Q&A: Schrödinger’s Cat
Schrödinger’s Cat
Question
Hello,
In the lectures on statistical doubt, you mentioned Schrödinger’s cat as an example of ontic doubt.
It is clear why quantum superposition in general expresses ontic doubt;
but I wonder why the cat thought experiment is defined as a paradox, and I am puzzled by presenting the cat as if it were in a superposition at a given moment.
That may cast the Copenhagen interpretation in a paradoxical light, but if so, then the problem is with the interpretation. I just saw now that there is also a sp
specifically
1. It is clear why the observer outside the box does not know the cat’s state;
2. It is clear why the unstable atom is in a superposition of an intact state and a decayed state, and accordingly also the beta particle that the detector will measure.
3. The collapse of the wave function to the atom’s decay—at the moment the detector measures the particle—necessarily happens at a stage when the cat is still alive.
4. The measurement of the particle (at the stage when the cat is alive) takes us beyond the macroscopic scale (we do not need this, because the collapse already occurred when the particle was released, but this is the stage where it is also visible on the macroscopic level).
5. We have proved the existence of a point in time at which the wave function collapsed and the cat is alive (that is, not in any superposition). Keeping our eyes closed for some additional time until the deterministic process that takes place from there until the cat’s death is completed is our choice. That is, from that moment on the doubt is already epistemic and not ontic.
What absurdity for Schrödinger’s and Einstein’s approach is there here? (Even according to Bohr’s Copenhagen interpretation, which they present as absurd.)
At first I thought about the precision according to which we define a description of the cat’s wave function at a defined time *in the future* when I will open the box—and right now it is indeed a superposition; still, even in that alone I do not see any absurdity: the cat is not alive and dead right now at the same time. It only has some current finite probabilities of being alive or dead in the future. There is ontic doubt *right now* whether *in the future* the cat will be alive or dead.
There is also a relational interpretation brought on Wikipedia, and there they really separate between the first measurement at the large scale (the cat’s knowledge of its own state) and the opening of the box.
Answer
I did not understand the question. It is sometimes defined as a paradox because it contradicts intuition. But there is no real paradox here. It is possible that the cat really is in a superposition.
It is also clear that it is impossible to measure that superposition, because when we measure, the cat will be in a classical state (alive or dead). This is not like the double-slit experiment, where the superposition can be measured. I discussed this in my comment after the third session at the Free Will conference B.
Maya Bar-Hillel’s lecture (7 minutes): https://www.youtube.com/watch?v=Nq7jY7P8Urk
And my response here (about 2 minutes, starting from minute 38:43): https://www.youtube.com/watch?v=tfXegNRNx-4
Discussion on Answer
Something got messed up. See here: <a href="https://youtu.be/fGJBHuIDgko?si=Y6QfNvpjdnCI_9ok" rel="nofollow">https://youtu.be/fGJBHuIDgko?si=Y6QfNvpjdnCI_9ok</a>
Around 35:40.
In the second video there is no 38:43.