: technique DEFINITION: The occurrence of natural radioactive carbon in the atmosphere allows archaeologists the ability to date organic materials as old as 50,000 years.

This temporary increase in warmth allowed forests to establish themselves for a time in the ice-free zones.

Determination of the radioactivity of carbon from a sample will reveal the proportion of C14 to C12, and this will in turn, through the known rate of decay of C14, give the age of, or more accurately the time elapsed since the death of, the sample.

CATEGORY: technique DEFINITION: The most likely statistical age of an object dated by radiocarbon.

Two things in the method have to be allowed for: first, the 'date' given is never exact.