Holographic Principle Could Apply To Our Universe 129
New submitter citpyrc sends this news from the Vienna University of Technology: The "holographic principle" asserts that a mathematical description of the universe actually requires one fewer dimension than it seems. What we perceive as three dimensional may just be the image of two dimensional processes on a huge cosmic horizon. Up until now, this principle has only been studied in exotic spaces with negative curvature. This is interesting from a theoretical point of view, but such spaces are quite different from the space in our own universe. Results obtained by scientists at Vienna (abstract) now suggest that the holographic principle even holds in a flat spacetime, like ours.
tits (Score:2, Funny)
I am pretty sure they have 3 dimensions.
Direct confirmation difficulties (Score:5, Funny)
To most slashdotters it remains only a theory
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To most slashdotters it remains only a theory
Most slashdotters will swear they're only 2 dimensional!
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Holograms or it didn't happen!
Re:tits (Score:5, Informative)
Tits exist in at least Four Dimensions.
I've found that over time, they extend their vertical dimension in a much larger proportion than the loss to the original horizontal dimension...
Entropy causes Sagging, film at 11.
Ace Rimmer (Score:1)
Ace Rimmer. What a Guy!
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Turing was a faggot who resisted his correction therapy and is a terrible example of a scientist.
Yup, all he came up with was those stupid faggot computers that never worked anyway!
Thanks for posting this (Score:2)
I feel much thinner now!
Don't answer that [Re:Thanks for posting this] (Score:2)
"Honey, does this projection make my ass look 4D?"
Armchair physicist only (Score:1)
Astrophysicists have excellent limits on the amount perception for 3D for 2D universal dimensions, at least as the story goes. We've got an excellent idea what is out there based on emission in the far infrared, interstellar scintillation, absorption line studies, reddening studies, etc. We have very good limits on the 3d cloud density, too, from comet statistics. There are even a number of direct observations based on microlensing surveys, and there's a shadow survey, too, looking at large star fields. In
1D compression, AKA "Serialization" (Score:2)
Just about any dimensional space can be represented in fewer dimensions, or even 1 dimension, if you accept some lossy-ness or fuzziness. Imagine a string of digits and codes with the structure: x,y,z,type;x,y,z,type;x,y,z,type;x,y,z,type, etc... Where x, y, and z are coordinates in 3D space and "type" is the type of particle. Example single particle encoding: "3629342.3442, 4872042.3987, 193203.0482, Electron". There may need to be more "state" info about a given particle to make it workable, but you get t
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God's Linux box. Just hope he didn't back up the universe to Hillary's server.
Re:1D compression, AKA "Serialization" (Score:5, Interesting)
Just about any dimensional space can be represented in fewer dimensions, or even 1 dimension
But that all misses the point here. The point of the holographic principle is not that one can imagine a 3D encoding onto a 2D surface, e.g. a holograph, but that the maximum possible information in a volume is not proportional to volume, but to surface area. That implies the fundamental mechanics of the universe can't be something like "voxels". We observe a universe which we can measure in 3 spatial dimension down to the Plank length, in principle, but that can't be what's really going on, at least if the holographic principle holds.
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I would mod you up, but this is too interesting to pass up.
What I always wonder about is what the exact limitations are that the holographic principles imposes on a volume. Our intuition tells us that a volume can contain all possible configurations of 'particles', but apparently (given the holographic principle) it can't. Some configurations are just not possible or undetectably equivalent to others, leading to the lower information content in a volume (if I understand the principle correctly).
Now I can ea
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Our intuition tells us that a volume can contain all possible configurations of 'particles', but apparently (given the holographic principle) it can't.
Or to look at it another way, it can, but the HP just puts (more) limits on what is possible.
IANAP, but there are other arrangements which are already impossible. The laws of physics see to it that there are no free quarks, for example, or that there are only certain orbitals electrons can occupy around atoms.
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the maximum possible information in a volume is not proportional to volume, but to surface area
How does that square with the idea of two unit cubes, each of which has a surface area of 6, but put together have a surface area of only 10? Is it just that "information" doesn't add up that way?
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Really just guessing here, but it might have something to do that you can only put so much stuff into a given volume before it begins to collapse and thus forms inner bounderies (i.e. black holes) and that this property is not additive. The reasoning would be:
For information you need states.
States have an associated energy.
The more states you use, the higher the energy density will be.
Energy density equals mass density.
Amassing enough volume units with a given density will eventually lead to collapse.
The la
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The sibling post is on the right track. Informaton density requires mass density, and mass density distorts space, putting limits on what's possible. The whole idea of the Planck length comes from that in the first place.
Because of the way black hole formation works, if you have a fixed density in a small region of space, with no black hole, if you extend that density to a large enough region of space you get a black hole - exactly according to surface are being the limit.
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But what the in-falling observer sees as the spatial axis, the distant observer sees as the time axis. And special relativity means distance is a matter of perception, and all of this must vary smoothly. There's no way to make stacked cubes work with those requirements - it's bad enough to allow for smooth rotation of axes in Euclidean space, but with the continuously varying metric of GR it's right out.
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Perhaps it could, but those voxels/cells aren't really independent. General Relativity requires space to be differentiable (smooth) which in turn means that value of one cell limits possible values f
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"Dimension" is a perspective, a human artifact. The universe doesn't classify itself. 3D space as we perceive it may just be a useful lie to ourselves--a handy model but only an approximate model. We can throw in time and think of our world as 4D, but that doesn't mean that time is or is not a "dimension". It's only a perspective or model we can choose to use or not.
For a simpler version of this, imagine a 2D world where each time "slice" is stacked onto each other kind of like really thin pancakes from OUR
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What's the exact definition? A "dimension" is any factor an observer wants to analyze or treat separately. Eye color in people can "be" a dimension(s) if we want it to. (I would only disqualify a factor if it's identical to another factor.)
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You appear to be talking about spacial dimensions. I'm talking dimensions in general.
Bozhe moi! (Score:2)
We present the analytical calculation of entanglement entropy for a class of two-dimensional field theories governed by the symmetries of the Galilean conformal algebra, thus providing a rare example of such an exact computation.
Bozhe moi!
This I know... from nothing.
What I'm going to do.
I think of great Lobachevsky and I get idea - haha!
(NB: Lobachevsky developed the mathematics of non-Euclidean geometry with negative curvature.)
not goin for it (Score:1)
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Just don't freak out when you find you can pass your hand through your cat.
It only works on cats. I don't know why, ask Schrodinger. Something to do with Youtube fame particles (YFP), I think.
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You can pass your hand through many animals; just start at the back and use plenty of lube.
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I don't think that's what Dr. Schrodinger had in mind.
Now it makes sense (Score:1)
Huh (Score:1)
I thought Sheldon gave up on string theory in the 5th season, or was it the 6th.
I love reading about this stuff... (Score:3)
I love reading about this stuff, but it's hard to understand without a background in science :(
Can someone explain it to us like we're 10?
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Now: you're living in a TV that someone ELSE is watching. (The FSM watches a separate channel on Each of His Noodly Appendages -- that solves the multiverse theory, too. And it's turtles all the way down, so FSM is also watching himself at the same time. [See? Science mixed with Religion is Truthful, Informative, AND Fun.
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All are welcome.
Re:I love reading about this stuff... (Score:5, Informative)
Sure. I don't work in physics, but here is my understanding of the holographic principle.
Imagine that you are in a bathtub. There is a certain kind of physics that dictates the motions of waves in the bathtub. Now, you might believe that you need to understand the entirety of water to predict its future motion. You could develop a theory of water in bathtubs, and run experiments to verify if they are true.
After a lot of thought, you might come across the realization that in order to understand the mechanics of the water in the bathtub, it is only necessary to understand the way the surface of the water moves, or maybe even how the water interacts with the edge of the bathtub. This means that you've reduced the dimension of your theory in some way. While this analogy isn't true, there are examples of where it is-- for instance, the physics of harmonic oscillators, like strings, drumheads, etc, can be understood by looking at the boundaries of those oscillations.
Now, in physics, there are several ways that holography shows up. The most famous of these holography theories is called the AdS/CFT correspondence. It conjectures that a certain 5 dimensional string theory can be understood as a 4 dimensional field theory on the boundary. Now, I think that this perspective is interesting to physicists not because of the dimension change (dimensions in theoretical physics usually have little correlation with the observable dimensions of spacetime) but because it was one of the first known correspondences where a string theory reproduced the results of a field theory. Quantum Field theory is the most validated theory of physics we have, but it is thought to have foundational errors. String theory is suppose to offer a way out, but is... hard.
Hope that helps!
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That did, thanks for the informative and interesting post!
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God already told us about the 4 corners of the earth
Four corners? [timecube.com]
I wish there was an easy way to understand it (Score:2)
Scientists of Vienna University of Technology pointed out that holographic effects can be demonstrated from flat (two dimensional) surface, and surrounding reality is possibly following the same principles.
Now, if you think about it, that is a reasonable hypothesis, however, it should be noted that the opposite effect can also be realized when four (or five or more) dimensional reality is projected into three dimensional surrounding (let's call it 4D->3D), perceived by humans. Example understandable by h
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number of dimensions? in what way?
current quantummumbojumbo that has already de-evolved into multiverse, current tech singularity ai-blabla etc already resemble ancient philosophical debates... in that they're silly to most people and seemingly also silly to those familiar in actual research and not "futurology" or whatever.
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All in all, two thousands years ago, in Greece, people were arguing if the world rests on the backs of three elephants or three whales, and assumed that the world is flat.
The Greeks knew that the world was a sphere and also came up with a fairly good estimate of its circumference. Check out
https://en.wikipedia.org/wiki/... [wikipedia.org]
also, there are no elephants in Greece ... ;-)
ignatius
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Actually, I think the Greeks pretty much agreed that the Earth is a sphere with a radius of about 6000 km (Erosthenes-roughly 240BC) What they were arguing about is whether it or the sun is the center of the universe (Aristarchus of Samos-about the same time)
(Don't you just love it when some bozo comes along and knitpicks your rhetoric?)
So, the world is flat after all? (Score:5, Funny)
It would seem that ancient wisdom triumphs and we live in a 2D world.
Huh? (Score:1)
Screw Popularizations! (Score:2)
I have no doubt that the holographic principle is an interesting mathematical representation of certain physical laws. It is no doubt quite useful in solving certain problems and may even be suggestive of new phyisical theories.
However, it's just nonsense to get excited just because you know that the physical laws can be represented in fewer dimensions. OF COURSE THEY CAN. You can always code the information about any functions/distributions/whatever in n dimensional space in fewer dimensions. The holog
Does this reasoning recurse? (Score:1)
Re:quacks get front page (Score:5, Informative)
The holographic universe theory has been around for at least 25+ years [amazon.com]
When you have famous astronomers and people such as
* "The stuff of the universe is mind-stuff" - Astronomer Arthur Eddington
* "... our brains mathematically construct hard reality by interpreting frequencies from a dimension transcending time and space. The brain is a hologram, interpreting a holographic universe." - Cyberneticist David Foster
* "Today there is a wide measure of agreement... that the stream of knowledge is heading towards a non-mechanical reality; the universe begins to look more like a great thought than like a great machine" - Astronomer James Jeans
saying the universe appears to function like a holographic mind then I find ANY sort of calculations that can give credence to this theory is definitely interesting.
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> I for one don't want to give Physics research a blank check to investigate some unobservable math fantasy.
You mean like String Theory, and Dark Energy ?
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I'm not an expert, but I thought string theory had dozens of dimensions while the holographic universe has only three (including time)? Looks like a pretty big difference to me.
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Not to nitpick: but no you are wrong.
A theory is just as it states, a theory. Testing of the theory simply serves to give "weight" to said theory when comparing it to other theories describing the same domain.
An untestable theory might very well be something that is less important to discuss as part of scientific discourse (it has no "weight") but it is still a theory.
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You think you sound a lot smarter than you do.
Nice try though. I always try to encourage the less equip. But since you obviously have trouble using google I have gone and made it nice and easy for you:
https://en.wikipedia.org/wiki/Theory
You will note it proves my case...or not. Either way I am done with this discussion.
Re:Not a theory! (Score:5, Insightful)
It's all a matter of philosophy. There's been a bit of churning the past few decades, but I prefer this simple differentiation: A theory is a predictive model, an hypothesis is a testable prediction. The utility of a theory is then determined by the success of the hypotheses it generates.
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you don't know anything about logic at all do you? Apparently not.. because it is all latin and I don't see any latin here so you are a moron
Well, looks like I'm the only one who thought this was funny. If it was a bit shorter I'd borrow it for my sig.
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Looking at the comment following yours it appears you have some sort of anonymous fool throwing mud at your proposition. Unsurprisingly they offer nothing by way of improvement on your position. I guess it's more fun for a shallow mind to follow mud with mud than attempt a reasoned argument.
I'm sure you're hardly bothered by such idiocy but I wanted to take a moment to point out that in my humble opinion your post provides a beautifully elegant and balanced summary of the scientific method at work. Perhaps
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Better would be to say that it is not a scientific theory, I suppose.
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So how come if I say "The Theory of creationism" on Slashdot I'll get crucified?
How come that theory shouldn't be taught alongside the Theory of Evolution?
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So how come if I say "The Theory of creationism" on Slashdot I'll get crucified?
Prefixing "the theory of..." to something does not instantly promote it to the level of a sensible scientific idea.
As an exercise for the reader, look at "the theory of astrology" or "the theory of a flat Earth".
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So how come if I say "The Theory of creationism" on Slashdot I'll get crucified?
You'll not get crucified as such-- any more, that is only a Christian church punishment. Slashdot has never crucified anyone and physics and bandwidth limitations being what they are, Slashdot will never be able to crucify anyone. Your post will likely be ridiculed, modded down, and mostly ignored. You'll need to go elsewhere for the cross and nails.
The thing is, the "theory of creationism" is an inherently bad theory since it does not lead to hypotheses that can be tested with the scientific method. OTOH,
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>The thing is, the "theory of creationism" is an inherently bad theory since ......
It is even worse theology. It requires belief in a deity that created everything to deliberately fool us. Once you go down that road 'died on the cross for my salvation (and yours also if you are interested,)' evaporates. Not having any of that.
Re: Not a theory! (Score:1)
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The word "theory" implies that it is testable.
In this case it is testable, as there are a couple interferometer based experiments working toward testing it.
But it continues to witlessly push forward on the assumption that the proponents could win the argument (grant money) if it could sell enough books and achieve mainstream popularity.
You don't get a grant for just being popular. You get a grant for proposing to do something, and that something has to both fall under the directives of a particular grant program, and get good reviews about the chances of achieving something and usefulness from other scientists.
I for one don't want to give Physics research a blank check to investigate some unobservable math fantasy.
Like several other new proposed theories in physics, this is not without observation. It is an extension of already seen
Re:Not a theory! (Score:5, Interesting)
The word "theory" implies that it is testable.
"Falsifiable" is a better word here. You don't need to be able to do controlled experiments (tests) in order to have a solid theory - an influx of new observations of the universe as we find it works just as well.
And the holographic principle is certainly falsifiable.
1) It imposes a limit on the amount of entropy in any given volume - find a system which can be in more than the allowed number of states, and isn't inside a black hole, and this theory is dead.
2) It sets a really high value on the entropy of black holes. Black holes become the dominant source of entropy in our universe. This has consequences in cosmology that are fundamental, if the only reason entropy is increasing in our universe is this assigning of entropy to black holes. There are certainly physicists playing with that idea, as it could be career-making, true or false.
3) It has deep implications for the evolution of black holes - how they evaporate. This will be a lot harder to prove (I don't think we'll validate Hawking radiation in my lifetime), but might be possible to falsify by finding a black hole that's clearly not allowed by theory.
Heck, there are implications for particle physics that are still being understood, and lots there is testable now with the LHC. The more and farther you reason from a premise like this, the more likely it is to matter to something easy to measure, or at least possible to measure.
The reason the discovery of the Higgs boson was such a big deal is that it confirmed a bunch of really abstract theory in quantum mechanics that is very, very far from anything we can measure, except at the end of this very long chain of reasoning there's this prediction of this new oddball particle (that there's no other reason to expect - it come from deep in the abstract math of QM, not from anything else we measured). So finding that particle confirms that whole crazy chain of logic. Something similar will eventually happen for the holographic principle.
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Why not? And who exactly is asking for a "blank check"?
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Why not? And who exactly is asking for a "blank check"?
Since we're on the topic, I'd like a blank check!
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I've never understood the rationale behind a holographic universe. I'm not saying it's impossible, but Occam's razor would seem to suggest it's unlikely.
If I understood correctly, the theory goes something like this: Information cannot be destroyed, yet the actions of a black hole on its surroundings (i.e. what we can observe from outside) are completely determined by its twodimensional event horizon, therefore a volume of that size can only contain as much information as what is present on that surface are
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but why is everyone so sure information cannot be "destroyed" (rendered inaccessible) in a black hole?
It was my understanding that all events need to be reversible. If information falling into a blackhole disappears or is otherwise not accessible anymore, then the act of falling into a blackhole is non-reversible. The reason everything needs to be reversible is because time is just a dimension. You can go forward or backwards, but if information is lost, then you can no longer go backwards. This has a lot of ramifications.
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The brain in the jar being fed false/artificial stimulus has been around for much longer.
However we have no way of testing that you are just a brain in a jar, or an actual person. Because it comes down to what our senses tell us.
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You mean Botzmanns Brain, of course. But i think that Boltzmann deviced it to show how proposterous the outcome is. Noone actually thinks it is the truth. If i did then that would mean you (and everyone else) are basically a figment of my own imagination.
Also, i think it is not directly linked to what we now call the holographic principle. That one was thought up by Gerard 't Hooft some decades ago.
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