That cat in the box again

Elizabeth I

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Elizabeth I
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Suppose that Schrodinger's poor cat is shut up in that damn box again, with all the factors in place for the experiment to go forward. Once the box is sealed, the cat suddenly dies due to a cause that has nothing to do with the experiment (it doesn't matter what.)

Will the body begin to decay prior to the box's being opened? Or is that a silly question? Is the whole scenario outside the parameters of Schrodinger's experiment, so that one has nothing to do with the other?
 
Hi

Elizabeth I said:
Suppose that Schrodinger's poor cat is shut up in that damn box again, with all the factors in place for the experiment to go forward. Once the box is sealed, the cat suddenly dies due to a cause that has nothing to do with the experiment (it doesn't matter what.)

Will the body begin to decay prior to the box's being opened? Or is that a silly question? Is the whole scenario outside the parameters of Schrodinger's experiment, so that one has nothing to do with the other?
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Well - since it's a Gedankenexperiment to demonstrate the problems with superposition using a Gedankenkatze, and since Gedankenkatze obey the rules of the Gedankenexperiment, one of which is that you can't tell anything about the cat without opening the box, I'd say that decomposition is beyond the scope of the experiment... unless you include Gedankenverrottung.
 
Gagglegnash said:
Hi




Well - since it's a Gedankenexperiment to demonstrate the problems with superposition using a Gedankenkatze, and since Gedankenkatze obey the rules of the Gedankenexperiment, one of which is that you can't tell anything about the cat without opening the box, I'd say that decomposition is beyond the scope of the experiment... unless you include Gedankenverrottung.
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Well, I know, but you can think that the cat dies suddenly, can't you?
 
Yes, it will decay. You just won't know about it until you open the box.

If we could know the initial state of the cat exactly, and the Hamiltonian for the system (a mathematical thingy that determines the time evolution), we could (in principle) know that the cat is dead without opening the box, by calculating the final state from the initial state. Unfortunately, no experiment can determine what the initial state is (and no computer would be powerful enough to calculate the final state, but that's a practical matter and therefore irrelevant here).
 
If the box was not sealed then the cat would decay and start to give off gas (which dead animals do when dead. This is not a subject for this thread and is not to be disputed). The amount of gas given off would depend on the probability of the cat being dead. When the box is opened it is reasonable that the cat is found alive.

If an electron has a choice of two holes (let us call them A hole and B hole) to go though and 50% probability of going though either one, which one does it go though?
A. A or B
B. Both.

The electron would go though both holes. It would then interfere with itself and form a pattern on the photographic plate located beyond the holes.
 
rjh01 said:
If the box was not sealed then the cat would decay and start to give off gas (which dead animals do when dead. This is not a subject for this thread and is not to be disputed). The amount of gas given off would depend on the probability of the cat being dead. When the box is opened it is reasonable that the cat is found alive.
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Huh??

The correct answer is as Fredrik says - the cat will have decayed.
 
Elizabeth I said:
Suppose that Schrodinger's poor cat is shut up in that damn box again, with all the factors in place for the experiment to go forward. Once the box is sealed, the cat suddenly dies due to a cause that has nothing to do with the experiment (it doesn't matter what.)

Will the body begin to decay prior to the box's being opened? Or is that a silly question? Is the whole scenario outside the parameters of Schrodinger's experiment, so that one has nothing to do with the other?
Click to expand...

The purpose of the experiment is not really about whether the cat lives or dies, but whether the atom decayed. It's intended to detect a quantum event, and the cat is just an artistic flourish. Any atomic decay detector will suffice.

The macro scale event of the cat's natural death would be caused by more than one single quantum event - it would be the superposition of quadrillions of quantum events, and therefore could not be represented by superposition of probabilities in the same way as an individual atomic decay would be. This is believed to be the reason that macro events are causal - the wave properties wash out, which makes events quite predictable, but also means they can be modeled to 'happen' in the absence of detection.

This month's SEED has an interesting article on acausality: [The Reality Tests: A team of physicists in Vienna has devised experiments that may answer one of the enduring riddles of science: Do we create the world just by looking at it?]
 
rjh01 said:
If an electron has a choice of two holes (let us call them A hole and B hole) to go though and 50% probability of going though either one, which one does it go though?
A. A or B
B. Both.

The electron would go though both holes. It would then interfere with itself and form a pattern on the photographic plate located beyond the holes.
Click to expand...
I've been told the answer is most probably mu.
 
Elizabeth I said:
Suppose that Schrodinger's poor cat is shut up in that damn box again, with all the factors in place for the experiment to go forward. Once the box is sealed, the cat suddenly dies due to a cause that has nothing to do with the experiment (it doesn't matter what.)

Will the body begin to decay prior to the box's being opened? Or is that a silly question? Is the whole scenario outside the parameters of Schrodinger's experiment, so that one has nothing to do with the other?
Click to expand...


This would be outside the scope of the thought experiment. The dead cat would behave in exactly the same way as any other dead cat would in the same situation. Quantum mechanics wouldn't be involved.

Imagine that the experiment involved putting a dead cat in the box, and you have exactly the same situation.

I'm possibly a bit short of patience with scenarios involving dead cats right now, as one of my cats seems to be approaching that state.
 
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Mojo said:
This would be outside the scope of the thought experiment. The dead cat would behave in exactly the same way as any other dead cat would in the same situation. Quantum mechanics wouldn't be involved.
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Exactly. That's because the cat is composed of so many atoms that any possible "macroscopic" quantum effects will be washed out.
 
Mojo said:
This would be outside the scope of the thought experiment. The dead cat would behave in exactly the same way as any other dead cat would in the same situation. Quantum mechanics wouldn't be involved.

Imagine that the experiment involved putting a dead cat in the box, and you have exactly the same situation.

I'm possibly a bit short of patience with scenarios involving dead cats right now, as one of my cats seems to be approaching that state.
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I'm so sorry. Didn't mean to make a sore spot worse, even if inadvertently.
 
If the experimenter opens the box, but does so inside a sealed room, how does the outside world know if the experimenter knows if the cat is dead or not?
And if he announces the result on the Internet, but nobody tells the universe at large, how do the Martians know if Earth knows if the experimenter knows if the cat is dead or not?

I mean , where does the whole thing stop?
 
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I thought ;) the whole point of the thought experiment was to demonstrate how absurd some of the conclusions people claimed were a result of QM?
 
The Wikipedia article supports my recollection: http://en.wikipedia.org/wiki/Schrödinger's_cat

....snip....


Schrödinger's mind-game was meant to criticize the strangeness of this. Influenced by a suggestion of Albert Einstein, Schrödinger extrapolated the concept to a larger scale. He proposed a scenario with a cat in a sealed box, where the cat's life or death was dependent on the state of a subatomic particle. According to Schrödinger, the Copenhagen interpretation implies that the cat remains both alive and dead until the box is opened.

Schrödinger did not wish to promote the idea of dead-and-alive cats as a serious possibility; quite the reverse: the thought experiment serves to illustrate the bizarreness of quantum mechanics and the mathematics necessary to describe quantum states.


...snip...
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And, of course, the cat being dead and alive only "happens" (in some sense of the word) if you subscribe to the Copenhagen interpretation, right? In the many-worlds view, that problem disappears (as does the one that started this thread).
 
You know, the cat dying of natural causes before the radioactive particle decayed.
 
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