Wiens has a Ph D in Physics, with a minor in Geology.
His Ph D thesis was on isotope ratios in meteorites, including surface exposure dating.
Dating is not necessary to demonstrate that evolution is a fact.
Potassium (K) is one of the most abundant elements in the Earth's crust (2.4% by mass).One out of every 10,000 Potassium atoms is radioactive Potassium-40 (K-40).The curie was named after Marie and Pierre Curie who discovered the element radium. The half-life of an isotope is the time on average that it takes for half of the atoms in a sample to decay.For example, the half-life of carbon-14 is 5730 years.With 18 protons and 22 neutrons, the atom has become Argon-40 (Ar-40), an inert gas.
For every 100 K-40 atoms that decay, 11 become Ar-40.Overview of Methods Superposition Stratigraphy Dendrochronology Radiocarbon C14 Radiometric Dating Methods Obsidian Hydration Dating Paleomagnetic/Archaeomagnetic Luminescence Dating Methods Amino Acid Racemization Fission-track Dating Ice Cores Varves Pollens Corals Cation Ratio Fluorine Dating Patination Oxidizable Carbon Ratio Electron Spin Resonance Cosmic-ray Exposure Dating This is an excellent overview of dating methodologies, and is a chapter in a textbook on Archaeology.You may find it useful for the clear definitions, and for excellent links on a variety of topic.For each dating or chronological method there is a link in the box at right to take you to that section of this page.There, you will find a brief description of the method, plus links to take you to other webpages with more extensive information.Radiometric dating--the process of determining the age of rocks from the decay of their radioactive elements--has been in widespread use for over half a century.