He was employed at Caltech's Division of Geological & Planetary Sciences at the time of writing the first edition.He is presently employed in the Space & Atmospheric Sciences Group at the Los Alamos National Laboratory.You cannot predict exactly when any one particular grain will get to the bottom, but you can predict from one time to the next how long the whole pile of sand takes to fall.


Most processes that we are familiar with are like sand in an hourglass.
In exponential decay the amount of material decreases by half during each half-life.
This paper is available on the web via the American Scientific Affiliation and related sites to promote greater understanding and wisdom on this issue, particularly within the Christian community.
Introduction Overview The Radiometric Clocks Examples of Dating Methods for Igneous Rocks Potassium-Argon Argon-Argon Rubidium-Strontium Samarium-Neodymium, Lutetium-Hafnium, and Rhenium-Osmium Uranium-Lead The Age of the Earth Extinct Radionuclides: The Hourglasses that Ran Out Cosmogenic Radionuclides: Carbon-14, Beryllium-10, Chlorine-36 Radiometric Dating of Geologically Young Samples Non-Radiogenic Dating Methods for the Past 100,000 Years Ice Cores Varves Other Annual-Layering Methods Thermoluminescence Electron Spin Resonance Cosmic Ray Exposure Dating Can We Really Believe the Dating Systems? Rightly Handling the Word of Truth Arguments over the age of the Earth have sometimes been divisive for people who regard the Bible as God's word.
Most of the elements in nature are stable and do not change.
However, some elements are not completely stable in their natural state.
Many Christians have been led to distrust radiometric dating and are completely unaware of the great number of laboratory measurements that have shown these methods to be consistent.
Many are also unaware that Bible-believing Christians are among those actively involved in radiometric dating.
It has become increasingly clear that these radiometric dating techniques agree with each other and as a whole, present a coherent picture in which the Earth was created a very long time ago.