Peter Gluck <peter.gl...@gmail.com> wrote: The simplest explanation of this contradiction is that "they" do not want to > tell what the isotopic ratio of Cu is
No, the simplest explanation is that they are having difficulty doing mass spectroscopy, and they keep getting conflicting results. Many people do, even experienced researchers at major universities. Mizuno used to send a sample to three different groups of experts and get three different answers. With some samples, that is. It depends on the element, the extent of the shift, and the type of spectrometer. Some shifts are large and easily detected. - Jed
