But what is the scale at which this switch happens? If we had a technically perfect experiment, would we be able to observe large objects in these superposition states? This is the question posed by Schrödinger's thought experiment in which a cat is placed in a sealed box with a flask of poison and a single radioactive atom, which will undergo decay at a random time. If the atom decays, the flask is broken and the cat is poisoned; if it does not, the cat lives on. By waiting for the atom to decay, does the cat exist in both states at once as the atom does? We know that when we open the box, we must find the cat alive or dead, but is it a property of the universe or the observer that makes the cat "choose" its state?