Living organisms from today would have the same amount of carbon-14 as the atmosphere, whereas extremely ancient sources that were once alive, such as coal beds or petroleum, would have none left.

Carbon dating non organic video

Finally, Libby had a method to put his concept into practice. The circular arrangement of Geiger counters (center) detected radiation in samples while the thick metal shields on all sides were designed to reduce background radiation.

The concept of radiocarbon dating relied on the ready assumption that once an organism died, it would be cut off from the carbon cycle, thus creating a time-capsule with a steadily diminishing carbon-14 count.

Radiocarbon dating would be most successful if two important factors were true: that the concentration of carbon-14 in the atmosphere had been constant for thousands of years, and that carbon-14 moved readily through the atmosphere, biosphere, oceans and other reservoirs—in a process known as the carbon cycle.

In the absence of any historical data concerning the intensity of cosmic radiation, Libby simply assumed that it had been constant.

Theoretically, if one could detect the amount of carbon-14 in an object, one could establish that object’s age using the half-life, or rate of decay, of the isotope.

In 1946, Libby proposed this groundbreaking idea in the journal Physical Review.

It showed all of Libby’s results lying within a narrow statistical range of the known ages, thus proving the success of radiocarbon dating.

Top of page The “Curve of Knowns” compared the known age of historical artifacts associated with the Bible, Pompeii, and Egyptian dynasties with their age as determined by radiocarbon dating.

Based on Korff’s estimation that just two neutrons were produced per second per square centimeter of earth’s surface, each forming a carbon-14 atom, Libby calculated a ratio of just one carbon-14 atom per every 10 carbon atoms on earth.