Holographic Principle Could Apply To Our Universe

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.

Comments

Windows 10 Will Free Your Desktop

[Anonymous Coward]

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Re: Windows 10 Will Free Your Desktop

[Anonymous Coward]

Go suck holographic 2 dimensionals cock along the time continuum

quacks get front page

[Anonymous Coward]

Glad to see every quack with just enough pull get on Slashdot

Re:quacks get front page

[UnknownSoldier]

The holographic universe theory has been around for at least 25+ years

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.

Re:quacks get front page

[michelcolman]

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 area. Since you can imagine any area of the universe collapsing into a black hole, and again no information can be lost there, the entire universe can only contain as much information as a twodimensional sphere, so the universe really only has two dimensions.

But why is everyone so sure information cannot be "destroyed" (rendered inaccessible) in a black hole? Many laws of physics break down in black holes, what makes you so sure the second law of thermodynamics will hold?

And it's not like this second law is really a "law" in the strictest sense. Mathematicians would never call this a law. It's like people observing a box with red and blue marbles in it. When they shake the box and then look inside, the marbles are all mixed up. Therefore, they introduce the "law" that the marbles will always be mixed up after shaking the box, and it will be impossible for all the blue marbles to be on one side and the red ones on the other.

Now this second law does turn out to be very practical. Because for all intents and purposes, given enough particles, you may reasonably expect to never see a violation of the second law. And certainly on the scale of the universe, it would be... well... "impossible".

But black holes are not like the rest of the universe. Extrapolating the second law, which isn't even really a real law but kind of a quasi-law, to black holes (which we know little about, apart from speculation) and then jumping to the conclusion that this must mean that the whole universe is twodimensional, is just silly. It's people performing "logical deductions" without asking themselves if that particular step actually makes sense.

Also, the fact that we can only see a certain amount of information from outside the black hole, does not mean that more information could not be present inside. What if you drop into the black hole? Of course you wouldn't survive, but if you disregard that detail, couldn't you find all the "lost" information inside? Applied to the universe, this might mean that you could replace a chunk of the universe with a sphere of that size, and you could calculate the effect of that chunk on its surroundings based on that twodimensional sphere, but that doesn't mean the information inside does not exist.

Also, if gravity inside a black hole is so strong that our usual laws of physics break down, it doesn't seem outrageous to assume that information could indeed really be lost there. Why not? Which is more likely? Information getting lost in a singularity, or our threedimensional world being only twodimensional? I would say Occam's razor favors the former.

Information gets lost all the time anyway, in the expanding universe. There are plenty of galaxies that are moving away from us so quickly that we will never be able to see their light. We are "losing" information all the time, yet this doesn't seem to bother anyone.

Really, maybe I'm missing something, and by all means feel free to enlighten me, but I fail to see a compelling reason to assume the universe has only two dimensions, it seems to be an unlikely solution looking for a problem.

Re:quacks get front page

[Anonymous Coward]

25 years ago people were listening to Rick Astley.
Tells you how much they knew back then.
Anyway, i wouldn't take the word of astronomers and cyberneticists to describe the underlying foundations of the observable universe. You realy need physicists for that. Try Leonardo Susskind.

Re:quacks get front page

[Anonymous Coward]

The holographic principle doesn't derive from the 2nd law of thermodynamics or conservation of information. It derives from math that allows a lower dimensional description, typically on a surface boundary of a volume of interest, to contain all of the information needed to describe the the volume within. There are already physical laws that this is inherently true for (electromagnetism) and it is more of a question of doing this for things in general. The conservation of information doesn't enter into later, when trying to determine the consequences of such a theory.

And while the conservation of information is closely related to entropy and the second law of thermodynamics, information isn't the same as entropy, and the possibility of local violations of the second law doesn't conflict with the conservation of information. Defining everything and giving an full introduction to physical information theory is a bit much for a comment, especially since that information is already online with at least a couple free course notes available.

And it's not like this second law is really a "law" in the strictest sense. Mathematicians would never call this a law

Mathematicians call it the law of large numbers.

Re:quacks get front page

[jellomizer]

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.

Re:quacks get front page

[Anonymous Coward]

You forgot "Neo, it's not real" -Morpheus

Geeze get your citations right!

Re:quacks get front page

[Methadras]

The holographic universe theory is nothing more than the evolution of existential reality theory. I personally don't believe in it, but then again, I haven't seen any evidence to remotely suggest that the universe operates like a hologram or is constructed like one. I just take it at face value for what I can see and what is tested, known, accepted, validly peer-reviewed scientific method-based knowledge. There is still so much we do not know that I have a hard time wrapping my head around the top down perception of what or how the universe is constructed. I come from a bottom-up approach. Find all the fundamentals and build from that upward.

Re:quacks get front page

[Anonymous Coward]

The holographic universe theory is nothing more than the evolution of existential reality theory....Find all the fundamentals and build from that upward.

The holographic principle, in particular things like AdS/CDF, are nothing more than applying math to the fundamentals. When looking at those fundamental principles, at least as we know them now, and the math shows that if you know what happens on the boundary you know what happens inside the boundary, you end up with a holographic principle. The basic concept is a bottom up concept, although some of the potential implications may be more top down.

Re:quacks get front page

[Bengie]

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.

Re:quacks get front page

[noodler]

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.

tits

[Anonymous Coward]

I am pretty sure they have 3 dimensions.

Re:tits

[Grog6]

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.

Starlight Glimmer 2016

[Anonymous Coward]

Vote Starlight Glimmer for President in 2016. As the social justice candidate, Starlight invites all of America to experience true friendship for the first time. Starlight believes in an America where nobody flaunts their special talents because they have no special talents to flaunt. Free yourself and choose equality as your special talent.

Ace Rimmer

[Anonymous Coward]

Ace Rimmer. What a Guy!

mappings

[Anonymous Coward]

Back in 1978 I wrote an article in Personal Computing describing the idea of simulating n dimensional worlds using a n' dimensional description, where n' is fewer than n. In other words, a simple Turing machine can simulate a complete universe, The possibility that this is the foundation of what we experience is not surprising. We are the shadows on the wall of the cave after all and the existence of mathematics in itself shows that nature is not parsimonious with its possibilities.

Re:mappings

[Anonymous Coward]

Turing was a faggot who resisted his correction therapy and is a terrible example of a scientist.

Re:mappings

[Sardaukar86]

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!

Niggers

[Anonymous Coward]

What dimension are niggers from?

Re:Niggers

[Anonymous Coward]

You should probably ask your mother since so many of them wind up in her bedroom, the back seat of her car, the kitchen counter, and the sofa.

Thanks for posting this

[the_other_one]

I feel much thinner now!

Breakfast?

[Anonymous Coward]

Is that the smell of kippers ... mmm smokey!

Re:Breakfast?

[Brad1138]

I'll be back for Breakfast!

Armchair physicist only

[Anonymous Coward]

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 short, we've got pretty good numbers and we're not going to discover that there's either a 3D or 2D universe.

1D compression, AKA "Serialization"

[Tablizer]

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 the general idea.

Re:1D compression, AKA "Serialization"

[Anonymous Coward]

Gosh just imagine a machine equipped to deal with such intricacies, a "universal computer" if you will.

Re:1D compression, AKA "Serialization"

[Tablizer]

God's Linux box. Just hope he didn't back up the universe to Hillary's server.

Re:1D compression, AKA "Serialization"

[Anonymous Coward]

That's nothing new, and it isn't really anything esoteric.

I'm immediately reminded of "flattening" multi-dimensional arrays.

Suppose you have an 3x3 grid represented by an array of arrays:

A=[
[1,2,3],
[4,5,6],
[7,8,9]
];

(broken into lines for clarity)

If you want coordinate x,y, you do:

v=A[y][x]

(if x=2, y=1, then v=A[1][2]=6)

You can flatten this into one dimension:

A=[1,2,3,4,5,6,7,8,9]

And access it like so:

v=A[y*width + x]
(again, if x=2, y=1, then v=A[y*3+x]=A[1*3+2]=A[5]=6)

For this to work, only of the dimensions needs to be bounded (in this case, width). The other dimension can grow as much as you want.

Re:1D compression, AKA "Serialization"

[Anonymous Coward]

You are an ignorant dumb Academic.

Re:1D compression, AKA "Serialization"

[Anonymous Coward]

Except that the idea of a "dimension" in math and physics is not about encoding, but about the relative relationship between those numbers. For a vector space, the dimension is the minimum number of basis vectors, vectors that cannot be created by a linear combination of the other vectors. Changing how your write out the numbers doesn't change that relationship. If you cram it all into a single number, either you're going to just have to redefine all of the vector operations such that you're back to the same object written differently, or you will end up with a number that lacks all of the relationships of the original vector space and no longer is meaningful to treat it as 1D or any number of dimensions.

Re:1D compression, AKA "Serialization"

[lgw]

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.

Re:1D compression, AKA "Serialization"

[dinfinity]

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 easily come up with some layman stabs at configurations which I'd deem physically unreachable, but I'm fairly convinced that it's a bit more complex than that.

Re:1D compression, AKA "Serialization"

[Anonymous Coward]

wow, it amazes me , for how idiotic and non-computer literate most Republicans are, that they congregate here and think that they can get slash dotters to turn from Democrat to Republican by making these dumb wisecracks that even a fifth grader can debunk.

Case in point, the actual Wow freakout kid turned out the be a poster named narcc who tried to "school me" on formal logic, when I actually have a masters degree Electronics and Computer science from MIT. He gets on and tries to debunk a bunch of stuff by attacking my logic and starts posting this Karnaugh type notation that is TOTALLY WRONG!.. and all the while doesn't even attempt to debunk my actual point.. and then after all the commentary cools down, his mom out's him on here.. and states she took away his internet privileges and cancelled his WOW account again!

I had no idea the WOW kid was a republican but it stands to reason with how narrow minded, short sighted, hyper religious they are and how they rely on emotion rather than logic in arguments.

God would have his own linux box if God existed , but there is no God, so there is no God's Linux box so you will have to deal with Hillary's server or the universe as it is because there is no Magic "God is in his heaven" to save republicans from their narrow minded bullshit. They will never accept it either because they are victim to the Dunning Kruger effect, like most dumb people.

Re:1D compression, AKA "Serialization"

[Anonymous Coward]

This complete misses the point of what dimension is unfortunately. The idea you could encode 2D and higher real numbers into a single real number goes back to the end of the 19th century when showing that the cardinality of R^n is the same as R. However, that doesn't change the number of dimensions it takes to represent R^n in general, because the concept of dimension has a specific meaning.

Re:1D compression, AKA "Serialization"

[Tablizer]

"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 perspective; we are given a God view. The higher we go in the stack, the more recent the time of their world. It's kind of like a flip-book, except it may be continuous instead of discrete pages.

We could cut into and study the pancakes to observe any time of this 2D world we want. But to the inhabitants of the 2D world, only the currently active "slice" (the present) is all they are capable of influencing and directly observing, outside of memories. It's just like our limited relationship with time.

We don't know what the "right" perspective is of our universe or if there even is ONE "right" one. There are only relationships (such as relationships between particles). How one chooses to perceive or project or represent these relationships is ultimately arbitrary.

Re:1D compression, AKA "Serialization"

[wonkey_monkey]

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?

Re:1D compression, AKA "Serialization"

[wonkey_monkey]

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.

Re:1D compression, AKA "Serialization"

[Ignatius]

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 larger the volume, the lower the (mass-, thus energy-, thus information-) density has to be to prevent collapse.

So the information capacity is sublinear in volume thus I = O(V^e) with the exponent e smaller than 1. The holographic principle states that e=2/3. This again is not implausible from a naive point of view, given that volume increases with the third power of the radius while gravity decreases with the inverse square.

ignatius

Re:1D compression, AKA "Serialization"

[Anonymous Coward]

"That implies the fundamental mechanics of the universe can't be something like "voxels"."

Well, that's a point of view. Specifically, it's the point of view of the outside observer.
Meanwhile, someone falling into a black hole still sees 'voxels' as he/she falls through the horizon of a black hole. At the horizon he/she notices nothing special. From the observers point of view the person falling in spreads over the horizon into a 2D surface, but never passes the horizon.
The holographic principle is part of a paradox. (I love how Gerard 't Hooft says 'Paradox'.)

Re:1D compression, AKA "Serialization"

[Anonymous Coward]

You still seem to be missing that that dimension is a precise mathematically concept. Yes, it connects to the real world through a mathematical model, but it doesn't magically mean you can chose models with different dimensionality, and you can't just go on about "dimension" in some wish-washy sense.

Even the holographic principle is not saying the universe is 2D, despite how some pop-sci pieces try to dumb it down in such a way. Other posts make a good analogy to electromagnetism. Electromagnetism is inherently about a three dimensional space. However, if you are given all of the electric and magnetic field information on a 2D boundary surface, that gives you all the information you need to computer the fields within the 3D space within. It doesn't change number of dimensions of the original volume. Similarly, things like AdS-CDF equivalence will let you compute math in a space with one less dimension and get an answer relevant to a space with the extra dimension, but it is still a space with that extra dimension.

Even in your flip book example, you end up with three dimensions regardless of whether your within the flip book or looking without. Nothing about your perspective change has changed the minimum number of basis vectors needed to describe a spacetime position within that system.

Re:1D compression, AKA "Serialization"

[ultranova]

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".

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 for nearby cells. Laws of physics could also be understood as rules of how values can vary across time- and lightlike paths. Put these effects together, and I suspect the result is the holographic principle.

Re:1D compression, AKA "Serialization"

[Tablizer]

precise mathematically concept

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.)

Re:1D compression, AKA "Serialization"

[Anonymous Coward]

The vector space definition is the one relevant to things like the holographic principle and when talking about 3D vs. 2D geometric spaces. It is the size of a set of basis vectors, a set of vector such that every vector in the space can be made of a linear composition of of the basis vectors, while none of the basis vectors can be made of the others. This idea can be generalized in some sense for a topological definition, but in principle is pretty similar.

You can't represent a higher dimensional space with a lower dimensional one in general while maintaining the original properties. Things like the holographic principle isn't about doing so, but about how a lower dimensional slice or boundary can contain all of the information need to know what is going in the higher dimensional space, because of the particular properties and constraints provided by general physics principles.

Re:1D compression, AKA "Serialization"

[lgw]

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.

Re:1D compression, AKA "Serialization"

[lgw]

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.

Re:1D compression, AKA "Serialization"

[Tablizer]

You appear to be talking about spacial dimensions. I'm talking dimensions in general.

When a penis is slowly inserted into my anus

[Anonymous Coward]

I very much feel multi-dimensional

Don't answer that [Re:Thanks for posting this]

[Tablizer]

"Honey, does this projection make my ass look 4D?"

Bozhe moi!

[Okian Warrior]

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.)

Re:Bozhe moi!

[Anonymous Coward]

Props for using Tom Lehrer lyrics without attribution, like the song advises ! :-)

I will believe this

[Anonymous Coward]

when I see a nigger get a job without government help or affirmative action for once in my life. We gave them a damn job when they first got here and it's never been good enough since then.

Direct confirmation difficulties

[Tablizer]

To most slashdotters it remains only a theory

Re:Direct confirmation difficulties

[Gr8Apes]

To most slashdotters it remains only a theory

Most slashdotters will swear they're only 2 dimensional!

Re:Direct confirmation difficulties

[michelcolman]

Holograms or it didn't happen!

Not a theory!

[Anonymous Coward]

The word "theory" implies that it is testable. But the mental fabrication of the Holographic Universe already admits to its untestable nature. 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.

theory (countable and uncountable, plural theories) -
        (sciences) A coherent statement or set of ideas that explains observed facts or phenomena, or which sets out the laws and principles of something known or observed; a hypothesis confirmed by observation, experiment etc.

hypothesis (plural hypotheses) -
        (sciences) Used loosely, a tentative conjecture explaining an observation, phenomenon or scientific problem that can be tested by further observation, investigation and/or experimentation.

I for one don't want to give Physics research a blank check to investigate some unobservable math fantasy.

Re:Not a theory!

[UnknownSoldier]

> 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 ?

Re:Not a theory!

[MrBigInThePants]

>The word "theory" implies that it is testable.

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.

Re:Not a theory!

[Anonymous Coward]

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 phenomena and theories. This is in the same way that observations confirming Newtonian mechanics also confirm relativity because it makes the same predictions in the situations tested by older experiments.

Re:Not a theory!

[lgw]

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.

Re:Not a theory!

[Anonymous Coward]

If there even a practical difference between String Theory and Holographic Universe?

Re:Not a theory!

[Anonymous Coward]

No. You are thinking of words like conjecture and hypothesis. But even the word hypothesis is well accepted to only be about a conjecture that you can test with observations or experiments.

Please share a little more information to help demonstrate that I am wrong. I at least gave some carefully isolated Wiktionary definitions. You rejected them and went through some circular reasoning.

You don't have to publicly admit that you did this if you don't want to, but please reexamine your post and think how little it offered to the thread.

Re:Not a theory!

[Anonymous Coward]

"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.

Having observation was not a requirement, and if you read my OP more carefully you would realize what I said.

A theory that can never be observed is different than a theory that we have no observations. The way the Holographic Universe conjecture is stated, it does not permit any measurements to disprove it. Either direct or indirect.

Re:Not a theory!

[Anonymous Coward]

The latter has a growing list of testable predictions, including many that are within reach of current equipment (and even a few experiments already started to test it). The former makes predictions that are either not testable in the near future or are identical to ones old theories make. That sounds like a pretty big practical difference.

Re:Not a theory!

[Anonymous Coward]

if you read my OP more carefully you would realize what I said.... way the Holographic Universe conjecture is stated, it does not permit any measurements to disprove it

You complain of them not reading more closely, yet completely disregard what was said in the above comment (and others above) that there are tests... that it is falsifiable (referenced even in the part you quoted).

Re:Not a theory!

[narcc]

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.

Re:Not a theory!

[qeveren]

Better would be to say that it is not a scientific theory, I suppose.

Re:Not a theory!

[Anonymous Coward]

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.

HMMM I haven't seen a bigger mess than this in years.. 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 wow freakout kid... get the remote control out of your ass and shut the fuck up! Adults are talking here!

Re:Not a theory!

[microTodd]

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?

Re:Not a theory!

[PopeRatzo]

I for one don't want to give Physics research a blank check to investigate some unobservable math fantasy.

Why not? And who exactly is asking for a "blank check"?

Re:Not a theory!

[Anonymous Coward]

Because if it were true, the supposed uniformity of nature would be so complete jizzicked that no one at all could do science on account of its foundational principle being falsified.

Wiseass.

Re:Not a theory!

[Anonymous Coward]

A post above clarified this: "Better would be to say that it is not a scientific theory, I suppose".

You can have untestable theories all you like, but a Scientific Theory is held to be a set of ideas and principles that make predictions that have been tested. The Theory of Evolution makes testable predictions, has been tested and works. But the various creationism hypotheses haven't made such predictions, and are largely indistinguishable.

The reason "Theory of creationism" is problematic is that people use the term carelessly around scientists (or people with scientific interest), trying to overload the same term in order to elevate its standing. next to other, "real", scientific theories. They try to push it into school science lessons, as an "alternative theory", when it's not a Theory and the context requires correct use of terminology. So your crucifixion results from you being seen as a snake-oil salesman, which might be unfair but there we are.

Actually - and the thing everyone is missing here - is that the term "Theory" tends to mean something else again amonst mathematicians, to mean "an area of mathematics". So, Group Theory, Number Theory, String Theory, etc. Given that the first line of the summary uses the term "mathematical description of the universe", I'd say that that was the context we should be using. And ... before anyone else points it out - I don't think creationism is a mathematical theory either!

Re:Not a theory!

[michelcolman]

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.

Re:Not a theory!

[MrBigInThePants]

very funny.

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!

[Sardaukar86]

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 it's original; perhaps instead it's ancient and I'm showing myself to be embarrassingly poorly read by failing to recognise its origin. Either way I find it inspirational, thank you.

I chose to reply rather than mod you up because I found your post remarkable and.. well, I guess I needed to remark upon it. Apologies if the points would have been of greater value to you!

Re:Not a theory!

[tehcyder]

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.

Re:Not a theory!

[tehcyder]

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".

Re:Not a theory!

[kilfarsnar]

I for one don't want to give Physics research a blank check to investigate some unobservable math fantasy.

Why not? And who exactly is asking for a "blank check"?

Since we're on the topic, I'd like a blank check!

Re:Not a theory!

[Will.Woodhull]

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, The theory of evolution has produced innumerable hypotheses, some of which were proven wrong while others were shown to be correct, and each of these tests has been fed back into the theory to improve its accuracy of its predictions.

This does not negate the CS Lewis quote from your sig line:

"You cannot find out which view is the right one by science in the ordinary sense." - C.S. Lewis on Intelligent Design

Lewis is stating that science is limited to questions of how things work, and cannot be used to address other questions, such as why they work, what purpose does the universe serve, where is the ultimate meaning. For persons who go through life with their eyes open, these are the wonderfully important questions, but they are not amenable to the scientific method.

Re:Not a theory!

[Anonymous Coward]

The first line in the wikipedia page you linked:

For theories in science, see scientific theory.

So, if we are talking about a theory on what happened to your lunch in the break room fridge, you are correct. If we're talking about some kind of sciency type idea, you are wrong. Now all we need do is figure out which applies to this thread...

Hope that helps.

Re:Not a theory!

[Anonymous Coward]

Bingo! This isn't about the holographic principle, it's about the idea of equivalency! This sort of "fact check" against basic symmetries minus one is awesome, because between the stronger LHC and this, we can finally start throwing out all the junk theories that have accumulated in twenty years of little to no data. We can start a serious faculty cleaning with these sorts of tools to disprove their mathematically logical but non applicable fashions. Many string theorists might want to dust of the CV...

Re:Not a theory!

[ananamouse]

>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!

[hawkinspeter]

Ask your bank. I got a whole book of blank cheques from my bank.

Re: Not a theory!

[timesuredoesfly]

Theory means it can not be proven wrong. If a hypothesis is able to be tested and not proven wrong or inconclusive it is a fact/law not theory. You should all be very open minded in science, unlike religion, science can be proven wrong and it does not diminish the overall value of science in general. Even an idea as wild as a holographic(matrix) universe deserves its chance under the microscope.

Re: Not a theory!

[Anonymous Coward]

Theory means it can not be proven wrong.

Anything in science can be proven wrong, as observations are a limited subset of what is out there. Nonetheless, many concepts in science are labeled theory, and are falsifiable. You can go back to old examples including ones proved wrong like caloric theory, to modern ones still withstanding tests like the general theory of relativity.

it is a fact/law not theory.

There is no hard difference between a law and theory in science, with a law typically just being simpler, more well established theories. When looking at a list of "laws" in different fields, you'll typically see a mix of things named law and theory.

Re: Not a theory!

[Anonymous Coward]

A lot of theories aren't as testable as they should be, but what would you call them then. Theories aren't necessarily the same as a hypothesis...

Re:Not a theory!

[Bengie]

Dark energy is an observable effect.

not goin for it

[SupRcoW]

holographic universe....... right....

Re:not goin for it

[Tablizer]

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.

Re:not goin for it

[Anonymous Coward]

You can pass your hand through many animals; just start at the back and use plenty of lube.

Re:not goin for it

[Tablizer]

I don't think that's what Dr. Schrodinger had in mind.

Now it makes sense

[Anonymous Coward]

My wife has always said I was two dimensional.

Huh

[koan]

I thought Sheldon gave up on string theory in the 5th season, or was it the 6th.

I love reading about this stuff...

[JThundley]

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?

Re:I love reading about this stuff...

[Anonymous Coward]

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?

Stuff ..
Pictures.
Not real.
Me Tarzan, You chetah. AAAAAAhhhh
Unga BOOonga.

Re:I love reading about this stuff...

[Anonymous Coward]

Why don't you google it like you're 5 and stop making me think of the r-word.

Re:I love reading about this stuff...

[grep -v '.*' *]

The people in your TV set don't know they're living in a 2-dimensional universe; it's all 3D to them but obviously 2D to you. (Ignore LGs new curved TV screen -- that doesn't count.)

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.] )

Just hope they don't hit the pause button to go get a sandwich. And Heaven forbid they change the channel! (But: how would you know?)

No, I don't understand it either. And until you can demonstrate an experiment that unambiguously demonstrates it, it's not science -- just guesswork.

Maybe they need two 5-year-olds to explain it all to them; that older 10 year old isn't working out so well.

Re:I love reading about this stuff...

[Anonymous Coward]

Well in principle, it is the same mathematical principle as the number of connections in a fully interconnected cluster of computers which is described by :

Number of connections = [N (N - 1)] / 2

same concept that the number of fully connected interconnects between each machine is the number squared , minus itself and that result divided by two.

this same concept extends to the fact that any dimensional geometric representation of a n dimensional form can be thought of as a n-1 dimensional projection of a higher dimensional object one dimension higher.. Not hard to understand when you realize that a square is a 2 dimensional projection of a cube.. a cube is a 3 dimensional projection of a hypercube.. and so on.

of course the Wow freakout kid.. little Narcc is going to come on here and spread his bullshit that "I haven't seen a bigger mess than this in a long time" trying to look all smart, before he gets his internet privileges taken away by his mom again.. I bet he hasn't gotten his connection back or his WOW account since the last time he had a temper tantrum about my posts that he was too dumb to understand. Oh well he is an idiot that is why there is a you tube video of him having a temper fit and sticking a remote control up his ass.

Re:I love reading about this stuff...

[Anonymous Coward]

Wow this totally makes sense,.. This totally explains how I went from 25 to 35 so quickly with nothing to show for it.
Our Noodly master has a DVR and hit the fast forward button.

Re:I love reading about this stuff...

[PopeRatzo]

The people in your TV set

All are welcome.

Re:I love reading about this stuff...

[laughingman4929]

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!

Re:I love reading about this stuff...

[Anonymous Coward]

"... and stop making me think of the r-word."

Readers? ;)

Re:I love reading about this stuff...

[Anonymous Coward]

"Can someone explain it to us like we're 10?"

Well, that's gonna be hard.
First thing to say is that everything can be described as information, bits.
So the composition of an atom can be described in some number of bits.
And it's velocity or any other observable phenomenon can be encoded in a bunch of bits.
So you can describe anything in the universe as bits of information.
Twice the stuff, twice the bits, more or less.

Here comes the weird stuff.
In our universe there is a limit to how much information you can put in one place.
The more information you put together the more space it takes up.
Put some information (perhaps a bunch of atoms) together and there will be a minimum sphere of space that they will take up.
Usually this sphere is much smaller than the atoms so you don't see it but you can compress the stuff so hard hard that it becomes smaller than the sphere. The stuff then collapses into an infinitely small thing in the middle of the sphere. We call the sphere a black hole and its surface is called the event horizon. The infinitely small stuff in the middle is called a singularity.

But it turn out that if you put in twice the amount of stuff/information in one place that this sphere does not grow twice in volume.
It grows to twice the area !
It looks like all the stuff inside the sphere is organized on the 2D outer layer of the sphere. That's also where there is room for stuff to be added to the black hole. So there seems to be no inside and everything that falls in just adds to the surface, not the volume.
That is called the holographic principle.

Re:I love reading about this stuff...

[Anonymous Coward]

Our universe is just a security feature on God's credit card.

Re:I love reading about this stuff...

[JThundley]

That did, thanks for the informative and interesting post!

Gas diffusion

[Anonymous Coward]

If the universe is a hologram, can someone explain why gas diffusion is a function of r^3 and not r^2 as one might expect in a 2D universe?

Re:Gas diffusion

[Anonymous Coward]

Electric field drops off as 1/r^2 instead of 1/r as it would in a 2D universe, yet the electric field follows a holographic principle in the sense that defining it on a 2D boundary will completely determine its value within the contained 3d volume.

hologram heaven

[Anonymous Coward]

holograms, in our head, approved for use by the military on people?

* "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

Holograms are approved for use by the military on people: http://oregonstatehospital.net/d/otherfiles/1997-07%20Non-lethal%20Weapons%20Terms%20and%20References,%20Institute%20for%20National%20Security%20Studies,%20U.S.%20Air%20Force%20Academy,%20Colorado.pdf

A hologram, creating a hologram, which a hologram picks up and constructs in holographic nature within it's holographic self? That's a satellite projection, into an environment or even a human, all three holograms - the human, a hologram, renders it within it's mind which is also a hologram. -Physicist, Todd Giffen

-Todd Giffen
http://www.obamasweapon.com/ http://www.drrobertduncan.com/

Min num of directions to navigate Riemann Sphere

[Anonymous Coward]

They're probably right. The Riemann Sphere to describe infinite limits over complex numbers (which are 2-dimensional numbers) requires 4 directions to navigate. While there's symmetry of very large numbers (approaching the point at infinite) with their recipricols (approaching the point zero), if those numbers are to be treated as distances, then the distances are very assymetric in comparing those numbers closer to infinite with those numbers closer to zero. Therefore, a minimum of 4 directions are required to access any point in the Riemann sphere. God already told us about the 4 corners of the earth (UT,AZ,CO,NM or a place in China?) and that his chariot is set up to move in 4 directions (apparently only 4 directions are required to move throughout the universe). Since He created this universe, this hollographic idea may be getting near to the truth.

Re:Min num of directions to navigate Riemann Spher

[Guy Harris]

God already told us about the 4 corners of the earth

Four corners?

I wish there was an easy way to understand it

[Trachman]

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 humans is the theater of shadows (3D->2D), or three dimensional cathode ray projector, know as tube television (again 3D->2D).

It is always possible to project more dimensions to less. At the same time, 2D->3D Holographic effects allow explanation of some of the known quantum phenomena, such as probability of where the electron will be at anytime as opposed to the earlier teachings that electrons "orbit" around the nucleus of the atom.

Holographic effects also alleviate "understanding" of "spooky action at the distance (quantum entanglement)", but that is where the limits of the quantum teachings, understandable by the commoners end.

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.

Our incomplete understanding of surrounding world raises way more questions than we have answers:

1. If currently scientists say that the space is unlimited, perhaps the number of dimensions is also unlimited....
2. Quantum entanglement has been demonstrated and is a scientific fact, the problem is that nobody can prove that all of the particles are not UN-entangled.
3. Why the speed of light is finite, then why quantum entanglement does not care about the distance and is instant.

  I truly believe that in the next several decades there will be so many new inventions and experiments related to the quantum world, that our current discussions will resemble discussions will resemble ideas debated by Hellenistic scholars. I just hope that one day a smart individual will be able to explain everything so that we could understand, and find relationships between all the components the same way we understand the relationship between Ohms, Volts and Amperes.

Re:I wish there was an easy way to understand it

[gl4ss]

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.

Re:I wish there was an easy way to understand it

[Anonymous Coward]

No, 2000 years ago the greeks, as well as most other people who spent any time at all looking at the sun and it's shadows new damn well the earth was round. Just because morons like you believed the dumb bitch that had sex with minors when she told you that long ago people were dumber than you.
Believe me, there are plenty of stooges like you. Your type of moron believes anything they are told. I doubt you could sail a boat across the lake, much less an ocean. I doubt you could name six constellations while reading your horoscope. You probably can't even grow a tomato plant. Can you? Why don't you buy one of those hanging tomato plants for 1000x the cost of a seed and see how long it takes you to kill it. You know nothing scoundrel.

Re:I wish there was an easy way to understand it

[Anonymous Coward]

It is always possible to project more dimensions to less.

But typically projection to fewer number of dimensions involves the loss of information. You can always make a 2D shadow from a 3D scene, but there will be multiple possible scenes that will produce the same shadow. It is a much more special case when you can represent something with fewer dimensions, without loss of information.

An example of this is electromagnetism, where if you know the field values on a 2D boundary of a volume, Maxwell's equations allow you to determine the field everywhere within the volume. It isn't a case of projection, but that the 2D boundary contains all of the information, at least under Maxwell's equations.

Re:I wish there was an easy way to understand it

[Ignatius]

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/...

also, there are no elephants in Greece ... ;-)

ignatius

Re:I wish there was an easy way to understand it

[vtcodger]

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.

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?)

I just hope that one day...

[Anonymous Coward]

I wish you luck. I, on the other hand, plan to be dead by then.

So, the world is flat after all?

[janimal]

It would seem that ancient wisdom triumphs and we live in a 2D world.

Holographic universe eh?

[Anonymous Coward]

I hope their "research" is not with public funding.

Huh?

[Sqreater]

What?

Screw Popularizations!

[logicnazi]

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 holographic principle is just doing it in a way that isn't horribly ugly (probably preserves certain properties that aren't even mentioned in popularizations). In fact it's not at all uncommon for the information about the solution to some (class of) mathematical problems to be fully reflected in the behavior of that solution on some smaller dimensional part.

In short, while this may be quite interesting to the people actually doing the math if you aren't you certainly shouldn't pretend this gives you some deep insight into what the universe is "really" like.

Re:Screw Popularizations!

[Anonymous Coward]

You can always code the information about any functions/distributions/whatever in n dimensional space in fewer dimensions.

Well, you can't code a generic function into a one dimensional real number, as the cardinality of the set of functions is larger than that of the set of real numbers...

Anyway, yes, you can encode any n-dimensional real number space into a single dimensional space, but that completely misses what dimension means in mathematics. It isn't about how many numbers you need to encode a position, but how many numbers you need while maintaining a certain relationship between those numbers (a vector space). This is why you can't say all 3D space scan be just reduced down to a 1D space, even though you can make a one-to-one mapping between all 3-tuples of real numbers and the set of single real numbers.

And while many problems can reduce to a lower dimensionality by making certain assumptions or problem specific constraints, holographic principles do so in general, and show that taking a particular slice of a higher dimensional space contains all the information you need to know what the rest of the space is doing. You can do this easy enough in classical physics, where if you know the electric field everywhere on a sphere, you can calculate the electric field anywhere within the sphere.

Re:Screw Popularizations!

[Anonymous Coward]

Well, you can't code a generic function into a one dimensional real number, as the cardinality of the set of functions is larger than that of the set of real numbers...

True. But in Physics it is reasonable to just care about analytic (or holomorphic) functions, a fact that is used by procedures like regularization.
And those have the same cardinality as the reals.

The fuzz about the holographic principle is also about the fact that it assumes a discreteness at the plank level. And now the question is if the maximum number of qbits (in a volume) are proportional to volume in plank units or somethingelse. The naive answer is of course that the maximum number of qbits or the entropy is proportional to the volume (in plank units), but some ideas suggest that the entropy is proportional to the surface area instead.

This means that anything in the universe with an entropy >= the max entropy defined by the surface forms an event horizon, that "hides" any potential (higher) inner entropy from the rest of the universe forever. All in all it comes down to the fact that we do not really understand event horizons and entropy/information
and we have no real clue about the combination of those.

My personal view is that entropy/information and events are the most fundamental elements of reality and that everything else (including particles and space time) are just emergent features of a causal network of events. Entropy is just the result of the fact that the universe is incapable of forgetting.
While e.g. Turing machines (and typical cellular automatons) can easily loose information, the universe cannot. This means that the most fundamental objects get entangled with each other more and more when they form causal relations and the signal to noise ratio gets lower and lower.
Think of a table with billiard balls and no friction. Even if the initial state is kind of ordered (but contains some randomness), if the balls are in motion and never loose momentum then at some point the movement of the balls will look random. The small randomness from the initial state will slowly spread while the balls bounce against each other and exchange information/momentum. With each collision with other balls the current ball gets entangled/effected by more and more other balls and the momentum of the current ball becomes more random.

In other 'news', ancient aliens, matrix, santa

[Anonymous Coward]

It's really sad what passes for 'science news' these days. It's almost as sad as what passes for 'journalists'.

This is not new

[Anonymous Coward]

The holographic principle is nothing new. I don't know why it's being posted as "news" when it's not. I read about it years ago.

Does this reasoning recurse?

[FredGauss]

Disclaimer: IANAP If an n dimensional space can be explained by an n-1 dimensional projection, can said n-1 dimensional projection be explained by an n-2 dimensional projection? But more importantly... what implications does this have for infinite stacks of turtles?

Re:Does this reasoning recurse?

[Anonymous Coward]

If an n dimensional space can be explained by an n-1 dimensional projection, can said n-1 dimensional projection be explained by an n-2 dimensional projection?

In the case of AdS/CFT, the n-1 dimensional system is rather different than the n dimensional one, so you can't keep applying it.

Use your words

[Anonymous Coward]

one AC posted some reasonable definitions:

[scientific] theory (countable and uncountable, plural theories) -
                (sciences) A coherent statement or set of ideas that explains observed facts or phenomena, or which sets out the laws and principles of something known or observed; a hypothesis confirmed by observation, experiment etc.

hypothesis (plural hypotheses) -
                (sciences) Used loosely, a tentative conjecture explaining an observation, phenomenon or scientific problem that can be tested by further observation, investigation and/or experimentation.

Maybe this is just semantics but I would argue that other words we can use instead that can fit better than the precise meaning of [scientific] theory and hypothesis. Other words one could use are conjecture, supposition, postulation/posit, hunch, or SWAG (silly wild-ass guess).