Why is Schrodinger's Cat entangled? Or is it not?

QuantumPixel
Messages
7
Reaction score
1
Why is Schrodinger's Cat entangled? Or is it not? I recently saw a poster on deviantart that said this: http://browse.deviantart.com/art/WANTED-Schrodinger-s-Cat-130508078
It said it was in a superposition, that i get, but the entanglement? That i don't get.

-QuantumPixel
 
Last edited by a moderator:
Physics news on Phys.org
since you understand the first part then the rest will be easy to understand hopefully. The fact that the state of the cat (dead or alive) is unknown before opening the box makes its state a superposition of both. When the box is opened by the observer, the observer becomes entangled with the cat and this forms an observer state corresponding to the cat being dead or alive, and hence the observer state is entangled with that of the cat.
 
Well actually in the Schrodinger's Cat thought experiment long before the box is opened decoherence has occurred transforming the pure state into an improper mixed state. Observationally there is no way to tell an improper mixed state from an actual one so its perfectly OK to assume it was in the observed state prior to observation - hey presto - issue resolved.

Thanks
Bill
 
Last edited:
Dundeephysics said:
since you understand the first part then the rest will be easy to understand hopefully. The fact that the state of the cat (dead or alive) is unknown before opening the box makes its state a superposition of both. When the box is opened by the observer, the observer becomes entangled with the cat and this forms an observer state corresponding to the cat being dead or alive, and hence the observer state is entangled with that of the cat.

Now i understand. Thanks for your time and contribution.

-QuantumPixel
 
  • Like
Likes Dundeephysics
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
If we release an electron around a positively charged sphere, the initial state of electron is a linear combination of Hydrogen-like states. According to quantum mechanics, evolution of time would not change this initial state because the potential is time independent. However, classically we expect the electron to collide with the sphere. So, it seems that the quantum and classics predict different behaviours!

Similar threads

Replies
6
Views
224
Replies
143
Views
10K
Replies
17
Views
2K
Replies
2
Views
2K
Replies
14
Views
3K
Replies
5
Views
1K
Replies
3
Views
1K
Replies
1
Views
3K
Back
Top