Some scientists prefer the terms chronometric or calendar dating, as use of the word "absolute" implies an unwarranted certainty of accuracy.Absolute dating provides a numerical age or range in contrast with relative dating which places events in order without any measure of the age between events.The methods work because radioactive elements are unstable, and they are always trying to move to a more stable state. This process by which an unstable atomic nucleus loses energy by releasing radiation is called radioactive decay.The thing that makes this decay process so valuable for determining the age of an object is that each radioactive isotope decays at its own fixed rate, which is expressed in terms of its half-life.Radiometric dating is used to estimate the age of rocks and other objects based on the fixed decay rate of radioactive isotopes.

Absolute dating is the process of determining an age on a specified chronology in archaeology and geology.

So, if you know the radioactive isotope found in a substance and the isotope's half-life, you can calculate the age of the substance. Well, a simple explanation is that it is the time required for a quantity to fall to half of its starting value.

So, you might say that the 'full-life' of a radioactive isotope ends when it has given off all of its radiation and reaches a point of being non-radioactive.

The best estimate from this dating technique says the man lived between 33 BC. From the ratio, the time since the formation of the rock can be calculated.

The boat of a pharaoh was discovered in a sealed crypt and reassembled in a museum near the pyramids (see Fig. The age of our galaxy and earth also can be estimated using radioactive dating.