Saturday, March 27, 2021

Is the universe REALLY a hologram?

[This is a transcript of the video embedded below.]


Do we live in a hologram? String theorists think we do. But what does that mean? How do holograms work, and how are they related to string theory? That’s what we will talk about today.

In science fiction movies, holograms are 3-dimensional, moving images. But in reality, the technology for motion holograms hasn’t caught up with imagination. At least so far, holograms are still mostly stills.

The holograms you are most likely to have seen are not like those in the movies. They are not a projection of an object into thin air – however that’s supposed to work. Instead, you normally see a three-dimensional object above or behind a flat film. Small holograms are today frequently used as a security measure on credit cards, ID cards, or even banknotes, because they are easy to see, but difficult to copy.

If you hold such a hologram into light, you will see that it seems to have depth, even though it is printed on a flat surface. That’s because in photographs, we are limited to the one perspective from which the picture was taken, and that’s why they look flat. But you can tilt holograms and observe them from different angles, as if you were examining a three-dimensional object.

Now, these holograms on your credit cards, or the ones that you find on postcards or book covers, are not “real” holograms. They are actually composed of several 2-dimensional images and depending on the angle, a different image is reflected back at you, which creates the illusion of a 3-dimensional image.

In a real hologram the image is indeed 3-dimensional. But the market for real holograms is small, so they are hard to come by, even though the technology to produce them is straightforward. A real hologram looks like this.

Real holograms actually encode a three-dimensional object on a flat surface. How is this possible? The answer is interference.

Light is electromagnetic waves, so it has crests and troughs. And a key property of waves is that they can be overlaid and then amplify or wash out each other. If two waves are overlaid so that two crests meet at the same point, that will amplify the wave. This is called constructive interference. But if a crest meets a trough, the waves will cancel. This is called destructive interference.

Now, we don’t normally see light cancelling out other light. That’s because to see interference one needs very regular light, where the crests and troughs are neatly aligned. Sunlight or LED light doesn’t have that property. But laser light has it, and so laser light can be interfered.

And this interference can be used to create holograms. For this, one first splits a laser beam in two with a semi-transparent glass or crystal, called a beam-splitter, and makes each beam broader with a diverging lens. Then, one aims one half of the beam at the object that one wants to take an image of. The light will not just bounce off the object in one single direction, but it will scatter in many different directions. And the scattered light contains information about the surface of the object. Then, one recombines the two beams and captures the intensity of the light with a light-sensitive screen.

Now, remember that laser light can interfere. This means, how large the intensity on the screen is, depends on whether the interference was destructive or constructive, which again depends on just where the object was located and how it was shaped. So, the screen has captured the full three-dimensional information. To view the hologram, one develops the film and shines light onto it at the same wavelength as the image was taken, which reproduces the 3-dimensional image.

To understand this in a little more detail, let us look at the image on the screen if one uses a very small point-like object. It looks like this. It’s called a zone plate. The intensity and width of the rings depends on the distance between the point-like object and the screen, and the wavelength of the light. But any object is basically a large number of point-like objects, so the interference image on the screen is generally an overlap of many different zone plates with these concentric rings.

The amazing thing about holograms is now this. Every part of the screen receives information from every part of the object. As a consequence, if you develop the image to get the hologram, you can take it apart into pieces, and each piece will still recreate the whole 3-dimensional object. To understand better how this works, look again at the zone plate, the one of a single point-like object. If you have only a small piece that contains part of the rings, you can infer the rest of the pattern, though it gets a little more difficult. If you have a general plate that overlaps many zone plates, this is still possible. So, at least mathematically, you can reconstruct the entire object from any part of the holographic plate. In reality, the quality of the image will go down.

So, now that you know how real holograms work, let us talk about the idea that the universe is a hologram.

When string theorists claim that our universe is a hologram, they mean the following. Our universe has a positive cosmological constant. But mathematically, universes with a negative cosmological constant are much easier to work with. So, this is what string theorists usually look at. These universes with a negative cosmological constant are called Anti-de Sitter spaces and into these Anti-de Sitter things they put supersymmetric matter. To best current knowledge, our universe is not Anti De Sitter and matter is not supersymmetric, but mathematically, you can certain do that.

For some specific examples, it has then been shown that the gravitational theory in such an Anti de Sitter universe is mathematically equivalent to a different theory on the conformal boundary of that universe. What the heck is the conformal boundary of the universe? Well, our actual universe doesn’t have one. But these Anti-De Sitter spaces do. Just exactly how they are defined isn’t all that important. You only need to know that this conformal boundary has one dimension of space less than the space it is a boundary of.

So, you have an equivalence between two theories in a different number of dimensions of space. A gravitational theory in this anti-De Sitter space with the weird matter. And a different theory on the boundary of that space, which also has weird matter. And just so you have heard the name: The theory on the boundary is what’s called a conformal field theory, and the whole thing is known as the Anti-de Sitter – Conformal Field Theory duality, or AdS/CFT for short.

This duality has been mathematically confirmed for some specific cases, but pretty much all string theorists seem to believe it is much more generally valid. In fact, a lot of them seem believe it is valid even in our universe, even though there is no evidence for that, neither observational nor mathematical. In this most general form, the duality is simply called the “holographic principle”.

If the holographic principle was correct, it would mean that the information about any volume in our universe is encoded on the boundary of that volume. That’s remarkable because naively, you’d think the amount of information you can store in a volume of space grows much faster than the information you can store on the surface. But according to the holographic principle, the information you can put into the volume somehow isn’t what we think it is. It must have more correlations than we realize. So it the holographic principle was true, that would be very interesting. I talked about this in more detail in an earlier video.

The holographic principle indeed sounds a little like optical holography. In both cases one encodes information about a volume on a surface with one dimension less. But if you look a little more closely, there are two important differences between the holographic principle and real holography:

First, an optical hologram is not actually captured in two dimensions; the holographic film has a thickness, and you need that thickness to store the information. The holographic principle, on the other hand, is a mathematical abstraction, and the encoding really occurs in one dimension less.

Second, as we saw earlier, in a real hologram, each part contains information about the whole object. But in the mathematics of the holographic universe, this is not the case. If you take only a piece of the boundary, that will not allow you to reproduce what goes on in the entire universe.

This is why I don’t think referring to this idea from string theory as holography is a good analogy. But now you know just exactly what the two types of holography do, and do not have in common.

171 comments:

  1. I din't think it was wise of string theorists to call it holography either, it kind of leads to the wrong intuition, at least for me, as the real world whicj isn't really there, and is a kind of hologram.


    I was reading about it just this morning and it seems to have some some relationship with how black hole entropy is related to not volume but the surface area of the event horizon. This to me seems plausible simply because from the perspective of a far off observor matter falling into a black hole looks like it gets increasingly squeezed into a very thin shell and so the entropy is squeezed into from volume into area.

    I think this also connected to how QCD is given by coincident D-branes and these are the UV completions of black branes, which are the higher version of a black hole singularity in super-gravity theories.

    It goes back to an old idea of Einstein, Infeld & Hoffman of treating elementary particles as singularities. Actually, Brandom Carter did a calculation in 1968, that showed a black hole with the same mass, charge and angular momentum as an electron also has the same magnetic moment as an electron. Which is interesting, because typically we need QED, to get the right gyromagnetic ratio of 2 correct. However, he also showed it to be a naked singularity ...

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  2. From a metaphysical perspective, regardless of whether or not the universe is holographically-based similar to that of an optical hologram, the one parallel that some of us idealists like to suggest is that just as a *laser hologram* requires the conjoined relationship between a laser and that of the information encoded on a photographic plate (working together in tandem) in order to explicate three-dimensional phenomena from the patterns of information,...

    ...likewise, the universe requires the conjoined relationship between consciousness and that of the quantum underpinning of reality (again, working together in tandem) in order to explicate three-dimensional phenomena from the patterns of quantum information.

    Now I realize that this sort of speculation is not well received in this forum, nevertheless, I furthermore suggest...

    (again, from the perspective of idealism and the claim that all of reality is "mind-based")

    ...is that whatever the mechanism is that transforms patterns of information within our own minds into the three-dimensional features of our dreams when we "shine" our consciousness inward, is the same mechanism that transforms the patterns of information of the quantum into the three-dimensional features of the universe when we "shine" our consciousness outward.
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    1. I'm actually quite fond of philosophical idealism, simply because so many physicists are, well, physicalists. It's useful to have a wider idea of the options we have to think about the nature of reality.

      I don't want to sound as though I'm beimg a contrarian for the sake of being a contrarian: I seem to be heading towards philosophical Platonism in my later years.

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    2. That's an interesting idea about dreams and consciousness. I am interested in how dreams interact with waking reality, I think they can be more than brain-noise.

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    3. Mozibur5:39 PM, March 27, 2021

      " so many physicists are, well, physicalists."
      100% of the *evidence* is "physicalist", that's the point. If you know of anything that is demonstrably not ultimately physical you should publish the evidence and collect your Nobel Prize. Not all physicists are "physicalist", some are fantasists like those who think there is evidence of a multiverse or universe fine-tuning.

      "It's useful to have a wider idea of the options we have to think about the nature of reality. "
      Of course, you can't analyse human morals or society in terms of the Schrodinger equation, but everything is ultimately physical as far as is known. There is no other way to think of the foundations of reality except as Physics (up to the precision of measurement, and based on all observations thus far).

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    4. Keith D. Gill11:16 AM, March 27, 2021

      "the claim that all of reality is "mind-based")"

      Right, so there was no reality before brains evolved. Another genius point, Keith. *Your* "reality" is mind-based - it's called mental delusion.


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    5. Hi Keith , That Mind-Reality harmony I don't think works; some of us are badly thought, now well, to think about a Melon, first there must be a Melon

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    6. Mozibur wrote:
      "I'm actually quite fond of philosophical idealism, simply because so many physicists are, well, physicalists. It's useful to have a wider idea of the options we have to think about the nature of reality."

      Yes, Mozibur, especially when considering the fact that the "measurement problem" and the question of what it is that instigates the "collapse" of the wavefunction, is yet to be resolved.

      To which I speculatively suggest that the holographic model provides a better answer to the "collapse" mystery. And that's because it offers-up the possibility that consciousness...

      (being metaphorically similar to the laser in the laser hologram)

      ...simply interacts with the quantum in such a way that (as mentioned earlier) allows it to explicate the "phenomenal" (3-D) features of the universe from their "noumenal-like" fields of information.

      In other words, it's not so much a situation of "collapsing" waves, but more of a process wherein (loosely speaking) "software-like" fields of information are decoded* by consciousness to reveal that which the fields encode.

      *(Again, similar to the way our consciousness decodes the information that underpins the (holographic-like) three-dimensional features of our dreams).
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    7. C Thompson wrote:
      "That's an interesting idea about dreams and consciousness. I am interested in how dreams interact with waking reality, I think they can be more than brain-noise."

      Hi, C Thompson, what makes you think that our dreams have anything to do with our waking reality?

      (Warning, I'm about to introduce more unwelcome speculation...:))

      Yes, dreams are way more than just "brain-noise." For if there exists the possibility that our minds (souls/consciousnesses) might survive the death of the physical body...

      ...then I suggest that our dreams...

      (which display three-dimensional phenomena that seem to be "almost as real" as the reality we experience outward)

      ...represent a preliminary glimpse (or preview) of the ultimate potential of our minds in that higher context of reality.
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    8. Luis wrote:
      "...That Mind-Reality harmony I don't think works; some of us are badly thought, now well, to think about a Melon, first there must be a Melon"

      Hello, Luis. I'm not sure of what you're getting at. Would you please clarify your point.
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    9. If there is "mind stuff" and it is absolutely unlike "matter stuff" there would be no way for them to interact. An old problem with dualism. Neutral monism tried to solve that problem (I think) by supposing that there is one kind of "stuff" and it is both mind-like and matter-like. Echoes of Leibnitz windowless monads? What a mess. Maybe it IS better to shut up and calculate.

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    10. Rick Lubbock wrote:
      "If there is "mind stuff" and it is absolutely unlike "matter stuff" there would be no way for them to interact."

      I wouldn't be so sure about that, Rick.

      I mean, isn't mind stuff interacting with matter stuff every time we decide to raise an arm or clinch our fingers into a fist?

      Now just take that limited control that our mental wills have over the holographic-like fabric of matter and witness how we have total control over the holographic-like fabric of our minds.
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    11. Just for the record, and this has been discussed at this site previously, experiments have shown that consciousness is not a necessary ingredient in quantum effects. Serious people should absorb that evidence and move on.

      Yes there are and will always be gaps in our understanding. That is not valid evidence that magic is hiding in those gaps. Everything we do understand has physical mechanisms. Therefore the winning way to bet is that unknown physical mechanisms are in the gaps.

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    12. Hi Keith ,My point of view is that our consciousness cannot interfere with the quantum world or harmonize with it because our consciousness interacts with the reproduction of reality in our brain, not with reality itself, that is what the rest of the body does; that reproduction, the dreams, the symbols, the good or bad theories and even our confusions are made of the same, neural processes; The good thing about this is that you can have wrong theories in your brain and it does not explode for that reason, it continues to work perfectly; our consciousness has been shaped by reality; but not at the quantum level, so having absurd and contradictory interpretations of quantum physics cannot be taken as facts. Always think that your consciousness operates with a reality reproduced in your brain, to that reproduction your consciousness has been adding a theoretical assembly; You can do it because they are made of the same, neural functions.

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    13. The reason it is not well-received is that it relies on spooky "theory" of consciousness that has zero evidence base other than your beliefs. That's a religion, not science.

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    14. Keith D. Gill10:29 AM, March 28, 2021

      I told you not to sniff the glue, Keith.

      "For if there exists the possibility that our minds (souls/consciousnesses) might survive the death of the physical body..."
      The reported functions of the "mind" have been shown to correlate precisely with observed functioning of the brain: brain damage to particular parts of the brain correlate exactly with loss of certain mind functions. So what do you think happens if the brain stops functioning altogether - if all the brain is damaged for good? One might conclude that all the functionality of the mind is also lost for good.

      By the standards of commonsense it is a fact that the mind is emergent from the brain; in the highest criminal court in the land, the brain would be found guilty of producing the mind. It is only by the exacting standards of natural science that an epsilon of doubt remains.
      Meanwhile, your speculation that the mind might survive death meets only the non-standard of la-la land insanity using Alice in Wonderland as its main text. You might as well tell us you suspect you are the reincarnation of Napoleon.

      "...then I suggest that our dreams....represent a preliminary glimpse (or preview) of the ultimate potential of our minds in that higher context of reality."
      And you write this garbage on a computer designed based on the carefully observed quantum behaviour of the electron, in a house powered and made comfortable by technology running on the principles of electromagnetism, and are only still alive to have your dreams because of advances in the science behind sanitation, agriculture and medicine, etc.

      Maybe you would prefer it if these advances hadn't happened and you more quickly got to test your theory??

      You are an evolved ape and your mental delusions are explained in psychiatry texts. These are the facts.

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    15. @Keith D Gill - definitely.
      I've had an interest in science from a young age but spent several years cultivating an interest in 'woo' concepts like telepathy, clairvoyance and dream meanings and dream predictions, so I bring a bit of that with me. I think dreams do help us integrate our waking minds but without the fetters of consciousness. If developed, can give us tools for insights and information about the external world our waking minds don't have such easy access to. My dreams are often a weird scramble of things but when I was more conscientious about cultivating them, I had messages about my future, and my current circumstances. It took focused effort though.
      There are some instances of major scientific and industrial breakthroughs arrived at via dreams.
      If everything was set out at the Big Bang, perhaps some people can access that information from an earlier part of it.
      I know that I'm running counter to established science here so nobody needs to call me out on that. :)

      @ Mozibur
      I'm pretty sure I'm the worst philosophical/woo thinker here. It's possible to be philosophical and understand science, I think, as long as one prioritises scientific rigour.

      @Rick Lubbock
      Probably, but where's the fun in that?

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    16. JimV wrote:
      "Just for the record, and this has been discussed at this site previously, experiments have shown that consciousness is not a necessary ingredient in quantum effects."

      Hi, JimV.  Are you implying that the "measurement problem" has been resolved?

      In other words, have any of the experiments given a clear and irrefutable answer as to what it is that causes the collapse of the wavefunction?
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    17. C Thompson12:58 AM, March 29, 2021

      "I had messages about my future,"

      No, you didn't.

      "There are some instances of major scientific and industrial breakthroughs arrived at via dreams."
      Maybe brains continue working subconsciously on problems people have been working on consciously. I wouldn't describe that as "major scientific advances arriving via dreams", though. The knowledge gained over years of training needs to be there in the first place,

      "If everything was set out at the Big Bang, perhaps some people can access that information from an earlier part of it."

      And maybe not.

      "I know that I'm running counter to established science here so nobody needs to call me out on that. :)"
      You are running counter to sanity. You claimed you wanted to learn more science. That involves accepting being called out when talking nonsense. Evidence is all that counts. Feelings count for nowt in Physics.

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    18. Jim Birch wrote:
      "The reason it is not well-received is that it relies on spooky "theory" of consciousness that has zero evidence base other than your beliefs. That's a religion, not science."

      We are participating in a blog thread titled:

      "Is the universe REALLY a hologram?"

      It is a thread offered-up by a world renowned theoretical physicist in which we are discussing the "spooky" possibility that the "solid-appearing" features of the universe might be an "illusion" that, in essence, is a three-dimensional "projection" from a two-dimensional plane of information. All of which is based on a theory that does not seem to offer any explanation as to how that two-dimensional plane of information is transformed into three-dimensional phenomena.

      So unless you can explain exactly what it is that (in Kantian parlance) converts "noumena" into "phenomena," then I suggest that we leave all options (including consciousness) on the table.
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    19. RE: "Are you implying that the "measurement problem" has been resolved?"

      Somewhat, with some remaining fine points. When there is an exchange of relevant information (e.g., charge polarity between charged particles via photon emission and absorption) between particles, quantum wave-like behavior of the particles resolves into discrete behavior. None of the participants involved need to exhibit any capability of what we consider conscious behavior. People still disagree somewhat on how to model that mathematically, but them's the facts. As far as I know.

      Consciousness itself does not seem like big mystery to me, given what we know of the universe's properties. It is a mystery in the same sense as "why are there electrons?", but seems predictable to me given the Standard Model and what we know of neuroscience. I see it as roughly analogous to the operating system of a computer, which receives external inputs from the environment, uses unmonitored internal routines to process them, then makes relevant outputs back to the environment. Its requirements include computational capability (e.g., neurons), which includes memory and logic, ability to sense external inputs, and ability to produce external outputs.

      As I pointed out however, suppose it was 1821 instead of 2021 and we did not know all those things. We still knew that everything we could make sense of was governed by physical laws, and if induction is not the way to bet we are screwed anyway, so we should expect the unknown to resolve itself in the same sensible way.

      Contra-induction, as a fellow student who had taken a philosophy course once told me, is self-justified in the following way: since it has never worked before, it is bound to work this time. It sounds silly, but in my observation some people do think that way, at least occasionally.

      (This blog could probably use a Garbage Forum where extreme off-topic stuff such as this comment could be forwarded. A wiser, more considerate person than myself would not have responded.)

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    20. JimV wrote:
      "...When there is an exchange of relevant information (e.g., charge polarity between charged particles via photon emission and absorption) between particles, quantum wave-like behavior of the particles resolves into discrete behavior..."

      You seem to be alluding to "decoherence."

      If so, then let me quote for you something that Sabine said to me in the "Schrödinger’s Cat – Still Not Dead" thread after I pointed out to her that (allegedly) decoherence does not collapse the wavefunction:

      Sabine wrote:
      "...It is correct that decoherence does not collapse the wave-function. I didn't say it does..."

      Therefore, if you are indeed referring to decoherence, then the "measurement problem" (or the question of what it is that instigates the collapse of the wavefunction) is still not resolved by what you are suggesting.

      (Btw, a "wiser" and more "CONSIDERATE" person would not resort to cheap insults when conversing with others.)
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    21. @Steven Evans
      I absolutely agree with you that dream-answers are born of knowledge and training. I'm not going to get the Theory of Everything pop up in my sleep whilst I struggle to understand the underpinnings.
      I'm completely sane. I'm able to hold several seperate fields of ideas in my mind at once and be aware that they contradict each other. I'm also aware that Dr. Hossenfelder and others here might think I'm wrong.
      There are those who claim 'science doesn't understand everything' to justify the woo they spout, but to some degree that's true both in my experience and other accounts I believe to be given in good faith. The dreams I was referring to were experienced personally as revealing their meaning after I dreamt them. It could've been assigning meaning after the fact, but to me they meant something the second I woke up.
      You're welcome to disbelieve me but not to question my mental status, thanks.

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    22. C Thompson4:22 AM, March 30, 2021

      "There are those who claim 'science doesn't understand everything' to justify the woo they spout, but to some degree that's true"

      There is no evidence of clairvoyance, telepathy or any of the other "woo" you mentioned. These have all been tested and no supporting evidence found.

      "It could've been assigning meaning after the fact,"

      Do you reckon?

      "but to me they meant something the second I woke up."

      ??? Dreams do not contain information about the future except by chance. How old are you, 6?

      "You're welcome to disbelieve me but not to question my mental status, thanks."
      I don't think you are lying, but you are completely insane. You cannot distinguish at all between your imaginings and reality, and you think you can interpret your imaginings in any way you want.

      Like Keith, your only interest in natural science is to find out where you think you can hide away your whacko ideas from refutation. But yours and Keith's ideas are meaningless, evidence-free nonsense to begin with.

      Like suggesting superdeterminism might mean people can access this superdetermined physical info and determine their future..

      This is drivel of the very first order.

      You need to start by getting a marble, a metre rule and a stopwatch and measuring gravity. You'll find that, up to the precision of your measurements, it's a fixed number. Not the number you dreamed last night. Not your favourite number. Not the date of your birthday. This is what we call "reality". Welcome.

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    23. Keith D. Gill1:49 PM, March 29, 2021

      "a "wiser" and more "CONSIDERATE" person would not resort to cheap insults when conversing with others."

      A wiser and more considerate person would try to learn something and stop making the same disingenuous, evidence-free claims. Let's not pretend you are trying to do anything except try to rationalise some crazy ideas which you are desperate to be true. Why you want the universe to be other than it is, I cannot begin to guess. It's utterly bizarre behaviour.

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    24. Mr. Gill, As far as what I know, what I told you was correct. If you have a technical reference which explains it differently I will check it. I did not use the terms wave-function or collapse or decoherence because those terms have to do with the mathematical models of QM and have different connotations for different people (e.g., there is no "collapse" in some models, so referring to as something to be explained makes no sense in those models), and I prefer to describe physically what happens. If you think there is a different process at work you are free to publish it, have it confirmed by experiment and claim your prizes.

      However, despite different people having different semantics, everyone who works with QM gets the same results, and those results agree with experiments. Despite this, they argue about models and semantics because people have different preferences. Dr. Scott Aaronson recently described his QM understanding as a "Zen" process, in which he knows how to make the calculations and doesn't worry about the interpretation.

      If we didn't know how to make calculations which agree with experiments, that would be a legitimate gap for your god-of-the-gaps argument (if such arguments were legitimate to begin with). I don't think people arguing about interpretations is.

      Note also that someone who did not say "decoherence causes collapse" will disagree with someone who said she did, either because she has a different model, has not picked a model, or has picked that model but did not say so in her post.

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    25. @Steven Evans I'm 40.
      I'm here to have a pleasant time talking with people, not have a pathetic troll like you shit over the comments.
      Why do you care whether what anyone says agrees with your sensibilities, since this isn't your blog?
      Please go and glue yourself to a bus or such, for science.

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    26. Steven,

      Ah, another complaint about you. Look, if you can't stop insulting people I'll no longer approve your comments. There'll be no sorting and sifting - I don't have time for that. You're either in or out.

      C Thompson,

      Sorry about that. He's verbally abusive but most of it seems to be born out of frustration. As they say, dogs that bark don't bite, though having been literally bitten by several barking dogs, I suppose one shouldn't pay too much attention to that saying.

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    27. Dr. Feynman is quoted in James Gleick's "Genius" as saying something interesting about dreams. Paraphrasing from memory, Dr. Feynman once had a dream that his mother had just died, and woke up very agitated, and called her on the telephone (from California to New York) only to find that she was alive (and lived for many more years). It then occurred to him that perhaps many people have similar dreams, and if so, some of them are bound to be true by random happenstance.

      That of course is always the dilemma of any scientific investigation, to separate true cause and effect from random correlation, and why anecdotes are not accepted as valid data unless they can be repeated either in controlled, blinded experiments, or if that is not feasible, by statistical analysis of a large number of natural occurrences. In the latter case, however, it has turned out that motivated reasoners can, consciously or unconsciously, misuse statistical analysis to get the result they want. Therefore, peer review by disinterested experts is also necessary.

      Physics in particular uses a very high level of statistical certainty (5 sigma) as part of its scientific standard.

      In the same vein, Dr. Feynman is also quoted as saying something like, "Science requires not fooling yourself, and you are the easiest person for yourself to fool." (Since you would like to believe you have made an important discovery.)

      (I have managed to fool myself quite a few times.)

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    28. JImV wrote:
      "Mr. Gill, As far as what I know, what I told you was correct."

      I never said that you were wrong.

      JimV wrote:
      "...I did not use the terms wave-function or collapse or decoherence..."

      No, you didn't, but when I asked you the following:

      "Are you implying that the "measurement problem" has been resolved?"

      ...you responded with this:

      "...Somewhat..."

      To which you then provided a perfectly reasonable and cogent explanation that, to my mind, seemed to be a direct reference to recent theories regarding "decoherence."

      However, due to the fact that according to Wiki, decoherence...

      "...does not solve the measurement problem, as the founders of decoherence theory admit in their seminal papers....Decoherence does not generate actual wave-function collapse...."

      ...then you implying that your explanation "...somewhat..." solves the measurement problem, makes no sense.

      JimV wrote:
      "...Note also that someone who did not say "decoherence causes collapse" will disagree with someone who said she did,..."

      Jim, I am not questioning the veracity of your statements, I am simply suggesting that you stay mindful of their "unspoken" implications. Because even though it is true that you did not use the terms "wave-function" or "collapse" or "decoherence," they (especially decoherence) were certainly implicit in your explanation of how an exchange of relevant information causes particles to resolve into discrete behavior.

      All of which begs the question: what exactly would that "discrete behavior" be if there is no collapse of the wavefunction, which suggests that the particles are still in a state of superposition?

      And just to add a final point to this, what we are discussing is not off topic, for it is indeed relevant to the search for an answer to, again, the measurement problem, of which the "Holographic Model" provides an interesting alternative to that of "collapsing" waves of some sort of nebulous informational essence.

      And yes, there are other models in which it is suggested that no such collapse occurs; the most famous being the "Many Worlds Interpretation of Quantum Mechanics."

      However, don't even get me started on how utterly ridiculous that one is.
      _______

      Delete
    29. @Steven Evans:

      The point is that the mind hasn't yet bern reduced to physical phenomena. Physicalists - of whom yiu appear to be one of - **assume** this. It by no means has been proven.

      If you believe that you have a proof that mind is physical, well publish the proof and reap the awards. Though I expect we'll be waiting for a long time.

      As for me, I believe that the mind is not physical phenomena qua physical, in the sense explainable by physics. My proof - I don't have one. But any number of physicists have tried and failed. The basic problem is that of experience, what philosophers call qualia or quiddity. The thisness and actual being of beings.

      If you don't agree - well, you're free to disagree.

      Delete
    30. Mr. Gill, thanks for your reply. Having read it I am not sure what we have left to argue about.

      You say my physical explanation was "a perfectly reasonable and cogent explanation" which is a generous concession; if so then it being "somewhat" a model for what some refer to as "collapsing the wavefunction" doesn't seem like much of a stretch, and I did also say "with some fine points remaining". You mentioned the MWI; I have read Dr. Sean Carroll, a MWI advocate, explain what seems to be happening on the QM level with much the same terms I used; also Dr. Scott Aaronson, who does not recommend any particular interpretation. So yes, what I described, in my mind, largely explains what some call wavefunction collapse, but a) I know I am not aware of all the fine details of ongoing arguments; and b) I do not want to endorse "wave function collapse" specifically because not all QM experts use that terminology.

      While by no means an expert, I am not aware of any experiments which run counter to my (previous) description, and am aware of some which strongly suggest it. (In particular the two-slit experiment using C60 molecules at a range of temperatures.)

      Delete
    31. @Steven Evans:

      The point of mind based realities is that they're nothing directly to do with our own minds. Philosophers explore that option because the matter-mind divide is difficult to cross from the matter side. Also, it has a long tradition in philosophy, both in the East, say from Abhinavagupta's Kashmiri Shavism and also Vedanta, and in the West, as in Plato's Forms and Ideas.

      Please don't display your ignorance so freely: I know physicists as a breed don't like philosophy as a rule (they seem to have forgotten that physics was born in philosophy, for example the peripatetic school, ie the school of Aristotle, already had the vectorial rule for the addition of velocities/forces - and this over two millenia ago - amd no doubt this informed Newton and his earlier predecessors in the modern renaissance of science in the West), but you really take the biscuit.

      Delete
    32. C Thompson6:37 AM, March 31, 2021

      You are here to try to push the idea that the supernatural, like getting messages from the future in your dreams, is not ruled out by natural science. Unfortunately for you, there are facts in the world, and receiving messages from the future in dreams isn't one of them.

      Sabine Hossenfelder9:20 AM, March 31, 2021

      "Look, if you can't stop insulting people I'll no longer approve your comments. "

      Fair enough. It's your blog.

      Delete
    33. C Thompson4:22 AM, March 30, 2021

      "I'm able to hold several seperate fields of ideas in my mind at once and be aware that they contradict each other."

      The field of knowledge relevant to your claims about dreams and telepathy is psychology. All these supernatural claims have been checked by experiment and found to be unsupported. There is no evidence to support your claims.

      "I'm also aware that Dr. Hossenfelder and others here might think I'm wrong."
      It is the evidence that states that you are wrong. There is no evidence for your claims either in natural science nor in any other field. Any careful check of what you claim has led to a negative result.

      The question you need to ask yourself, then, the question of the age of QAnon, is why you continue to believe in things that are shown to have no supporting evidence when carefully checked.

      Delete
    34. Keith D. Gill11:07 AM, March 31, 2021

      "However, don't even get me started on how utterly ridiculous that one is."

      MWI is a vague speculation with no physical process posited to explain the branching, so might be considered currently unscientific. But as a mathematical model it is coherent. It is not clear what you might mean by claiming it is "utterly ridiculous".

      Claiming consciousness is a necessary part of the description of the quantum cannot be concluded from the evidence, and faces the problem that 13.7bya the observable universe was a hot, dense, tiny quark-gluon plasma behaving according to quantum physics.

      But consciousness has only ever been subjectively reported by biological systems with complex brains. No plasma has ever claimed to be conscious. The sun doesn't smile, for example.

      Delete
    35. Mozibur3:30 PM, March 31, 2021

      "The point is that the mind hasn't yet bern reduced to physical phenomena."
      Well, not to the standards of science, but empirical evidence shows a detailed correlation between the mind is emergent from the brain. And no-one has come up with any other reasonable explanation of the mind.

      "Physicalists - of whom yiu appear to be one of - **assume** this. It by no means has been proven."

      This is incorrect. First, "physicalism" is just a slur. All the evidence suggests that all phenomena are ultimately physical. It's not proven, and no-one is assuming it, but it is the case as far as is currently known, and there are no known exceptions.

      "If you believe that you have a proof that mind is physical, well publish the proof and reap the awards. Though I expect we'll be waiting for a long time."

      You have misunderstood the situation. The situation is that all phenomena are ultimately physical as far as we know. There are no known exceptions. Not even one among all the quadrillions of observations. But, if you have evidence of a phenomenon which is demonstrably not ultimately physical, you should publish and we will cheer your receipt of the Nobel Prize.

      "As for me, I believe that the mind is not physical phenomena qua physical, in the sense explainable by physics. My proof - I don't have one. "

      So if you don't have any evidence of this, why would you believe it? That is irrational.

      "But any number of physicists have tried and failed. "

      Neuroscience's analysis of the brain is far, far from complete, thus this point is irrelevant.

      "The basic problem is that of experience, what philosophers call qualia or quiddity. The thisness and actual being of beings."

      Great. And now you just need to demonstrate how qualia and quiddity cannot emerge from a physical brain alone, and identify what else is involved. Good luck. Let me know when you're done, and show all your working.

      "If you don't agree - well, you're free to disagree. "

      You have provided no arguments or evidence to support your claims. It's not that I disagree with you, current evidence doesn't support your claims.

      I am therefore not "free to disagree", but as a rational being, or "bot" as some might say, I am bound to point out that you have no point.

      All you have told us is that you suspect the mind cannot be explained by the brain alone, but you provide no evidence to support your suspicion, you don't tell us what else is involved, and the analysis of the brain is far from complete so you are second-guessing the next several thousand years of neuroscientific research by claiming science can't find an answer. It's trivially not a tenable position.

      I think there are 2 points which will unmuddle your thinking:
      1) 13.7bya the universe was made of only quarks and gluons. It still is.
      2) Evolution explains how a complex brain arises from physics. These brains apparently come with minds.

      If you want to retell this tale starting from consciousness, good luck explaining all the empirical evidence!

      Delete
    36. @Steve Evans: I don't give a dry fart what you think.

      Delete
    37. C Thompson5:54 AM, April 01, 2021

      " I don't give a dry fart what you think."

      It's not what I think, it's what the evidence tells us. You are rejecting the scientific method in favour of wishful thinking.

      Delete
    38. @Dr. Hossenfelder: Thank you.
      The expression I'm familiar with is 'their bark is worse than their bite.' Yappy dogs are the likeliest biters, in my experience.
      Steven is being civil now though, which is good.
      Frustration is no reason for rudeness; you yourself disagree with whole sections of physics without, as far as I know, personally insulting anyone.
      I enjoy the discussions in the blog's comments sections that go off the beaten track.

      Delete
    39. We're are really getting far afield from the holographic subject of this post, but since "qualia" have been raised as possibly non physical phenomena, I would like to give a different perspective.

      First, what is "physical"? Is a magnetic field physical? Yes, physical is anything we can make some sort of measurement of and model with "physical laws" so as to make predictions of its behavior. Photons have no rest mass, but still are physical.

      Second, what are "qualia"? As I understand it, qualia are the sensations we get from sensory impressions of specific things via our nervous system and neurons. E.g., the color red is a frequency of photons which is detected by certain parts of our retinas and transmitted to our neurons by the optic nerves.

      Apparently some philosophers struggle with questions such as, "why does 'red' produce the distinct sensation it does in our brains?" To me, this is a similar question to, "Why are there photons?" Certain things exist in our universe, such as photons, electrons, and sensations produced by electrical and chemical signals in our brains. Science does not tell us why fundamental things exist, it detects them and categorizes them and models them with physical laws. But it would be stranger to me, if having evolved retinas and nerve cells and neurons, different sensory inputs did not produce different distinct sensations, or no sensations at all (in which case we would not have any way to know we had experienced them).

      So I consider "qualia" a physical fact of this universe, which evolution found (by random search) as a useful way to distinguish different experiences which can happen to complex organisms.

      Window 7 has some way to detect/experience the key-presses I am making to type this. Perhaps the philosophers should worry about that also.

      On another issue, I should have noted previously that although Dr. Aaronson does not completely believe in the Many Worlds Interpretation, he cites it as the best pedagogical version. That is, in teaching graduate students QM, his experience is that after he explains that interpretation, students who were confused on how to apply the mathematical processes of QM often then find the mathematical structure falling into place in their minds. (See his fairly recent blog post on the Zen of QM, and its comments, for details.)

      Delete
    40. JimV wrote:
      "...You say my physical explanation was "a perfectly reasonable and cogent explanation" which is a generous concession; if so then it being "somewhat" a model for what some refer to as "collapsing the wavefunction" doesn't seem like much of a stretch,..."

      It was reasonable in terms of being a cogent reference to decoherence, of which, again, according to Wiki, the very founders of the theory admit that it "does not solve the measurement problem"...."does not generate actual wavefunction collapse...".

      Therefore, if your explanation alludes to something that does not actually generate wavefunction collapse (not even "somewhat"), then you cannot claim that it is a model for something that does.

      So, yes, what you suggested is indeed a stretch.

      JimV wrote:
      "...While by no means an expert, I am not aware of any experiments which run counter to my (previous) description, and am aware of some which strongly suggest it. (In particular the two-slit experiment using C60 molecules at a range of temperatures.)..."

      The problem with your referencing the double-slit experiment is that you are not taking into account the question of what it is that collapses the wavefunction of the humans performing the experiment.

      In other words, because their bodies (and some say their minds) are made of the same waving substance as that of the experimental apparatuses, then what is it that keeps everything from simply spreading-out and merging into one giant wavefunction? - (Indeed, a situation which ultimately extends outward until ending in the theorized "Universal Wavefunction" that incorporates the entire universe.)

      In which case, it is "speculatively" suggested that because matter is composed of a waving substance that does not seem to possess any inherent means for transforming itself into positionally-fixed phenomena,...

      ...then because mind and consciousness seem to be so radically different from matter, then perhaps it is consciousness that does it.

      Now, of course, that too could be wrong, but that's the gist of the argument.

      And regardless of how strongly some humans will insist that it does, again, no, decoherence does not solve the problem.

      To understand where I am coming from, it is essential that you try to imagine the universe as being completely devoid of any form of life or consciousness whatsoever, and then ask yourself would the stars and planets still exist in their three-dimensional forms?...

      ...Or...

      ...Would they exist in a purely informationally-based context consisting of dynamically-moving, algorithmic processes exchanging information in a two-dimensional plane, as is suggested in the holographic model?

      As an idealist (right or wrong), I personally prefer the second option.
      _______

      Delete
    41. Mr. Gill, I have two-and-a-half counter arguments:

      A) None of the authorities who actually work with QM, that I know of, think consciousness has anything to do it. For example, Dr. Aaronson, who teaches graduate courses in QM and is heavily involved in the development of quantum computers, recently wrote these things:

      From Dr. Scott Aaronson's post "The Zen Anti-Interpretation of Quantum Mechanics":

      What is an “observer”? It’s exactly what modern decoherence theory says it is: a particular kind of quantum system that interacts with other quantum systems, becomes entangled with them, and thereby records information about them—reversibly in principle but irreversibly in practice.

      In the comments:

      ... thinking about the deSitter cosmology of our universe, and how, as Bousso and Susskind pointed out, it leads to decoherence that’s irreversible even in principle (e.g., from light escaping from the earth that will never bounce back) … this was a huge factor that led me down the Zen path over the last decade. For it alerted me to the possibility that, as diametrically opposed as the Everettians and Copenhagenists seem in their rhetoric, there is a sort of synthesis of their views possible. In that synthesis, we don’t give up on unitary evolution applying always and everywhere, but we also say that, without changing any known laws of physics, there is something fundamental and non-emergent that it means for a measurement to have definitely, irreversibly happened and yielded a definite outcome. Namely, it means that the records of that outcome are headed in all directions toward the deSitter horizon of the observable universe at the speed of light.

      Later in the comments:

      So to my mind, that leaves only two major categories of question still standing under the “interpretation of QM” umbrella:

      (1) Questions like “how can we understand ‘measurement’ as just a special case of unitary interaction among system, measuring apparatus, and environment?” This sort of question can actually be addressed with concrete physics calculations, and I think that to a large extent, decoherence theory has successfully done it over the past half-century.

      (2) Questions like Leo’s “If I open the box and see the cat is alive, should I be relieved, or remain sad because half of the cat’s measure has died?” ... I don’t dismiss them at all. But I feel like by this point, they might be subjects not only for philosophical arguments that endlessly go around in circles, but for poetry and fiction and other imaginative works.

      B) Various experimental attempts have been made to test for a conscious effect and none has been found. My favorite was not such an experiment but found what seems to me to be contra-evidence. As I mentioned, the two-slit experiment has been done using carbon-60 molecules (there is a paper on arxiv). It was done at very low temperature at first, then repeated at increasing temperatures. Interference patterns formed at the low temperatures, then gradually degraded and disappeared as the temperature of the molecules was increased. There was no difference in the consciousness of the experimenters. What differed was that at higher temperatures the molecules were more apt to radiate thermal photons and interact with the environment, exactly as described in my previous explanation, which you regard as cogent but unproven.

      (B+C)/2 I regard the success of neural net simulations of neurons in the ALphaGo series of computer programs as strong evidence that a deterministic computer of sufficient power and sensory equipment could think as well as any human. So thought to me is another physical process, consistent with the Standard Model of Physics. (I have mentioned reasons before why humans do not innately understand their own brains, and will spare repetition of them here.)

      Delete
    42. JimV wrote:
      "...Mr. Gill, I have two-and-a-half counter arguments:
      A) None of the authorities who actually work with QM, that I know of, think consciousness has anything to do it. For example....From Dr. Scott Aaronson's post "The Zen Anti-Interpretation of Quantum Mechanics":
      What is an “observer”? It’s exactly what modern decoherence theory says it is: a particular kind of quantum system that interacts with other quantum systems, becomes entangled with them, and thereby records information about them—reversibly in principle but irreversibly in practice..."

      Eventually, we're just going to have to end this by simply agreeing to disagree.

      However, allow me to make one last effort to clarify my argument.

      According to Wiki (bracketed interjection mine):

      "...In quantum mechanics, wave function collapse occurs when a wave function—initially in a superposition of several eigenstates—reduces to a single eigenstate due to interaction with the external world....Calculations of quantum decoherence show that when a quantum system interacts with the environment, the superpositions apparently reduce to mixtures of classical alternatives. Significantly, the combined wave function of the system and environment continue to obey the Schrödinger equation. <--- [that's the important point]. More importantly, this is not enough to explain wave function collapse, as decoherence does not reduce it to a single eigenstate..."

      In other words, even though the process of decoherence may indeed have the (alleged) effect of reducing the initial superposition into "mixtures" of classical alternatives,...

      ...nevertheless, the combined wavefunction of the system and its environment still exists in a state that Heisenberg would have referred to as being a ghostly raw "potentia," wherein the (still superpositioned) quantum essence has yet to be promoted into a context of something that we call "REAL" (such as a particle with an observable attribute of, say, position, or perhaps angular momentum, etc.).

      And therein lies the crux of the "Measurement Problem."

      Because if decoherence is not the catalyst that promotes (or explicates) particles from their ghostly (superpositioned/still obeying the Schrödinger equation) state, and into something that we call "real,"...

      ...and if you guys are determined not to allow the possibility that consciousness might be the catalyst,...

      ...then other than the "no-collapse" alternatives,...

      (which lead to phantasmagorical theories that suggest there exists infinite copies of ourselves residing in infinite copies of this universe)

      ...then what other options are there that could function as the mechanism that transforms waves of ghostly quantum "noumena" into the positionally-fixed, 3-D "phenomena" that we call reality?

      Name those options.

      (And whatever you do, I beg of you, please do not continue to insist that decoherence is the mechanism I am asking for, for I'm pretty sure I have already debunked that option.)  
      _______

      Delete
    43. Keith D. Gill11:01 AM, April 02, 2021

      You assume that the superpositioned state is not "real". But in the double slit experiment interference is observed, so you have to hold off from your claim. The interference is real.

      "Name those options."
      MWI - currently an unscientific speculation, but mathematically coherent
      Pilot-wave - ditto
      Superdeterministic models - Dr. H. claims hers and Tim Palmer's is partially scientific.

      There is no suggestion that wave collapse can only be caused by conscious beings.

      Delete
    44. @Steven Evans:

      Physicalism is not a slur. It's a philosophical position, check it out on the online Stanford Encyclopedia of Philosophy (SEP).

      That all phenomena is reducible to physical phenomena is the position that you and they take.

      Quiddity and qualia is the experience of actual phenomena. I along with many others maintain it has not been reduced to physics, and hence physicalism doesn't obtain.

      I don't expect you to agree. But whilst GR and QM are, by consensus, theories that physicists agree upon; physicalism, as far as mind goes, is not. And if you can't see that, well, I can't help you ...

      Delete
    45. @Steven Evans:

      I'd also suggest that the reason that you thought of physicalism as a 'slur', is that you indulge in a great deal of trolling, ie slurring. Please stop it, it is not conducive to civilised debate.

      Delete
    46. "Physicalism" is a term used by people who deny that everything we have ever observed is physical for those who point out that anything beyond "physicalism" is unscientific qua definition. Someone who uses this term as an accusation is someone who, in my experience, is unable to comprehend rational arguments.

      Delete
    47. Mozibur12:56 AM, April 03, 2021

      I haven't written that there is a complete theory of the mind describing how it's emergent from the brain. Though all the empirical evidence suggests we can make the commonsense conclusion that it is.

      You claim that you "suspect" that the mind isn't just emergent from a physical brain.

      So what is your evidence for this suspicion?

      At what point between 13.7bya and today did the universe suddenly become more than just physical?

      At what point in the development of a foetus does it become more than just physical? 3 weeks? 4 months? When does the woo enter the baby's head?

      At what point in the evolution of species on Earth did species appear that weren't wholly physical?

      Delete
    48. @Steven Evans:

      I've pointed out before that my rationale for thinking physicalism is untenable, is that qualia and quiddity has not been reduced to physics, despite many clever people trying. It's not called the hard problem of consciousness for nothing. Though you seem to think it is easy or simple.

      If you happen to disagree, well you have every right to do so. However, there are plenty who don't.

      All you're pointing out is that empirically speaking we've reduced everything else to physics.

      Except here, 'everything' is actually a microscopic part of what makes for human life: ethics, love, hate, morality, democracy and justice.

      It's in this sense, GUTs, a Grand Unified Theory (of Everything) and TOEs a Theory of Everything are completely lacking in descriptive power - as far as names go. They name particular species of unified theories.

      Huey Newton, a revolutionary black panther, and actually a founder of the Black Panther Party, and likely an athiest, given the association of marxism with athiesm had something useful to say about religion:

      "As far as I am concerned, when the all the questions are not answered, when the extraordinary is not explained, when the unknown is not known, then there is room for God because the unexplained and the unknown is God. We know nothing about God, really, and that is why as soon as the scientist develops or points out a new way of controlling a part of the universe, that aspect of the universe is not God. In other words, once when the thunder crashed it was thunder it was God Clapoing His Hands Together. As soon as we found out that thunder was not God, we said that God had othet attributes but not that one. In that way, we took for ourselves what was His before. But we still haven't answered all the questions, so He exists. And those scientists who say that they can answer all of them are being dishonest."

      "We know that operating within reality does not mean that we accept it; we're operating within it so that reality can be changed."

      Personally, even when I was an athiest, I didn't deny the possibility that the other side could be right (except for a mercifully short, militant phase) and I certainly didn't think that they had nothing valuable to contribute which many do, under Dawkin's 'God Delusion' influence. As far as I am concerned the search for spirit is part of humanity's makeup - though of course not for all. This is what a scientist, empirically looking at the writings, speeches, sayings and testimony of all the people who have lived on this planet would justifiably conclude.

      Delete
    49. Keith Gill's challenge:

      If not consciousness, "....then what other options are there that could function as the mechanism that transforms waves of ghostly quantum "noumena" into the positionally-fixed, 3-D "phenomena" that we call reality?"

      First of all, why is consciousness an option? What is the mechanism by which it performs this function? I know of no evidence of any. Without that, you are simply assuming what you would like to be true. As I have mentioned, since experimental evidence points the other way, the burden should be on you to explain this unknown mechanism, and make testable predictions.

      Secondly, what I have proposed is a physical mechanism, which the evidence does point to. That is all I feel we are entitled to from within this universe. Science cannot tell us why anything exists, except in terms of more fundamental observations. Sooner or later a boundary is reached where there are no longer answers. At that point it does no logical good to invent extraneous magic of gods or consciousness which cannot be tested.

      What I am saying is that the explanations of the form "god did it" or "consciousness does it" add zero explanatory value without evidence. They simply trade one set of unknowns for another. In fact, they add negative explanatory value since the explanations they propose conflict with evidence, such as the C60 two-slit experiments. In addition to explaining how they work, you must explain away all the inconsistent evidence; e.g., "god doesn't do tests".

      I reside satisfied at the boundary where I have a physical mechanism I can point to, and do not feel entitled to know why that particular mechanism works in this universe. I can use that mechanism to predict the results of the next C60 experiment, or any experiment involving quantum-to-classical behavior (based on whether the particles involved are apt to have some physical interactions).

      Delete
    50. Mozibur10:15 AM, April 03, 2021

      "my rationale for thinking physicalism is untenable, is that qualia and quiddity has not been reduced to physics, despite many clever people trying. "

      This is not a "rationale", it is an assumption. Neuroscience hasn't completely explained the emergence of the mind from the physical brain, but that doesn't mean it won't. Stick to the facts.

      "It's not called the hard problem of consciousness for nothing. Though you seem to think it is easy or simple."

      It's called the hard problem of consciousness by "philosophers" wanting attention and funding and who will be making zero contribution to its solution. Darwin has explained how a complex brain evolved, I suspect the rest will be just crossing the t's and dotting the i's.

      "If you happen to disagree, well you have every right to do so. However, there are plenty who don't."

      You are not paying attention. You state that you believe the mind is more than physical. This is untenable, because there is no evidence the mind is more than physical and you have provided none.So you don't "believe" that the mind is more than physical, ** you are under the trivially mistaken impression ** that holding that the mind is more than physical is a tenable position. It isn't a tenable position, because there's no evidence to support the position. And I don't "happen to disagree" with you. I don't disagree with you at all.I am diagnosing your mistake.The evidence disagrees with you. What you are claiming is unsupported by any evidence.

      "All you're pointing out is that empirically speaking we've reduced everything else to physics."

      That's not quite the situation with the mind and the brain. Empirically, they are tightly correlated. And the point is that you have not demonstrated anything that can't be reduced to Physics. Not even 1 phenomenon. Zero. Yet, through mistaken logic, you think this allows you to "believe" that the mind is not wholly physical. You have no evidence to support such a position.

      "athiest"
      This is a redundant word. Gods and demi-gods aren't real. They are characters in the fictional tales of primitive peoples.

      "I didn't deny the possibility that the other side could be right"

      It's not about sides, it's about evidence. And you have provided zero evidence that the mind is not wholly physical. Meanwhile, all the empirical evidence suggests that, at least from a commonsense point of view if not to the standards of a natural scientific theory, the mind is emergent from the brain.Your "belief" is based on nothing more than wishful thinking.Writing "qualia" doesn't show that neuroscientists won't one day have a theory that completely describes the subjectively reported phenomenon of the mind in terms of the brain.

      "As far as I am concerned the search for spirit"

      There is no such thing as a "spirit" in any biology book or other natural scientific book. This is the problem. You are writing about things that are not known to exist. I literally have no idea what you mean by a "spirit" beyond its metaphorical meaning.

      You might as well be telling me how wizards, dragons and voodoo are real.

      "This is what a scientist, empirically looking at the writings, speeches, sayings and testimony of all the people who have lived on this planet would justifiably conclude. "

      Who cares? There's still no such thing as a "spirit" and there's zero evidence the mind is anything other than wholly physical.

      Your basic problem is that you don't know how to distinguish between the real and the imagined.Natural science is the tool you need.

      Delete
    51. Steven Evans wrote:
      "...You assume that the superpositioned state is not "real". But in the double slit experiment interference is observed, so you have to hold off from your claim. The interference is real..."

      The interference that is taking place in the interim space between the double slitted wall and that of the phosphorescent screen in the double slit experiment, is most certainly NOT "observed." It is only "inferred" by reason of the pattern that develops on the screen.

      Indeed, it is literally impossible to "directly" observe what is taking place between the wall and screen. And that's because any attempt to do so instantly collapses the wavefunction, thus eliminating any possibility of ever observing it - as it really is - in its unobserved state.

      Besides, Bohr and Heisenberg didn't think the unmeasured (superpositioned) quantum realm was very real either, at least not real in the sense of possessing specific attributes such as, again, position, or angular momentum, etc., of which (allegedly) Heisenberg's ghostly "potentia" only acquires *after* a measurement is performed.

      And it's not that there isn't something "real" there, for I consider anything that exists on the opposite side of absolute nothingness as being "real" in some context or another.

      No, it's just that its true form and nature...

      (again, "as it really is" in its unobserved state)

      ...exists in a ("non-local") context of reality that is literally inaccessible to our senses and measuring devices.

      As physicist and author Nick Herbert playfully asserted in one of his books:

      “...Legendary King Midas never knew the feel of silk or a human hand after everything he touched turned to gold. Humans are stuck in a similar Midas-like predicament: we can't directly experience the true texture of quantum reality because everything we touch turns to matter...”

      (Continued in next post)
      _______

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    52. (Continued from my prior post)

      Steven Evans wrote:
      Me:
      "...Name those options..."
      Steven Evans:
      "...MWI - currently an unscientific speculation, but mathematically coherent..."

      The MWI is precisely what I was referring to when I spoke of the "no-collapse" option that is responsible for, again, the phantasmagorical theory of there being infinite copies of us and the universe which, regardless of how elegant or appealing the "math" is, is pure and utter nonsense. Indeed, nonsense on a scale that puts to shame anything a theist or idealist might propose.

      I mean, how can anyone take seriously a theory that allows for the ridiculous possibility that all 7.8 billion of us humans, along with the earth and our entire universe, may have - instantaneously - come into existence a mere 10 minutes ago (make that 10 seconds ago) as a result of the interaction between particles of methane from a bear farting in the woods in an alternate universe that our own universe (just now) branched-off of (again, perhaps 10 seconds ago)?

      And that's just one of its many absurd implications.

      Steven Evans wrote:
      "...Pilot-wave - ditto..."

      Yes, an old Louis de Broglie (now de Broglie–Bohm) theory that has gained renewed interest via a recent experiment that uses oil droplets bouncing on interfering waves of oil in which a "pilot wave" of oil guides a particle (of oil) in a way that seems to mimic what is taking place in the double slit experiment.

      However, an article in *Quantamagazine* titled:

      “Famous Experiment Dooms Alternative to Quantum Weirdness”

      ...sums-up the verdict on the highly misleading oil bath experiment in the article's subtitle:

      “...Oil droplets guided by “pilot waves” have failed to reproduce the results of the quantum double-slit experiment, crushing a century-old dream that there exists a single, concrete reality...”

      It's one thing to devise an experiment where oil droplets bounce on *material* waves of oil as a demonstrative analogy to help visualize what the pilot wave theory is suggesting.

      However, it is something else altogether to mislead us into thinking that *quantum* waves...

      (especially the ones that are associated with a single electron moving through the interim space between the wall and screen of the double slit experiment)

      ...are in any way similar to those oil waves which are created from a material process that we can easily understand.

      What I am getting at is that if there is indeed a pilot wave that delivers a solid and fixed particle to a specific region on the screen of a double slit experiment, then not only do we have to wonder what the pilot wave is made of, but what happens to it after it finishes its task?

      In my opinion, the pilot wave theory creates more questions than it answers, for it doesn't seem to explain the true nature (or ontological status) of the waves it is referring to.

      Steven Evans wrote:
      "...Superdeterministic models - Dr. H. claims hers and Tim Palmer's is partially scientific..."

      Are you suggesting that superdeterministic models are devoid of quantum mechanical features such as wavefunctions existing in states of "superposition"?; that Sabine's model does not contain wavefunctions that propagate in accordance with Schrödinger's equation, thus, implying that wavefunction collapse is not a feature of Sabine's model?

      I wonder if Sabine would agree with that?

      Steven Evans wrote:
      "...There is no suggestion that wave collapse can only be caused by conscious beings..."

      That's true.

      However, until the mystery of what it is that instigates the collapse of the wavefunction is irrefutably resolved, then it is imprudent to rule-out consciousness simply because its role in the process is yet to be verified or proven in a lab setting.
      _______

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    53. Keith,

      "Are you suggesting that superdeterministic models are devoid of quantum mechanical features such as wavefunctions existing in states of "superposition"?; that Sabine's model does not contain wavefunctions that propagate in accordance with Schrödinger's equation, thus, implying that wavefunction collapse is not a feature of Sabine's model?"

      If I may, I think his point is that the model *does* contain superpositions and also contains a mechanism to convert these "ghostly" (not my word) states into what we observe, in contrary to the above claim that no one knows how to do that.

      Also, the oil droplet experiment has nothing to do with pilot wave theory. You are confusing two different things entirely. What Steve wrote is correct, what you wrote not. (Though I see how the Quanta piece might cause that confusion.)

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    54. Sabine wrote"
      "...If I may, I think his point is that the model *does* contain superpositions and also contains a mechanism to convert these "ghostly" (not my word) states into what we observe, in contrary to the above claim that no one knows how to do that..."

      Sabine, what is the "mechanism" to which you are referring?
      _______

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    55. Sabine wrote:
      "...Also, the oil droplet experiment has nothing to do with pilot wave theory. You are confusing two different things entirely...."

      Sabine, I do realize that I may be relying on dubious sources, but if you Google the following:

      "Silicone oil droplets provide a physical realization of pilot wave theories."

      ...then the first thing that appears is this:

      "...Experiments using silicone oil droplets on a vibrating bath provide a remarkable physical realization of pilot wave theories. They give us a physical picture of what the quantum world might look like if this is what’s going on – and this theory is still deterministic. The particle is never in two places at once and there is no randomness..."

      So I don't understand why you are insisting that the oil droplet experiment has nothing to do with pilot wave theory.

      Please explain.
      _______

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    56. Sabine wrote:
      "...What Steve wrote is correct, what you wrote not. (Though I see how the Quanta piece might cause that confusion.)..."

      Actually, Sabine, in the post I was responding to, Steven didn't write anything pertaining to the pilot wave theory.  He simply offered it up (named it) as an option in my challenge.

      So what exactly did he "write" to which you are insisting that he is correct about?
      _______  

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    57. Keith,

      You haven't provided any sources. I am simply telling you that the oil droplet experiments have nothing to do with what Steven referred to as pilot wave theories. Pilot wave theory makes the exact same predictions as quantum mechanics, by construction. I don't know what's there to explain, you can just look up the derivation. Or, if you can't follow the derivation, ask anyone who knows how Bohmian mechanics works.

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    58. Keith,

      "Sabine, what is the "mechanism" to which you are referring?"

      Additional terms in the master equation, it's explained here.

      Delete
    59. Keith,

      "So what exactly did he "write" to which you are insisting that he is correct about?"

      That there's no wave-function collapse in pilot wave theory.

      Delete
    60. Sabine wrote:
      Me:
      “So what exactly did he "write" to which you are insisting that he is correct about?”
      Sabine:
      "That there's no wave-function collapse in pilot wave theory."

      Sabine, I do realize that you probably don't have the time (or patience) to carefully scrutinize everything that us "BackReActioners" (knuckleheads) write in this comment section. However, my goodness, you sure did extract a lot of information from this:

      Steven Evans wrote:
      "MWI - currently an unscientific speculation, but mathematically coherent
      Pilot-wave - ditto"

      ...which is absolutely all that Steven had to say about pilot wave theory.

      And in regards to the idea of there being no wavefunction collapse in the pilot wave theory, according to Wiki:

      "...Many authors have expressed critical views of de Broglie–Bohm theory by comparing it to Everett's many-worlds approach. Many (but not all) proponents of de Broglie–Bohm theory (such as Bohm and Bell) interpret the universal wavefunction as physically real. According to some supporters of Everett's theory, if the (never collapsing) wavefunction is taken to be physically real, then it is natural to interpret the theory as having the same many worlds as Everett's theory....David Deutsch has expressed the same point more "acerbically": pilot-wave theories are parallel-universe theories in a state of chronic denial..."

      Personally (not that my opinion is important or proof of anything), I think that some (yet to be understood) variation of the "Holographic Model" is closer to the truth (cue the closing music to Robert Lawrence Kuhn's show). :)
      _______

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    61. Keith,

      Well, let's just wait what he has to say about it.

      I don't know why you bring up the quote about many worlds. I am familiar with the comparison, but it's entirely besides the point. Whatever you may think about the empty branches, the point is that they're unoccupied, hence no collapse.

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    62. Sabine, just out of curiosity, as I reflect back on one of your prior statements where you asserted that your superdeterministic model:

      "...*does* contain superpositions and also contains a mechanism to convert these "ghostly" (not my word) states into what we observe..."

      ...does your model imply the existence of "parallel universes" that branch-off of our universe in a way that is similar to the MWI model?
      _______

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    63. Keith,

      "...does your model imply the existence of "parallel universes" that branch-off of our universe in a way that is similar to the MWI model?"

      No. Why not read the paper?

      Delete
    64. Keith D. Gill 11:43 AM, April 05, 2021

      You have attacked a parody of MWI and your conclusions about bear flatulence are not valid, so you have not shown the essential point of MWI to be "utterly ridiculous". The essence of MWI is simply that only the physical effect of one of the apparently superpositioned states remains for us after a certain event, and the rest...who knows? The "many worlds" talk is just marketing hype. The question is just whether all but one of these superpositioned states disappear from our physical radar (MWI) or the collapse is explained (SD).

      MWI is just a physically vague, mathematically coherent speculation. So people who claim to be convinced by it are trivially mistaken, as there is no evidence to support it, and people who claim it is utterly ludicrous are mistaken, as it's too vague to start drawing conclusions to check.

      "then it is imprudent to rule-out consciousness "

      ?? But consciousness is completely undefined in physics. How do you measure consciousness? So how could there be a physical theory of consciousness causing collapse? It's meaningless nonsense. There is no coherent physical theory to rule out.

      (P.s. you are right. I wrote nothing about pilot-wave theory.)

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    65. Steven Evans wrote:
      "...You have attacked a parody of MWI and your conclusions about bear flatulence are not valid,..."

      I did not "attack" a parody, I "created" a parody (in the spirit of Schrödinger's - live cat/dead cat - "parody"), in order to demonstrate the absurdity of the MWI's implications to those who are so "lost in the elegance of the math" that they are incapable of visualizing what the highly popularized idea of "branching universes" actually means.

      Furthermore, it's not called the - "...*MANY-WORLDS* Interpretation of Quantum Mechanics..." for no good reason, for according to Wiki:

      "...The many-worlds interpretation (MWI) is an interpretation of quantum mechanics that asserts that the universal wavefunction is objectively real, and that there is no wavefunction collapse. This implies that all possible outcomes of quantum measurements are physically realized in some "world" or universe.....The many-worlds interpretation implies that there are very many universes, perhaps infinitely many..."

      The bottom line is that because the "many worlds" aspect of the theory is being pushed by "seemingly" credible physicists (such as Sean Carroll and Max Tegmark, for example), far too many people are taking it seriously. Hence my extreme (yet thoroughly valid) "parody."
      _______

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    66. Keith D. AM, April 06, 2021

      Everett produced a mathematical model whose predictions fit with the empirical evidence for "this branch". But there is no physical description of how the so-called branching or splitting occurs, and assuming there are "infinitely" many physically real branches is simply speculation.

      You are drawing physical conclusions from the model which it is not known can be drawn from it, and then declaring that the unjustifiably drawn conclusions show the model is "utterly ridiculous". The key question is whether physically there can be shown to be a split or a collapse or something else. MWI may be a capacious mathematical model that contains a kernel of physical truth for all anybody knows.

      The point is there is a real physical problem here (as with "dark matter", but unlike with inflation, universal fine-tuning, the other multiverse AFAIK), so theorists have no choice but to poke at it within the empirically confirmed constraints.

      "far too many people are taking it seriously"

      It is a speculative mathematical model which is currently unscientific. One can take it seriously as such, unless one can produce evidence to rule it out, which you haven't. Anyway, you believe in "spirits" and are an "idealist", whatever they are.


      Delete
  3. If you take a holographic plate and cleave it in half both copies will have the same image. However, the solid angle of view of that object is reduced. As a result, the left and right pieces will contain information about those respective sides. If you cut it into smaller pieces the view of the object becomes more of a “keyhole” image. Consequently, there is a reduction in the amount of information available, but it is less than a proportion expected, say for cutting in half a reduction in information by a half.

    The holographic principle was really introduced by Susskind with black holes. Objects observed to approach the black hole appear to be Lorentz contracted to near zero length, and optical effects spread it across the surface of the black hole. Hence, the horizon contains everywhere quantum information about any object that entered the black hole. In that sense it is similar to the holographic plate. With Hawking radiation, it also implies the quantum field on the horizon determines the quantum field in the 3-dimensional bulk. I am not so sure about the utility of arguing over the thickness of a holographic plate. If you say that long enough, I am sure some clever quantum optics experimenter will turn a graphene sheet into a holographic sheet, which quantum mechanically is essentially two dimensional.

    This then leads to the question on whether the entire observable universe is a hologram. A first order idea of this is to consider the CFT on the boundary CFT_4 ≃ ∂AdS_5. This boundary is an Einstein space, has zero curvature or Λ = 0 and can be extended to Λ ≥ 0. This CFT_4 model can contain gauge-like gravity, and so our observable universe may in effect be the holographic screen for an anti-de Sitter spacetime of 1 dimension larger. On a level of greater subtlety the observable universe may be a holographic screen in AdS_5. A tensor network with bounded causal regions that are entangled will have holographic screens, and we may be on one of these screens. This is what the Ryu-Takayanagi formula is about. In fact, it would be the inflationary spacetime that is on this screen, so there is one level up on the multiverse.

    Can we ever know this or make observations to support this? That is impossible to answer, and it could well be that any data supporting or refuting this may come in another century or two. Just working out how to look for Guth-Valentin level pocket worlds or universes is a tough enough of a challenge.

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    1. This is based on various comments on this page:


      The question of importance is not whether AdS_5 exists, or there is an inflationary manifold that is on the boundary of the AdS_5 or on a holographic screen, but whether the structural relationships involved play an underlying role in physics. In a sense we can say that epistemology precedes ontology. The Maldecena result AdS/CFT is similar to the Gauss-Bonnet theorem that a topological index of a manifold is given by an integration of curvature inside the manifold plus a surface integration of the surface curvature, or Gauss fundamental form, on the boundary. If the topological index is zero, say the Euler characteristic vanishes, then the curvature in the interior and that on the boundary are equal.
      The AdS_n spacetime is a quotient of two groups SO(n-1,2)/SO(n-1,1). The importance is really the group structure, and SO(4,2) is equivalent to SU(2,2) of twistor geometry. There is a general system of quotients of groups that define spaces or other groups, This is a complicated business I have found. It is similar to the theory of Iwasawa group decomposition, which is an extension of Cartan theory. What is really important then is not whether there are actual spaces involved, but whether there are quantum states that are defined by these structures. Again, epistemology precedes ontology.

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    2. "the structural relationships involved play an underlying role in physics. In a sense we can say that epistemology precedes ontology."

      On a slightly tangential note it seems that the concepts of ontology and identity (and its corollary concept of additivity) are the most confusing even in a scientific discourse and not on the same footing as that of epistemology. Basically, we can approach any knowledge (in a sense, that we can still share with each other, human-perception-wise) only from a side of structural relations.

      Then we implicitly (ourselves representing some recorded tacit knowledge of interactions, either evolutionary or memory-wise) or explicitly (knowing the context) use reductions to compress some relations in order to reduce energy expenditure and approach more complex knowledge. In a way creating some static sections (atemporal) of dynamic processes (temporal) in those selected structural relations (which by definition reflect our physiology/'how things are' and often reflect atemporal characteristics of our implicit knowledge, those we intellectually call abstractions, invariants or principles and mostly vaguely feel some of them as perceptions and emotions, which themselves pack some dense information processing systems; the dark and unexamined sides of which represent dogmas, beliefs, myths, etc. - mostly unprocessed stuff)

      These common reductions we later call objects (or evolutionary shaped perception does that implicitly, and we later simply re-discover that) and assign to them a quality of 'being real' (existence, ontology, etc.) Just in order to simplify and synthesize experience. Later we [perception] can recognize them more and more easily, i.e. identify, and by means of comparison (what details can be omitted) define additivity, thus opening them to conceptualization and manipulation and to more complex knowledge.

      So far, no problem. Where does the problem begin? We forget that objects (as concrete, so abstract) only exist in our specific perception (i.e. any possible measurable model by extrapolation). Perception which we are predisposed to habitually neglect and take for granted as some unified identity ("obvious"), as a monolithic object itself. Hence, forgetting that objects are just representations hiding some "packages of interactions" or processes, including the perception itself. So objects are hiding compressed reductions, including the way of reduction itself of a specific perception (instances of which are integrated by universally deducible invariants, like TR & QM). Identifying them as things one can "obviously bump into" from the perspective of a thing that "can bump into" them. Hence, coming up with things around the process of observation and consequently extrapolating to some object of the observer itself. And constantly forgetting about this.

      Hence, ignorance of the fact of forgetfulness of the process of local observation (as identification of a dynamic process for a static section of that process) basically leads to ontology. In that sense a local emergent consciousness (felt as a monolithic thing) is just a peculiar yet dense enough inability of some self-reflecting process to process information simultaneously (computation according to a computational paradigm, i.e. universal Turing machines, Wolfram model, etc.), i.e. no omnipresence and no omniscience - hence, space, time and separation.

      In that sense epistemology as the theory of know-ing, i.e. of some dynamic process, and ontology as the attempt to find absolutes and identify 'thingness' (it's irrelevant whether it's 'concrete' or 'abstract', both cases are just attempts to compress information just by different channels/instruments/organs), i.e. just some static section in that stream, are on completely different grounds. I.e. ontology may be used out of convenience (or consensus) in its proper environment but must be remembered for what it is, then there is no problem.

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  4. Hi everybody,I must be not very intelligent, I do not see a way for something to be projected in the external area of ​​a black hole, rather I see that it is projected transversely and in an orbital sense, and in that direction all the "information" you want enters.

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    1. Hi Luis, I think there's nothing wrong with your intellect. I know I'm quite intelligent and knowledgeable but that seems to mostly evaporate when I deal with physics and such.
      I imagine that a black hole sort-of squeezes out and regurgitates information as Hawking radiation after the original information/substance is distorted inside.
      Is that making any sense?

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    2. This comment has been removed by the author.

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    3. It is a quantum mechanical physics.

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    4. Quantum physics based on the dominant geometry outside the black hole; but I suppose that the black hole transforms the geometry within itself and its surroundings; If geometry is a consequence of the way the fields are organized, a black hole is the best candidate to transform the geometry; then the external area of ​​the black hole is only from our perspective; but from within we do not know what the external direction is. It seems to me.

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    5. @Luis
      Hi again, having read more about black holes and what happens to information therein, my conception was incorrect.

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  5. Have the mathematicians made progress in making the physicists' AdS/CFT duality any more precise?

    Thanks in advance!

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    1. Not that I know of, but actually the physicists have been doing quite well on that.

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  6. With some of the partial differential equations (PDEs) of classical physics, we know that having the boundary value can uniquely determine the solution in the bulk, so in a sense, having a field whose evolution is governed by a PDE restricts the amount of information in the bulk to that which can be represented on the boundary.

    While this is far from AdS/CFT duality, is the idea that the information in an N-dimensional volume might be restricted to be that on its N-1 dimensional boundary really an earth-shattering insight?

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    1. Minus the free solutions. I believe we had this exchange already 10 years ago!

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    2. Your memory is way better than mine!

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    3. @Arun "Never was there a time when I did not exist, nor you, nor all these kings; nor in the future shall any of us cease to be."

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    4. Yes, @Vadim, but that doesn't imply anything about memory.

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  7. I've found adS/CFT in the "boundary" of the uncertainty of Planck scale seeing there anti-de-Sitter space and Λ < 0 at this scale of quantum effects. At macroscopic scale the Λ > 0 seems to be the case. The universe net Λ can be natural zero.

    The holographic principle works by Unruh/Hawking radiation calculations just being gravity dynamic ála Verlinde but not as growing bubbles but collapsing due to elementary particle -connected virtual "proper time factory" spheres.

    The analogue with real holograms could be still better than thought just because of thickness of Unruh/Hawking temperature-like term with connection to full bath of wave environment (em, neutrino, etc). In a way you can calculate the whole gravitational field out of "sink positions"...

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  8. Holograms only capture the details present at the surface of 3D objects. No information is recorded about the internals. So it is a fancy 2D->2D mapping, yet a non-trivial one. So where is the dimensional reduction supposed to come from?

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    1. A hologram with X-rays is possible in principle. In practice it is tough.

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  9. "The Unreasonable Effectiveness of Mathematics in the Natural Sciences" is a 1960 article by the physicist Eugene Wigner. In the paper, Wigner observes that a physical theory's mathematical structure often points the way to further advances in that theory and even to empirical predictions.

    But the logic implicit in mathematics does not inform what processes in reality to apply those mathematical constructs to. String theory seems to predict a holographic nature to the organization of the universe. But this prediction includes some unsavory characteristics that the universe might also encompass. Somewhere in our universe there might exists black strings, bubbles of false vacuum, negative energy, naked singularities, Anti-de Sitter spaces, and numerous other unpleasantness that may be interesting in principle to think about but clearly crackpot to impinge on our notions of what might actually be real.

    What mathematics does not tell us is what conditions might possibly bring these predictions to life in the real world. The universe is comprised of a very few fundamental absolutes. Most of reality emerges from these absolutes. The way reality emerges is what mathematics’ sometimes misses. In my opinion, the big undiscovered questions that exist today in science are centered on these misses.

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    1. I don't think it is unreasonable at all. After all, the Pythagoreans - of which Plato was one - conjectured this two and a half millenia ago. Personally, I see mathematics as the aspect of Necessity in the world. I mean, it is necessarily the case that 2+2 = 4 ...!

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    2. Only once at least 2, addition, equality and 4 are defined as well as couple of axioms. Before that it's meaningless.

      The fact that a * 0 equals 0 isn't some universal truth spawned from primordial point or passed from previous universe or whatever other non-creationist mechanics you prefer. Creator alone could have made that fundamental, in whichever form you want to imagine it. "Thou shall not kill" has for all intense and purposes exactly same weight.

      We've set up some rules and guidelines and now expect universe to oblige. Anthropic principle is only minor delusion, anthropomorphising the heavens is our mortal sin.

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  10. The information we get about reality comes to our minds through our senses, but having been fooled by my senses more than once I am willing to admit that there may be more to reality than what we get through our senses.

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    1. I think it's quite possible that science is yet to find and detail at least some of the ways people can sense and interact with reality. Or, that things currently dismissed as pseudoscience might have something to them after all.

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    2. C Thompson7:08 AM, March 30, 2021

      Based on what do you think it's "quite possible"? Based on a "feeling" or an "intuition", a dream perhaps? More drivel.

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    3. @Steven Evans You must sadly want for entertainment, to await comments to shit on in this blog.

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    4. C Thompson6:52 AM, March 31, 2021

      "You must sadly want for entertainment, to await comments to shit on in this blog. "

      That's not an explanation of why you think it's "quite possible that science is yet to find and detail at least some of the ways people can sense and interact with reality."

      What exactly do you think or feel the 10s of thousands of brilliant, full-time researchers with decades of experience in biology and neuroscience have missed, but you think "quite possibly" exists?

      If you can determine the reality of nature with no expertise and just feelings, why are we wasting all these billions of dollars on scientific research when we could just ask you what you feel the answer is, like the oracle of ancient Greece?

      I suggest that there is nothing in your personal experience which contradicts any of the results of natural science. I also suggest that your claims of the supernatural would be proved incorrect under the most cursory examination by an experimental psychologist.

      Do you agree that you have zero evidence for your claim here?

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  11. What if dimensions are themselves relative? If a theory of strings works in one dimensionality and its dual with point particles in another, why should dimensions be real. Why not look for an invariant under dimensional transformations and work for there. Probably being done already.

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  12. In my opinion, the Holographic universe exposes a possible inconsistency in the logic of science. First, the big picture of Hawking radiation implies that black holes generate energy from nothing. The Hawking radiation catalyzed by a black hole partitions nothing into a positive and a negative energy component. Science abides this revolutionary concept because the gravitational black hole balances the energy conservation equation of the universe by neutralizing the negative energy component through the internal mechanics of the black holes internal energy processes.

    Among other things, the Holographic universe implies that naked singularities must exist. This particular construct is distasteful to science. The naked singularity has so far been considered intuitively undesirable and this emotional reaction has produced a conjecture forbidding their existence, the so-called cosmic censorship conjecture.

    The conjecture simply states that a physically “reasonable” system of energy will not, under “reasonable” initial conditions, evolve into a naked singularity. The original intent of the conjecture was of course to prohibit the formation of naked singularities in classical general relativity so that, for example, a non-rotating system would radiate away all multipole moments sufficiently rapidly that the final state would be a Schwarzschild black hole. However, there are many counter examples in the literature where naked singularities do indeed form from classically reasonable initial conditions.

    Without cosmic censorship, the ubiquitous production of naked singularities throughout the universe implies that energy is being continually generated from nothing. This idea makes science displeased, but logic has no problems with this idea.

    The existence of naked singularities is still difficult to understand physically, and several suggestions have been made to maintain the viability of the cosmic censorship hypothesis. One is merely to reiterate that it holds classically but needs some fine tuning to describe the set of physically reasonable set of states from which a collapse in the singularity may begin.

    But the collapse of the naked singularity might be just another feel good idea that might not behave as is expected or desired. The naked singularity might do what it is driven to do by the dictates of its environment.

    Next, the naked singularity could be a storehouse for negative energy. Now if the naked singularity exists in a coherent state, then superposition would hide the contents of the naked singularity as dark matter. Being seeded by superconductivity and coherence, the ubiquitous populations of these singularities would entangle easily to form Bose condensates that would preclude their gravitational collapse of the individual members of the open ended aggregation.

    All this sets the stage for a matter creation cycle. This cycle starts out with energy generation from the partition of nothing into positive and negative energy. The negative energy is stored under superposition around the singularity, and the positive energy condenses into more baryonic matter. This baryonic matter is predisposed to form more coherent naked singularities that can store more negative energy but cannot be detected because of superposition that results from coherence.

    In overview, this matter creation cycle creates an ever expanding universe with a proportionally fixed amount of dark matter and dark energy cohabitating with a small fixed proportion of baryonic matter that lacks any antiparticle creation. If this cycle were in place from the creation of the universe, a small initial seed of primordial energy could have initiated a ever expanding amount of dark energy and dark matter that retains its proportionality with baryonic matter and all the while avoiding any production of antimatter over the eons in an ever expanding Holographic universe. The universe would mostly be AdS but hidden from the minority proportion of baryonic matter in which we live our lives


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    1. Hi Axil, my understanding/guess is that energy of a black hole comes from the material of the star it originated from, and from any matter or radiation that fell into it?

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    2. Naked singularities are not related to gravitational black holes. These micro black holes are a consequence of tachyon condensation. Ashoke Sen took the fear out of tachyons for physicists when he characterized tachyon condensation. In the late 1990s, Ashoke Sen conjectured that the tachyons carried by open strings attached to D-branes in string theory reflect the instability of the D-branes with respect to their complete annihilation. The total energy carried by these tachyons has been calculated in string field theory; it agrees with the total energy of the D-branes, and all other tests have confirmed Sen's conjecture as well. Tachyons therefore became an active area of interest in the early 2000s.

      OK, so open-string tachyons and closed-string tachyons in twisted sectors are more or less understood by now. Physicists no longer panic or abandon the theory when they see a tachyon. Instead, they calmly interpret these tachyons as sources of instabilities – instability that annihilate objects or whole chunks of spacetime and that may (but don't necessarily have to) lead to a new stable world with some interesting objects that may be left over.

      For this reason, it was Ashoke Sen and his apprentices such as Edward Witten who unified nothingness and somethingness in physics – i.e. in string theory (because no other theory can achieve similar unifications) – and who discovered new perspectives on the somethingness in between and that's my explanation why both Sen and Witten deserves their $3 million Breakthrough prizes.

      I am interested in relating the abstractions of string theory to real world engineering applications. I want to know the ways and means of how these naked singularities annihilate objects or whole chunks of spacetime and that may lead to new stable conditions with some interesting transformed objects that may be left over.

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    3. Thanks for the reply, Axil.
      Do you have any ideas how to actually apply string theory physics to objects in engineering you would like to share?

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    4. Thanks for the interest, C Thompson
      Regarding: " Do you have any ideas how to actually apply string theory physics to objects in engineering you would like to share?"

      There are many systems that produce these predicted structures described in the Sen and Witten version of string theory. The name ascribed to these bubbles of nothing are Exotic Vacuum Objects (EVO). So the engineering is well established, but no one understands the physical principles upon which these systems function. The EVO seems to demonstrate vacuum decay up to a certain threshold where its growth is auto self amplifying, then the EVO explodes in a Bosenova.

      I would like to understand Sens' theory to map the character and behavior of the EVO to the descriptions and predictions defined in string theory.

      It amazes me that these theorists do not realize that their understanding and predictions of reality is actually real. Yes, the EVO does annihilate objects or whole chunks of spacetime and that this behavior oftentimes leads to new stable conditions with some interesting transformed residue that remains.

      For instance, can string theory explain why this residue is always stable and no radiation is produced when destabilization is in process. Is it a result of the time effects of the singularity that seems to be the active agent in this destabilization process or is it a quantum mechanical issue?

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    5. I'd hazard a guess and say time effects.
      Intriguing. Thanks again, Axil.

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  13. If theory is true, since surface needs to store as much information as volume, it means we can compute valid combinations of radius of the universe + number of dimensions for which this is true.

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    1. Holographic principle is directly connected to the maximum speed of causality. Every sphere surface can store the amount of Plancian information which can be propagated from inside volume as a projetion of physical events.

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  14. Being not an expert, and having read the posts, I would like to ask if there is a consensus in the scientific community concerning the number of dimensions of the universe we are living in? Only four ? Eleven ? Twenty-six ?

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    1. Dear Paps57,

      That's actually wrong question. The amount of dimensions is choosable. It's only about description of geometry and topology, connections and actions, scalar properties, restrictions for embeddings etc.

      The right question could be something like "At what grade of emergence we want to study?" Most obviously we try to understand in the level of mammal's brain. But that's not always the best practise...

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    2. Thanks for retargeting the question. I can only roughly guess what you mean due to my too limited knowledge on that topic.
      Don't you think that the scientific discussions would attract more followers if they would be done in using more common mammal concepts? Basic people like me need a representation with which they can start something with. I mean, even if the mathematics can be formulated in a way not depending on the number of dimensions, we get the sensation to live here and now. A democratic description should perhaps takes this basic fact into account ; or not ? So far I can Experiment it, I don't get the feeling that I live in the function projecting, e. g. a 5d universe into my 4d one.
      What do you think ?

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    3. I think that popular descriptions need to focus on human observables, not speclative mathematical artefacts at all. Every one has a possibility to study physics as deep as want until curiosity or capability stops..

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    4. At the moment it is four spacetime dimensions. The theories with extra dimensions are still speculative as they have not yet been detected.

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  15. Question for Bee: is there a classification of conformal theories on the boundary?

    The train of thought is - all the conformal theories on the boundary must have a suitable dual spin-2 bulk degree of freedom, thereby proving that gravity is a necessary part of the AdS/CFT duality.

    If I asked this too ten years ago, my apologies in advance.

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    1. Hi Arun,

      For the examples that are well understood and rigorously tested it's not just any odd CFT, but CFTs with a specific field content, the most famous example being N=4 supersymmetric YM. So I think the answer to your question is no, but not for the reason you seem to allude to. It's not like in general there's not "gravity in there", but that the field content doesn't have an equivalence in the bulk.

      Delete
  16. Steven Evans,
    Here is how dreams could contain information about the future. Suppose someone has a dream about some future event that might happen to them. Then its possible that their future actions might be influenced by the dream in such a way as to bring about that future event. its a matter of interpretation. How one looks at the flow of human events. In a way its like horoscopes, which are written to be interpreted in many ways so that seem to be correct.

    Not a lot of people are able to look at these subjects with the rigor that you yourself do. But that doesn't mean that they are crazy or insane. It just means that rightly or wrongly they are open to possibilities that you yourself reject, And while I agree with you about religion and other similar subjects, cutting everybody some slack is necessary to keep the discussion moving forward. So my rule of thumb is to not write anything on line that you wouldn't say to someone standing close enough to punch you in the face. A rule of thumb learned by experience

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    1. Steve Bullfrog, thank you. You might be right.
      I am interested in how the Universe works and also why people have tended to operate the way they do, which is often without anything approaching scientific rigour.
      Despite Steven Evan's disbelief, I am assuredly quite sane. I have been interested in science, the occult and psychic abilities since I was in high school and persued it online more over the last 12-odd years or so. I have friends and acquaintances who've shared their experiences with me too, plus I'm interested in what others in the blog think, of some of my ideas, including if they respectfully disagree.
      I have much admiration for Sabine Hossenfelder; I've learned quite a lot from her videos and writing. I enjoy the different points of view and discussions here.
      I doubt Steven Evans would dare to talk to Dr. Hossenfelder like he does to her blog commentariat.

      Delete
    2. Talking about strange dreams, I had a strange one the other night. I was by the bath room door, and all the lights were off. Suddenly I had a strong sensation that there was something hideous hiding behind the open door and then all at once I was picked up off the floor and hurled back into the room.

      Luckily, I opened my eyes at that point...!

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    3. C Thompson7:42 AM, March 31, 2021

      "I have been interested in science, the occult and psychic abilities "

      That's a bit like saying you are interested in human rights, child murder and genocide.
      The occult and psychic abilities are not real - they are not supported by the evidence. These kinds of claims have been checked carefully by psychologists and found to be unsupported by any evidence.

      "I have friends and acquaintances who've shared their experiences with me too,"

      This is just anecdote, not evidence of anything.

      "plus I'm interested in what others in the blog think, of some of my ideas, including if they respectfully disagree."

      Your ideas are incorrect. You have confused what you feel and think with what is real. There is no experimental evidence that humans can access information about the future via dreams.

      "I doubt Steven Evans would dare to talk to Dr. Hossenfelder like he does to her blog commentariat."

      Well, you and Keith mostly. I'm on my final warning anyway. Cause and effect. I am still allowed to politely point out when your claims are not supported by any evidence though, so speak to you again soon!

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    4. Eep!
      I had one recently with some version of Sabine in it.
      I don't remember at all what it was about, but she had no business being there. XD

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    5. @Steven Evans
      Whatever.
      I am certainly not pushing anyone to believe in what I think; everyone is free to disagree with or ignore me, especially given whose blog this is.

      Delete
    6. C Thompson8:24 AM, April 01, 2021

      "I am certainly not pushing anyone to believe in what I think;"

      How could you push anyone to do so? There is no evidence to support your claims.

      "everyone is free to disagree with"

      Anyone rational is bound to disagree. If there is no reason to think something is true, why would one think it is true?

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    7. Perhaps I'm mostly irrational, then.
      I am still interested in actual science.
      I'm not asking for anyone to believe me, I thought some people here might be interested in my points of view. If they aren't, fine. If everyone here thinks I'm batty, also fine. I just want them to be civil if they respond.
      I assume that every other commenter is at least as able to discern facts or fancy for themselves as you are.

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    8. Hi C Thompson, you have a problem, I don't know exactly what it is; if you want reality to obey your wishes or find evidence of your beliefs in science; In the first case, science will tell you that you are wrong; and in the second the religion will tell you that it is also wrong; remember that Christ said "This generation of hypocrites demands proofs; but proofs will not be given"; ha ha ha

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    9. Luis, Jesus wasn't a scientist, and I'm an atheist.
      Nobody has really bothered to link to any scientific argument except to tell me that science says I'm wrong.
      At this point, I'm over it. I'll say I'm wrong too.
      Let's move on.

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    10. Hello C Thompson, exactly, Jesus is not a scientist, as a theologian he would answer you more or less something like this, "you will not believe by evidence but by faith",

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    11. Hi Luis,
      I'm still waiting for Science to descend majestically and tell me I'm wrong. /joke
      Having watched the latest 'Science Without the Gobbledygook' video, I would have to acknowledge there's no other dimensions or whatever tucked away, I suppose.
      I also gave many caveats as to how non-scientific my suggestions were. (Unscientific as in outside of science like religion is, whether I think my ideas might be or not. I have watched the relevent SH video 2 or 3 times).
      I'm also doing my best to understand Superdeterminism by the explanations online since I want to understand the evidence for it rather than just take it for granted as if Dr. Hossenfelder and her colleagues were delivering scriptures.
      I'm currently typing this on my phone in a nightclub, sorry if it didn't come out quite sensibly.

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    12. This comment has been removed by the author.

      Delete
    13. Hello C Thompson, I understand well what you mean, doubting, questioning, confronting ideas is part of the dynamics of thinking; I give you an example, chess has developed a theoretical framework based on the experience accumulated in a couple of centuries, each opening takes the player through several safe paths until a play where the theory begins to be undefined; almost all games between professional players develop rapidly up to these limits, after that limit the theoretical "debate" begins. The foundation to act like this is the debugging of errors over 2 centuries that gives consistency and effectiveness to the theory. I hope my example will serve you

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    14. It does, Luis.
      I can't play chess, but I know how the game works. One could say I'm at the same level with physics.
      I accept that my ideas might not fit into the rules of the game, even though there's a great number of possible outcomes, if I can stretch your example further.

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    15. @Steve Bullfox, sorry for getting your name wrong earlier.

      Delete
  17. Holograms distribute information intriguingly. If you cut away half a photo of two people, all image data on one person is lost. But if you cut away half a holographic image, both people remain visible.

    But how can that be? How can half an image retain all the original information?

    It doesn’t, of course. What gets lost is resolution. This loss shows up best by cutting the hologram into ever-smaller pieces. The people become two blobs, then one blob, then just a hazy light.

    To analyze this, think of the image as residing in one space (call it xyz) and the hologram as residing in another space (call it pqr). Cutting out smaller sections of the hologram is equivalent to localizing the hologram into increasingly confined regions of pqr space, which increases the fuzziness in the xyz image. Conversely, allowing the hologram to fill all of pqr enables the sharpest possible images in xyz. Notice, however, that since the hologram’s resolution is finite, the finer details of the xyz image stay blurry even if the hologram fills all of pqr space. This inverse relationship between hologram localization and image precision means pqr and xyz possess an uncertainty relationship.

    More precisely, xyz and pqr are said to be conjugate spaces with a Fourier duality relationship. In practice, this means xyz and pqr encode precisely the same bits of information in seemingly very different ways.

    I say “seemingly” because the relationship is, in fact, fully symmetric. If you make a holographic image of a single point of light, the resulting hologram appears very uniform. However, if you then make a second hologram from the first one, the resulting image is no longer smooth but has a highly localized spot corresponding to the original light. A clever and intentionally incomplete variant of this hologram-of-a-hologram inversion process creates the aluminized, pressed-plastic Rainbow (or Benton) holograms seen on credit cards [1].

    Holograms with localized spots are uncommon because our universe is biased towards localizing objects into xyz space. This bias means our classical world continually breaks its own lovely underlying Fourier symmetry in a process better known as wave collapse or particle localization.

    But if fermionic physics incessantly keeps particle images mostly in xyz space by breaking some Fourier symmetry, what is the other side of that symmetry? In other words, what is this naturally occurring holographic equivalent of the classical world?

    Physics answered this question decisively about a century ago with the advent of quantum mechanics. Physicists call the conjugate of xyz space momentum space. The “photographic emulsion” underlying both spaces is mass-energy. Because mass-energy is finite and conserved, the total resolution of this conjugate system is also finite. Note that, unlike ordinary holograms, xyz and momentum space must share the same information-carrying “emulsion” of mass-energy. This forced sharing induces complex dynamics that favor the localization of antisymmetric fermions (the mass image) over the localization of symmetric bosons (the momentum image). The resulting multi-scale, self-sustaining hologram increases in complexity over time. The implications are particularly fascinating at black hole surfaces, which become integral parts of the overall information flow instead of being truly isolated from it.

    All discussions of “quantum uncertainty” are at their hearts discussions of the blurring that must occur as mass-energy images shift localization between xyz and pqr. There are, alas, no parallel universes or multiverses in any of this. There are only the limits of what the finite mass-energy emulsion can encode. Finally, it is worth mentioning that because the time vector’s conjugate is scalar energy, it is classical time that most flagrantly violates the system’s overall Fourier symmetries. Intriguing, that.

    [1] https://en.wikipedia.org/wiki/Rainbow_hologram

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    1. At Mozibur too.
      Thank you. Your answers tell me more about what a hologram is (so far the main topic here) than the parallel discussion concerning the dreams. Physics is a very difficult science. It is asking self discipline and thousands of hard work. By side I remark that it must also be a very dangerous topic since most of people intervening on this blog or on similar blogs do it behind a mask. That fact is in contradiction with the intention motivating the existence of this kind of blogs: a democratic diffusion of basic knowledge to the public. As common representant of the public, I ask me why it is so. I got the answers progressively. My conclusion after seventeen years is : it is effectively a dream to believe that one can really freely teach the public about physics with a blog or with a Website.
      Fortunately for the public, there are actually thousands of good videos /courses on Internet which are spreading the basics.
      So, thanks again.

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    2. Hi Vadim; If any scientific discussion were divided between two levels, between neophytes on the one hand and between specialists, you would find yourself with the same dual mind-matter problem; Remember that all propositions like multiverse, 20 dimensions or whatever, fine tuning were not invented by religious people, they were specialists; In addition to the fact that the word INFORMATION has a totally subjective connotation; The very word OBJECT, what really defines ?, Can something be defined outside a time interval?, that is, does something exist in the time interval (0-0) ?, I don't think so; Does THE NOTHING exist? Nothing seems to be a way of discriminating from our conscience at a classical level; but at a quantum level, does THE NOTHING exist ?; I mean, many of the words we use are suspiciously subjective and others may not make sense on a quantum level; it's just my opinion.

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    3. Even worse is that the same terms can mean different things even in physics: I just found out that there are black holes both physical and theoretical.
      'Information' is a different beast regarding black holes and such.

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    4. Paps57, thank you. I am glad my comments about holograms were helpful.

      I have long been fascinated by holograms. I bought my first one [1] when I was eleven or twelve. It was not until I was in college that the more sophisticated (and quite beautiful) thick-film (Denisyuk) holograms that work in ordinary light became commercially available. My first one of those showed the inside of a mechanical watch. I do not know what became of it; perhaps it is still packed aware in some box? What fascinated me most about that hologram was the shiny flat arrow end of the second hand, in which I could see a blurry reflection of my head moving left and right. Not bad for a bunch of dark dots in a transparent matrix!

      I found the mathematics of Fourier transforms that underly such holograms just as fascinating. Fourier duality relationships are more common than folks realize. For example, any radio dial is an example of a Fourier transform since it converts the continuous and spatially diffuse cycling of a radio wave into a specific number or location on a frequency dial or number line. As any radio frequency engineer knows, there is also a fascinating relationship between sloppiness and the ability to convey information. Small gaps separate radio stations because exact radio frequencies — what folks call base frequencies — carry no information! Only when modulates base frequencies in a fashion that undermines their perfection can you transmit meaningful information. Similarly, “broadband” radio systems carry so much information that they spread the base frequency out so much that it forms, well… a broad frequency band!

      All of that sounds irrelevant to quantum mechanics, but it is not. For example, why do atoms have volume? It’s because the electrons, when interpreted as oscillating quantum wave functions, lack exact (point-like) “spatial frequencies” in their wave function representations. Any atom has a triplet of “spatial frequency” numbers, what we would more typically think of as xyz location. While very precise in comparison to human size scales, this location can never be exact. Just as radio stations require a bit of a gap on both sides to contain information, atoms require a bit of “spatial bandwidth” to maintain their information content in a finite space.

      I should hasten to add that the frequency interpretation of xyz locations is highly uncommon outside of momentum-space quantum wave functions. That’s because space is isotropic and attaches no energy cost to any spatial frequency, making it trivial to think of xyz locations as pure numbers rather than frequencies. This isotropic behavior of xyz is in sharp contrast to momentum space, where higher frequencies have higher energy costs (more momentum). Thus for xyz space but not pqr, it is possible to set the origin and axis orientations of xyz numbers arbitrarily. That’s handy since it’s why tape measures work so well!

      Atoms actively and ferociously defend their tiny gaps in space through an intriguing and still somewhat mysterious (even after a hundred years) mathematical feature called antisymmetry, or Pauli exclusion. Along with the energy isotropy of xyz, it’s one of the features that makes localization of mass-energy in the xyz image of space more likely and conspicuous.


      [1] Stong, C. L., How to make holograms and experiment with them or with ready-made holograms. Scientific American, 1967, 216, 122-134
      https://www.jstor.org/stable/24931411

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    5. Addendum: How is holographic quantum duality relevant to AdS/CFT?

      Sometimes it helps to recognize how accidents of history impact human perception.

      People do not think of quantum mechanics as holography mainly because holography did not arrive on the scene until about two decades after quantum mechanics. Yet both are based profoundly on wave mechanics and Fourier relationships. Quantum mechanics even has xyz and momentum wave functions that are equivalent and interchangeable via Fourier duality.

      The main advantage of quantum mechanics’ holographic interpretation is that it moderates the human tendency to create paradoxes that do not exist in the actual data. Particle-wave duality, for example, becomes a matter of asking which of the two complementary holographic images (space or momentum) contains the highest degree of localization in a given situation. Holographic duality also avoids the paradox-riddled human tendency to assume there “must” be a “true” point-like particle hiding “somewhere” in at least one of its two (why only one?) quantum wave functions. With holographic duality, the only issue is which wave function is more localized.

      Here’s another critical point: In holographic duality, bits are also holographic images with finite resolution. There is no room for an “abstract” bit that is independent of the mass-energy image or can grow arbitrarily small. For example, while the spin up-or-down state of an electron compactly represents one bit, the holographic resolution role of surrounding equipment in determining what is meant by “up” or “down” for the electron cannot be ignored.

      But what does any of this have to do with ‘t Hooft’s remarkable and deeply insightful 1993 paper [1], in which he first postulated the holographic principle, specifically in the context of information density at the event horizon “surface” of black holes? After all, 3D-to-3D holographic quantum duality trivially falls into the Denisyuk thick-film class of holograms, not the projective 2D-to-3D (or 3D-to-4D) holograms of Ads/CFT ilk.

      Strings, supersymmetry, and AdS geometry were all added later to ‘t Hooft’s work. Since no experimental evidence exists for these three ideas, it is prudent to ignore them. ‘t Hooft’s paper is still the sandwich’s real meat, especially since the layers of bread slapped around it have gone a bit moldy in the decades since.

      The core of ‘t Hooft’s impressive argument is that some form of information density magic is going on at the event horizon of black holes. He makes a persuasive case.

      Holographic quantum duality becomes abruptly relevant when ‘t Hooft introduces the idea of “One Boolean variable per Planckian surface element.” In other words, ‘t Hooft assumes that bits are simpler and more fundamental than the rest of reality and so can be made arbitrarily small, including down to Planck scales.

      This idea is just wrong. Bits are more classical than particles since the only way they can achieve near-100% reliability is by using classical equipment to stabilize and give meaning to quantum numbers such as spin orientations. Bits are, in effect, one of the purest possible forms of xyz holographic image projection and thus powerfully constrained by the resolution available in that hologram.

      The simplest surmise is that bits do exist on the event horizons of black holes, but only at the far lower densities enabled by the actual and finite mass of the black hole. Interestingly, in holographic duality, such bits must link via the momentum space image to the rest of the universe.

      Thus, matter in a quantum holographic black hole cannot be genuinely black. It can only become highly inaccessible and concentrated at the event horizon.


      [1] ’t Hooft, G. Dimensional Reduction in Quantum Gravity. arXiv, 1993.
      https://arxiv.org/abs/gr-qc/9310026

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  18. Steven Evans might be harsh sometimes, but that's because your blog attracts people who from a scientific and logic point of view say things that are absolute nonsense. You can always not approve his comments, but then we'll have things like "dreams could contain information about the future" (!) or "I have been interested in science, the occult and psychic abilities" (!!) both statements that negate what common sense, logic and science is all about. Steven can't stand it, and he says it. He confronts and shows how ridicule these things are. It's your call but for me the blog get's poorer without Steven comments.

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    1. MBC6:52 PM, March 31, 2021

      Thanks for the vote of confidence. But Dr. H. is right. And there are clearly stated commenting rules for the blog. Light sarcasm is going to be the way forward for me.

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    2. Please do and please note that straightforwardness is not ruled out.

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    3. 'Ridiculous' may be a factual assessment but I get to say it anyway, and it's up to Dr. Hossenfelder to approve comments or not.
      Steven Evans was behaving like some nasty creature who left reeking piles of guano everywhere.

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    4. "Only losers cry out for fair play" (Unspiek, Baron Bodissey)

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    5. There aren't any special prizes for putting up with shit, nor for being shitty.

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    6. You are wrong. There is at least one, the Bullshit Prize. Congratulations! You really deserve it.

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    7. Bravo you win. Go and tell your mum.

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  19. I also think that this blog is interesting in great part because people like Steven (i.e. boasting some real solid knowledge under their belts) write their thoughts, occasional musings and/or occasionally respond/analyze other messages showing inconsistencies, etc. In general, do whatever anyone likes, as there are obviously no homicidal messages here.

    Yeah, perhaps not everything could be dry and official or pleasant and tidy but that's often how we learn. There are basically two options for laymen (including myself) - they are ignored or answered straightforwardly (w/o second thoughts). I personally would take the second option anytime. Otherwise, we are going to a system of "levels of access", i.e. stratification, where trained people talk among themselves and laymen among themselves and they hardly mix. Or everyone moves to GitHub (or better - Coq) and we forget how to talk at all. To me personally that is appalling (that there is no open channels of communication w/o layers of policies, etc.), hence, the message.

    I personally haven't read anything extreme in above messages, just some involved conversation (c'mon! smoking room talks - you all are free to call me jackass or insane anytime), but maybe I don't get something (culturally or otherwise). Making it all dry and official may lead to outflow of incentive of a person with knowledge to answer (that is, pay or no pay systems!).

    On more concrete notes. Steven major arguments are steeped in knowledge, not opinion (i.e. to which most personal experiences, especially of untrained to understand them men belong, like in psychological cases and even altered states of consciousness, induced by psychedelics and some types of practices, which are still in accord with science, some are just pushing the envelope, but that's a different thing). Most of such arguments, especially concerning the topics of telepathy and the like, are neatly organized and covered in a book by Carl Sagan, "The Demon-Haunted World" written *exactly* for those purposes - to clarify what's wrong with such claims, opinions, how they may lead to mass psychosis, and further on to how are they different from scientific knowledge and how science works. That book is accessible to anyone who can read.

    PS Maybe book recommendations is generally a cool feature to have! I would certainly be interested if people, here and there, leave references to literature (any literature). But that's just my opinion. Still working with...
    "The first principle is that you must not fool yourself — and you are the easiest person to fool."

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    1. I think the best aspect of this blog is the mix of conversations. (I've probably been to enthusiastic in sharing my interests, to be honest).
      A great thing is how people are debating each other, another is the sharing of knowledge.

      That one has better knowledge than others is no excuse for incivility, though. I appreciate that Steven Evans has taken on being more polite.

      If Sagan etc. thoroughly debunk my speculation, I'll be just as interested in finding that out.

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    2. *Too enthusiastic. I wish blogs let us edit comments.
      For the record, if Dr. Hossenfelder or another presenter I watch ever made a video debunking paranormal/psychic stuff, I'd enjoy seeing what they say.

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    3. Hi Vadim; If any scientific discussion were divided between two levels, between neophytes on the one hand and between specialists, you would find yourself with the same dual mind-matter problem; Remember that all propositions like multiverse, 20 dimensions or whatever, fine tuning were not invented by religious people, they were specialists; In addition to the fact that the word INFORMATION has a totally subjective connotation; The very word OBJECT, what really defines ?, Can something be defined outside a time interval?, that is, does something exist in the time interval (0-0) ?, I don't think so; Does NOTHING exist? Nothing seems to be a way of discriminating from our conscience at a classical level; but at a quantum level, does NOTHING exist ?; I mean, many of the words we use are suspiciously subjective and others may not make sense on a quantum level; it's just my opinion

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    4. @Luis "would find yourself with the same dual mind-matter problem"
      You find a division where there is none.

      "divided between two levels"
      It was a simplification to transfer the meaning. I don't want to formulate a philosophy. But even that is expressed by many philosophers of science.

      The point is simple enough to understand but not easy to implement in life. The first task is to find out what is known and how it is known. Then to grasp 'methodology' what constitutes scientific knowledge. And mainly what's the difference between knowledge distilled through that mill (backed by observations, math, critical thinking, etc.) and opinion (and personal experience). Admitting that is not always easy as the structure to understand some abstractions may require some serious study. Yet, in most cases it is either clear to the person himself (or made clear). The only trouble is in finding the shortest path on the map of knowledge, so to speak, as Wikipedia et al, do not transfer such structure.

      Then one can see what is involved, what methodology, structure of knowledge, what are the requirements in order for that knowledge to be approved (btw, criteria are ridiculously high in science & engineering). And on basis of that see the difficulties and proper questions or inconsistencies. That forms a basis for thinking. Then one can ponder about his case (whatever it is, most usually claimed 'strange' experiences are well studied and end up in neurophysiological circuitry, mediators, activation of different neural nets, etc.). The trouble is in seeing structure in both methodology (which is easy to grasp, as stated, e.g. Feynman, "What is Science?" transfers the whole message) and knowledge itself (that can be hard, depending on what person already knows and his capacities).

      So it's not a question of "professionals vs laymen" as such. But of personal responsibility for one's own thinking (in a sense of response-ability). I.e. one can know very little or nothing at all, yet is still capable to think and to learn - that does not require any prerequisites (exaggerating a bit, as that is also a physiological habit which must be worked out, but nothing exceptional) but willingness to think.

      If a person does not wish to learn, then exactly the opposite to openness happens, as nobody wants to talk in circles and waste their time, first - ignored, then some system of ratings is implemented (or moderators are introduced) which pushes him further down, i.e. stratification is inevitable. As it is happening all over the Internet. It's only a matter of time & resources and it will appear here (when Sabine will hopefully reach a million subscribers or so). Which in my personal opinion is a disgrace [that trend] as we are further and further isolate ourselves in our little bubbles and do not learn this way.

      Abstractions like information and object are very well defined in their respective contexts - check Shannon & Turing for information, and object is highly context-dependent.
      All your other questions just indicate holes in your epistemology, i.e. you are confusing contexts and mix everything into one heap.

      But back to the main question, which seems to be a rhetorical one, "why cant we learn to communicate on our own without any need to reach for authority?"

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    5. Hi Vadim, I think you did not understand my point, just try to say that subjectivism in any of its forms can be present in any human group regardless of its knowledge or scientific degree; Also try to say that not even the scientific methodology is a guarantee of objectivity since subjectivity is in every word and concepts, I don't think there are scientists and theorists who fully trust them, nor do I think they are so obedient. I ask you a question, I hope it is a legitimate question, do you believe that time and space exist a priori or a posteriori of quantum fields or is it a way in which fields are expressed or is it just a general methodological framework?

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    6. @Luis "do you believe"
      There is no need to believe in anything.

      But it's a question for a theoretical physicist and the one closely working on GR at that. So it's a methodological digression, to begin with, "I don't know".

      But further I can only consider that question based on my limited knowledge (and understanding of current state of affairs) and experience. Again, methodologically important as I'm stressing that it's not "my opinion", I just can consider that subject. So in a way, I start, o horror, philosophizing. But that's the only mode which is available to me currently (i.e. "I don't know, but I can think").

      So if you ask me about my understanding of spacetime, it's fully in accord with that expressed by Max Born in his "Einstein's Theory of Relativity":
      "In itself the four-dimensional space-time continuum is structureless. It is the actual relations of the world-points in it, which experiment discloses, that impresses a measure-determination and a geometry on it."

      The book is utterly beautiful on more than technical level and is a true philosophical work of an ingenious man, which might even be called truly spiritual as it is full of concern for generations to come and life in general. It is highly recommended as one of the best expositions of TR to general public, w/o the need to go into field equations derivation and tensor nightmare (which is impossible without proper math knowledge).

      And the beautiful answer Terry gave above is also approaching that delicate subject (in terms of energy-momentum) from somewhat information theoretic perspective but in the same vein.

      So in a way, it is indeed "just a general methodological framework". But those questions are quite delicate as they require some solid general knowledge (naturally, better good one, but who has it, i.e. working knowledge of field equations, peculiarities of experiments, computation models, etc.) of the structure of the theory (high levels of abstractions, but not illusions!).

      What I attempted to express is that it's more fruitful to start from the beginning, from the simple. But if you truly want to approach understanding of TR, then Max Born's book is in my opinion one of the best I've encountered (even better than Einstein's one for the general public, which is btw also solid and doesn't require any special math knowledge).

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    7. Hi Vadim, "Believe" is a very important word; The reason for my question is not to know about TR, what I was trying to say is that when you do not have a complete knowledge of the nature of "something", any answer will have some subjective content, I think that an objective knowledge is not reached from another objective position directly, lots of fruitless propositions are thrown into the trash along the way, which end up being" subjective trash "; but induced by "objective" knowledge, which forces the researcher to constantly question the objective bases of what he investigates. If the researcher had the luxury of totally refining his knowledge to the strictly objective, and not having speculations, hypotheses, philosophical positions, even "beliefs"; then the investigative process is paralyzed

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    8. @Luis You haven't got it. Read Feynman's article (carefully, it has it all).

      The rest is a word salad. You write about something without knowledge of it or understanding how to approach it, i.e. ask a researcher if he has such problems [not mockery, a serious proposal].

      You see where the trouble lies. You think something. Then you think that you know how another thinks [i.e. about another thinking which is alien to yours]. One can think about that, but in that case one has to understand the subject matter, study the thinking of a proper researcher (which is even more difficult) and study one's own thinking in relation to that 'other' thinking (what philosopher does). From all of them, the last one is the most difficult (not touching on a moment of practicality), but only in that case one can start thinking of some 'subjectivity' as an object of some study. That is, only after one's subjectivity has become 'like a stone', like a thing to the observer. Otherwise, the word subjective does not mean anything but unreflected mass of beliefs and prejudices. Like a pink elephant. What's the relation of pink elephant to spacetime or anything else? None, isn't it? It might have some relation to the thinking itself and how it cooks associations but that's another matter.

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    9. Hi Vadim ,from a materialistic perspective, the only thing that can be called "subjectivity" is human thought, objectively speaking, subjectivity is real because our thinking exists, if our thinking is objective or not depends on experience, in the case of the researcher It depends on the experiment, for example, Feyman diagrams are a subjective resource and are limited objective, since they do not contain complete information about reality. Subjectivity is not a bad word, the process of thinking is totally subjective, and that includes beliefs, prejudices, art, philosophy, science; objectivity is determined by correspondence with reality; And now comes my question, Does quantum theory and GR, their concepts and interpretations, correspond 100% to reality? Are they 100% objective, without any subjective content?

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    10. Ok, let's try a bit differently (naturally, if you want), but the situation won't move unless you:
      1. Read "What is Science?" by Feynman,
      2. Notice a case with elucidation of the principle of inertia,
      3. Notice how the situation was created by the father and the son ran to check,
      4. Notice the last sentence in the paragraph (what we observe and how we name it).
      That's in a nutshell how a thinking (not a 'thought', but a process) of a researcher operates (at least begins).

      Then check the situation, where Richard puts a question "What is Science?" to *himself* (I assure you he is not acting up):
      1. Notice the context,
      2. Notice that his thinking is already a thinking of a brilliant scientist (aware of that),
      3. Notice that he starts thinking about thinking of a teacher, *and* a group of teachers (generalizes to education), and his own thinking in that regard (how to share what is truly important? how to transfer the essence w/o chaff? how to "push", "stir", "move"? a genuine concern) and how his talk is organically developed around that,
      4. Notice that he doesn't speak "from authority" but creates a situation and elucidates all the necessary abstractions in the process (dynamically), going from examples to relations to principles (whether he names them or not is secondary). Leaving it to the audience to make up their minds.

      After that you may think and consider your operational understanding of the world and see what thinking (as a process) produces in response to that concretely. The observer in my reply above was not a proper reduction (not euphemism for 'subjectivity'), the process of observation was meant, which is instigated by a specific interaction. Then you can see (the process of observation) what comes up in such thinking and its clarification along the way.

      Otherwise, it's not even conceptual. You cannot talk of pink elephants in terms of yellow monkeys. Whether you call it 'subjectivity', 'human thought', 'real', 'reality', it's all something that can be replaced by 'unknown' in best case scenarios, but gibberish in most. And constantly referencing to other unknowns from the unknown that interests you personally is walking in circles. I.e. not only one will not know what exactly he wants, but he will not know that he wants (and how to approach it). So a question, "What do you really want?" will be a tautology in such case, and a question, "Do you really want something?" will either not be a clear one or be taken as an insult.

      PS "You" is impersonal (one, each, I, ego, human, etc.) except for cases where it's specified.

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    11. Vadim, Feyman describes the methodology, and in the book he should simplify how thinking works, but how many dead ends has his thought taken to arrive at a valid proposal? Here I call a valid proposal, one that can be demonstrated in a experiment, Now, what would happen if a proposition were impossible for the moment to be demonstrated by an experiment, but it is supported by the concepts and scientific methodology and also suggests that our consciousness or something conscious extends throughout the universe? Would not this provoke a variety of positions from materialism to all kinds of subjectivism? Would not this provoke a revision of the scientific bases to reorient or take a position? Or do theorists not make speculations and wait for God to give them the answer? The different positions that theorists, researchers and the public take will be varied, and that is my original argument, I have not traveled in circles.

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  20. Vadim6:35 PM, April 01, 2021

    "(i.e. boasting some real solid knowledge under their belts) "

    I have no expertise in physics. Dr. H. is a pro at a world class institute. Better to focus more on the blog posts than the rows below the line ;)

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    Replies
    1. Yeah, I get involved at times for no good reasons... But then again, I don't think there is such a thing as 'off-topic'. Some linguists postulate that that's how we learn to process uncomfortable situations - we express them, and only then we may process them and let them go.

      But not messing around with a jock of nerds :-)

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  21. I wonder how intensive debat there occurred in the topic of physics/math on something else; believings and feelings...

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  22. @Dr. Hossenfelder: Are some of my comments not making it through to the comment queue or are they not being approved?
    Some of the comments I've tried to make haven't been published and I am just trying to work out why. Thanks.

    ReplyDelete
    Replies
    1. Hi C Thompson:

      I seem to have missed some of your earlier comments, sorry about that. I have gotten a lot of spam comments in the past days that the filter didn't catch, and if that happens I sometimes I miss a "real" comment in between. This issue normally resolves within a few days; I guess it's because Google updates the spam filter. In any case, I hope it's all appeared now.

      Delete
    2. They're all there, thanks. I noticed I tend to comment a lot so trying to not spam here.
      If I do ever cause annoyance, please let me know.

      Delete
    3. Not an issue in principle, but in practice maybe keep in mind that if I get a lot of comments from the same sender in short period of time, it increases the risk that I miss approving one of them because I might mistakenly think I approved it already.

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  23. Sabine,

    this was the best explanation of holography which I have ever seen. Thank you!

    But the idea that the universe could be a holographic system shows me, which degree of weirdness theoretical physics has meanwhile reached.

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  24. C.T.,
    Re Bullfrog vs. Bullfox. That's quite alright. I can always use another alias. I see that Steven Evans has maligned your sanity. Welcome to the Steven Evans badge of honor club.

    ReplyDelete
    Replies
    1. Lol!
      There is a song by our esteemed Dr. Hossenfelder about being the thorn in such people's sides. These lyrics are pretty appropriate:

      Some of them say I’m not bright
      Some tell me that I am trite
      The only thing that they get right
      Is that I’m ev’rything that they dislike
      ...
      It's hilarious that such people are stuck thinking about little old me so much.

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  25. I was thinking about the holographic universe this morning as I was cleaning out the cat box. It occurred to me that I was involved in an olfactory hologram that had many of the same elements as a visual hologram. There was the substrate, the cat box and kitty litter. The information, deposited in the substrate by our cats, the odor perhaps holographic like wafting up and being carried through the house by the energy of air currents, and the observers, me and my wife.

    A visual hologram has the same five basic elements. the substrate, the information encoded in the substrate, the hologram itself, the observers, us, and the energy projecting the hologram, in this case photons. Turn off the light, no photons, no hologram.

    One would think the holographic universe would have the same elements if it were to be more of a hologram than my olfactory hologram There would have to be some substrate. Some unobservable surface out there somewhere, The substrate, being an unobservable, counts as a strike against the theory. Then there is the encoded information on the surface. I have not seen any detail about how the information is formated and encoded. Strike two. Then there is the universe which is supposed to be the hologram. I'm willing to admit the universe exists. Then there is the the observes, us and what ever other intelligent creatures might be lolly gagging around the universe. finally there is what ever undefined force or energy is projecting the hologram from two dimensions into three dimensions. Where the energy comes from to maintain the projection is unknown, and also unobserved. Count that as strike three.

    AS a lay person trying to assess the veracity of various far out theories, perhaps the biggest tell that there are big problems with the theory is that important elements of the theory are ill defined unobservables, and not much work seems to be being done by competent physicists to clarify the missing elements. So I would conclude that f nobody is trying to make a career out of the Holographic Universe then the theory is probably a real dead end.

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    Replies
    1. Hi Steve Bullfox,
      I like this olfactory analogy. I too wonder how that information of the Universe would actually be encoded. I asked that in the next post but so far nobody has answered.

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  26. Hi Sabine,
    one question - you say "Now, we don’t normally see light cancelling out other light. That’s because to see interference one needs very regular light, where the crests and troughs are neatly aligned. Sunlight or LED light doesn’t have that property. But laser light has it, and so laser light can be interfered."

    But photons dont normally interact or interfere with each other as they are bosons, just with themselves? I think the reason laser light in holograms is used is that it is monochromatic and the image is sharp, multiwavelengths of light produce blurry images.

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    Replies
    1. Stevo,

      An interference is not an interaction. And, yes, needless to say, you also can't align crests and throughs if you have different wavelenghts, but monochromatic light alone won't do.

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    2. Hello Stevo,
      if you like, you can also create interference fringes with a tungsten wire lamp (Edison lamp) and a spectrum of some 100nm. But the coherence length is only a few µm. That means the two arms of an interferometer must be exactly the same length within 1µm to see interference. And it is impossible to create a hologram with it.
      Stefan

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  27. Dear Sabine,
    ignore my last post. I get your meaning now

    ReplyDelete
  28. you guys can argue with a computer but can you sing, dance, and resonante and learn when reason has its limits

    ReplyDelete

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