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1

Interaction between a physical object in a superposition, and another object, usually causes the second object to also go into a superposed state, that will be correlated in some way with the original superposed state. For example, this is true of the quantum-mechanical description of a measurement interaction - some part of the measurement device has to ...


3

when I open the box and see the cat dead, there should be a timeline split, creating a universe where the cat is alive instead of dead. Is this possible? I know we can't really know for sure, but is it possible? One has to keep in mind clearly that physics is about mathematical models that fit data and predict new observations. One can have an infinity of ...


8

$\renewcommand{\ket}[1]{\left \lvert #1 \right \rangle}$ $\renewcommand{\bra}[1]{\left \langle #1 \right \rvert}$ We can see how decoherence really works, why it messes up superposition states, and why it's particularly prone to messing up states of large objects all through a very simple example $^{[a]}$. Single two-level system Suppose we have a quantum ...


0

Let's consider a qubit that has two "classical states" $\left|0\right>$ and $\left|1\right>$, e.g. a current in a flux qubit that flows in one direction or in the other direction, while superpositions of these states are "non-classical" and will decohere into a mixed state of the classical states. What I'm going to demonstrate now is that a ...


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This description is based on the philosophy of the qm. In de broil interpretation bohmian mechanics is deterministic. But dehorence is normal in systems that can have lower preferred configuration. It is not forbidden so it can be achieved.


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We make a habit of treating classical statistical mixtures as being "ignorance" probabilities — the "reality" of a situation is that exactly one outcome holds, and we are just quantifying the information we have about the outcomes. Schrödinger's cat is really just a classical problem involving a nondeterminstic event, and we would like to treat the ...


0

Schrödinger's cat is a thought experiment about Heisenberg's cut. The box where the cat and its death-via-decay mechanism live really represents Heisenberg's cut itself. The aim of the cat proposal was to show how weird it is to accept that QM can describe any physical system, not only elementary ones, by applying its concepts to a system including a ...


1

Well, first of all, Schrödinger's cat is just a thought experiment. What the thought experiment's main point is that the radioactive substance is both decayed and not decayed when not observed. What observed means here means an act that can be used to get information about the system, with or without a person or any other conscious thing. It could be like a ...


0

There have been many questions and answers about this topic here on StackExchange. One type of response is to say that it's not a serious thought experiment, one then notes that it's not really possible to put a macroscopic object like a cat in a coherent superposition. But one can then argue that it's in principle possible (the laws of physics do not ...


0

parallel definition and parallel universe is one of your answers . you can imagine that you cant look inside the box because this work can decline the attention and the accuracy so if I let you to open the box there is two possibility 1. in one universe you have an alive cat and you might get happy also the other possibility is you ll open the box and run ...


1

Schrodinger, I take it, was dramatising the epistemological and ontological paradoxes implicit in QM by considering a cat as opposed to a particle contained in a box; and hugely succesfull too, as we're still discussing it almost a century on, and its probably more widely known that his eponymous equation. Cats, compared to particles, are vastly macroscopic ...


0

In any quantum experiment, as soon as the state of the system can in principal be known (be it because of emitted photons available to the experimenter, an interaction with the environment we may be able to read off the state, or any other means by which the observer can determine the state) it decays and ends up in one of the basis states. That's precisely ...


5

It is because of quantum statistical irreversibility, which is closely related to entropy, as the OP suspected. Qualitatively it is quite easy to understand this. From the laws of quantum mechanics on the microscopic level emerges a classical behaviour for macroscopic (i.e. many particle objects). Of course this is not sufficient though and does not give a ...


-3

For the cat (which is the subject of the experiment), it is irrelevant if you observe it or not. Its state will be the same at a given 't'. Also, that state is not dependent on the observation happening or not (although, opening the door when the cat is alive will influence the cat's behavior, but that is another matter). Universally, it is the observer ...


0

The cat has no quantum state, it is a classical object, which, along with everything else in the experiment, is just "overhead" to make it accessible to the general public. There is the decaying lump of radioactives, and the Geiger counter (detector). This is the quantum level stuff; the rest is just classical embellishment. It makes no sense whatsoever to ...


4

In Schrodinger's cat experiment, the scientist is assumed to be an "classical observer" of the state of the cat, and thus all observations made by the scientist are assumed to be classical observations adhering to physics as we knew it before quantum mechanics came along. The thought experiment focuses on what sorts of statements about reality that ...


4

Large classical objects such as cats or humans are next to impossible to place in a superposition of states. They basically decohere immediately. As far as i know the largest object placed in a superposition is a micromechanical resonator and there is currently work being done on placing a bacterium in a QM superposition ( quantum superposition of a ...


5

This is an excellent question and stresses one of the weird features of quantum mechanics. Indeed, the scientist would in turn be in a superposition. And we could even measure this if we'd be able to maintain coherence of such large systems. Ultimately, your question is asking for the solution of the Measurement problem: Why don't we see any ...


29

In a bubble chamber experiment, film was the detecting medium, but film was taken automatically, by the thousands of frames. These bobbins of film went to the various laboratories involved in the experiment, and were scanned for interesting events which were measured and the cross sections for the interactions recorded. This is a clear example of an ...


34

This is is known as the Wigner's friend thought experiment. According to the many World's interpretation, the superpositions are not a problem. The whole universe ends up in a superposition where all experimental outcomes are realized, but such a superposition is entangled with the environment, from a macroscopic point of view it takes the form of a ...


8

It depends of what interpretation of quantum mechanics you are using. By interpretation it is meant that the mathematical predictions of the quantum mechanics formalism are the same, but the philosophical meaning of each is what differs. In the copenhagen interpretation that you seem to describe, the wave function collapses when a conscious observer makes a ...


0

Whether the cat is dead or alive - from the observers point of view - does depend upon observation. Whether the cat is in fact dead or alive does not depend upon observation. As something cannot be simultaneously dead and alive this thought experiment can only be a negative critique. Observation or non-observation has no bearing on the thing. So a star may ...



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