What is radiometric dating
Hutton's theories were short on evidence at first, but by 1830 most scientists concurred that Noah's ark was more allegory than reality as they documented geological layering.
Using fossils as guides, they began to piece together a crude history of Earth, but it was an imperfect history.
But it wasn't until the late 1700s -- when Scottish geologist James Hutton, who observed sediments building up on the landscape, set out to show that rocks were time clocks -- that serious scientific interest in geological age began.
Before then, the Bible had provided the only estimate for the age of the world: about 6,000 years, with Genesis as the history book.
All rocks and minerals contain long-lived radioactive elements that were incorporated into Earth when the Solar System formed.
The use of radiometric dating was first published in 1907 by Bertram Boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of the Earth itself, and can be used to date a wide range of natural and man-made materials.As radioactive Parent atoms decay to stable daughter atoms (as uranium decays to lead) each disintegration results in one more atom of the daughter than was initially present and one less atom of the parent.The probability of a parent atom decaying in a fixed period of time is always the same for all atoms of that type regardless of temperature, pressure, or chemical conditions. The time required for one-half of any original number of parent atoms to decay is the half-life, which is related to the decay constant by a simple mathematical formula.Radioactive elements are unstable; they breakdown spontaneously into more stable atoms over time, a process known as radioactive decay.Radioactive decay occurs at a constant rate, specific to each radioactive isotope.