An experiment that proves the primacy of consciousness!!!?

[Adur Alkain]

Hello all,

I've been trying for some time to formulate a consistent idealistic interpretation of quantum mechanics. I have called my most recent attempt the "observational interpretation", because it is based on a new theory of observation. The exciting news about this interpretation is that it makes some unexpected predictions about the observable behaviour of quantum systems: it isn't just an interpretation, it's a proper theory!

Trying to figure at an experiment that would make it possible to test those predictions, I discovered that such an experiment had already been done... and that (apparently) the predictions of my theory were met!

I believe those results contradict most (if not all) other interpretations of quantum mechanics. They certainly contradict my original interpretation, which I called "the idealistic interpretation" (I presented it on this forum in an essay titled "The Marriage of Physics and Idealism").

I'll summarize my theory in a few sentences, and then I'll briefly explain the experiment. These are the main points of the observational interpretation of quantum mechanics:

1. Observation is the only physical reality. The physical world is the observed world.

2. Every physical interaction is an act of observation.

3. There is only one observer: consciousness.

4. Consciousness is not a physical phenomenon. It underlies physical reality. There is only one consciousness, pervading the whole universe.

5. Consciousness determines the transition from potentiality (probabilities) to actuality (definite states). Every physical interaction is an interaction between a physical system and consciousness. That is observation.

6. In order to interact with the physical world, consciousness needs the medium of living organisms. The physical bodies of living organisms (like humans) are the “observation instruments” that consciousness uses to observe the physical universe.

7. There is a clear distinction between observation and measurement. Observation is performed by consciousness, the one and only observer. Measurement is carried out by living organisms (e.g. human scientists). Measurement is local. Observation is nonlocal.

The experiment

Here is the experiment that can be used to test this theory. It is based on a well-known experiment published in Physical review, March 2002, by S. P. Walborn, M. O. Terra Cunha, S. Padua and C. H. Monken.

An argon ion pump laser is set up to emit single photons. Each photon passes through a special nonlinear crystal called beta-barium borate (BBO), where it is converted to two entangled, longer wavelength photons. The two entangled photons go off in two different directions, p and s.

The s photons (those which go down path s) travel through a double-slit to detector Ds. The p photons travel directly to detector Dp. Detector Dp is configured to measure the polarization of each registered photon. Detector Ds is configured to measure both the polarization and the location of each photon.

With this set up we should observe an interference pattern on detector Ds. In other words, each s photon somehow “goes through both slits at once”.

(Source: Wikipedia)

A quarter wave plate (QWP) is now put in front of each slit. This device is a special crystal that changes linearly polarized light into circularly polarized light. The two wave plates are set so that given a photon with a particular linear polarization (x/y), one wave plate will change it to right circular polarization while the other will change it to left circular polarization.

Because p and s photons form entangled pairs, by measuring the linear polarization of each p photon, we can know the polarization of the corresponding s photon before it reaches the quarter wave plates. With this configuration, it is possible to figure out which slit the s photon went through, without disturbing the s photon in any way.

(Source: Wikipedia)

According to the observational interpretation, it is not necessary to actually measure the polarization of p and figure out what slit s passed through. Once the quarter wave plates are introduced, the mere possibility of making that measurement is enough to make the interference pattern disappear.

The explanation for this “weird” effect is that, by introducing the quarter wave plates, we are creating an entanglement between the probabilities of an s photon passing through slit 1 or slit 2 and the probabilities of observing our own physical bodies (our sense organs) in certain corresponding states. In a way, by setting up the experiment we are “forcing” consciousness to observe the path each photon is taking through the double-slit.

Each experiment is a question that we ask nature. Nature is forced to provide the answer. If we pay attention to the answer or not is irrelevant.

These experimental results predicted by the observational interpretation are inconsistent with other formulations of quantum mechanics.

According to most mainstream interpretations, a quantum superposition of states disappears (the wave function collapses) the moment the quantum system interacts with a macroscopic object (the measurement apparatus).

In our double-slit experiment, it is obvious that the interaction between the entangled photons and the macroscopic detectors plays no role in the transition from a superposition to a definite state. In the first configuration of the system, with the two detectors in place, an interference pattern is observed.

Could it be that the “collapse of the wave function” is caused by the interaction of the s photons with the quarter wave plates, introduced in the second configuration?

This possibility can be discarded by placing a polarizer on the p path. This polarizer acts as a “quantum eraser”, making it no longer possible to know the linear polarization of s photons before they reach the quarter wave plates, and therefore making it no longer possible to figure out which slit each s photon goes through. Once the polarizer is in place, the interference pattern reappears.

Traditional interpretations of quantum mechanics cannot account for this.

There you have it! If I'm correct, this experiment directly shows the fundamental nature of consciousness.

If you want to check out the original experiment, you can find it here.

You can read an article explaining the experiment for non-professionals here.

And if you would like to read the essay where I explain my theory more fully, I posted it here.

Any comments and criticisms would be much appreciated!

[Aditya Prasad]

I am sorry to say that the delayed-choice quantum eraser doesn't contradict any of the existing interpretations. I haven't read the entirety of your post in detail, but this:

According to most mainstream interpretations, a quantum superposition of states disappears (the wave function collapses) the moment the quantum system interacts with a macroscopic object (the measurement apparatus).

is not correct. They say that the superposition becomes decoherent when it entangles with sufficiently many degrees of freedom in the environment. In fact, a superposition is not detectable after it entangles with any other observable (even one on the same particle).

[Marco Masi]

Precisely. As an idealist I say to my idealist friends: stop trying to see in the delayed choice and quantum eraser experiments evidence supporting idealism more than any other quantum phenomena does already (why is that not ample evidence for it already?). These experiments do not violate orthodox quantum mechanics or do not imply any temporal retro-causality. And stop also in seeing in quantum mechanics any “role of the observer” in the measurement process that necessitates a "mind or consciousness that collapses the wave function" (at least not in the form of an alter, it would be more interesting to analyze this from the perspective of M@L). There is no such thing in quantum mechanics (with or without Wheeler and his friend) and one doesn't need such misconceptions to support an idealist view. BK reformulated this a bit more elegantly invoking contextuality, but trying hard to reintroduce a wrong idea through the back door won’t make it become true. Contextuality doesn't need or imply any mind or conscious observer either. And to insist in pointing out that there is a measurement problem won't make it automatically a magic wand that confirms any idealist claim. The fact that the measurement problem isn't completely explained by decoherence alone is true, but it is a formal mathematical problem that needs mentation for its solution no more no less than any law of classical physics would need. The real problem is that we, as idealists, have one thing in common with physicalists: the confirmation bias. We love to jump to conclusions when something seems to confirm our ideological background, but does not. Quantum mechanics as it is, without any extra ingredients, points directly to an idealist view of reality and is a slap in the face to physicalism. We have it in front of our nose and there is no reason to search for it elsewhere in contrived and complicated experiments.

[Aditya Prasad]

Thanks Marco. I would agree with everything you said except this:

On Tuesday, April 14, 2020 at 7:12:01 AM UTC-5, Marco Masi wrote: 

The fact that the measurement problem isn't completely explained by decoherence alone is true, but it is a formal mathematical problem that needs mentation for its solution no more no less than any law of classical physics would need.

It seems to me that this depends on how you frame the measurement problem. The way I use the term, it asks why there only ever seems to be one result of an experiment, when any proper formalism requires that we model it as having potentially many. And, of course, when this transition happens (if indeed it does).

That question leads to the following observations. A (not necessarily tight) upper bound for when I can say there is one result is when I see the result. And no evidence exists for a tighter bound. In fact, any event before "I experience a result" must be stated in purely physical terms, and the standard formalism demands that we therefore treat it unitarily. As we try to tighten this bound, we find ourselves having to make precise terms like "I" and "experience." If we do that carefully enough, we start to discover that what we've been calling "the world," "experience," and "I" are in fact the same thing.

Actually, now that you've forced me to spell it out, I quite like this summary and might use it elsewhere :)

[Adur Alkain]

Hi Aditya, thanks for your comment!

But if you had read my post, you would have noticed that the experiment I'm presenting is not a delayed-choice quantum eraser. It is a simple double-slit experiment. Look at the diagrams I included: there is no quantum eraser.

The quantum eraser (which was indeed included in the experiment carried out by Walborn et al.) is only useful to show that decoherence (or any interaction of the quantum system with the environment) doesn't explain the disappearance of the interference pattern. Introducing the polarizer ("quantum eraser") doesn't take the environment away.

I'm sorry, but decoherence doesn't explain anything in this experiment.

[Aditya Prasad]

Hi Adur, you say:

According to the observational interpretation, it is not necessary to actually measure the polarization of p and figure out what slit s passed through. Once the quarter wave plates are introduced, the mere possibility of making that measurement is enough to make the interference pattern disappear.

The s photon's position is entangled with its polarization. Every interpretation of QM will tell you that therefore the position cannot interfere. There's absolutely nothing here that isn't taught in a first-semester QM or quantum optics class.

Here's a helpful tutorial if you'd like to follow along with the math (in a setup that is slightly different but effectively the same): https://arxiv.org/pdf/1602.06162.pdf

[Adur Alkain]

Hi Marco,

I don't think you read my post. The experiment I'm presenting is not a "contrived and complicated experiment". It is a simple double-slit experiment. It is not a quantum eraser experiment.

On Tuesday, 14 April 2020 14:12:01 UTC+2, Marco Masi wrote:

Precisely. As an idealist I say to my idealist friends: stop trying to see in the delayed choice and quantum eraser experiments evidence supporting idealism more than any other quantum phenomena does already (why is that not ample evidence for it already?). These experiments do not violate orthodox quantum mechanics or do not imply any temporal retro-causality.

I said nothing about retro-causality. But the experiment I'm presenting does violate orthodox quantum mechanics. Here is the key: there is no measurement going on. We don't need to actually measure tthrough which slit each photon is passing. The mere possibility of making the measurement makes the interference pattern disappear. If you can explain this phenomenon using "orthodox quantum mechanics", I would be very interested to hear that explanation!

And stop also in seeing in quantum mechanics any “role of the observer” in the measurement process that necessitates a "mind or consciousness that collapses the wave function" (at least not in the form of an alter, it would be more interesting to analyze this from the perspective of M@L).

Precisely! In my theory, the "mind or consciousness" of the human "observer" plays no role in the "collapse of the wave function". When I talk about consciousness in my theory, I mean M@L.

There is no such thing in quantum mechanics (with or without Wheeler and his friend) and one doesn't need such misconceptions to support an idealist view. BK reformulated this a bit more elegantly invoking contextuality, but trying hard to reintroduce a wrong idea through the back door won’t make it become true. Contextuality doesn't need or imply any mind or conscious observer either. And to insist in pointing out that there is a measurement problem won't make it automatically a magic wand that confirms any idealist claim.

I'm not pointing at the measurement problem. My theory resolves the measurement problem in an elegant, simple way. In my theory, measurement doesn't play a role in the "collapse of the wave function".

 

The fact that the measurement problem isn't completely explained by decoherence alone is true, but it is a formal mathematical problem that needs mentation for its solution no more no less than any law of classical physics would need. The real problem is that we, as idealists, have one thing in common with physicalists: the confirmation bias. We love to jump to conclusions when something seems to confirm our ideological background, but does not. Quantum mechanics as it is, without any extra ingredients, points directly to an idealist view of reality and is a slap in the face to physicalism. We have it in front of our nose and there is no reason to search for it elsewhere in contrived and complicated experiments.

 

I totally agree!  My theory is as simple as can be, as is the experiment I'm presenting. What I'm trying to show is what we have in front of our nose: everything is happening in consciousness!

[Aditya Prasad]

But the experiment I'm presenting does violate orthodox quantum mechanics. Here is the key: there is no measurement going on. We don't need to actually measure tthrough which slit each photon is passing. The mere possibility of making the measurement makes the interference pattern disappear. If you can explain this phenomenon using "orthodox quantum mechanics", I would be very interested to hear that explanation!

It's really very simple. Without the QWPs the (position) state is |L> + |R>. With the QWPs the (polarization-position) state is |A>|L> + |B>|R> (where I'm just using |A> and |B> as orthogonal polarization states). If you apply the Born rule to this state, you find that the chance of getting an interference result like |L> + |R> is zero.

Another way you could say it is that the photon's polarization measures its position, and so there is a measurement going on. Really, the fact that measurement / entanglement / the mere possibility of recovering this information eliminates interference is QM 101, day 1. I strongly urge you to take an actual course in QM so that you can understand all of this very clearly. Until then I fear comments from me / Marco / anyone else who knows QM will be in vain.

Cheers,

A

[Adur Alkain]

Thanks Aditya!

I'll read that tutorial and see if I can find out what you mean by "The s photon's position is entangled with its polarization.Therefore the position cannot interfere.".

Sounds intriguing! :)

[Aditya Prasad]

No problem. 

If you have a superposition, and it becomes entangled with any other observable, then it's no longer in a pure superposition, and cannot interfere with itself. The "other observable" doesn't have to be another particle; it can be a different property of the same particle. The point is that there exists some information somewhere that provides information about the first observable's value.

[Marco Masi]

Adur, you are right, I didn't read your post and was only responding to Aditya's comment. Unfortunately I don't have time to follow discussions now. Don't take it personally! ;) 

[Aditya Prasad]

In case the below wasn't clear, the point is that the "measuring device" at the slits can be any physical observable at all--including some other property of the photon itself (in this case, its polarization).

[Adur Alkain]

Aditya,

I've read the tutorial you sent me and I've found that the experimental setup is very different to the setup of the experiment I'm talking about. Even so, reading it through made me rethink some of my ideas, which was helpful. Thanks!

(However, I must say the tutorial is not aimed at first-semester students, but at upper-level students (including Ph.D. students). The results of the paper show that many upper-level students in quantum mechanics struggle with these concepts. In other words, this is not QM 101 day 1, like you said.)

I'm sure you are aware that QM as taught formally in universities doesn't usually deal with interpretations. There is no interpretation whatsoever in the tutorial. Most professional physicists have no interest in interpretations of QM, they leave that to philosophers. This is the famous "shut up and calculate".

A mathematical equation is not an interpretation. You can use maths to show that, yes, the mere presence of the polarizer destroys the interference, but that doesn't explain anything.

And it's not true that every interpretation predicts this result. I think the experiment performed by Walborn et. al. is important. I encourage you to check it out, you can find it here. It is an actual experiment, not a thought experiment. And there are at least some interpretations that are disproven by this experiment.

For example, Wigner's "consciousness causes collapse" interpretation is completely incompatible with the results shown by this experiment. It is clear that the conscious mind of the experimenter plays no role.

I guess the same can be said of other subjectivist interpretations, like QBism (but I don't know this well enough to be sure). Any theory that ascribes a role to what human observers know about quantum systems has to be discarded (I think).

It's not good enough to say "there exists some information somewhere". Well, it's good enough for getting the maths right and making the correct predicitons. I get that. But that's not a true interpretation. It leaves all the important questions (important for philosophers, at least) unanswered.

Where is that information (the information about the photon's polarization that causes the interference to disappear)? That's they key question, I think.

In their paper, Walborn et. al. write:

"A 100% effective which-path marker is prepared such that |M1〉is orthogonal to |M2〉. In this case, a measurement of M reduces |Ψ〉to the appropriate state for the passage of the particle through path 1 or 2. However, the disappearance of the interference pattern is not dependent on such a measurement. The which-path marker’s presence alone is sufficient to make the two terms on the right-hand side of equation (2) orthogonal and thus there will be no cross terms in |〈r|Ψ〉|2. Therefore, it is enough that the which-path information is available to destroy interference."

The last sentence (which I highlighted in boldface) is the closest they come to any sort of interpretation. But here is the question: what does it mean that the WPI is available? Available to whom?

I have to admit that I was wrong when I said that traditional interpretations of QM cannot account for the result of this experiment. I realize now that the old Copenhagen interpretation (which I think is still the best one) is perfectly capable of dealing with this. The two detectors have to be treated as a single measurement apparatus. Therefore, the interaction of the photons with the measurement apparatus including the WP marker makes the wave function collapse, etc. The quantum eraser destroys the entanglement between the two photons, thus erasing the WPI and bringing back the interference.

According to Copenhagen, measurements are carried out by the measurement apparatus. There is no need to include a conscious agent. This is fine, but the question remains: what is a measurement? What does it mean, to do a measurement? Copenhagen doesn't have a clear answer.

I would like to know if the Many-Worlds interpretation can also "explain" this experiment. I guess the Many-Worlds move would be to say that decoherence accounts for the disappearence of interference. I don't think that would really work as an explanation, but it doesn't matter. The Many-Worlds "theory" is too preposterous to be taken seriously, in my humble opinion.

The point is: I was wrong in saying that no other interpretation is consistent with this experiment. But I think I'm right in saying that no other idealist or consciousness-based interpretation is consistent with this experiment. I'm not aware of any other interpretation of QM that includes consciousness as a factor and can account for these experimental results.

For me the most exciting part is that my interpretation, unlike all other interpretations of QM, is not an ad-hoc theory. I wasn't aware of this experiment. And I'm not familiar with the mathematical equations (taught in QM 101, no doubt) that predict these results. My interpretation is not based in experimental data or maths, but in a basic philosophical notion: idealism.

My goal is to formulate an interpretation of QM that is consistent with idealism. We all feel intuitively that QM somehow supports idealism. But I have never come across an actual interpretation of QM that tries to make sense of quantum phenomena from the point of view of idealism.

My interpretation is just a very rough sketch so far, but I think it could include the seed of something bigger. It solves the measurement problem, giving a very clear explanation of what observation and measurement mean. And I think it provides a framework for further theoretical and experimental developments. I even think this simple idea could be used to finally integrate QM and relativity. (It's only a hunch, but I have some ideas of how to do it.)

Anyway. I'm not going to stop doing this, I'm having too much fun with it!

Your comments and criticisms are always very helpful, Aditya. Thank you again!

On Wednesday, 15 April 2020 20:34:32 UTC+2, Aditya Prasad wrote:

[Aditya Prasad]

On Monday, April 20, 2020 at 2:50:17 PM UTC-5, Adur Alkain wrote:

Aditya,

I've read the tutorial you sent me and I've found that the experimental setup is very different to the setup of the experiment I'm talking about. Even so, reading it through made me rethink some of my ideas, which was helpful. Thanks!

(However, I must say the tutorial is not aimed at first-semester students, but at upper-level students (including Ph.D. students). The results of the paper show that many upper-level students in quantum mechanics struggle with these concepts. In other words, this is not QM 101 day 1, like you said.)

Indeed, this isn't the simplest tutorial out there. It goes beyond your setup, all the way to the eraser punchline. I thought that might be useful.

Perhaps "day one" was an exaggeration, but if you ask any beginning quantum computing student to tell you what happens when you measure one qubit that's entangled with another, they will be able to tell you: there's no interference.

It has been known for a long time that which-path information destroys interference. The question "available to whom" applies just as well to a regular detector at the slits as it does to a polarizer-as-detector. There's nothing new in this experiment.

I can't encourage you enough to actually learn the basics of QM before believing you've added something new. The math is absolutely critical to understanding subtle flaws in these kinds of arguments. There are very obvious problems with your explanation that I'm apparently incapable of communicating to you, and I don't mean that as any kind of insult. I wish you well on your quest.