The Mudcat Café TM
Thread #165504   Message #3971030
Posted By: DMcG
11-Jan-19 - 05:04 AM
Thread Name: BS: science surprises
Subject: RE: BS: science surprises
Really short half life isotopes have to be local decomposition products of other radioactive elements. Francium, for example, has a half life of 22 minutes. That is not a problem if the elements it decays from have a long life (eg Neptunium at up to 2 million years). But even so, given we are talking about moving physical objects at a tiny fraction of light speed, even 2 million years is not very long to cross the distances involved.