Quantum entanglement and Two slit experiment

In summary: Thanks. How does another particle observe a wavefunction?Particles can interact with each other, which can cause a wavefunction to collapse. This can happen through processes such as scattering or measuring the particle's properties.
  • #1
itsonelouder
15
0
Hi.

Firstly, I'm not a physics student but was just wanting some answers to questions from those that are, so I thought I'd try you lot. :smile:

1. Has anyone proved that quantum entanglement doesn't happen at the macro level?

2. Regarding the 2 slit experiment and how consciousness collapses a wave to particle, has anyone proved that it doesn't happen on a macro level?

Layman's language would be much appreciated :wink:

Thanks very much.
 
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  • #2
itsonelouder said:
Hi.

Firstly, I'm not a physics student but was just wanting some answers to questions from those that are, so I thought I'd try you lot. :smile:

1. Has anyone proved that quantum entanglement doesn't happen at the macro level?

2. Regarding the 2 slit experiment and how consciousness collapses a wave to particle, has anyone proved that it doesn't happen on a macro level?

Layman's language would be much appreciated :wink:

Thanks very much.

Welcome to PhysicsForums, itsonelouder!

1. It is generally believed that any entanglement of macro objects will self-decohere (ending the entanglement) in relatively short time spans. The system more or less needs to be closed to maintain the entangled state. That does not mean that it is impossible, and some experimentalists are working on accomplishing this.

2. I don't know of any way to prove or disprove that consciousness causes wavefunction collapse. However, it is generally not believed to be a factor.
 
  • #3
DrChinese said:
I don't know of any way to prove or disprove that consciousness causes wavefunction collapse. However, it is generally not believed to be a factor.
And definitely not if you have a professionnal training in the field of neurosciences and cognitive psychology.
Only a totally ignorant in neurosciences could believe that the heart of microphysics could have anything to do with the neuronal machinery of consciousness.

However, for the social psychologist who is interested in rumors and collective deliria, the history and development of this believing is an interesting and rich corpus.
 
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  • #4
DrChinese said:
Welcome to PhysicsForums, itsonelouder!

1. It is generally believed that any entanglement of macro objects will self-decohere (ending the entanglement) in relatively short time spans. The system more or less needs to be closed to maintain the entangled state. That does not mean that it is impossible, and some experimentalists are working on accomplishing this.

2. I don't know of any way to prove or disprove that consciousness causes wavefunction collapse. However, it is generally not believed to be a factor.

Thanks.

1. So it hasn't been disproved, it isn't out of the realm of possibility. Isn't the universe a closed system though? All matter coming from the quantum field, and the matter is the same as the field? One field of energy, therefore a closed system?

To quote Einstein: We may therefore regard matter as being constituted by the regions of space in which the field is extremely intense...There is no place in this new kind of physics for the field and matter, for the field is the only reality."
Einstein


2. I thought that conscious observation was believed to be the influencing factor, because as soon as conscious observation occurs the wavefunction collapses? So has no scientist proved this phenomena can't occur with everyday objects?

Sorry if I'm repeating myself.
 
  • #5
Jacques_L said:
And definitely not if you have a professionnal training in the field of neurosciences and cognitive psychology.
Only a totally ignorant in neurosciences could believe that the heart of microphysics could have anything to do with the neuronal machinery of consciousness.

However, for the social psychologist who is interested in rumors and collective deliria, the history and development of this believing is an interesting and rich corpus.

So if consciousness isn't causing it, what is? And has it been proven conclusively that consciousness doesn't collapse the wavefunction?
 
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  • #6
itsonelouder said:
So if consciousness isn't causing it, what is? And has it been proven conclusively that consciousness doesn't collapse the wavefunction?

Lots of things can "observe" a wavefunction. Any kind of sensor or particle that interacts can collapse its wavefunction.

Has it been proven conclusively that consciousness doesn't collapse the wavefunction? No, it hasn't.

Now answer me this, has it been proven conclusively that the universe isn't actually riding on the back of a giant tortoise made of jello and paper clips by deranged monkeys strung out on crack and diet pepsi?
 
  • #7
carlgrace said:
Lots of things can "observe" a wavefunction. Any kind of sensor or particle that interacts can collapse its wavefunction.

Has it been proven conclusively that consciousness doesn't collapse the wavefunction? No, it hasn't.

Now answer me this, has it been proven conclusively that the universe isn't actually riding on the back of a giant tortoise made of jello and paper clips by deranged monkeys strung out on crack and diet pepsi?

But there's nothing to suggest your last hypothesis. Yet, doesn't experimental evidence repeatedly show the collapse of the wavefunction when it's consciously observed?
 
  • #8
itsonelouder said:
But there's nothing to suggest your last hypothesis. Yet, doesn't experimental evidence repeatedly show the collapse of the wavefunction when it's consciously observed?

Not at all. If you put photon detectors in each of the slits that click when a photon passes them you destroy the interference pattern even if you aren't in the room listening to the click.

So, either photon counters are conscious, or there is no evidence consciousness is needed to collapse wavefunctions.

Wavefunctions collapse when they are "observed" by anything... people, machines, other particles...
 
  • #9
itsonelouder said:
But there's nothing to suggest your last hypothesis. Yet, doesn't experimental evidence repeatedly show the collapse of the wavefunction when it's consciously observed?

There is no reason to suppose that consciousness is a factor, no. It would be like saying that light travels at c only when we measure it. There is no hypothetical mechanism for a role for the mind.
 
  • #10
carlgrace said:
Not at all. If you put photon detectors in each of the slits that click when a photon passes them you destroy the interference pattern even if you aren't in the room listening to the click.

So, either photon counters are conscious, or there is no evidence consciousness is needed to collapse wavefunctions.

Wavefunctions collapse when they are "observed" by anything... people, machines, other particles...

Thanks. How does another particle observe a photon? Does that mean photons behave as a wave in a vacuum, but a particle in non-vacuum. And how do you know it's a wave when it's not being observed? That sounds impossible.
 
  • #11
itsonelouder said:
Thanks. How does another particle observe a photon? Does that mean photons behave as a wave in a vacuum, but a particle in non-vacuum. And how do you know it's a wave when it's not being observed? That sounds impossible.

A particle observes a photon by interacting with it. For example, it is partially scattered by the interaction. And for two particles to interact, they need a definite position.

I think you are missing the point of quantum mechanics. A photon is not a wave sometimes, and a particle at other times. It possesses both particle-like and wave-like qualities. This is the so-called Copenhagen Interpretation favored by Niels Bohr. Richard Feynman thought photons are particles that have some wave-like "quantum weirdness" nature. So while there is some room for debate, I don't believe anyone really believes photons behave as a wave in a vacuum, but a particle in non-vacuum.

How do we know photons have wave-like nature? Because that theory leads to predictions that can be tested by experiment, and these experimental results match theory to an astounding accuracy. That is really, really strong evidence that quantum mechanics is either a deep truth of nature or an accurate aspect of some deeper truth.
 
  • #12
It's absolutely fascinating stuff, so I'm going to go away and read up some more and maybe get back to you. I'm not sure about this observer thing and what constitutes an observer.

Thanks very much so far :smile:
 
  • #13
Quick question. You mentioned that interaction with particles constitutes an observer. But when the photon behaves like a wave when passing through the two slits, isn't it interfering with the particles in the material the slits are made of? And what about the air particles?
 
  • #14
carlgrace said:
A particle observes a photon by interacting with it. For example, it is partially scattered by the interaction. And for two particles to interact, they need a definite position.
The idea that particles must collapse each other's wave functions if they interact conflicts with my understanding of quantum mechanics. I thought that you could instead construct the wavefunction of the two-particle system, and this wavefunction would not collapse when the two particles interact.
 
  • #15
Consciousness, consciousness, consciousness...

itsonelouder said:
... if consciousness ... consciousness ...
Using so heavily a technical and specialized word implicitly asserts that you understand and master it.
If so, please do not hesitate to give us a scientific definition, which has a practical use.
Please remember us the exact role of the raphé.
Please remember us the exact role of the locus coeruleus.
Please remember us the exact roles of the hippocampi and the amygdalia.
Antonio Damasio has also given us several names of nuclei in the cerebral stem, which are not in my neuro-anatomy atlas, and all play a crucial role in consciousness. Please explain them.
Please explain the roles of parietal associative areas in self-consciousness of our own body.
We begin to know them by cerebral accidents - mainly vascular ones.
...

From the evolutionary point of view, please explain when began the "consciousness" used by the Copenhagen fairy tales. Before or after mastering the fire ? Before or after elaborating wood tools then stone tools ? Before or afer the separation of primates from rodents ?
Please explain us how the planets and stars could achieve their nuclear and chemical reactions, looooooooooong before Copenhagen physicists began to suck their mothers, then observe quantum reactions.
Thank you !
 
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  • #16


Jacques_L said:
Using so heavily a technical and specialized word implicitly asserts that you understand and master it.
If so, please do not hesitate to give us a scientific definition, which has a practical use.
Please remember us the exact role of the raphé.
Please remember us the exact role of the locus coeruleus.
Please remember us the exact roles of the hippocampi and the amygdalia.
Antonio Damasio has also given us several names of nuclei in the cerebral stem, which are not in my neuro-anatomy atlas, and all play a crucial role in consciousness. Please explain them.
Please explain the roles of parietal associative areas in self-consciousness of our own body.
We begin to know them by cerebral accidents - mainly vascular ones.
...

From the evolutionary point of view, please explain when began the "consciousness" used by the Copenhagen fairy tales. Before or after mastering the fire ? Before or after elaborating wood tools then stone tools ? Before or afer the separation of primates from rodents ?
Please explain us how the planets and stars could achieve their nuclear and chemical reactions, looooooooooong before Copenhagen physicists began to suck their mothers, then observe quantum reactions.
Thank you !

Has it been proved that consciousness is a function of the brain? Many forms of life display consciousness of their surroundings and they don't have a brain. Or is it just a by-product of life?

There would have to be consciousness of your surroundings before all of what you say. Without consciousness you wouldn't be conscious of anything and so you wouldn't be able to do anything. ;-)

Well obviously stuff was happening before life. What was causing that i don't think anyone knows do they? But there's some natural force/order/beauty to the universe. Look at the fractal geometry in nature. I never said consciousness has to exist for stuff to happen.
 
  • #17
carlgrace said:
Not at all. If you put photon detectors in each of the slits that click when a photon passes them you destroy the interference pattern even if you aren't in the room listening to the click.

This may seem a silly question, but in the case of the above, has it been proven that the wavefunction collapsed "before" you observed it's collapse.
 
  • #18


itsonelouder said:
Has it been proved that consciousness is a function of the brain? Many forms of life display consciousness of their surroundings and they don't have a brain. Or is it just a by-product of life?

Have you heard the of term "Separation Conscious" yet?

It's the idea that consciousness is a distinct separate thing from both the mind and body, meaning that we are aware of our five senses, through which we also perceive biochemical reactions that we call emotions, just as we are aware of our thoughts, which can cause the limbic system of the brains to stimulate the autonomic nervous system, which also affects the body producing biochemical reasons that we again we interpret as emotion. This is just the same as saying that the sight of an attractive woman can make a man amorous or the thoughts of having been robbed can make one angry.

The point is we are aware of our feelings and thoughts, although those things are distinctly separate from our awareness of them. So is the brain the source of consciousness? I have to say the brain, as we commonly think of it as the organ that allows us to reason and remember, is a kind of computer at the disposal of the consciousness. I also tend to think the solar plexus may more likely be the attachment point between the conscious and the mind/body dichotomy, although at the moment I lack a proof of it.
 
  • #19


syberraith said:
Have you heard the of term "Separation Conscious" yet?

It's the idea that consciousness is a distinct separate thing from both the mind and body, meaning that we are aware of our five senses, through which we also perceive biochemical reactions that we call emotions, just as we are aware of our thoughts, which can cause the limbic system of the brains to stimulate the autonomic nervous system, which also affects the body producing biochemical reasons that we again we interpret as emotion. This is just the same as saying that the sight of an attractive woman can make a man amorous or the thoughts of having been robbed can make one angry.

The point is we are aware of our feelings and thoughts, although those things are distinctly separate from our awareness of them. So is the brain the source of consciousness? I have to say the brain, as we commonly think of it as the organ that allows us to reason and remember, is a kind of computer at the disposal of the consciousness. I also tend to think the solar plexus may more likely be the attachment point between the conscious and the mind/body dichotomy, although at the moment I lack a proof of it.

I've done some meditation in my time and I know that it's possible to be conscious of your thoughts as opposed to feeling you are the thoughts. In other words, observing the trance-like state of conditioned thought processes and seeing them as not self. But I get the feeling there is no dualism there, everything being a manifestation of the same substance.
 
  • #20
Yes, absence of dualism. The power of thought to draw the consciousness in is quite strong. That's why some many people identify with their thought. It's easy to do.

By quieting the mind and relaxing as much as possible, one can begin to become aware of just being aware and amplify upon that. "The Power of Now" was an incredible help to me along those lines.

I had meditated for decades before reading that with varying levels of success. Although after reading that book, zoom, up to a whole new level. I also use binaural beats quite a lot, although those actually remap activity in certain part of the brain.
 
  • #21
The Power of Now was a turning point for me too. It made sense of the Buddhist meditation I'd tried in the past. I found Eckhart gives people a bit too much "to do" though. You might like to look at Adyashanti's "True Meditation" which approaches it from a completely different angle. His teachings and his approach to meditation have been very beneficial to me. You can find his introduction to true meditation here along with some of his teachings:
http://www.youtube.com/user/evignektar
 
  • #22
I can see mediation relating to human psychology in some way but I can't grasp it's linkage with quantum mechanics.
 
  • #23
conciousness arises from neural activity, has this not been shown? stimulating the brain affects your conciseness, indeed we can turn off parts of the brain and with it we lose conciousness. Where is there any evidence that conciousness is separate from the brain? if you take certain chemicals/drugs that we know act on the brain and body chemistry in certain ways we know it changes how we perceive ourselves and our conciousness. Where in that is there evidence for separation of the the elements of brain and conciousness? Thats if we even can agree on what defines conciousness.
 
  • #24
Tolle has a lot of good insight however, he is rather wordy and repetitious. I have to look into Adyashanti. I've found Osho ("What is Meditation") is interesting to listen to too, although he's quite a character.

***

How does meditation and consciousness relate to QM?

Well in my own humble unproven subjective view, in deep meditation when the mind is quiet and one can feel the the most basic neural impulses attempt to initiate thoughts, it almost seems like those impulses are small Wizard of Oz pushing buttons and pulling levers on a neural level.

It takes a leap of faith, or as I prefer to think of it the presumptive step of inductive logic, to view the conscious as affecting the neural activity on a molecular level, and the only way I can image that happening is though manipulating quantum states.

Since we know QM is based upon Heisenberg's Uncertainty Principle, all my previous statement really means is that consciousness can affect the density probability, skew it one way or the other, of wave functions for particles quantum states in or around neurons. I think that's a reasonable hypothesis.

***

What experiments have shown is that memory is associated with the brain, and that the brain/CNS seems to conduct and process sensory information. Although you have to consider if one remains aware even if the connections between one's awareness and one's memory banks and or lines of sensory communication are turned off or severed temporarily.

How would one be aware of the passage time or transpiration of events in such a isolated state? So, even though a person lacks a recollection of things that happen when they were "unconscious" as well as lack the brain wave evidence of "consciousness" it would be an err of logic to claim that their awareness stopped along with the stoppage of their sensory inputs and connection to their memory.

How would a consciousness free of attachment to a body in space-time even be aware of its own existence without sensory information, memory, and reasoning facilities which are all provided such a body? It's a question well worth some refection.

Remember one of the basic tenets of logic is that it's impossible to prove a negative, such as "It's not raining" Only positives can be proven: I observe rain drops falling from the sky, therefore it's raining." This is to say, even though in some cases there appears to be an absence of any signs of consciousness, it would be wrong to conclude that consciousness ceased to exist during the time of the absence of any signs of its presence.

I realize that's kind of a sketchy, although I hope you can still get the idea.
 
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  • #25
DrChinese said:
consciousness... However, it is generally not believed to be a factor.

itsonelouder said:
Thanks.

1. So it hasn't been disproved, it isn't out of the realm of possibility.
:smile:
You do not fully appreciate the art of understatement of DrChinese.
The result is hilarious.
 
  • #26
Jacques_L said:
:smile:
You do not fully appreciate the art of understatement of DrChinese.
The result is hilarious.

Yeah well, what do you expect from a non-physicist
 
  • #27
Jacques_L said:
:smile:
You do not fully appreciate the art of understatement of DrChinese.
The result is hilarious.

Heh... you noticed!

(Always trying to be polite to new posters... they may not appreciate some of us sharks.)

So just wondering, itsonelouder... is eleven really one louder than ten?
 
  • #28
DrChinese said:
2. I don't know of any way to prove or disprove that consciousness causes wavefunction collapse. However, it is generally not believed to be a factor.

I think it can be proved by the fact that we could have a series of instruments making the measurement without human (consciousness) looking at it.

at some point when the human reads from these instruments he/she would see the results happened prior to his/her looking.

one could still argue that the instruments results only happened when a human looked...but then we could have a clock.

one could argue that even the clock happened when the human looked...but then

you have a clock and so many instruments...now not all of them could be waiting for a human consciousnesses to trigger their results...

second if someone applied the above argument then it would be applicable to the whole universe and the universe did not exist till human consciousness looked at it...

long story short...(most/all) things happen in the universe without humans/life/consciousness looking at it...
 
  • #29
San K said:
I think it can be proved by the fact that we could have a series of instruments making the measurement without human (consciousness) looking at it.

at some point when the human reads from these instruments he/she would see the results happened prior to his/her looking.

Thank you, this is what I'm getting at.

Has anyone done an experiment to show that the wavefunction collapses before the person carrying out the experiment reads the result? Like you said, done with the use of a clock.
 
  • #30
San K said:
second if someone applied the above argument then it would be applicable to the whole universe and the universe did not exist till human consciousness looked at it...

long story short...(most/all) things happen in the universe without humans/life/consciousness looking at it...

In a sense the universe doesn't exist "as we see it" though. I mean the atom is essentially empty space and I've heard that the nervous system essentially makes sense of the chaos that's "out there".

But I obviously agree that human history is minuscule in relation to the history of the cosmos and we don't have to be here for stuff to happen. I've never thought that.
 
  • #31
San K said:
I think it can be proved by the fact that we could have a series of instruments making the measurement without human (consciousness) looking at it.

at some point when the human reads from these instruments he/she would see the results happened prior to his/her looking.

one could still argue that the instruments results only happened when a human looked...but then we could have a clock.

one could argue that even the clock happened when the human looked...but then

you have a clock and so many instruments...now not all of them could be waiting for a human consciousnesses to trigger their results...

second if someone applied the above argument then it would be applicable to the whole universe and the universe did not exist till human consciousness looked at it...

long story short...(most/all) things happen in the universe without humans/life/consciousness looking at it...

DrChinese said:
Heh... you noticed!

(Always trying to be polite to new posters... they may not appreciate some of us sharks.)

So just wondering, itsonelouder... is eleven really one louder than ten?

:biggrin: it is, but not as loud as 12, which is really pushing it!
 
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Related to Quantum entanglement and Two slit experiment

1. What is quantum entanglement?

Quantum entanglement is a phenomenon in which two or more particles become connected in such a way that the state of one particle is dependent on the state of the other, even if they are separated by a large distance.

2. How does quantum entanglement work?

Quantum entanglement occurs when two particles interact and become entangled, meaning their states become linked. This link remains even if the particles are separated, and any change in the state of one particle will affect the state of the other.

3. What is the two slit experiment?

The two slit experiment is a thought experiment used to demonstrate the wave-particle duality of light and matter. It involves sending particles, such as photons or electrons, through two slits and observing the resulting interference pattern on a detector screen.

4. How does the two slit experiment relate to quantum entanglement?

The two slit experiment is often used to explain the concept of quantum entanglement. It shows how particles can behave as both waves and particles, and how their states can be affected by their environment, including other entangled particles.

5. What are the practical applications of quantum entanglement and the two slit experiment?

Quantum entanglement and the two slit experiment have many potential applications in fields such as quantum computing, cryptography, and teleportation. They also provide valuable insights into the fundamental nature of the universe and the behavior of particles at the quantum level.

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