Today I will tell about what is called the mother of all thought experiments in the field of QM. It is called the Schrodinger’s cat experiment. Schrodinger is considered as one of the founding fathers of QM. I will try to explain the simple version of it.
Suppose there are 2 steel boxes, one is empty and another has a live cat in it. The box having the cat has a detector to detect an electron also. Also there is a mechanism in which if an electron is detected then it will open a bottle having poisonous gas which can kill the cat. The whole set up is made up in such a way that it is not possible to know from outside whether the cat is alive or not.
Suppose a single electron is sent to both the boxes at the same time. (Remember the double slit experiment, it is possible as per QM. Is it possible to know if the cat is dead or alive? https://read.cash/@aniruddhasen/wave-particle-duality-be6fb905
One explanation suggested by Neil Bohr called the Copenhagen interpretation, suggests that the cat is both dead and alive at the same time!! Let us see why he thinks so. The single electron that was sent is in a superposition state that is it is in both the boxes in the same time and is in a wave form until it is measured by observation. Here as the box is sealed so we cannot say whether the electron inside is in wave form or particle form. We cannot say conclusively whether the electron detector has detected the electron or not to collapse it into particle resulting in the release of the gas. Or is it possible that the cat’s observation collapsed the electron resulting in its own death. Therefore his argument was that the cat is both dead and alive at the same time. It is similar to as if the cat is in itself in a superposition state.
Another point of view was given by Schrodinger himself. He said the cat is either dead or alive. The result is deterministic that is the cat can be either alive or dead and there cannot be any ambiguity about its state. It is a guess whether the cat is alive or dead, with no way to know unless the box is opened.
This debate has been going on for decades between two schools of thoughts. Bohr’s in deterministic view saying the cat is both dead and alive at the same time and Schrodinger’s deterministic view that the cat can be either dead or alive.
Such is the craziness and haziness of the nature of quantum world that different views with different interpretations are given, with conclusive proof still eluding the scientists.
The question of the observer again comes here and it encroaches upon the philosophical domain of consciousness. Various types of questions arise about the observer:-
Is the human playing the role of observer?
Can animals and trees also be the observer?
Can detectors also be observer?
Can these sub atomic particles observe themselves?
Is consciousness required to be an observer?
Did some conscious being observe the world to collapse it to its present state?
Who was the first observer to collapse the world and the universe as we see it?
Is there an omnipresent observer?
We know that our process of intervention in the sub atomic level through observation and measurement is not liked by these sub atomic elements and they immediately collapse to its physical reality.
It only leads to more questions than answers.
( When I first studied about this experiment for me it seemed both a question of QM as well as philosophical in nature)
No cats were harmed in this experiment as it was a thought experiment.
Cats is very dingerous