If some way could be found to sort those atomic nuclei of a particular isotope that were

about to decay, from those that would not decay until later, one could control the half

life of a sample, a result that would have many uses. That this might be possible, is

suggested by the fact that we can sort, from a sample of certain atoms that have equal

probability of being found spin up or spin down,those that are "up" vs. those that are

"down", and this sorting remains valid for some time afterward. As to sorting nuclei

according to the likelihood that they will decay soon, the key is to find a process to

do it. One scheme that comes to mind is to exploit the fact that certain nuclei emit

more beta particles toward one rather than the other magnetic pole. This would suggest

sorting them magnetically. However, this actually will not help because this procedure

will determine only what will be the probable direction in which the resultant sample

will decay, not its rate.

Another idea: Inasmuch as E=mc^2, each particle oscillates at a quantum frequency that

is proportinal to its mass-energy. But this invokes the energy-time uncertainty

relationship, which states that if the state of a system exists for a finite length of

time, then the energy of that state cannot be established more precisely than about

h/(delta T). Pursuant to Einstein, neither can its mass be precisely established. The

trick is, then, to exploit the fact that a nucleus that will decay soon has a less

definite mass than one that will decay later. Let be measured the masses very, very

precisely, setting up the process to weed out nuclei whose exact mass differs

significantly from the mean. The leftover nuclei would have a higher chance of lasting

longer than average.

Any other ideas?