Working out ratios of the radioactive and stable carbons tells you the age of the sample.But the older the sample the less carbon-14 remains, and what is left becomes harder to find.They were sufficiently preserved to allow researchers from the National Alliance of Shidlovskiy “Ice Age” to piece together the lion’s morphology. The typical carbon nucleus contains six protons and neutrons, but some have an extra neutron or two, producing carbon-13 and the radioactive carbon-14.But to find out when the lion died, the Russians contacted Vladimir Levchenko at the Australian Nuclear Science and Technology Organisation (ANSTO). Eventually, carbon-14 decays into the stable carbon-13 and carbon-12 isotopes.And so on, Libby thought, with smaller and smaller fractions. He verified his tool’s accuracy with a piece of Pharaoh Senusret III’s funeral boat. Libby’s handmade detection tool has since been surpassed with more precise instruments that require smaller samples.And while carbon dating fractions get too small past 60,000 years, mimic aging techniques using other elements have cropped up to fill in the void.For example, if half the original carbon-14 levels are present in a discovered antler, then its owner died 5,730 years ago.If a fourth of the original carbon-14 levels are present, then the animal died happened 11,460 years ago. To prove his theory correct, he extracted pure carbon from ancient samples and built his own radiation detection tool.
ANSTO’s isotope ratios date them at around 28,700 years old.Each powder sample was then placed inside a particle accelerator and turned into a particle beam, enabling Levchenko to count the radioactive carbon atoms as they hit a detector.From their isotope ratios, he calculated the age of the lion’s bone and claw to be a little more than 61,000 years old – making it the oldest bone sample to be reliably carbon dated.In the 1950s, he reasoned that if the atmosphere has a dependable ratio of regular carbon to carbon-14, that same ratio should be found in any living thing.But since death means that plants and animals do not absorb any new carbon, a preserved leaf or bone should have, when plucked out of the earth, a drastically different regular carbon to carbon-14 ratio.