Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: nilak on 01/10/2016 05:51:41
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Consciousness causes the wave function to collapse acording to this interpretation. The wave function of any quantum object says that it can go anywhere with a certain probability. Once we make a measurement we can predict future position drawing a probability distribution. Say we launch a 1kg copper ball at 10mps from towards a infinitely large flat screen 10m away. There is a probability p(1000) to land at 1km away from center is extremely low, but it not zero. The ball is a superposition of being everywhere in the universe until it is observed and pinpointed. The probability to be observed on a straight line is something like 10exp1000/10exp1001. The superposition seem to be true, otherwise quantum computers wouldn't work . If we make a measurement at 5m and find the ball on center then p(1000) reduces further. I can now conclude that the whole universe is in a superposition of all possible states but only the consciousness reduces the wavefunctions of the quantum objects it observes to only one however obeying Heissenberg's principle . This needs to be consistent with the past. In the case of quantum eraser experiment it seems that the quantum objects predict what the consciousness will find out and reduce their superposition to only one posibility at the position of measurement then again it continues the wave function from there. All consciousness observers have their own "observed" universe that is always consistent with the past. When two consciousness observers exchange information, quantum eraser effects occur and they will not be able to tell the differences between their own "observed" universes. Q bits for example are in a superposition of being equally 0 and 1 (up or down). Since the universe is made of quantum objects like that it means the whole universe is a quantum system. At a large scale we don't see the probabilities game and things seem certain. I think there a many other exciting conclusion we can draw.
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The Copenhagen interpretation is wrong.
We are not special and neither is our consciousness. The universe exists objectively, not subjectively.
The uncertainty principle confuses a lot of people. All it is saying is that measuring a particle alters its position or momentum. It doesn't mean that reality is undecided before observed. That's ludicrous. Whatever did the universe do before we even arrived on the scene?
If you want to know my thought it's that the future already exists. QM has devised numerous methods to try and trick the results of QM but these fail because the future cannot be tricked.
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Consciousness causes the wave function to collapse acording to this interpretation.
The interpretation does not refer to the consciousness of the observer but to the interaction with the device making the measurement. For example, a photon hits a detector and ceases to exist - its wave function has collapsed - and we know where it was when it hit. Bohr was very clear that the result can and should be described classically using ordinary language.
The wave function is only a probabilistic description.
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Yes, you are right. It is actually the Neumann–Wigner interpretation derived from Copenhagen interpretation.
However in the delayed choice quantum eraser the measurement doesn't perturbe the path of the photon going to the screen.
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If you want to know my thought it's that the future already exists. QM has devised numerous methods to try and trick the results of QM but these fail because the future cannot be tricked.
I also said that the quantum objects predict the future and this is seen in the DS quantum eraser. It suggests the future is already known or it already exists.
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Consciousness causes the wave function to collapse acording to this interpretation.
The interpretation does not refer to the consciousness of the observer but to the interaction with the device making the measurement. For example, a photon hits a detector and ceases to exist - its wave function has collapsed - and we know where it was when it hit. Bohr was very clear that the result can and should be described classically using ordinary language.
The wave function is only a probabilistic description.
Must the interaction be with a "detector" or simply with another object?
The "observer" is an integral part of the physical universe ,is it not ? There is no such thing as a disembodied observer (or a pure observation) ,is there?
PS is there no way to format posts?
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One of the problems of human vanity is that some people confuse mathematical approximations to reality with reality itself. Another is the introduction of "consciousness" into discussions of science, particularly if it is used without definition.
The word "observation" in physics simply means an interaction with a "third-party" object known as the observer. If that interaction is to have any effect on said object, it must involve the transfer of energy between the observed phenomenon and the observer so it must alter the nature of the interaction. We can model all this with collapsing wavefunctions but if we reduce the energy transfer to zero, there's nothing to prevent the interaction taking place in the absence of an observer.
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On topics such as this you will get the most straight forward answer from Alan. You should take it in and remember it.
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One of the problems of human vanity is that some people confuse mathematical approximations to reality with reality itself. Another is the introduction of "consciousness" into discussions of science, particularly if it is used without definition.
The word "observation" in physics simply means an interaction with a "third-party" object known as the observer. If that interaction is to have any effect on said object, it must involve the transfer of energy between the observed phenomenon and the observer so it must alter the nature of the interaction. We can model all this with collapsing wavefunctions but if we reduce the energy transfer to zero, there's nothing to prevent the interaction taking place in the absence of an observer.
If the object is "third-party" what are the other two parties ?
Are they two particles (or fields?) that meet one another?
It seems strange that a third party needs to be involved. Is there any way to explain why this should be so other than apparently it is?
Do you have an example of an interaction where the energy transfer is zero?
Might that be when positive transfers exactly match negative transfers?
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Murray Gell-Mann's quantum flapdoodle is still alive and well. Unfortunately, there are experts who perpetuate it.
I've just finished Vlatko Vedral's "Decoding Reality". New Scientist describes it as: "by turns irreverent, erudite and funny". In my opinion, it is by turns promising, disappointing and misleading. He certainly gives the impression that the reality of the Universe is the result of our observation/interpretation of information.
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Murray Gell-Mann's quantum flapdoodle is still alive and well. Unfortunately, there are experts who perpetuate it.
I've just finished Vlatko Vedral's "Decoding Reality". New Scientist describes it as: "by turns irreverent, erudite and funny". In my opinion, it is by turns promising, disappointing and misleading. He certainly gives the impression that the reality of the Universe is the result of our observation/interpretation of information.
If I understand the gist of your contribution ,I myself have in the past been the victim (a self victim ,probably) of this wishful belief (that we create the world by observing it)
Can we put this idea to bed by pointing out its internal contradictions? -there must surely be a few .
Does anyone have one or two to hand ? (aside from the obvious absurdity)
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Let's nail down the coffin on this one.
Common sense, evolution, and even the bloody bible, tell us that the universe created us, therefore reality cannot be a construct of the human mind. It's obviously the other way round.
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One of the problems of human vanity is that some people confuse mathematical approximations to reality with reality itself. Another is the introduction of "consciousness" into discussions of science, particularly if it is used without definition.
The word "observation" in physics simply means an interaction with a "third-party" object known as the observer. If that interaction is to have any effect on said object, it must involve the transfer of energy between the observed phenomenon and the observer so it must alter the nature of the interaction. We can model all this with collapsing wavefunctions but if we reduce the energy transfer to zero, there's nothing to prevent the interaction taking place in the absence of an observer.
If the object is "third-party" what are the other two parties ?
Are they two particles (or fields?) that meet one another?
Any two things that interact
It seems strange that a third party needs to be involved. Is there any way to explain why this should be so other than apparently it is?
I explicitly said that there is no need for a third party, but the presence of one will inevitably alter the outcome (sorry, I said nature. nonsense!) because it absorbs energy emanating from the interaction.
Do you have an example of an interaction where the energy transfer is zero?
Can't think of one, but I'm talking about the energy transferred to the observer, not betwen the interacting bodies.
Might that be when positive transfers exactly match negative transfers?
Now you mention it, I can imagine some chemical process where two configurations of a molecule are in a dynamic equilibrium
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Can we put this idea to bed by pointing out its internal contradictions?
I think Alan covers this quite succinctly, including Zowie's question:
Whatever did the universe do before we even arrived on the scene?
I never thought I would see Alan resort to the Bible to support an argument, but "if it's there, use it", seems a good motto.
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I explicitly said that there is no need for a third party, but the presence of one will inevitably alter the outcome (sorry, I said nature. nonsense!) because it absorbs energy emanating from the interaction.
Excuse my lack of familiarity with the process but if there are potentially 3 objects involved in the interaction,does this require the process to be synchronous with all three objects contributing to the same event (I realize "event" is a term from Spacetime and Relativity and so anticipate it may not be applicable to this situation but I am out of my depth and so hope the odd mistake in terminology or maybe concept can be allowed -and corrected)
By the way ,am I venturing into Feynman diagram territory at all ?(I understand they are extremely useful but I have not really learned much about them)
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Definition of an Inertial Observer
I don’t remember who said it, but I have just found this among some notes.
“It is important to realize that an “observer” is a huge information-gathering system, not simply one man with binoculars. In fact, we shall remove the human element entirely from our definition, and say that an inertial observer is simply a coordinate system for spacetime, which makes an observation simply by recording the location (x, y, z) and time (t) of an event.”
I find myself wondering to what extent "recording" is relevant.
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One of the problems of human vanity is that some people confuse mathematical approximations to reality with reality itself. Another is the introduction of "consciousness" into discussions of science, particularly if it is used without definition.
The word "observation" in physics simply means an interaction with a "third-party" object known as the observer. If that interaction is to have any effect on said object, it must involve the transfer of energy between the observed phenomenon and the observer so it must alter the nature of the interaction. We can model all this with collapsing wavefunctions but if we reduce the energy transfer to zero, there's nothing to prevent the interaction taking place in the absence of an observer.
I was initially strongly angainst the " consciousness collapsing the wave function" or even against the observer collapsing the wave function , which makes more sense, but I couldn't find a convincing better explanation yet for the double slit experiment, delayed choice and for the quantum spin.
The mathematical approximations are the result of the experiments interpretations. "Superposition" is a mathematical concept that emerged from interpretation of experiments, but can you tell whether it is real or not ?
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Let's nail down the coffin on this one.
Common sense, evolution, and even the bloody bible, tell us that the universe created us, therefore reality cannot be a construct of the human mind. It's obviously the other way round.
The universe exists independently of the human mind but it is different than what we observe.
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I explicitly said that there is no need for a third party, but the presence of one will inevitably alter the outcome (sorry, I said nature. nonsense!) because it absorbs energy emanating from the interaction.
Excuse my lack of familiarity with the process but if there are potentially 3 objects involved in the interaction,does this require the process to be synchronous with all three objects contributing to the same event (I realize "event" is a term from Spacetime and Relativity and so anticipate it may not be applicable to this situation but I am out of my depth and so hope the odd mistake in terminology or maybe concept can be allowed -and corrected)
Two billiard balls collide. No observer. Sound waves emanate and dissipate into space. Outcome 1.
Two billiard balls collide. Microphone and tape recorder. Some sound energy is converted to electrical signal thence to magnetic signal. Outcome 2.
Tree falls in forest. Bugs eat tree. Outcome 1
Tree falls in forest. Zen master observes photons and phonons emanating from event, wonders what would have happened if he hadn't been there, writes book, causes confusion among entire human race. Outcome 2.
No simultaneity required. The observation takes place some time after the event.
Now someone is bound to raise the question of the double slit experiment. Here's my interpretation.
There is no question of the photon "interfering with itself". That is confusing two models of photon behavior: a wave can interfere constructively or destructively but a particle cannot interfere destructively with itself or an identical particle. The use of an integrating observer (a photographic plate) confuses the issue because a single photon cannot interact with several film grains - it only has enough energy to blacken one grain. So what you are seeing is the spatial probability distribution of photons integrated over time. Now cover one slit. Since the probability of a photon passing through that slit is now 0 the spatial probabilty function downstream of the slits must revert to the function associated with one slit.
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Are all observations equal ?
Do some observations share more than others in the overall energy transfer of the reactions?
On the face of it an observation of a single photon from a supernova seems of less consequence than that of a delicate microphone placed next to a nuclear explosion....
When the description is of a collapse of a waveform as a result of an observation does this description apply equally to the mechanics involved in the making of the observation or (as I think I may have heard ) is it possible to make the observation without any physical connection at all to the event that is being "observed" -a sort of "passive or deduced observation" if I heard it right?
I mean does the waveform of the observing mechanism collapse along with or as well as the waveform of the thing that has been observed?
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I think you are making this much more complex and esoteric than it needs to be.
Reread the last paragraph of Alan's last post. Experiments with sources which release single photons at a time show the characteristic build up of the interference pattern over time.
A big problem here comes from the use of the word observation which is really used in the context of interaction. A photon hitting a leaf interacts with the atoms in the leaf whether seen or not. We are only talking about single interactions at a time, the microphone you mention might pick up millions of interactions in the microsecond before it is destroyed, but observation refers only to the individual interactions.
In your final sentence you use the word waveform, do you mean wavefunction? This is only a description of the item's probability of position etc. When it collapses the probability is 1 for position, momentum etc. Imagine you have a deck of cards, before dealing the top card you can only say the probability of it being a particular card is 1/52, once the card is dealt the probability of it being a particular card is 1, it's wavefunction has collapsed.
The wavefunction of the observing mechanism will change with the interaction eg a photon hitting a photoelectric material will change the energy of an electron causing it to move, hence its wavefunction will change, it would only collapse if it too was detected.
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I think you are making this much more complex and esoteric than it needs to be.
Reread the last paragraph of Alan's last post. Experiments with sources which release single photons at a time show the characteristic build up of the interference pattern over time.
A big problem here comes from the use of the word observation which is really used in the context of interaction. A photon hitting a leaf interacts with the atoms in the leaf whether seen or not. We are only talking about single interactions at a time, the microphone you mention might pick up millions of interactions in the microsecond before it is destroyed, but observation refers only to the individual interactions.
In your final sentence you use the word waveform, do you mean wavefunction? This is only a description of the item's probability of position etc. When it collapses the probability is 1 for position, momentum etc. Imagine you have a deck of cards, before dealing the top card you can only say the probability of it being a particular card is 1/52, once the card is dealt the probability of it being a particular card is 1, it's wavefunction has collapsed.
The wavefunction of the observing mechanism will change with the interaction eg a photon hitting a photoelectric material will change the energy of an electron causing it to move, hence its wavefunction will change, it would only collapse if it too was detected.
I see . So in my microphone scenario we are ,in theory really just talking about the interaction between two particles in the explosion and any one particle in the microphone ?
Can I still ask if there is a symmetry between these three objects so that (like perhaps in a three card trick) any one of the three can in principle play the role of "observer"
Yes my use if "waveform" instead of "wave function" shows the threadbare state of my knowledge in this area but I feel in my own mind I am making some progress in my understanding (it feels like a lot to me -a matter of scale of course ;) )
If others can learn anything from my misunderstandings and the clarifications/redirections that would be the icing on the cake.
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Can I still ask if there is a symmetry between these three objects so that (like perhaps in a three card trick) any one of the three can in principle play the role of "observer"
Which 3 objects do you refer to?
If we take the case of a photon hitting a detector the photon ceases to exist, it is hard to imagine how this could be an observation from the point of view of the photon. Remember, we are talking about the collapse of the photon's wavefunction being detected.
Don't t worry about misunderstanding, we all started in the same place.
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Which 3 objects do you refer to?
If we take the case of a photon hitting a detector the photon ceases to exist, it is hard to imagine how this could be an observation from the point of view of the photon. Remember, we are talking about the collapse of the photon's wavefunction being detected.
Don't t worry about misunderstanding, we all started in the same place.
Well it would be the photon , the particle on the screen impacted and the first particle in the detector that received information about the event(if that is the right term )
I see that there is an asymmetry in term of time (the detector is later than the other two ) and so my "threesome" scenario seems to have failed on that count anyway:(
What about a twosome?(the photon and the particle on the screen) Are they equal partners? Do they both see their wavefunction collapse at the same time dependent on a third party involvement albeit postponed in time?
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What about a twosome?(the photon and the particle on the screen) Are they equal partners? Do they both see their wavefunction collapse at the same time
If the photon is detected by the movement of an electron in the detector then the photon ceases to exist and the electron acquires energy hence its wavefunction will change (not collapse), eg it could become a free electron.
Don't get too hung up over this idea of the wavefunction collapsing, it is only a description of probability not a causative. It's like saying a car has hit a brick wall so it's speed has collapsed, the car does not hit the wall because it's speed collapsed. There is nothing magical about this.
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In the delayed choice quantum eraser the photon is basically detected without any interaction or any energy lossless. The which way path is determined observing its twin. The problem is that since the twin pair is entangled when you do a measurement on one photon it affects the other. Now here comes another trick. They let the first twin hit the screen, and let the other free to fly further without any measurement. After a while ( some ten ns) they decide to make a measurement. Guess what? The photon goes back im time and takes a the route they actually detected.
My opinion is that for some reason photons that interfere cannot be detected and when they reach the screen they are filtered as background radiation.
The fact that the observer disturbs the measurement is acceptable. The measurement on the twin particle disturbing the interference is very weird, plus entanglement we know is about the spin not the wavefunction. But then photons going back im time or predicting the future! ? That is almost absurd. But if it is actually what happens then the implications get very exciting.
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the photon is basically detected without any interaction
Amazing. Please describe a detector that does not require any interaction or energy exchange with the object detected. (Remember to patent your device before publication).
Here's a simple event. Hydrogen fuses to produce helium and releases several gamma rays at once from the sun. An observer on earth detects some gamma radiation 8 minutes later. An observer on Mars sees some 15 minutes later. An observer orbiting Betelgeuse sees one 650 years later. How did the hydrogen atoms know when to fuse?
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the photon is basically detected without any interaction
Amazing. Please describe a detector that does not require any interaction or energy exchange with the object detected. (Remember to patent your device before publication).
the photon is split in two after passing the slits by a barium borate crystal. Then chosing to detect or not one twin changes the wavefunction of the other. Simultaneity is not required.
Here's a simple event. Hydrogen fuses to produce helium and releases several gamma rays at once from the sun. An observer on earth detects some gamma radiation 8 minutes later. An observer on Mars sees some 15 minutes later. An observer orbiting Betelgeuse sees one 650 years later. How did the hydrogen atoms know when to fuse?
Sorry, I can't see the analogy of your example with the DCQE experiment.
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One photon in, two photons out, means that energy has been exchanged. But suppose that we have in fact generated two photons each with half the initial energy. Detect one, and you have absorbed half the energy.
MY example demonstrates that simultaneity of event and observation is not requied.
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... Another is the introduction of "consciousness" into discussions of science, particularly if it is used without definition...
We don't quite need a good definition. It is simply a human watching a result on a display of a detector versus s not watching the display but detector and display still plugged working.
Ps.
The fist simplistic definition useful im QM context was stated by Neumann. It basically says, that a device can make a measurement and then display the result. To read the result, you can use another device but it will still display its own measurement and so on. Human are capable of doing the measurement, but also to be selfaware of their own measurements. However, there are more recent experiments which demontrate that the wavefunction collapses when the "which way" is determinable regardless of a human mind being aware of the measurement.
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One photon in, two photons out, means that energy has been exchanged. But suppose that we have in fact generated two photons each with half the initial energy. Detect one, and you have absorbed half the energy.
MY example demonstrates that simultaneity of event and observation is not requied.
I understand something elese from this experiment.
Imagine you let a snowball roll down a hill. There are two initial ditches (A and B) that lead to two gates. Each gate is fitted with a blade that cuts the ball into two equal parts. Then they roll down through one of another 4 short ditches (d1 and d2 for Gate A and also e1 and e2 for B) then the ditches become flat. Down lower at 100m there are two gates (GAand GB) that catch the ball if the ball went through d1 or e1. The other half goes through d2 or e2 and after 200m reaches a man, at a position m2 for path A or another man n2 if it came through path B. The man that is at m2 or n2 is not allowed to whatch the ball until it reaches him. If the man at m2 or n2 decides to watch the ball then the other ball always gets caught into GA or GB.Otherwise they spread out all over the place.
For path A the ball will always get to man m2 and for path B always to man at n2.
For me the fact that the ball is split into two makes no difference anymore because it doesn't influence the which path at all.