Radiometric dating is based on
As water freezes and each molecule falls into place, atoms that don’t fit in the forming ice crystal are excluded. For example, zircon (a crystal) is perfectly happy to incorporate uranium, but excludes lead.Impurities, such as dissolved air, are either forced out or concentrated in the last region to freeze. It so happens that uranium decays into lead with a half-life of 4.5 billion years.Widgets Human evolution from an ancestral primate species is not a vague hypothesis, but a historical fact.Archaeological geology as a science had to precede the proposal of evolution, as an understanding of the immense age of the earth is necessary to understand evolution.This is the beauty of fundamental research: you never know what you’ll find when you start poking around.Choose: No Frames Layout Choose: Human Evolution Frames .Without the universal acceptance of the principle of evolution, there is no chance for the serious proposal of holism.
At the onset of the 20th century, most scientists had accepted the great antiquity of the earth, the theory of evolution and that humanity had evolved from an ape ancestor, but by 1908 the fossil evidence of early man was scarce.First, that radioactive isotopes have a fixed half-life (totally independent of their environment).And second, that the elements they were before and after the radioactive decay have different chemical properties. If an atom doesn’t interact chemically in the right way, then it won’t be incorporated into a forming crystal.There are many different kinds of radiometric dating that are used to date things that are non-organic (which is part of how we determine the age of the Earth).
They each rely on a couple of different (thoroughly verified) principles.
Carbon dating is the most famous form of “radiometric dating”.