How does Many Worlds theory explain Schroedinger's cat

daf2
Messages
1
Reaction score
0
As I understand it, when Schroedinger's "box" is opened, then a dead cat comes into existence in one universe and a live cat in another. However, in a variation to this experiment, in which there is say a 10% chance of the cat living and 90% dying, when the box is opened does one live cat come into being in one universe and 9 dead cats appear in 9 identical universes.

If this is the case then as the 9 universes with the dead cats are identical would they merge into one, which overall has the end effect of making the live/dead odds of 50%
 
Physics news on Phys.org
The way I understand it, the many worlds theory doesn't say that the dead/living cat "comes into existence" at all, but rather that the universe splits at every instant in which the cat might die. It just so happens that every second, there's a (let's say) 50/50 chance of the cat dying. The cat you observe depends on which cat exists in your universe. So (for the sake of argument) for t=1, there's 2 universes, one where the cat's living, one where it's dead. at t=2, there's 3 universes. one where the cat's living, one where it JUST died, and one where it died two seconds ago. From my understanding, it removes the whole idea of "observation" from quantum mechanics... but I'm in absolutely no way an authority on these matters and have possibly gotten more things wrong than right. This is just how I understand it.
edit: also, from my understanding, these universes live in the same space but have decohered from one another, so that they're on another frequency, so to speak.
 
daytripper said:
The way I understand it, the many worlds theory doesn't say that the dead/living cat "comes into existence" at all, but rather that the universe splits at every instant in which the cat might die. It just so happens that every second, there's a (let's say) 50/50 chance of the cat dying. The cat you observe depends on which cat exists in your universe. So (for the sake of argument) for t=1, there's 2 universes, one where the cat's living, one where it's dead. at t=2, there's 3 universes. one where the cat's living, one where it JUST died, and one where it died two seconds ago. From my understanding, it removes the whole idea of "observation" from quantum mechanics... but I'm in absolutely no way an authority on these matters and have possibly gotten more things wrong than right. This is just how I understand it.
edit: also, from my understanding, these universes live in the same space but have decohered from one another, so that they're on another frequency, so to speak.

Off topic, but do they go over this stuff in college?
 
renob said:
Off topic, but do they go over this stuff in college?

I know they go over the uncertainty principle and such but I don't know if they address the many worlds interpretation of quantum mechanics. I'm a second year CSC major at CalPoly (SLO) and know a few physics majors who have taken a course called "Modern Physics", which is basically quantum mechanics but I've no clue how deep they delve into the subject matter. I wish that class was part of my degree, though.
 
We didn't go over interpretations at all in my undergrad study. They're not really necessary for most work you'll do in the field. It's either a philosophical question, or a highly theoretical one.
 
I love how easily the line between philosophy and physics is blurred. Seems something worth doing (I don't know if I'll ever forgive Carlin for mocking our space program. haha).
 
I would like to know the validity of the following criticism of one of Zeilinger's latest papers https://doi.org/10.48550/arXiv.2507.07756 "violation of bell inequality with unentangled photons" The review is by Francis Villatoro, in Spanish, https://francis.naukas.com/2025/07/26/sin-entrelazamiento-no-se-pueden-incumplir-las-desigualdades-de-bell/ I will translate and summarize the criticism as follows: -It is true that a Bell inequality is violated, but not a CHSH inequality. The...
I understand that the world of interpretations of quantum mechanics is very complex, as experimental data hasn't completely falsified the main deterministic interpretations (such as Everett), vs non-deterministc ones, however, I read in online sources that Objective Collapse theories are being increasingly challenged. Does this mean that deterministic interpretations are more likely to be true? I always understood that the "collapse" or "measurement problem" was how we phrased the fact that...
This is not, strictly speaking, a discussion of interpretations per se. We often see discussions based on QM as it was understood during the early days and the famous Einstein-Bohr debates. The problem with this is that things in QM have advanced tremendously since then, and the 'weirdness' that puzzles those attempting to understand QM has changed. I recently came across a synopsis of these advances, allowing those interested in interpretational issues to understand the modern view...

Similar threads

Replies
76
Views
9K
Replies
3
Views
2K
Replies
143
Views
10K
Replies
4
Views
1K
Back
Top