Schrödinger's Cat is a thought experiment devised by Edwin Schrödinger in 1935. It was meant to be commentary on people trying to apply Copenhagen's interpretation of quantum mechanics to everyday things. It's an example of quantum superposition, involving a cat being both dead and alive at the same time. It is also used to explain some of the events of Zero Escape: Virtue's Last Reward.
A cat, a flask of poison, and a radioactive source are placed in a sealed box for an hour. Should, at any point during this time period, a Geiger counter inside the box detect radioactivity, the flask will be destroyed. The poison released will kill the cat. However, the radioactive source is small enough that it only has a 50% chance of being detected during the hour. Therefore, it would be impossible to know if the cat was dead or alive unless the container was opened and the cat was observed in either state. By this logic, the cat is simultaneously both dead and alive at the same time.
However, Schrödinger claims that this is ridiculous. He says that quantum superposition can't work for things like cats because organisms can't be both dead and alive at the same time. Though he intended to show that the current view of quantum mechanics was flawed, he ended up creating a theory still used and considered valid in modern times.
A much simpler analogy given by Phi in the Phi pathway is her tossing a coin and concealing the result; until the result is checked, it is both "heads" and "tails" according to the theory.
Virtue's Last Reward
The identity of Nonary Game: Ambidex Edition participant K; a mysterious, armored man claiming to be an amnesiac; is a matter of Schrodinger's Cat. The first decision the player makes in the game is whether or not to go through the Yellow Door, Magenta Door or Cyan Door.
If the player goes through either of the former two, they will eventually discover the corpse of an old woman; in the latter case, they will not discover this corpse but instead discover Antimatter Bombs.
Ultimately, in the Cyan Door route, the identity of the masked/armored player K turns out to be Akane Kurashiki; the very same old woman who is killed in the other routes. In those other routes, the identity of K is a clone of Sigma Klim known as Kyle Klim. This is because shortly before the start of the game in the Cyan Door routes, Dio failed to kill Akane, but in the Yellow/Magenta Door routes he succeeded.
Akin to how the cat in the thought experiment is alive and dead until the box is opened, both Akane and Kyle are in K's suit until the player decides which door to pass through.
After Sigma opens the safe to the Crew Quarters, he as well as Phi and Alice look at the items inside. Afterwards they have a look at a book called Schrödinger's cat. Sigma's cat tic starts. Sigma doesn't know what Schrödinger's cat is, so Phi begins to explain it to him. Sigma asks if it will be a long explanation, and she says it will be, so he asks her to tell him about it later since they need to escape.
While searching for the bombs in the Archives, Phi begins to explain her theory about their experiences in the Nonary Game: Ambidex Edition. Phi believes they can transport their consciousnesses across timelines, stating that they can move through worlds, like parallel worlds. After having Sigma move randomly to explain the many worlds theory, she goes on to explain and replicate Schrödinger's cat while Sigma's cat tic continues.
For this, she uses a toy lion as a cat, a weight as a radioactive material, and a jar of ink as poison. She then shuts the box, and says that if alpha waves hit the poison, the cat dies. The box is soundproof so they can't hear the cat. She asks Sigma if the cat is alive or dead, whatever his response it, she says he is incorrect and that since they don't know the status of the cat, it is both alive and dead. She opens the box and the cat is alive.
Phi uses this to explain the difference between results of Round 2, as one time, Sigma picked betray and Phi picked ally, and in another time, Phi picked betray while Sigma picked ally. Phi believes this has something to do with Zero Sr.'s plans.
After the Nonary Game: Ambidex Edition is over, ? goes and talks to Alice and Clover in the Treatment Center. The two lament over the fact that they're stuck in a Radical-6 destroyed future even though they understand why their presence was necessary. They then tell ? that they talked to Akane, and Akane said that it might be possibly to not only send their minds back to the past but their bodies as well. ? says that this would be a bad idea, as two Clovers and two Alices would create a paradox. The two tell him that Akane says the problem can be countered with Schrödinger's cat.
Zero Time Dilemma
Q-Team in the Biolab
In the Biolab, after completing the escape room, Q-Team -- Mira, Eric and Sean -- is consulted by Zero. Zero explains a series of vials Q-Team can access now; they contain Radical-6. Zero explains that if you inject R-6, you will contract is a virus and will have a 25% survival rate. However, if you inject yourself with R-6 and are suffering from Fanatic Bio R, then FBR and R-6 will cancel one another out and you will be completely cured. While a lethal virus, R-6 can also act as a life-saving antidote. Q-Team can now choose to inject the virus under the belief that it will save them from Fanatic Bio R, or they can neglect the virus if they are not suffering from it.
Zero tells them that he is a clairvoyant; he already knows if Q-Team will or won't decide to inject themselves. He states that if they do inject themselves, then they will be injected with FBR, and that if they do not, then they will not be suffering from FBR at all. Q-Team must now decide to inject themselves or not.