Schrödinger's Cat and Many-Worlds Interpretation

　　One of the founder of quantum mechanics, Schrödinger didn’t believe Bohr’s Copenhagen interpretation(哥本哈根詮釋). He issued a thought experiment(思想實驗) called Schrödinger's Cat(薛丁格的貓) in 1935.

　　The details of this experiment are as below:we put a cat, a flask with hydrogen cyanide(氰化氫,毒氣) and a radioactive matter into a box. Within one hour, the decay probablity of the matter is 50％. Once the decay happen, the detector will break the flask and then the cat will die. 

 

　　

　　According to Copenhagen interpretation, after an hour the cat will be in superposition states(疊加態), alive and dead. This is ridiculous because cat cannot be alive and dead simultaneously! If you open the box then the state of cat will collapse to a single state, alive or dead.

　　Another alternative interpretation is Many-worlds interpretation(多世界詮釋), which is well-known as parallel universes(平行宇宙). It is actually a physical theory! The cat is both alive and dead before the observation, but the alive and dead cats are in different branches of universes.

　　MWI indicates that every time we make a decision, there is another “me” in parallel universe chooseing another choice! But the point I want to say is “cat is wretched(可憐的).”, maybe rabbit is a good alternative!