Measuring the uranium-to-lead ratios in the oldest rocks on Earth gave scientists an estimated age of the planet of 4.6 billion years.Segment from A Science Odyssey: "Origins."Geologists have calculated the age of Earth at 4.6 billion years.

Some isotopes are stable, but some are unstable or radioactive.First, it provides no evidence whatsoever to support their claim that the earth is very young.If the earth were only 6000–10 000 years old, then surely there should be some scientific evidence to confirm that hypothesis; yet the creationists have produced not a shred of it so far.Furthermore, this energy could penetrate cardboard and even walls to fluoresce barium platinocyanide.Rontgen used the mathematical symbol for unknown to name this energy X-rays.The discovery gave scientists a tool for dating rocks that contain radioactive elements.Many elements have naturally occurring isotopes, varieties of the element that have different numbers of neutrons in the nucleus.