The age they came back with was only a few thousand years old. And kept their theory that dinosaurs lived "millions of years ago" instead. They then use potassium argon, or other methods, and date the fossils again.
A zircon is a mineral prized by geologists both because they are extremely durable and because they contain trace amounts of radioactive thorium and uranium, which allow for radiometric dating over timescales longer than the age of Earth itself.
Evidence of the earliest crust on Earth once came from a single grain of this mineral.
Scientists, using rigorous methods have established a process to eliminate this problem by calibrating radiocarbon dating results to items of a known age.
In this way, items of unknown age can be tested and an age determined to a reasonable degree of accuracy. More tomorrow where we explore the concept of isochron dating and how it neatly destroys most of the rest of these ‘issues’.
The barrel represents the earth's atmosphere in which the carbon-14 accumulates.