A Cat in a Box! Answered
Sorry, no hilarious picture - but a thought exercise!
Imagine a steel box (to shield the contents from the universe) that contains a cat. Inside this box is a device that contains a gas which may, or may not, cause instant death to the cat. One hour after the device is released in the steel box (with cat) - what is the state (assume only two states - alive or dead) of the cat?
Mind you, you have no method to measure the results of the possibly poisonous device - after all, measure the result and you change it! I imagine there are a few of you that have read about this very scenario in an academic setting :)