Then, only exceptionally well-preserved, pristine samples can provide reliable dates.At Warratyi rock shelter in the Flinders Ranges, South Australia, which shows signs of the oldest human occupation of the country’s arid interior, the oldest sample – a fragment of emu eggshell – has been radiocarbon dated to 49,000 years with reasonable confidence.This decay is an example of an exponential decay, shown in the figure below.

radiation dating game-13

Scientists know the half-life of C-14 (5,730 years), so they can figure out how long ago the organism died.

Carbon-14 dating can only be used to determine the age of something that was once alive.

It might take a millisecond, or it might take a century. But if you have a large enough sample, a pattern begins to emerge.

It takes a certain amount of time for half the atoms in a sample to decay.

They need to be active long enough to treat the condition, but they should also have a short enough half-life so that they don’t injure healthy cells and organs.

Radioactive dating is helpful for figuring out the age of ancient things.

“Unlike bone or charcoal, carbon preserved in eggshell is very stably locked in and unlikely to have been contaminated,” says Nigel Spooner, a physicist at the University of Adelaide in Australia who specialises in dating techniques.

For archaeologists such as Spooner trying to date the first occupation of Australia, older age limitations of radiocarbon dating are frustrating, as it is exactly this period in which they are most interested.

So along with radiocarbon dating, they use a technique known as optically stimulated luminescence (OSL) dating.

It finds the age of the sediment surrounding artefacts – sediment which may have once been outside sand trampled into caves tens of thousands of years ago – by measuring when it was last exposed to the sun.

Scratching around in a cave in the middle of nowhere, you find a bone.