Schematic representation of neutron capture event and indirect production of radioisotopes.
Nature can be very fickle and clues are normally concealed; the scene of the events needs to be visited many times and looked at with different eyes, as nature has left us with only a dim and discontinuous record with which to work.
Experienced detectives can extract more clues from the scene of a crime than can a lay person. Natural science is like a jigsaw puzzle, however, in nature at least half the pieces have been concealed.
Lu-Hf is shown to be a viable method for dating ancient terrestrial and extraterrestrial samples, but is unlikely to find wide application in pure chronological studies because it offers little advantage over existing methods.
The isochron method, which was thought by many to be quite reliable, has come under increasing suspicion. Zheng of Geochemical Institute of the University of Gttingen, Germany: “…Some of the basic assumptions of the conventional Rb-Sr isochron method have to be modified and an observed isochron does not certainly define a valid age information for a geological system, even if a goodness of fit of the experimental data points is obtained in plotting 87Sr/86Sr vs. This problem cannot be overlooked, especially in evaluating the numerical time scale.
Examples of recent downscales: John Horgan, “Blame It on the Moon: Australian ‘Solar Varves’ Turn Out to be Mostly Lunar,” Scientific American, Vol.