Basically, Shrodinger said that if you put a cat in a box with a vial of a deadly poison, whose glass had a 50% chance of shattering(thus giving the cat a 50% chance of dying and a 50% chance of living) you would create a scenario in which the cat would be simultaneously alive and dead, until you opened the box and looked at the cat.
I'd like to point out that its commonly misunderstood that schrödinger thought that the cat could both be dead and alive. the whole reason behind this thought experiment is to prove that quantum mechanics are flawed for some degree and that the cat can't possibly be both dead and alive.
here's the original quote from schrödinger:
One can even set up quite ridiculous cases. A cat is penned up in a steel chamber, along with the following device (which must be secured against direct interference by the cat): in a Geiger counter, there is a tiny bit of radioactive substance, so small that perhaps in the course of the hour, one of the atoms decays, but also, with equal probability, perhaps none; if it happens, the counter tube discharges, and through a relay releases a hammer that shatters a small flask of hydrocyanic acid. If one has left this entire system to itself for an hour, one would say that the cat still lives if meanwhile no atom has decayed. The psi-function of the entire system would express this by having in it the living and dead cat (pardon the expression) mixed or smeared out in equal parts. It is typical of these cases that an indeterminacy originally restricted to the atomic domain becomes transformed into macroscopic indeterminacy, which can then be resolved by direct observation. That prevents us from so naively accepting as valid a "blurred model" for representing reality. In itself, it would not embody anything unclear or contradictory. There is a difference between a shaky or out-of-focus photograph and a snapshot of clouds and fog banks
Probably, haha :) I was actually meant to be revising physics when I was on, so i had my physics book right there to double check :P
That sorta counts as revision... :P
It's an experiment where a cat was put in a box and a poisonous gas in a container was broken randomly, and at any given time, because the gas was released at random, you cannot tell whether it is alive or dead, so it must be presumed that it is both alive and dead. It supposed to prove some quantum theory or something. Never really read anything about it, so I could be completely wrong about everything, but that's what I've heard from my friends talking about it and stuff.