On Mon, Apr 30, 2012 at 9:10 PM, <[email protected]> wrote: Nanospire report that the isotopes generated are short-lived. > Assuming their measurements are accurate, why should this be? >
Short-lived isotopes are generally a signature of hydrogen or deuterium fusion, neutron capture or something that looks like one of these things (e.g., Mills' Hydrino hypothesis). Start at one of the gray boxes in this table and move down or to the right by way of the addition of a proton or neutron. If you get beige or gold, the isotope is short-lived. - http://en.wikipedia.org/wiki/Table_of_nuclides_(complete) Protons and free deuterons are easy to create and, according to current physics, hard to add to a nucleus. Neutrons are hard to create according to current physics, and, when kept below a certain energy threshold, easy to add to a nucleus. Given the right conditions, there is also alpha capture (the addition of a helium nucleus), alpha decay, electron capture and decay and so on, and fission. These can all conceivably lead to short-lived isotopes. But when people talk about the appearance of unstable isotopes after a reaction, the first thing that comes to anyone's mind is neutron capture, since with thermal neutrons it is easy to bring activation of this kind about. Perhaps for this reason there is a question about whether the isotopes seen in the experiments are short-lived or stable or whether the isotope shifts are the ones expected for a certain kind of reaction -- or whether there are new isotopes at all. There appear to be conflicting statements, and one has to be wary of overly broad generalizations about what has been seen. But I understand that it's easy to measure whether there are unstable radioisotopes by using a Geiger-Muller counter. These devices are cheap and have been used and, I'm given to understand, rarely have such nuclear products been seen. The regular appearance of short-lived isotopes after an experiment, if this could be confirmed, is a serious problem for some theories to grapple with. Similar difficulties arise with isotope shifts, even to stable but uncommon isotopes. Eric
