Radiodating earth

17-Dec-2019 03:42

Radiometric dating or radioactive dating is a technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed.

The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay.

James Hutton, a physician-farmer and one of the founders of the science of geology, wrote in 1788, “The result, therefore, of our present inquiry is, that we find no vestige of a beginning, — no prospect of an end.” Although this may now sound like an overstatement, it nicely expresses the tremendous intellectual leap required when geologic time was finally and forever severed from the artificial limits imposed by the length of the human lifetime.

By the mid- to late 1800s, geologists, physicists, and chemists were searching for ways to quantify the age of the Earth.

All ordinary matter is made up of combinations of chemical elements, each with its own atomic number, indicating the number of protons in the atomic nucleus.

Some isotopes are stable, but some are unstable or radioactive.The rates of decay of various radioactive isotopes have been accurately measured in the laboratory and have been shown to be constant, even in extreme temperatures and pressures.These rates are usually expressed as the isotope's half-life--that is, the time it takes for one-half of the parent isotopes to decay.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.

Some isotopes are stable, but some are unstable or radioactive.

The rates of decay of various radioactive isotopes have been accurately measured in the laboratory and have been shown to be constant, even in extreme temperatures and pressures.

These rates are usually expressed as the isotope's half-life--that is, the time it takes for one-half of the parent isotopes to decay.

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.

Lord Kelvin and Clarence King calculated the length of time required for the Earth to cool from a white-hot liquid state; they eventually settled on 24 million years.