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Author Topic: what qualifies as observation?  (Read 3876 times)

Offline yamo

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what qualifies as observation?
« on: 19/12/2010 07:35:27 »
If i look at a tree do all the electrons on the surface facing me fall out of super state because i am looking at them?  I know their location..right there in front of me.  Since i see the tree don't i also see the electrons that make up the tree?


 

Offline Foolosophy

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what qualifies as observation?
« Reply #1 on: 19/12/2010 10:09:34 »
If i look at a tree do all the electrons on the surface facing me fall out of super state because i am looking at them?  I know their location..right there in front of me.  Since i see the tree don't i also see the electrons that make up the tree?

there are at least 2 distinct types of observations - the observations we are familiar with in the classical large scale world and the observations in the quantum world.

According to quantum physics (which is essentially a non-deterministic stochastic theory) an observation is really just interference or the trigger which collapses the wave function.

Perhaps the future will sprout a revolutionary deterministic theory of the micro or atomic world.
 

Offline Soul Surfer

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what qualifies as observation?
« Reply #2 on: 19/12/2010 11:16:06 »
Any particle can "observe" any other particle that interacts with it.  The electrons atoms and molecules in the tree are continually "observing" each other as they jostle together with heat radiation.  The air molecules are continually "observing" the tree and creating the air pressure that slows down the evaporation if its surface.  The light photons from the sun are continually "observing" the tree  by being absorbed and warming it up or being reflected and contributing to the tree's visibility   To this extent a person observing the tree by looking at a few of the photons that have ben reflected from it is entirely irrelevant and has no effect on it whatever.
 

Offline Foolosophy

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what qualifies as observation?
« Reply #3 on: 19/12/2010 11:35:16 »
Any particle can "observe" any other particle that interacts with it.  The electrons atoms and molecules in the tree are continually "observing" each other as they jostle together with heat radiation.  The air molecules are continually "observing" the tree and creating the air pressure that slows down the evaporation if its surface.  The light photons from the sun are continually "observing" the tree  by being absorbed and warming it up or being reflected and contributing to the tree's visibility   To this extent a person observing the tree by looking at a few of the photons that have ben reflected from it is entirely irrelevant and has no effect on it whatever.

And your definition of "observation" is a philosophical one perhaps???

Can you refer to a quantum or physical law/concept that allows or describes one electron OBSERVING another electron?
 

Offline Bill S

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what qualifies as observation?
« Reply #4 on: 19/12/2010 14:34:04 »
Surely, if one electron, or photon, or any other particle, could observe another the double slit experiment would never produce an interference pattern.
 

Offline QuantumClue

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what qualifies as observation?
« Reply #5 on: 19/12/2010 14:50:07 »
Well, Bill, a collapse of the wave function occurs on a particle when the probability density reaches 1 exactly. Waves interfere, the existences of other particles may not always collapse.I have always though of intereference without collapse as similar to Hardy's Paradox where an electron and positron can meet, but do not annihilate.
 

Offline Bill S

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what qualifies as observation?
« Reply #6 on: 19/12/2010 18:28:42 »
Quote from: QC
Well, Bill, a collapse of the wave function occurs on a particle when the probability density reaches 1 exactly.

Doesn't the whole concept of wave function collapse depend on which theory of quantum reality you accept?
 

Offline QuantumClue

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what qualifies as observation?
« Reply #7 on: 19/12/2010 19:15:56 »
As far as I know, the only theory which does not entertain it, is the many worlds, or parallel universe model.They have reality split and merging to one reality again, instead of a collapse.
 

Offline Bill S

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what qualifies as observation?
« Reply #8 on: 19/12/2010 19:49:32 »
Isn't there something odd about the wave collapse in Bohmian mechanics as well?
 

Offline QuantumClue

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what qualifies as observation?
« Reply #9 on: 20/12/2010 11:10:20 »
It's different... but you asked me about collapse models. The Bohmian interpretation has a collapse model, but still, quite different. In this interpretation, we are to believe that reality is on a set course using pilot waves. The collapse in this model happened at big bang - the wave function collapsed in a completely deterministic world.
 

Offline Soul Surfer

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what qualifies as observation?
« Reply #10 on: 20/12/2010 23:44:25 »
The process of "observation" of a quantum mechanical effect happens when an interaction takes place that resolves any quantum ambiguities that may exist. it is most definitely not a requirement hat a sentient being has anything to do with it.  Even the case of Shrodinger's cat was resolved when the light rays entering the opened box showed whether the cat was alive or dead and not when we saw this and realised it some nanoseconds (light travel time) and then milliseconds (brain response time) later.
 

Offline Foolosophy

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what qualifies as observation?
« Reply #11 on: 21/12/2010 04:02:42 »
it is most definitely not a requirement hat a sentient being has anything to do with it.  Even the case of Shrodinger's cat was resolved when the light rays entering the opened box showed whether the cat was alive or dead

It is not the light rays entering Shrodinger's box that collapse the wave function and push the cat's state into one of either being dead or being alive.

It is the very act of measurement/observation that interferes with the super state that the cat is in - ie cat is both alive and dead at the same time.

This is what collapses the quantum wave function and produces a specific reality in the quantum world.

But as we all know deep down inside the fate of the quantum world is one of being superceded by a purely deterministic analysis.
« Last Edit: 21/12/2010 04:06:43 by Foolosophy »
 

Offline yor_on

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what qualifies as observation?
« Reply #12 on: 21/12/2010 19:19:21 »
What a nice question Yamo.

From your point of view you definitely sees what is there, including that which is hidden inside it. That as we have a three dimensional reality plus time. The waves hitting your eyes have all interacted with what was in their path, like that tree, and so forced a 'state' to come to be before leaving whatever they interacted with. The question might be if this is enough, or if we need something 'conscious' to make it come true. But considering that the tree will be there tomorrow too I don't think so myself. So what was it 'observing'? You, or the waves/photons hitting it?

As for if those waves/photons hitting the 'surface' creates a 'chain reaction' defining all states in(side) the tree I don't know?

That becomes a weird one :)
 

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what qualifies as observation?
« Reply #12 on: 21/12/2010 19:19:21 »

 

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