# Square root of probability, 3.2.3

Eigenstates 3.3.2.3

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2.2

Decoherence is not a physical process.

Instead, it is a logical process of replacing one physical system (an experimental setup design) with another.

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Sometimes, it seems to be a physical process when we perform physical operations based on its logic. For example, when we want to execute our plan of replacing a physical system with another one which is identical but with detectors activated.

We do not really need to create another physical system to achieve that. We just have to switch on the not-yet-activated detectors already installed in the original experimental setup. The effect is identical to replacing the original.

— Me@2022-02-04 08:27:23 PM

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But for simplicity, we use the common quantum mechanics language for the time being:

The system has already decohered long before the radioactive trigger’s effect has reached the cat. Since radioactive atom touched the environment, the quantum state of the system has decohered.

Better language:

The behaviour of any macroscopic (aka observable) objects, before cat in the operation chain, has already provided the physical definitions of whether the atom has decayed and not.

— Me@2022-02-04 11:23:49 PM

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Before opening the box, the cat is not in a superposition state. Instead, it is in a mixed state.

The uncertainty is classical probability, which is due to lack of detailed knowledge, not quantum probability, which is due to lack of definition (in terms of physical phenomena difference).

— Me@2022-01-29 10:38:19 PM

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Most people will accept quantum mechanics once they realize that it follows the classical logic.

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Wrong:

1.  go-left

2.  not-go-left

3.  both go-left and not-go-left

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1.  go-left

2.  not-go-left

3.  “go-left” and “not-go-left” are meaningless

because they are

not defined by physical observable events;

in other words, not defined in terms of physical phenomena yet

That is still misleading because it acts as if we have to use 3-valued logic.

But actually, 3-valued logic is not needed at all. 3-valued logic will appear only if we insist on using the one-layer presentation to represent the actually two-layered logic structure. It is actually binary logic all along:

1.  “go-left” and “not-go-left” are defined

“Going-left” and “not-going-left” are physically distinguishable, because detectors are allowed in the experimental setup.

1.1  go left

1.2  not go left

2.  “go left” and “not go left” are undefined

“Going-left” and “not-going-left” are physically indistinguishable, because detectors of any kind are not allowed in the experimental setup definition; so “going-left” and “non-going-left” are logically meaningless.

On any layer, there are only 2 cases:

For any proposition $A$, either $A$ is true or $\text{NOT}~A$ is true, but not both.

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Most people will accept quantum mechanics once they realize that, in a sense, it actually creates the classical logic by making the world consistent.

— Me@2022-01-12 12:40:12 PM

— Me@2022-01-29 04:03:53 PM

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