After another 5,600 years, there is still one quarter left, and after an equally long period of time one eighth, etc.
Carbon-14 is thus said to have a half-life of 5,600 years.
Fortunately, it is so simple - which is probably not always the case with chemical research distinguished with the Nobel Prize - that everyone should be able to understand the conditions and principles for its execution.
Carbon-14 is a kind of carbon, an isotope of carbon with an atomic weight of 14, which is found in the carbon dioxide of the air.
But they do not even mention the basic problem that you cannot know the radioactive concentrations that existed in the rock in the past.
It would make no difference how accurate or high-tech the wristwatch was.
But without reliable witnesses the accuracy of the watch makes no difference.
You can only establish the time for the race if it was timed by two or more qualified eyewitnesses who observed the start, the progress and the finish.
This illustrates the whole problem with the radioactive dating of geological events.
Those who promote the reliability of the method spend a lot of time impressing you with the details of radioactive decay, half-lives, mass-spectroscopes, etc.