Ever since I went to a pumpkin carving party and mentioned
Schrodinger's cat people have asked me what it is.
Well, I just got a call from some co-workers who were out and about having a good time (and they didn't invite me). They called to ask about, you guessed it,
Schrodinger's cat So here is a much better explanation from Whatis.com (itself a very good website):
Schrodinger's cat is a famous illustration of the principle in quantum theory of superposition, proposed by Erwin Schrodinger in 1935. Schrodinger's cat serves to demonstrate the apparent conflict between what quantum theory tells us is true about the nature and behavior of matter on the microscopic level and what we observe to be true about the nature and behavior of matter on the macroscopic level.
First, we have a living cat and place it in a thick lead box. At this stage, there is no question that the cat is alive. We then throw in a vial of cyanide and seal the box. We do not know if the cat is alive or if it has broken the cyanide capsule and died. Since we do not know, the cat is both dead and alive, according to quantum law, in a superposition of states. It is only when we break open the box and learn the condition of the cat that the superposition is lost, and the cat becomes one or the other (dead or alive).
My explanation was pretty much on target, but I didn't know about the whole superposition thing.