[math-fun] permanently excited tantalum

"The most long-lived non-ground state <https://en.wikipedia.org/wiki/Ground_state> nuclear isomer is the nuclide tantalum-180m <https://en.wikipedia.org/wiki/Tantalum-180m>(180m 73Ta <https://en.wikipedia.org/wiki/Tantalum-180m>), which has a half-life <https://en.wikipedia.org/wiki/Half-life> in excess of 1,000 trillion years. This nuclide occurs primordially, and has never been observed to decay to the ground state. (In contrast, the ground state nuclide tantalum-180 does not occur primordially, since it decays with a half life of only 8 hours to 180Hf (86%) or 180W (14%))." More: https://en.wikipedia.org/wiki/Isotopes_of_tantalum So where do you get the radioactive stuff? And how do you rescue (excite) it? --rwg