Do we actually understand geologic processes? New technology brings new inf- mation and perceptions, which sometimes overturn imaginations based on simple observation and estimation, in conjunction with common sense inference. In 1902 1904, PierreCurieandErnestRutherford?rstformulatedtheideaofusingradioactive transformation of nuclides as a geologic chronometer. After a century of working with such tools, geology has advanced from a descriptive science to an analytic s- encethatformulatesconclusionsbasedonexactvalues.Thetechnologyofradiogenic isotope geology has created a branch of science...