Plus, significantly older radiodates for rocks of a known age show that radiometric dating is not reliable.
All the K in your body is also susceptible to this decay!
Geologists do not directly measure the age of a rock.
[to an accuracy of about 1%.] For none of the Ar would be entrained in the previous molten state.
All the K in your body is also susceptible to this decay! For this mineral is among the last to form - as it forms at the lowest temperature compared to the other components of granite.
Assigning a date requires that the rate at which the parent decays into the daughter element has been the same throughout the rock’s history.
It is similar to assuming that the constriction in an hourglass has always been the same diameter, and the same number of sand grains passes every minute.Finally in 1976, it was discovered that the earth is "really" 4.6 billion years old… The answer of 25 million years deduced by Kelvin was not received favorably by geologists.Both the physical geologists and paleontologists could point to evidence that much more time was needed to produce what they saw in the stratigraphic and fossil records. For this mineral is among the last to form - as it forms at the lowest temperature compared to the other components of granite.This mineral contains potassium, 40K, which may be dated by the Potassium-Argon method.They choose rocks containing radioactive “parent” isotopes that emit particles and radiation to become a different “daughter” element and measure ratios of elements to their isotopes.