Evidence of Earth's age

Overview
The scientific evidence from which the currently established age of the Earth (i.e. approximately 4.7 billion years) was determined is so overwhelming that many respectable scientists consider defending this evidence against "young Earth" theories to be a complete waste of their time. Nonetheless, the defense must be made in order to forestall the possibility of bystanders assuming no defense can be made.

See also scientific knowledge contradicted by young Earth theories