Scientists first make observations that raise a particular question. In order to explain the observed phenomenon, they develop a number of possible explanations, or hypotheses. This is the inductive part of science, observing and constructing plausible arguments for why an event occurred.
As indicated earlier, the Bible does not fix the age of the earth, contrary to the claims of Answers in Genesis. Historically, their claim comes from the work of James Ussher, Bishop in the Church of Ireland, from 1625 to 1656.
If we accept that the Bible is reliable, an age of about 6,000 years is unavoidable. See Biblical chronogenealogies. For nigh on two millennia, Christians have consistently calculated the age of the earth to be just a few thousand yearsâsee the table in Old earth or young earth belief.