> they have a pretty good handle on why atoms decay
Oh, they actually don't. Radioactive decay, AFAIK, is still an open physics mystery. We know it happens, we don't know why, what causes it, or if there even is a cause. We can predict factors that make it more likely.
> to the point they can predict some to be radioactive before it's actually observed to be (like Bismuth-209).
Right, but Xenon 124 wasn't predicted to be radioactive which is what makes it fascinating. It shows holes in what we can predict as being radioactive which is what makes me wonder about everything being radioactive but the timetable is too far out.
I don't actually think Xenon-124 being radioactive was a surprise. All the publicity related to observing the decay for the first time is phrased around 'hey we observed something that's very rare' not 'hey this thing happened we didn't expect to happen'.
Which seems to point even more towards, scientists have a pretty good handle on which ones are radioactive.
Where is the mystery? Any system can spontaneously transform into a new state with a probability greater than zero unless some conservation law prevents it. In a sense it's just quantum tunneling.
Can you be more specific? I believe quantum mechanics explains all of radioactive decay. Unless the GP meant that QM is mysterious, I don't understand the problem.
Quantum Chromodynamics, path integrals, and what other mechanisms you need for deriving the half life are extremely complicated, especially for that many particles, so of course it's hopeless without approximations, which can be wrong, or are even wrong by definition. But the fact that it's prohibitively hard to solve the equations for such complicated systems doesn't indicate a gap in our understanding. You don't even have to go to xenon, this is already the case for tritium.
Oh, they actually don't. Radioactive decay, AFAIK, is still an open physics mystery. We know it happens, we don't know why, what causes it, or if there even is a cause. We can predict factors that make it more likely.
> to the point they can predict some to be radioactive before it's actually observed to be (like Bismuth-209).
Right, but Xenon 124 wasn't predicted to be radioactive which is what makes it fascinating. It shows holes in what we can predict as being radioactive which is what makes me wonder about everything being radioactive but the timetable is too far out.