Is Our Universe Inside Another Larger Universe?


A wormhole is a hypothetical “tunnel” connecting two different points in spacetime, and in theory, at each end of the wormhole there could be two universes. Theoretical physicist Nikodem Poplawski from Indiana University has taken things a step further by proposing that perhaps our universe could be located within the interior of a wormhole which itself is part of a black hole that lies within a much larger universe.

Whoa. I may have just lost my bearings.

As crazy as the concept of wormholes sounds, it does offer solutions to the equations of Einstein’s general theory of relativity. In fact, wormholes – also called an Einstein-Rosen Bridge — offer such a great solution that some theorists think that real wormholes may eventually be found or even created, and perhaps they could even be used for high-speed travel between two areas in space, or maybe even time travel.

However, a known property of wormholes is that they are highly unstable and would probably collapse instantly if even the tiniest amount of matter, such as a single photon, tried to travel though them.

But would it work – and could matter exist — if we were inside a wormhole inside a black hole inside another universe? Poplawski thinks so. He takes advantage of the Euclidean-based coordinate system called isotropic coordinates to describe the gravitational field of a black hole and to model the radial geodesic motion of a massive particle into a black hole.

“This condition would be satisfied if our universe were the interior of a black hole existing in a bigger universe,” Poplawski said. “Because Einstein’s general theory of relativity does not choose a time orientation, if a black hole can form from the gravitational collapse of matter through an event horizon in the future then the reverse process is also possible. Such a process would describe an exploding white hole: matter emerging from an event horizon in the past, like the expanding universe.”

So, a white hole would be connected to a black hole a wormhole, and is hypothetically the time reversal of a black hole. (Oh my, I’m now dizzy…)

Poplawski’s paper suggests that all astrophysical black holes, not just Schwarzschild and Einstein-Rosen black holes, may have Einstein-Rosen bridges, each with a new universe inside that formed simultaneously with the black hole.

“From that it follows that our universe could have itself formed from inside a black hole existing inside another universe,” he said.

IU theoretical physicist Nikodem Poplawski. Credit: Indiana University

By continuing to study the gravitational collapse of a sphere of dust in isotropic coordinates, and by applying the current research to other types of black holes, views where the universe is born from the interior of an Einstein-Rosen black hole could avoid problems seen by scientists with the Big Bang theory and the black hole information loss problem which claims all information about matter is lost as it goes over the event horizon (in turn defying the laws of quantum physics).

Poplawski theorizes that this model in isotropic coordinates of the universe as a black hole could explain the origin of cosmic inflation.

Could this be tested? Well, there is the issue that to see if an object could travel through a wormhole, the observer would have to be inside the wormhole as well, since the interior cannot be observed unless an observer enters or resides within.

A possible solution is that exotic matter wouldn’t collapse the wormhole, so we’d have to create – and be made of – exotic matter to keep the it open. But perhaps, as Poplawski proposes, if the wormhole is inside a black hole inside another universe it would work.

Anyone ready to give it a try?

Radial motion into an Einstein-Rosen bridge,” Physics Letters B, by Nikodem J. Poplawski. (Volume 687, Issues 2-3, 12 April 2010, Pages 110-113.

Sources: Indiana University
, Internet Encyclopedia of Science

40 Replies to “Is Our Universe Inside Another Larger Universe?”

  1. This may explain the popularity of reality television. I think this guy’s onto something.

  2. Not Deep Space Nine, Stargate SG 1, one of my favorite shows. Take me to the gate, I’ll go tomorrow!

  3. To put some seriousness on this, there are reasons to presume connections between wormholes and black holes and cosmologies. I have only given Poplawski’s paper a a brief overview at this point. I will try to give a description of a wormhole. It is similar to a black hole from the standpoint of an observer on the outside. Gravity tends to focus the paths of particles inwards. There is a condition for this called the Hawking-Penrose energy condition, which basically says the energy E or T^{00} > or = 0. This energy condition for the wormhole is violated. Around where the black hole horizon is there is a shell of some sort, some exotic quantum field or matter, which violates this condition. So in falling particles on focusing paths must suddenly diverge from each other upon reacing this shell. The particles in effect go elswhere to diverge, for they can’t “back out.” This place elsewhere is a copy of the same gravity well with this “shell” and the particle diverge in this other region. This shell is sometimes called a Lancsoz function. So this defines a multiply connected topology for the spacetime.

    Curiously if one of the openings of the wormhole is Lorentz boosted out and then boosted back this results in a sort of time machine. Now there are clearly problems with this. Negative energy conditions means that a quantum field which composes the shell has no minimum energy value. Remember that Bohr solved the hyrdorgen atom by showing how quantum waves give a minimum energy level, the s shell. However for some quantum field which violates the Hawking-Penrose ehergy conditions has no low bound, and so the field can emit an infinite amount of energy as it falls down the various rungs of the ladder — endlessly. This is a divergence or disaster which is not likely to happen. It is also the case that worm holes are terribly unstable, which is unstable to the vacuum as well as any photon or particle which enters it.

    However, a quantum fluctuation by the Heisenberg uncertainty principle can momentarily dip into a negative value. So there is some probability that that a quantum virtual wormhole may exist for some moment in time — backwards time in fact. The region with a negative energy has a quantum probability of transitioning into an anti De Sitter (AdS) spacetime, which is related to a cosmology. The AdS spacetime has a negative curvature condition which it can “inherit” from the negative energy of the worm hole. In effect while the shell of negative energy connect up at different locations in spacetime, there are two three dimensional balls which are sewed together to define a three sphere. These 3-dim balls are the interior region of what would be a black hole. Bringing in time means there is a space S^3xR^1, which is the same topology of the AdS spacetime.

    So wormholes can be mathematical models of instantons or quantum tunneling states which generate nascent cosmologies. In this setting they are not really the sort of object we think of from science fiction lore. They are certainly not something we can traverse through into the “gamma quadrant.”


  4. So then you are saying that Wormholes generate new universes rather than intersect two physical locations in a single cosmology?

    Also, this notion of a Lancsoz function, I’m not sure I entirely understand it LC. In which spacial direction are the incoming particles directed towards if not “back out” of the wormhole’s gravity well? Are we adding dimensions here?

  5. Hi Lawrence

    Poplawski is comparing the Schwarzschild metric and the Einstein-Rosen solutions for collapse of a dust sphere – how does that relate to the topology you mentioned? Sounds like you have more of a grasp of this stuff than me.

    One implication is that black-holes that form via a collapsar produce daughter universes “genetically” related to our own. I wonder if we produce million-ton black-holes as Louis Crane has discussed for stardrives if that’ll form an E-R bridge and give birth to a new “white-hole Big-Bang” on the other side of the event horizon? And would accelerator created black-holes – if such can be made – could form E-R bridges or would they Hawking decay before the bridge can form?

  6. What kind of universe(s) may be hidden in the black hole in the center of our galaxy, the milky way, probably the nearest located black hole from earth?

  7. A infinite regression of such cosmological conditions may be implied given that there are Black Holes at the center of many galaxies in our universe. Everet’s quantum “many worlds” theory comes to mind as a identical consequence of these infinite universes.

  8. Getting there would only be half the challenge, getting back would be just as difficult if not more so. Even if we just sent a probe, we wouldn’t learn anything from the other universe unless we could retrieve information.

    Plus, would those universes behave the same way as ours – would physics be the same?

    Another thing – if I’m understanding this correctly, can opening a wormhole [i]create[/i] an new universe? If so, could we manipulate anything within that universe? Muhahaha!

    …and could that mean that this universe was “opened up” by intelligences in another universe? (I’m just saying, be prepared for some wild ideas)

    This at least opens up a can of worms, if not a worm[i]hole[/i]!

  9. davesmith_au,

    Plasma physics is a vital, and vibrant, part of contemporary astrophysics; for example, ADS returns nearly 900 entries with ‘plasma’ in the title in just the last year alone! None of that is in any way verboten here.

    May I suggest that BAUT Forum’s Against the Mainstream section as a good place to present the ideas you seem to think are worthy of further discussion?

  10. It amazes me that this science fiction is OK, yet discussions of “that topic” which is based on lab experiments and observations, is verboten here. Perhaps you should be re-named Universes Today… Just sayin’!

  11. “Today’s scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality”
    Nikola Tesla

    In a nutshell… GIGO.

  12. @ qraal and others: The wormhole replaces the event horizon of a black hole, at least as seen from the outside, by a shell of negative energy, where each point on that shell is identified with another point on an identical shell somewhere else. This means the topology of spacetime, say a simple Euclidean R^4 at large becomes T^2xR^2, a torus (doughnut) in a Cartesian product with a 2-plane. This has a different topology than a flat R^4. Now just as the shell identifies every point on the exterior shell with points on an identical shell, it does the same with the interior region of what defined the black hole. So the interior is a three dimensional ball of space “times” the temporal direction B^3xR ( R = real number line), which is identified with another B^3xR. The two R’s are identical, and all we have to do is “suture” together the two 3-dim balls. Well if you take two disks deformed into caps, like the two hemispheres of a globe, and glue them together you get a 2-dim sphere. The same happens here, but you have a 3-dim sphere.

    The above topology change is what is involved with the idea one can jump into a wormhole “here” and emerge from an identical opening somewhere else. A wormhole can connect not only two different regions of the universe (spacetime cosmology), but it can connect our spacetime cosmology with another one. Where these connections link up and how is not generally “controllable.” However, as I indicated above macroscopic wormholes are not likely possible. They are of some importance with quantum gravity. There is also another spacetime that is interesting, which is the Taub-NUT spacetime. This is similar to a black hole, but where the horizon exists not at some radius in space, but at some region of time — a very strange spacetime. This has some relationship to wormholes, in a way electric charge would be S-dual to a magnetic monopole charge. Combining the two as a quantum system results in a gravitational dyon of sorts which superstring properties.

    The interior region is this three dimensional space which moves in time. It is topologically the same as an anti-de Sitter spacetime. Now this is identified in some sense with a cosmology. So how can a cosmology exist inside something on the scale smaller than a nucleus? It sounds crazy. However, this is related to something called the holographic principle of strings and black holes. A string which falls towards a black hole will be observed to time dilate, Lorentz contract, and splay out over the horizon of the BH. This splaying out can be seen in the elongated shape of galaxies in Einstein lenses! So a string approaching a black hole gets wound around the black hole, and frozen there. Now if an observer waits long enough Hawing radiation will begin to destroy the BH as it radiates away. This will destroy the string over time and transform it into another string (or strings) which escape the black hole. However, for an observer who falls into the black hole with the string nothing particularly strange happens to the string at the horizon — nothing at all strange is observed to happen. However, as the string approaches the interior region of near infinite curvature we call a singularity, there the tidal forces start to pull the string apart and merge it with the singularity. I will avoid for now the physics of what happens there (very strange actually), but the string is transformed or destroyed in the interior. So two observers record very different results for this string! One says it is destroyed by Hawking radiation on the horizon, the other says it is destroyed by the interior region. The whole notion of locality with quantum gravity is gone! An assumption which has been used in quantum field theory is removed, think of it as excess baggage or some obstruction to progress.

    In this sort of holographic sense, a spacetime cosmology can be both the interior (or white hole region) of a wormhole, and a vast cosmological spacetime — equivalently! It is a bit odd and hard to wrap one’s brain around I will admit. However, you have to first accept the fact the universe is just plain strange —- I mean !*&#&*%^& strange!


  13. Indeed… I am still trying to wrap my head around how a string looks as it falls into a black hole – let alone what changes when it is a worm hole.

    I was always under the impression that as the sting descends into the BH it appears to rope around around it, redshift, slow down, stretch and warp, and in the end… just merely fades away over a long period of time. Would this be correct? Of course, this is all from the perspective of the observer, not what actually transpires to the falling string.

    Now the question would be… what does the string look like if it were falling to a stable macroscopic wormhole? (If one were possible).

  14. That is pretty close to the idea. The string warps around near the horizon, on a stratched horizon, so it almost completely covers the black hole. In fact everything which composed the black hole, which are ultimately composed of strings, do the same.

    Actually what this means is there are two entirely different descriptions of the same evaporation of the string. This becomes particularly relevant when the black hole is a quantum black hole. In this case the horizon fluctuates so the two descriptions are quantum mechanically in a superposition. This ultimately is a form of what might be called a hyper-quantum principle.


  15. RE: Nikola Tesla.

    From Wikipedia:

    In the years since his death, many of his innovations, theories and claims have been used, at times unsuitably and controversially, to support various fringe theories that are regarded as unscientific. Most of Tesla’s own work conformed with the principles and methods accepted by science, but his extravagant personality and sometimes unrealistic claims, combined with his unquestionable genius, have made him a popular figure among fringe theorists and believers in conspiracies about “hidden knowledge”.

  16. A good example of the “crisis” in astronomy.

    Pure fantasy dressed up as “science”.

  17. You don’t know the power of the theoretical side! I must obey the mathematics.


    – Your thoughts betray you, I feel the crisis!
    – There is no crisis!

    Everyone is gathered again to destroy this thread with nonsense. Thanks, folks!

    @ LBC

    I’m quite amazed that I can follow your explanations almost until the end 😉 . This means, I’ve actually learned something in the math-courses at university.

    Btw: Your description of “strings” getting destroyed either by Hawking radiation or tidal forces (depending on the observer’s point of view) — is this also the explanation how an external observer can “see” a black hole growing?
    I mean, from the external point of view no matter actually crosses the horizon and thus the BH should not become more massive — although we know that matter falling into the BH does not feel the horizon and just enters, which means the BH grows. Is your description also a solution to this problem?

  18. @ivan3man

    The irony is just too rich in digging up that one paragraph, which is mere supposition in the style of the notorious scienceapologist, in light of the subject of this article. Talk about cherry picking from a long, detailed and well cited biography on Tesla. So what if he was eccentric, most geniuses are. Einstein was a bit eccentric himself, big deal.

    The list of Tesla’s accomplishments is way too long to post here so interested parties can visit the hyperlink to Wiki above.
    The lesson is that as an empirical scientist (as opposed to theoretical mathematician) Tesla’s theories and inventions laid the foundation for all of the modern technology we enjoy today, regardless of anyones opinions about his personality or how a few questionable rogue’s might go too far with his work in their ideas.

    It’s just constant slander from some of you people.

  19. solrey, IVAN3MAN_AT_LARGE, Anaconda,

    The science stands on its own two feet.

    Whether you like, or dislike, a particular approach in one branch of science or other is irrelevant to the science itself.

  20. Anaconda:

    Pure fantasy dressed up as “science”.

    Oh, so what do you call “Symbols of an Alien Sky” on that Thunder[bollocks].info website that you and solrey like to frequent, then?!

    Hey, Jean Tate, why did you group me in with those two individuals, “solrey” and “Anaconda”, above?

    By referring to Nikola Tesla, I was merely pointing out the fact that pseudoscience proponents often like to associate themselves with a real genius and to quote the man out-of-context in order to give credence in support of their crazy and unsubstantiated claims, just like bloody creationists who often quote Albert Einstein out-of-context alleging his ‘belief’ in a god.

  21. Jean Tate wrote: “The science stands on its own two feet.”

    Please, this is only slightly better than those scientists that claimed higgs-boson particles from the future had come back to wreck the Hadron collider so Man could not discover them…ha ha ha LOL.

    Science is about empirical observation & measurement. This is mathematical jibberish posing as science.

    Jean, that you would stand up for this nonsense tells me you don’t understand or respect science.

  22. The ability to destroy a thread is insignificant next to the power of science!

  23. Anaconda,

    I will say this to you just one more time: you do not get to dictate to anyone what the nature of science is; no one has that power.

    If you do not like how science is done, in a particular field, you are welcome to your opinions of course.

    However, using the comments on Universe Today articles to promote your personal views on the nature of science is just as unacceptable as promotion of perpetual motion machines or overunity devices is.

    If you are interested, I can suggest some internet forums which welcome discussions of the nature of science, in general.

  24. believe it or not, i enjoy the endless mysteries of the universe. b/c as soon as one mystery is solved, new ones replace it. if we ever solved every mystery of the universe we’d be so bored. i think the universe is in on this awesome game of hide & seek. and if we ever do figure it out the universe will change all the rules again for kicks.

    seriously – enjoy the MYSTERY, people.

  25. I’m not sure why this article is posted on an eminent forum such as Universe Today.

    The author to this paper, who somehow got his picture connected to it, is taking speculative and mainly rejected ideas (wormholes, white holes) and mix them to an opaque mix. Of course you can combine faulty and conflicting ideas and prove just about anything. So what?

    First, wormholes. The idea that you can use such for time travel is rejected already by a simple semiclassical study in the arxiv. It runs up against a classical mechanics paradox.

    Presumably then, as they don’t work for all spacetime connections, they don’t work for any of them. (What would pick a preferential direction?)

    Remains that they can putatively exist by quantum fluctuations. But as any proposal that geometry can fluctuate they run up against recent observations that spacetime is observationally smooth well into the Planck regime. (That gamma ray observation last year, IIRC UT had it too.)

    There is no such thing as “quantum gravity” observed. One can quantize gravity just fine (specifically, its Lagrangian) and get the required graviton out of it at low energies. That is all one can request of an effective theory like GR.

    Geometric fluctuation is, apparently, daft. Theoretically it breaks down due to divergences at the high energies requested. Observationally it breaks down because it is rejected as per above. So presumably no wormholes either.

    [And especially, on the old and quaint topic of exotic matter for macroscopic wormholes: where is the evidence?]

    Second, white holes. The interest died down as they were found to have problems. Which I don’t know, but supposedly serious enough that they aren’t discussed much anymore.

    In conclusion, a speculative work at best, of which many pollutes the arxiv.

  26. DrFlimmer: The entropy of a black hole is determined by S = kA/4L_p, where L_p is the Planck unit of length, k the Boltzmann constant and A = 2pi r^2 is the area of the event horizon. The radius r = 2GM/c^2. The entropy is then a measure of the units of Planck area on the horizon. The area does change as matter is absorbed by the BH. The area is may be written as A = NL_p^2. The string length is related to the Planck length by L_p = gL_s, g = couling parameter, so the area is given by A = N(gL_s)^2. So the area does increase with each string attached to the stretched horizon.

    @Torbjorn Larsson: I agree there are no classical or macroscopic black holes. The metric fluctuations don’t exist in the way that loop variable people think. The fluctuation is concealed from the universe by the string.

    Well it looks as if it is time for my boot heels to be wandering from here. The blog page is now on page 2 of UT and the EU barbarians have scaled the walls and entered in force.


  27. @ LBC

    First of all, thanks!

    Do I get this right? The outside observer (far away) does not see the particle enter the BH, but he notices the change in the entropy of the BH and/or the change in the geometry around the BH?
    A change in the geometry should be observable, because somehow the increase of mass must be communicated to the universe. Otherwise a BH could grow and grow and nothing would happen.

    However, we still shouldn’t see the particle disappear. It becomes redder and redder but does not cross the horizon, from the observers point of view far away.

    Damn, I get a knot in my head again…..

  28. Good thing I checked this. I wrote “I agree there are no classical or macroscopic black holes.” I meant no classical wormholes. Classical black holes are fairly common.

    To the exterior observer at some constant proper distance from a black hole any string, which is a small but extended field configuration that appears as a particle on larger scales, slows down and is Lorentz boosted as it approaches the BH. This means that longitudinal modes (radially directed) get shortened and transverse modes appear to become elongated or distributed around the horizon. The high frequency modes of the string then appear to be of lower frequency, just as a longer string has longer standing waves than a short one. This is commensurate with the time dilation effect this exterior observes. This occurs until the string reaches a distance of d = L_p = sqrt{G-hbar/c^3) of the horizon. This is the so called stretched horizon of the BH, one Planck unit of distance from the mathematical horizon of general relativity. Now if the string has energy E < A + delta E^2, or the radius of the black hole increases by about a string length. The same occurs with the stretched horizon as well. So all the strings splayed out on the horizon now appear on a somewhat larger horizon. The event is a quantum transition, and the “old” description of the strings on the stretched horizon is in some quantum superposition with the new description at the transition. So the strings on the stretched horizon are in both positions at equivalently. This is a signature of the loss of locality in the description of fields in standard quantum field theory.

    What this means is that fields in the universe are holographically determined. The fields exterior to a black hole, or any even horizon such as the cosmological horizon, are holograms of fields on stretched horizons of one dimension lower. So the standard quantum field theoretic description of fields according to amplitudes of harmonic oscillators at every point is only a flat spacetime approximation. So the locality which underpins quantum field theory according to fields at every point on a spatial 3-dimensional surface is replaced fundamentally by a holographic description of fields on stretched horizons of one dimension lower, and these fields do not have a unique local description at every point in space. This is why one can have a string stretched out on the horizon of a BH while it has as well an equivalent description in the interior, or why the Hawking evaporation of the string is on the horizon is equivalent to its transformation as it approaches the BH singularity. The stretched horizon (ultimately a form of Dp-brane) is then dual to the interior singularity which is another Dp-brane. This is generalized into something called the AdS/CFT correspondence, where there is a duality between fields in an anti-de Sitter spacetime and conformal fields on a 5-dimensional sphere.


  29. err: I wrote energy E < A + delta E^2, which is supposed read that the area of the black hole horizon increases by A' = A + delta E^2. Need more coffee 🙂


  30. What this post does demonstrate is that there is such a low level of physical constraints on the concept of so-called “black holes” (Am I allowed to question the existence of “black holes” under this regime?) that basically anything goes…

    As long as you honor the concept by calling it a “black hole” even if by conjuring up of a set of ideas it makes a mockery of the existence of “black holes” to begin with.

    In that sense, this is a very good post because it illustrates the absurdity of “black holes”.

    Because you can imagine “black holes” to be anything…as long as you call it a “black hole”.

  31. Anaconda,

    Which part of ‘just one more time’ did you not understand?

    Black holes have been part of physics, astrophysics, astronomy, and cosmology for several decades now, and others here have provided you with a very great deal of helpful and informative material on this topic. They have been doing so for over a year now (google “Anaconda black holes” within this domain).

    Using the comments on Universe Today articles to promote your personal views on the nature of black holes is just as unacceptable as promotion of your personal views on the nature of science is.

  32. I think that in part what is happening here is what I call the certitude of minimal knowledge (CKM). This happens on a range of educational experience. A person can learn some physics up to some level, whether that be high school physics, undergraduate physics, and this is quite often seen with BS level engineers. A person learns some canonical elements of physics, where they then think the foundations of physics should conform to what they think. Such people read some layman’s literature on strange things about black holes, Hawking radiation, strings and so forth and find there is a void between what they know and the strangeness of these things. They then figure there must be a “simpler way,” and they set out on their intellectual steed Rocinante to conquer these evil windmills trampling down what should be rational physics. There are literally 10s of thousands of people like this, and the web is fertile ground for them. There are various alt-science camps, from EU stuff, or alternatives to Einsteinian relativity, to anti-quantum groups and so forth. The web is loaded with this stuff.

    Black holes exist. Without any reference to quantum gravity, strings, holography and so forth, basic astrophysical black holes clearly exist. They are virtually beyond question. Of course to understand them requires some idea of relativity theory. Einstein removed a certain obstruction from classical physics to establish this, which was to remove the notion of universal absolute time and generalize the idea of the invariant interval and local constancy of light speed. Quantum theory removed an obstruction on the distribution of energy and the notion of what was meant by a particle. Similarly with quantum gravity and cosmology further obstructions must be removed. This obstruction involves the notion of there being a locality to an event. Leonard Susskind, Juan Maldacena, and others have removed this in some partial sense. There is a question about the black hole complementarity and the nature of branes and string in the BH interior, and matters related to how our universe could be equivalent to the interior of a wormhole. These things require one to really wrap one’s brain around strange ideas and to be willing to abandon certain axioms or rules one has learned, even those in graduate school, and to replace them with more general statements. This is not easy to do, and one must first wrap one’s mind around quantum theory and relativity first, which depart from ordinary experience considerably as is, before pressing on to these foundational questions.

    This is entirely different from the CMK strategy, which is to reduce everything down to rules learned in (fill in the blank). I am aware to two people trying to reduce physics to Aristotle’s ideas of things. Einstein made a comment that it is easy to try to reduce physics to many complicated formulas based on known rules, but much harder to abstract new rules which permit a much simpler formalism. In the case of EU I find that people seem to have only a basis physics “101” idea of electromagnetism as it is, Anaconda could not answer a question about the impedance of free space (junior level problem), and yet seem to insist they have access to some crucial understanding of everything. The EU folks are in a curious way more into an ideology of physics, than an understanding of it.


  33. Oh god. Lol.

    Lawrence B., Torbjorn L., I usually really enjoy reading your discussions and points on various subjects posted on UT. But this.

    What the fuck. Lol !!

    Thanks for the interesting topic though =)

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