efore analyzing the arguments advanced by creation “scientists” for a very young Earth, I here summarize briefly the evidence that has convinced scientists that the Earth is 4.5 to 4.6 billion years old.
There can be no doubt about the Earth’s antiquity; the evidence is abundant, conclusive, and readily available to all who care to examine it.
Thus, the radiometric ages obtained from these oldest rocks are not necessarily the age of the first event in the history of the rock.
Moreover, many of the oldest dated rocks intrude still older but undatable rocks.
Three basic approaches are used to determine the age of the Earth.
The first is to search for and date the oldest rocks exposed on the surface of the Earth.
Radiometric dating verified that the relative time scale determined by stratigraphers and paleontologists (Figure 1) is absolutely correct, a result that could only have been obtained if both the relative time scale and radiometric dating methods were correct.
Present evidence indicates, however, that these intervals were rather short (100-200 million years) in comparison with the length of time that has elapsed since the Solar System formed some 4 to 5 billion years ago.
Thus, the ages of the Earth, the Moon, and meteorites as measured by different methods represent slightly different events, although the differences in these ages are generally slight, and so, for the purposes of this chapter they are here treated as a single event.
A particularly fascinating question about the history of the Earth is “When did the Earth begin?
” The answer to this question was provided by radiometric dating and is now known to within a few percent.