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Old Oct 2nd 2016, 04:07 PM   #1
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Classical objects

Donald Hoffman, a scientist, says that classical objects don't exist according to QM. Is this true?
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Old Oct 2nd 2016, 06:42 PM   #2
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It all depends on how you define the word "exists".
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Old Oct 3rd 2016, 05:01 AM   #3
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"Classical" objects could be viewed as an approximation to QM, that works for large objects.

At everyday scales the difference between the Classical description of an object and the QM description is immeasurably tiny.
Only when one deals with very small objects does the difference start to become apparent, and when you deal with the truly tiny, the difference becomes crucial.

I believe that there is also an effect whereby probability profiles of individual quantum entities interfere with the probability profiles of any other quantum entities they interact with,
in such a way as to reduce the probability of the low probability portions of the probability profiles and increase the probability of the high probability portion.

Thus the probability profiles of quantum entities within a macroscopic object are quite tightly constrained, while that of an isolated quantum object is very broad.
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Old Oct 3rd 2016, 06:08 AM   #4
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Originally Posted by Woody View Post
"Classical" objects could be viewed as an approximation to QM, that works for large objects.

At everyday scales the difference between the Classical description of an object and the QM description is immeasurably tiny.
Only when one deals with very small objects does the difference start to become apparent, and when you deal with the truly tiny, the difference becomes crucial.

I believe that there is also an effect whereby probability profiles of individual quantum entities interfere with the probability profiles of any other quantum entities they interact with,
in such a way as to reduce the probability of the low probability portions of the probability profiles and increase the probability of the high probability portion.

Thus the probability profiles of quantum entities within a macroscopic object are quite tightly constrained, while that of an isolated quantum object is very broad.
Do you mean QM regards tiny objects as nonexistent? I am confused
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Old Oct 3rd 2016, 08:53 AM   #5
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It is definitely confusing...

The theoretical (mathematical) descriptions of QM objects only provide a probability function for the values of the various properties of the object.
The mathematics will not give you precisely fixed value for all the properties of a QM object.

Strange to say, this is also what is found experimentally!
It is impossible to define where a QM particle is in the double slit experiment,
until it interacts with the macroscopic detector.

In a very real sense the existence of the QM object is not precise.
It is existing everywhere that it can exist,
but it is existing more where it is more probable that it should exist,
and less where it is less probable that it might exist.

Some of the other members of the forum might disagree with the details of the above description,
but I think it suitably shows the difficulties involved of trying to appreciate the nature of QM entities
they just simply do not behave in the same manner as "classical" objects.
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Old Oct 3rd 2016, 09:42 AM   #6
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Can we say that all the discussion about existence of the objects emerge from the reality that the place of the particles can not be detected until they are observed?
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Old Oct 3rd 2016, 10:05 AM   #7
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The position (momentum) uncertainty is certainly the most often quoted QM feature that follows this probabilistic behaviour.

However, I suspect that Donald Hoffman was trying to emphasise that there is a fundamental difference
between what we would normally understand by the term "exist",
(as it is used in every-day speech when referring to "classical" objects)
and what has to be accepted as the meaning of "exist" when referring to QM entities.

I guess that this is also what is indicated in post from Romsek
(in rather shorter form).

Last edited by Woody; Oct 3rd 2016 at 10:08 AM. Reason: re-wording
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Old Oct 3rd 2016, 10:39 AM   #8
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Originally Posted by Woody View Post
In a very real sense the existence of the QM object is not precise.
It is existing everywhere that it can exist,
but it is existing more where it is more probable that it should exist,
and less where it is less probable that it might exist.
aside from the wording I'm not sure I agree with this.

measurement causes wave function collapse and prior to this our understanding of existence is sketchy at best. We know there's a wavefunction, we understand it's properties, but to my knowledge we have no idea at all how this is physically manifested.
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Old Oct 3rd 2016, 12:30 PM   #9
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Talking Making it up as I go

Yes I tried to indicate at the end of my post that this was my own interpretation rather than the main stream physics explanation.
But then (as you indicate) the main-stream approach is pretty much "don't worry what it means, just apply the maths".

This interpretation vacuum leaves the way wide open for crackpots like me to come up with all kinds of ideas...
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Old Oct 3rd 2016, 03:11 PM   #10
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Can it be possible that particles are comsidered as nonexistent?
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