Talk:Holographic principle

message: * Why does Holographic Universe search -- go to Holographic principle? Please fix it. It should go to Michael Coleman Talbot (H0riz0n (talk) 14:48, 29 September 2009 (UTC)
replies: text: No it shouldn't. --Michael C. Price talk 18:49, 29 September 2009 (UTC)
thread_title:  Holographic Universe search go to Holographic principle 

message: Currently the article is almost entirely about black holes and the Bekenstein bound, but the essence of what physicists mean by the "holographic principle" goes beyond this, and says that the dynamics inside any volume should be understandable in terms of the boundary of that region or some corresponding region in a space with a different number of dimensions. As I understand it, the key piece of evidence for this is the finding in string theory that there is an exact equivalence between the dynamics predicted by string theory in a region of 5D anti-deSitter spacetime, and the dynamics predicted by ordinary quantum field theory on the 4D boundary of this region (the CFT stands for 'conformal field theory', which I gather is a specific class of quantum field theory). For a good layman's explanation of this stuff, see the Scientific American article by Bekenstein that I added to the external links section.
Without this sort of generalization, it seems like the holographic principle would be nothing more than a synonym for the Bekenstein bound, and most of the article at present is just duplicating stuff already seen in the Bekenstein bound article. If nothing else, the article at least needs to make it clear that the holographic principle is a hypothesis which goes beyond just talking about the boundaries of black holes. Hypnosifl 20:34, 2 December 2006 (UTC)
thread_title:  Article needs more on the [[AdS/CFT correspondence]] 

message: I removed a statement saying that the bound of entropy in space is Bek. Bound.  The Bekenstein bound - which is a bit controversial - is something else, a bound on the entropy of an obect of a given size AND energy.  S<A/4 is now part of the Covariant Entropy Bound (aka Bousso Bound).PhysPhD 22:33, 17 April 2007 (UTC)
thread_title: Bekenstein Bound

message: "One bit equals 2 nats" is false and must be fixed.
:Done --Michael C. Price talk 00:31, 1 July 2007 (UTC)
thread_title:  Error found (bits and nats) 

message: This reads as a great science article and as a lay person with some grasp of physics, it makes no sense to me. I would encourage knowledgable people to re-write it so that it as encyclopedia article- accesible to everyone. Sethie 16:45, 13 August 2007 (UTC)
replies: text: Agreed...I think the SciAm article (as stated above) is a good layman's reference, was written by Wheeler's student Bekenstein, and I will take a stab at paraphrasing in attempt not to re-write, but to add Beckenstein quotes here and there explain. riverguy42 aka WNDL42 (talk) 16:57, 30 January 2008 (UTC)
replies: text: Second update to "High level overview just now, comments and suggestions? WNDL42 (talk) 17:45, 7 February 2008 (UTC)
thread_title: Feedback

message: I would like to suggest adding a book to the references: "The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics“  by Leonard Susskind. This book gives a good overview and history by one authors of this priciple.  —Preceding unsigned comment added by Leifshu (talk • contribs) 17:01, 17 August 2008 (UTC)
thread_title:  The Black Hole War 

message: http://www.newscientist.com/article/mg20126911.300-our-world-may-be-a-giant-hologram.html?full=true --Wongba (talk) 18:55, 15 January 2009 (UTC)
replies: text: I must read the paper and see how they derive this graininess -- IIUIC the holographic principle is subsumed by the more general Bekenstein bound, which requires the information density scales inversely with the scale of the universe -- which seems weird until we recall that, holding the total energy constant, that the matter density scales with the inverse cube of the scale factor.  So there is more information per particle as the universe expands -- so no "blur out".--Michael C. Price talk 20:29, 24 January 2009 (UTC)

text: We agree that information density is decreasing ; my point is that it is decreasing less quickly than particle density, hence "there is more information per particle as the universe expands"; not perhaps a very profound observation, but sufficient to avert "blur out".--Michael C. Price talk 16:55, 25 January 2009 (UTC)
thread_title:  possible evidence of holographic universe 

message: This is a great reference, and it should be mentioned, and I haven't read it all yet. But my first impression after a cursory glance is that it is not completely fair to claim full priority for the earlier authors for the matrix formulation. But its unbelievable that they got so close so early, and they should definitely be mentioned.
The question is the physical interpretation. In the earlier paper, there's an interpretation that a certain large N limit of the matrix model will reproduce the membrane dynamics. I don't think you can say that this includes the holographic principle implicitly, although it might. It is motivated by string expansion, and this expansion contains some stunted version of holography inside, so it's hard to say "no this isn't holography" or "yes this holography" for sure.
The motivation is discrete chopping up of the M2 brane to get a good quantization, which does not give confidence that the matrix formulation will include the fivebranes and gravitons as well (but maybe the original authors understood it better). You could only be sure that everything is included by the holographic principle and by having a good black hole interpretation for the objects that are carrying the matrices around. That essential physical insight, that the D0 branes can serve as the "string bits" (or "membrane bits" in this case), came in 1995 from BFSS, immediately following Witten's famous analysis of D0 brane spectrum in IIA, and the D0-brane action was a reduction of more complicated D-brane actions in a light-cone way that has a physical interpretation which allows you to be sure that you can really reconstruct all the objects from the  large N matrix model, and that the finite N part is also physical, not just the limit. This is exactly AdS/CFT, but a little earlier.
I have to admit that the BFSS paper seemed like magic to me. I couldn't understand how something like that could ever have been dreamed up. This earlier reference helps a lot to understand how this type of magic works. So maybe it should read "following an approach pioneered in early work of deWit Hoppe and Nicolai, BFSS were able to intepret the matrix models proposed by the earlier authors as holographic actions for a physical black hole type in string theory and thereby give the first arguments that these form a complete nonperturbative formulation of M-theory."
There's also the discrete string-bit approaches, which led to other matrix models in low dimensions. Maybe these should be mentioned as precursors too.Likebox (talk) 20:34, 20 May 2009 (UTC)
thread_title:  deWit/Hoppe/Nicolai Matrix Models and Matrix theory 

message: The best reference for 'tHooft's ideas in a form closest to string theory is the stuff he did in the 80s regarding the black hole S-matrix and the deformation of the horizon for an infalling particle. One of these papers is reprinted in "Under the Spell of the Gauge Principle", and another is in some issue of Nuclear Physics B. The Nuclear Physics B article is better than the 1993 article, in my opinion, because it includes the "imaginary action" string action for radial black hole deformations from the analysis of small body impacts. While this is not precisely modern, its probably slightly wrong in details because the black hole is thermal, its close enough that the modern picture can be deduced from it. I don't know whether there is a good freely available link to these classic papers.Likebox (talk) 18:47, 27 May 2009 (UTC)
thread_title:  86 't Hooft work 

message: Would the Holographic Universe be an explanation for quantum entanglement? It strikes me rather simplistically that items can interact at a distance if they are really not at a distance, but only appear to be so - e.g. the location of the 'emitter' is given, the emitted particles appear to diverge, but in the "superbrane" they do not diverge until they are disturbed on a "superbrane" level. Until that point it should appear to us that finding state A of one "causes" the other to take on state B, while in reality you have simply pulled A out of an invisible bag meaning that B must remain. Could someone comment?158.143.136.205 (talk) 14:45, 29 October 2009 (UTC)
thread_title:  Holographic Universe and Spooky Action at a Distance 

message: In this article it says that the holographic principle implies that "volume is illusory". Wouldn't it be more accurate to say that space becomes emergent, so that space is illusory? (or at least, not fundamental) I really don't think I understand this stuff, but it doesn't seem to jive on a conceptual level with what I've read before. Danski14(talk) 22:32, 8 September 2010 (UTC)
thread_title: Is this correct??

message: There is a fundamental flaw, possibly, in this interpretation of the relation between entropy and information. It is said that the entropy is proportional to the amount of information. However, the Shannon information is a measure of the amount of information MISSING in a message = uncertainty.
This would imply that the amount of information (in the form of bits or nats) on the screen is actually decreasing (lost) as time evolves and the entropy increases, not the other way around.  —Preceding unsigned comment added by 217.128.46.38 (talk) 18:00, 16 November 2010 (UTC)
replies: text: These are not in conflict. Per both entropy (information theory) and entropy (statistical thermodynamics), the entropy of a system is the amount of information encoded within the parts of the system state you're calling "missing information". Calling this "missing" is a misnomer, as the information is present. The "non-missing" information in your terms would be the macroscopic properties properties of a system such as temperature and pressure of a gas (for thermodynamics) or length and total number of 1s and 0s (for a bit stream). The "missing" information is encoded in a detailed description of the system's microstate (for thermodynamics) or the actual pattern of bits involved (for a bit stream). "Entropy" in this article is referring to the amount of information encoded in the choice of microstate. --Christopher Thomas (talk) 07:39, 21 November 2010 (UTC)

text: You are thinking of information in human terms (a picture), not in terms of the number of microstates. The number of arrangements of atoms in which an uncorrupted photograph exists is much smaller than the number of arrangements of atoms in which a damaged photograph exists. To put it in terms of information storage, the universe is encoding information in exactly what damage occurs to the photograph. It isn't information we care about, but it's still there as part of the system microstate. As there are many more possible damaged phorographs than possible undamaged ones, the amount of information present (determined by selecting which damaged phorograph exists) has increased. --Christopher Thomas (talk) 19:21, 22 November 2010 (UTC)
replies: text: Entropy has been described by L.Susskind as "hidden information". It is a counter-intuitive fact (accepted by virtually all physicists; or rather corollaries of this 'fact' are generally accepted as being required for Physics to "work") that for ANY isolated system, the amount of information is constant. That is: information can be neither created nor destroyed. (As an arm-chair observer, I find this hard to buy, but there you go).  Entropy is the information which isn't 'available', and can be described as the number of microstates which are indistinguishable from the given state divided by all possible states. Entropy is a better term than "information" because it is more specific. If someone uses the term "information" they may mean the ensemble of possible states OR the ensemble of indistinguishable states OR the total ensemble of possible states less the indistinguishable states OR.... They're completely different things.  You can see how using the term often causes confusion. Your example of a photograph is fundamentally flawed: the weathering you describe is only possible in an open system. You failed to consider the ENTIRE (isolated) system (you MUST include the sunlight and rain, etc.!) The fact is that cause and effect require that any change to one silver particle (say) by one photon, could be "run backward" with the colloidal particle of silver emitting a photon and recovering its information (image pixel). IOW, the information encoded in the photo becomes encoded in the motions of the atoms and photons which interact with it. The information is NOT (in some theoretical sense) lost, but becomes hidden or unavailable. Its a subtle concept. It is even MORE difficult when dealing with quantum mechanics and the uncertainty principle. That's too complex to deal with here.(And I am not competent to deal with that, anyhoo.) And of course, talking about a "true" "isolated system" which isn't affected by external gravitational forces is fantasy...Abitslow (talk) 23:30, 1 March 2015 (UTC)
thread_title: Information

message: "That volume itself is illusory and the universe is really a hologram which is isomorphic to the information "inscribed" on the surface of its boundary"
Yes, in fact, we call this a shape and the Latin etymology of the word information means shaping or creating a shape.
We remark, indeed, at the quantum level, the macroscopic volume is an illusion; emptiness is the only true reality. Even universes composed of compact balls attached to each other obey to the holographic principle.
The introduction of the concept of "information" into physics is revolutionary but the shape... it has always existed in front of all physicists.
It's like the color of the wings of flies that remained hidden for 300 years just because we looked them on white cards... We had to watch them on black cards...or a black hole.
--Nipou (d) French Wiki  — Preceding unsigned comment added by 96.20.8.46 (talk) 21:25, 19 June 2011 (UTC)
replies: text: I don't see the relation you make with the concept of shape. (That would be more inline with a theory with conformal invariance.)TR 10:12, 20 June 2011 (UTC)
replies: text: He appears to be confused about what the holographic principle actually is. From what I can tell, his argument boils down to "the holographic principle describes a surface that bounds a volume, but topologists have been doing that for ages, so it's trivial". This doesn't demonstrate any understanding of the key points of the holographic principle, which is why I didn't consider it useful to respond to his/her original post. --Christopher Thomas (talk) 22:39, 20 June 2011 (UTC)
thread_title: The shape is now a physical concept?

message: Question: The limit to the density of information does not give us a formal limit to the largest buildable Schrödinger's cat? It would thus be a constraint on quantum entanglement.
--Nipou (d) French Wiki  — Preceding unsigned comment added by 96.20.8.46 (talk) 21:33, 19 June 2011 (UTC)
thread_title: Schrödinger's cat

message: I'm only a maths & theoretical physics undergrad, so I have no in-depth knowledge on this topic. I noticed the section Limit on information density says: “The holographic principle thus implies that the subdivisions must stop at some level, and that the fundamental particle is a bit (1 or 0) of information.”. Should this be qubit instead of bit? Wouldn't a quantum theory of thermodynamics presumably use qubits instead of bits? IMHO the use of "bit" in this context seems to me at odds with quantum mechanics and quantum information theory, which are surely essential to any fundamental description of reality, especially of the sort described in the above quote.
On a separate note, I wonder whether the more scientific terms "embedded" or "encoded" (the latter's used elsewhere in the article) might be more appropriate than the rather poetic terms "painted" and "inscribed" that the article occasionally uses: i.e. “the entire universe can be seen as a two-dimensional information structure "painted" on the cosmological horizon” and  “the universe is really a hologram which is isomorphic to the information "inscribed" on the surface of its boundary”. IMHO it would also make the article more consistent in its use of terms as well as sounding more encyclopedic.
Anyway, just my two cents. Annoyamouse (talk) 20:45, 2 December 2011 (UTC)
replies: text: On further thought, shouldn't this be a "qunat" (i.e. a quantum nat) since “The nat is the natural unit for information entropy.” (see Nat (information))? Personally, I've never seen the term "qunat" used on Wikipedia, though I guess it's just a special case of the qudit such that d = e. However, IMHO this seems to me to be the relevant unit of measure for what the article text is describing. As I'm only an undergrad, and have no knowledge of this field, it would be interesting to get an expert on this topic to give some feedback on what the correct unit is. By the way, I've retitled the section heading to "Bits or qunats?" instead of "Bits or qubits?" to reflect this second post. Annoyamouse (talk) 02:09, 7 December 2011 (UTC)
thread_title:  Bits or qunats? 

message: Equations are written on, like, paper and stuff. 192.139.122.42 (talk) 22:41, 24 October 2012 (UTC)
replies: text: you need better drugs yours are weak  — Preceding unsigned comment added by 88.108.239.94 (talk) 01:53, 28 October 2013 (UTC)
thread_title:  All physics is two-dimensional. 

message: I've recently edited this article, because of the undue weight given to Craig Hogan's claims. It is not justifiable to associate Hogan's claims with the whole holographic principle. If we leave aside the one self-cite and the 4 cites by experiments, this paper has earned exactly two citations since 2009, neither of which lend any credence to the idea that Hogan's idea is relevant to the whole holographic principle. In particular it doesn't seem to have anything to do with string theory, which makes the relevance of his claims for this page especially doubtful. Isocliff (talk) 18:50, 8 April 2013 (UTC)
thread_title:  Hogan's Holographic Noise 

message: Greetings, I find this fascinating.  Apparently two papers came out in Japan recently which lend some mathematical plausibility to this theory.  Someone smarter than me would have to do the heavy lifting of integrating the information into this page:
http://www.nature.com/news/simulations-back-up-theory-that-universe-is-a-hologram-1.14328
Thanks!  Joel J. Rane (talk) 10:00, 13 December 2013 (UTC)
replies: text: Hi Joel, do you think I should add more information or is it comprehensible as it is? I can't tell. Thanks! (talk) Alma 12:52, 20 December 2013 (UTC)
thread_title:  Recent Hyakutake Papers 

message: I question the wisdom of using "Recent" as a section title. It isn't a very good idea, unless this page is being frequently monitored and updated. What was recent in 2014 is going be NOT recent in a couple of years. I also question the relevance of the information in the section. A computer model of a Universe which isn't our Universe is hardly evidence AND CERTAINLY NOT EVIDENCE OF WHAT IS "TRUE"!! 
I'm out of my depth here, but our Universe is NOT AdS/CFT, is it? (I just read that Wikipedia article, which makes that very clear.) Somebody apparently believes that if the "right" result is obtained from a "toy model", then we can quote it as evidence. Rubbish. I don't see how it is even suggestive, since the holographic principle must at least be nearly as consistent as the theory (and speculations) used to obtain it in the first place, right? Starting with it, and modeling a toy Universe, is hardly meaningful. (Not saying it isn't worthwhile, but only to advance THE EXPERTS understanding. It doesn't significanly add to what we know. I think its counting angels dancing on the head of a pin: only of interest to fanboys and experts.)Abitslow (talk) 23:49, 1 March 2015 (UTC)
thread_title:  Recent Work 

message: The categorization of the article, and the introduction, talk a lot about string theory, as though the most important thing in the article is the relationship of the ideas to string theory. The rest of the article seems to say nothing at all about string theory. It looks like the results may be independent of string theory. If so then Occam's Razor tells us we should simplify by removing string theory from the central discussion. String theory could be perhaps referenced as a footnote to the article - nothing more.  — Preceding unsigned comment added by 54.240.196.169 (talk) 08:15, 28 April 2015 (UTC)
thread_title:  Remove string theory primacy 

message: As implied in the "see also" link, which suggests some relation, not just things editors happen to like, like, "see also: kittens". I don't know much about physics and whatnot, but as far as I know the holographic principle is not a "requirement" nor something that hints particularly more at the hypothesis that the universe is a simulation, than somehow "falsifying" the principle, or the non-instrumentalist interpretation, if it makes sense. To me it seems that the connection stems mainly from the notion that most known holograms are man-made things, so it's not that much different than just pointing at "physical laws" as a connection to the simulation hypothesis and vice-versa, since "laws" are man-made things. It just happens that we're more used now to the concept of natural/intrinsic "physical laws", without implying in creationism. The inter-link is also on the simulation hypothesis article. That and perhaps the term "matrix" and the movie with the same name. At a quick control+f scan, the inter-links are the only mentions of the linked concept in each article.
::The simulation hypothesis is a great shortcut to the answer, because anything you want to conclude is just placed in the assumptions.  That leads to a sort of war for who can create the greatest tautology, like saying ER%3DEPR. Maximum tautology size is the only possible measure of success.  For example, it can also be extended to include the binary structure of the genetic code being isomorphic with the King_Wen_sequence#Dual_hexagrams of the I Ching, as you can see here: https://stedt.berkeley.edu/pubs.html#mng5 .  However, we are all limited in what we can propose by the National Academy of Science, which has concluded that Intelligent_design is pseudoscience.  Physicists are clearly intelligent and they are designing (a theory of) the universe, therefore it is by NAS definition pseudoscience. Charles Juvon (talk) 02:34, 29 December 2020 (UTC)
thread_title:  What's the connection with the hypothesis that the universe is a simulation? 

message: Substituted at 18:10, 29 April 2016 (UTC)
thread_title: Assessment comment

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thread_title:  External links modified 

message: Here is the start of the second paragraph of the article. This sentence seems illogical to me. Can someone who knows what this is supposed to mean break it down in some way please? 
"In a larger sense, the theory suggests that the entire universe can be seen as two-dimensional information on the cosmological horizon, the event horizon from which information may still be gathered and not lost due to the natural limitations of spacetime supporting a black hole, an observer and a given setting of these specific elements,[clarification needed] such that the three dimensions we observe are an effective description only at macroscopic scales and at low energies."  — Preceding unsigned comment added by 82.72.139.164 (talk) 03:31, 20 June 2017 (UTC)
thread_title:  What does this sentence mean ?? 

message: Some have tried to create pixelated Bloch-like spheres, wired with many others - this requires a humongous amount of all possible connections; also that generates quantization noise, because the actual Bloch spheres aren't pixelated.
* this is a major question - if the holographic principle is true, then a classical computer may mimick (with bigger data) the quantum phenomena (it's not answered yet - some tried to use a noise generator - also we have to mimick all the quantum behavior, even the percentages of random non-entangled results versus random and entangled results)  — Preceding unsigned comment added by 2A02:2149:8227:F600:2056:F713:B40A:C68E (talk) 00:33, 12 May 2018 (UTC)
thread_title:  If the holographic principle is true a classic computer may mimick a quantum one 

message: As pointed out by Raphael Bousso, Thorn observed in 1978 that string theory admits a lower-dimensional description in which gravity emerges from it in what would now be called a holographic way.
Wearing my linguistic hat for a moment, the scope of this modifier is ambiguous. It could apply to the proposition that Thorn observed something in 1978 (or that Thorn observed something, not necessarily in 1978) or it could apply to how "string theory admits" or merely to the "lower-dimensional description" on its own terms, without necessarily going so far as to posit that "string theory admits" this. 
Sentence modifiers do so love impersonating lazy, hazy writing. Furthermore, it glides unctuously over such details as when Bousso pointed this out, and to whom, and if he pointed it out to anyone important, as something thought to be important at the time, why he's now being tucked into this sentence as a murky afterthought. — MaxEnt 14:40, 16 December 2018 (UTC)
thread_title:  As pointed out 

message: The information is not in both the 2D black hole sphere and the interior of the black hole.
It is in superposition and decides where to be materialized/reified/objectified after the measurement.
Measurement is to hit stuff with stuff; so natural "measurements" occur, because true black holes are hairy/imperfect and turbulent.
The higher the energy pressure, the more likely it gets to detect the particle moving afar from the holographic horizon it belonged. For a black hole the pressure is at the maximum. The "measured" particle appears as afar from the horizon as the energy of the measuring/hitting particle was. To measure = to be someone and to hit someone else. (Thus almost no particle becomes reified exactly at the horizon, because energies of measuring thrashers is usually high..... That's an issue. According to the standard view, no particle can ever reach an abolute zero energy when it acts a thrashing measurer of other particles in a black hole, so we have an eternal back and forward motion of particles which bounce off the black hole and immediately re-enter because all paths lead to the black hole... almost all, 99,999999...% with some Hawking radiation escaping. Actual black holes aren't as perfect as taught in universities.)
— Preceding unsigned comment added by 2a02:587:4111:8300:6c10:9423:59d1:91bc (talk) 09:14, 11 April 2019 (UTC)
thread_title:  Information is in [[superposition]] in 2D on the black hole hairy sphere, and inside 

message: It's constituents:
# 1/10 of its mass (that is not a constant, it changes with the mass of the black hole) is a conveyer of particles relatively near the black hole atmosphere (billions of kilometers and more); particles collide with other particles and re-enter in a vortex and not in a straight path the surface
# most of its mass, its dark energy; Dark energy is a phenomenon of space. It is not a weird particle, but a relativistic mechanism of spacetime. The extremely big black holes are 50/1 dark matter/matter and even more.
— Preceding unsigned comment added by 2a02:587:4123:6d00:6c10:9423:59d1:91bc (talk) 09:29, 11 April 2019 (UTC)
thread_title:  The black hole is a phenomenon which has components 

message: A system's lowers possible informational density is extremely crucial. If you try to delete or spread afar information at a very fast pace, the whole system explodes. Big Bang causality is linked to that.  — Preceding unsigned comment added by 2A02:587:4102:B000:DC36:6B05:57BD:8DE7 (talk) 15:23, 26 April 2019 (UTC)
replies: text: It appears that quite a few unusual ideas are being proposed in the above sections. What we need is references where people have published something about them. I suspect original research, in which case, Wikipedia is not the right venue. Graeme Bartlett (talk) 11:05, 28 April 2019 (UTC)
thread_title:  The problem with non defining the lower possible amount of information/holographic information content 

message: Travel to India; discuss to the professors and add here the link.
the Indian Institute of Science will do, but ask more professors
:We cannot get content by asking people. Instead the references have to be recorded somehow so that others can verify them. Normally these would be written references, but video or sound recordings are OK too if they are reliable.  Graeme Bartlett (talk) 11:50, 3 May 2019 (UTC)
thread_title:  Singularity isn't possible because there is a Plankian limit of compression (the holographic principle applies partially, so does the Schwarzschild radius; but not strictly for so small sizes [actuality is more unstable than these predictions, this means higher decay rate]) 

message: === which version of the article this comment is about === 
This comment is based on (it is about) the current version (that is, the "Latest revision as of 03:05, 25 February 2020" version) of the article. 
=== which sentence in the article this comment is about === 
In that version of the article, the last sentence before the beginning of the section of the article called "The AdS/CFT correspondence" says, (in part):The existence of such solutions conflicts with [...] and their effects in [...] including the holographic principle are not fully understood yet.[5] 
=== What does the word "yet" mean, there? === 
I may not I do not understand most of the science that this article is about. 
I do not understand all of that science, even when considering "only" those parts that are "fully understood" -- (by some person[s]) -- as of today. (Actually, I probably understand little or none of it). 
However, I do understand that footnote number "[5]" -- shown in square brackets at the end of the above quoted [partial] excerpt -- references a reliable source that is over a decade old. The word "yet" in that excerpt probably means either 
* [a] as of when the sentence that contains that word was written; 
OR 
* [b] as of the date (2009) of the reliable source that is mentioned in footnote "[5]" -- (and hence, is 'relied upon' by that footnote... which 'in turn' is 'relied upon' by that whole sentence). 
=== suggestion for a possible edit  === 
Either way, the meaning of that word ("yet") is not (necessarily) as of when the reader is reading the sentence that contains that word. 
It is (more like) as of some time in the past. 
Hence, I suggest that the sentence should be changed, to specify either [a] or [b].(probably "[b]" ... right?)
That could be done (e.g.) by inserting a parenthetical phrase, such as << (at least, as of 2009) >>, right before the words "not fully understood yet" in that sentence. Thus, the sentence would read something like this:The existence of such solutions conflicts with [...] and their effects in [...] including the holographic principle are (at least, as of 2009) not fully understood yet.[5] 
It might also be appropriate to change the word "are" to use the past tense ("were") instead. Maybe that could be done via a separate edit. 
=== Any comments? === 
Do you agree? --Mike Schwartz (talk) 08:40, 30 March 2020 (UTC)
thread_title:  possible minor change to the wording  

message: Do you agree? --Mike Schwartz (talk) 08:40, 30 March 2020 (UTC)
thread_title:  Any comments? 

message: Not sure so posted. Are physics articles from WP allowed?
Is the book by M Talbot, mentioned the work of David Bohm and one other physicist. RetrievedJuice23 (talk) 11:16, 24 May 2021 (UTC)
thread_title:  More references to physics articles 

message: “The three-dimensional world of ordinary experience––the universe filled with galaxies, stars, planets, houses, boulders, and people––is a hologram, an image of reality cited on a distant two-dimensional (2D) surface."
The word "cited" here feels wrong (or at least very odd), and indeed the majority of Google results (152 to 101) suggest the actual word used was "coded" rather than "cited", with the rest of the quote identical, suggesting that someone got it wrong somewhere (perhaps the book referenced) and people have been propagating the error ever since. 2601:245:4100:B781:D003:DE1:31E6:5F88 (talk) 02:02, 15 May 2022 (UTC)
replies: text: You're right, thanks for pointing that out. I've fixed it. Schazjmd (talk) 14:24, 15 May 2022 (UTC)
thread_title:  Is the Susskind quote wrong?