No. 67: Jan-Feb 1990
Strange as it may sound, the act of observing atoms to determine their energy states interferes with their quantum jumps between atomic energy levels. This is another "spooky" prediction of quantum mechanics theory.
This prediction was recently verified by W.M. Itano et al, at the National Institute of Standards and Technology, in Boulder. They employed radio waves to drive beryllium ions from one energy level to another. While the beryllium ions were jumping from one level to another, the researchers sent in short pulses of light to determine the ion's state. The more frequently they inter rogated the ions, the less apt they were to jump to new energy states, despite the stimulating radio waves.
(Peterson, L; "Keeping a Quantum Kettle from Boiling," Science News, 136:292, 1989. Also: Pool, Robert; "Quantum Pot Watching," Science, 246:888, 1989.)
Comment. It is logical, but perhaps not practical, to contemplate delaying or stopping radioactive decay by interrogating poised radioactive atoms.