Can anyone explain to me the idea of Shrodinger's cat?

Well, if you have the basic idea, it would be easier if you explained what you understand by the thought experiment; then it would be easier to answer the question.

I’m not a physicist, so I can’t give you all the technical details. Here is a newspaper column that attempted to answer this question:

Straight Dope on Schroedinger’s Cat

Since the cat is in a box that has a vial of poison that may or may not have been broken, the cat is considered alive and dead at the ame time, until the box it opened.

The fact that the possibility of the cat being alive is equal to the possibility of the cat being dead means that both outcomes are happening at the simultaneously until the truth is revealed.

@jf9434 Tell me what you think the idea is. Otherwise, how would I know what details you’re missing? Or what good are details if your conceptual understanding is faulty?

@hiphiphopflipflapflop and @the100thmonkey : I know that the cat is inside of the box, with a vial of poison, and that no one may open the box without ruining the experiment. Therefore, no one knows whether the cat is alive or dead. I suppose that my real question is why this information matters, when it so obviously cannot be true?

You’re lacking much detail on the setup.

“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.”

The deal with Schrodinger’s cat is that its fate is entangled with the quantum state of the atom, which is both decayed and not decayed at the same time. This is because at the quantum level both states can exist simultaneously in what’s called superposition.

An alternative interpretation of the “smeared out cat” is that the universe is constantly splitting with each quantum event. So, in one universe the cat is alive and in another parallel universe the cat is dead, but you don’t know which universe the cat is in until you open the box and peek inside causing the quantum wavefront to collapse, which determines which way the universe has branched. If this many worlds explanation seems a bit too weird, the other explanations are even weirder. If it’s any consolation, the underlying mathematics is unassailable, and constitute some of the most accurate and best verified equations in all of science.

The instrumentalist approach is not, in my opinion, “weirder”. It doesn’t attempt to account for “smeared-out” states. The theory predicts the outcome of experiments at the point of measurement (when the box is opened).