Schroedinger's Cat

A cat which is neither alive nor dead, but rather in a state of stasis, in a box. There is also in the box a geiger counter and a tiny radioactive particle, the counter wired to a vial of hydrochloric acid (that got your attention). After a set amount of time, the particle is 50% likely to decay, setting off a mechanism triggered by the geiger counter which smashes the vial and kills the cat. Supposedly, after that set amount of time, if no one looks in the box, the whole system is in a state of stasis because the cat is 50% likely to be alive and 505 likely to be dead, and is thus neither alive nor dead, but both. At least, until someone opens rhe box. There are all sorts of conundrums associated with this thesis, and it is very controversial.