Once we understand what we actually need to do we can apply the same principles to radioactive dating, and see if the methods do what they are claimed to do.
Picture a swimmer competing in a 1,500 metre race and an observer with an accurate wristwatch.
"[d] Deep ocean deposits supposed to contain remains of most primitive life forms are dated within 40,000 years.
"[b] Only three of the 15,000 reported ages are listed as `infinite.' "[c] Some samples of coal, oil, and natural gas, all supposedly many millions of years old have radiocarbon ages of less than 50,000 years.
Most young earth creationists reject all of these points.
As a scientific skeptics, we ask ourselves: is this really the case?
In centuries to come a body of a man or animal who lived and died in the 20th century would appear paradoxically of greater age since death than the body of a man or animal of the 19th century, and if the process of industrial use of fossil, therefore dead, carbon continues to increase, as it is expected will be the case, the paradox will continue into the forthcoming centuries.
But as the method was refined, it started to show rather regular anomalies.
First, it was noticed that, when radiocarbon dated, wood grown in the 20th century appears more ancient than wood grown in the 19th century.
But the basic concept of radioactive dating, sometimes called radiometric dating, is not difficult, especially since all of us regularly calculate how much time has passed: for example, since our birth, or since we started on a walk.
A swimming race is a familiar situation that illustrates the simple principles involved in measuring time.