How Does Measurement Influence the Schrödinger's Cat Paradox?

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Discussion Overview

The discussion revolves around the implications of measurement in the context of Schrödinger's Cat thought experiment, exploring the roles of observers, decoherence, and the nature of quantum superposition. Participants examine whether the cat itself can be considered an observer and how this affects the interpretation of quantum mechanics.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants suggest that the cat, as a macroscopic object, cannot be in a quantum superposed state due to decoherence, which raises questions about its role as an observer.
  • Others argue that the cat is indeed an observer, and its state (dead or alive) exists independently of external observation, leading to a discussion about the nature of knowledge in quantum mechanics.
  • A participant introduces the idea that the observer's knowledge can be framed as an XOR condition regarding the cat and an AND condition regarding the atom, suggesting a resolution to the paradox.
  • Another viewpoint posits that any interaction with a macroscopic object, not just measurement, can lead to wave function collapse, indicating a broader interpretation of what constitutes measurement.
  • There is a mention of the philosophical implications of measurement and observation, with one participant expressing a desire for more information on the topic.

Areas of Agreement / Disagreement

Participants express differing views on the role of the cat as an observer and the implications of measurement on quantum states. The discussion remains unresolved, with multiple competing interpretations presented.

Contextual Notes

Participants highlight the dependence on definitions of measurement and observation, as well as the implications of decoherence in macroscopic systems. There are unresolved aspects regarding the nature of wave function collapse and its relationship to measurement.

RAD4921
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In the famous thought experiment of Shroedinger’s Cat, we never consider the cat itself as an observer. The cat would no doubt be able to tell whether it is dead or alive without anyone opening the box. I think this is just a problem of semantics and if you were to replace the cat with a binary random number generator the paradox would still be there.
 
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The cat is supposed to be in a quantum supperposed state. Of course it is not happening with macroscopic objects. Macroscopic objects cannot be in a supeposed state because of decoherence due to large statistics. Is that what you mean when you say the cat is an observer, because it would destroy coherence ? Erwin's point was exactly that, if you talk to people about atoms, they do not listen. If you talk to them about the cute little kitty, and say you are going to torture it, then they listen. :smile:
 
The cat itself is an observer. The cat is either dead or alive. The rules of QM don't apply here. Only the outside observer's lack of knowledge is involved . His knowledge is in an OR state. The QM state is an AND state.

juju
 
This is not very accurate a statement : the observer's knoledge is a XOR about the cat and a AND about the atom, whence the paradox. As you said, the cat is an observer, or causes decoherence, and so the knowledge for the atom is a XOR too, and in the end there is no paradox.
 
That's right. but the XOR condition excludes an AND condition,
so there can be no superposition.

juju
 
The Grad student

A grad student pointed that out to me, that the cat is also an observer. I know what you mean by the macroscopic cat not being in a quantum supperposed state. I was more or less having fun with Shroedinger's Cat and I also wante to point out that the object being observed does not have to be what we might call an animate object. If there is such a thing as an inanimate obeject?
 
It must only be any macroscopic object, so that decoherence applies.
 
wave collapse

Well I always thought that the act of observation is supposed to collapse the wave function. I have also wondered if the collapse may due to the introduction of measurement and not a real property of the universe.I will admut though that I am more a philosopher than a physicist so any information would be helpful. Thanks
Rad4921
 
The collapse is said to be due to measurement. However, any interaction with a macroscopic object, be it measurement or not, will cause the collapse. It "could have been" a measurement, and can be called a "measurement" in a generalized meaning.
 

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