Among the best-known techniques are radiocarbon dating, potassium-argon dating and uranium-lead dating.
By allowing the establishment of geological timescales, it provides a significant source of information about the ages of fossils and the deduced rates of evolutionary change.
The “half your age plus seven” rule of thumb probably helps you avoid being a creep, but is it accurate?
Much to my surprise, when overlaying a line representing the rule of thumb on Kenrick and Keefe’s results (see red line in the figure below), you can see it closely matches the low end of the range (i.e., youngest preferred) for all but the oldest men.
and is now the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of the Earth itself, and can also be used to date a wide range of natural and man-made materials.
More slowly decaying isotopes are useful for longer periods of time, but less accurate in absolute years.The science of geochronology is the prime tool used in the discipline of chronostratigraphy, which attempts to derive absolute age dates for all fossil assemblages and determine the geologic history of the Earth and extraterrestrial bodies.By measuring the amount of radioactive decay of a radioactive isotope with a known half-life, geologists can establish the absolute age of the parent material.Biostratigraphy does not directly provide an absolute age determination of a rock, but merely places it within an interval of time at which that fossil assemblage is known to have coexisted.Both disciplines work together hand in hand however, to the point where they share the same system of naming rock layers and the time spans utilized to classify layers within a stratum.Check out the related Weekday Calculator which also calculates lunar age.There is also a live countdown clock which can count down to a date in the future or show the time elapsed since a date in the past.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.Radiometric dating is also used to date archaeological materials, including ancient artifacts.Different methods of radiometric dating vary in the timescale over which they are accurate and the materials to which they can be applied.