The Universe As Hologram 532
Several readers sent in news of theoretical work bolstering the proposition that the universe may be a hologram. The story begins at the German experiment GEO600, a laser inteferometer looking for gravity waves. For years, researchers there have been locating and eliminating sources of interference and noise from the experiment (they have not yet seen a gravity wave). For months they have been puzzling over a source of noise they could not explain. Then Craig Hogan, a Fermilab physicist, approached them with a possible answer: that GEO600 may have stumbled upon a fundamental limit where space-time stops behaving like a smooth continuum and instead dissolves into "grains." The "holographic principle" suggests that the universe at small scales would be "blurry," its smallest features far larger than Planck scale, and possibly accessible to current technology such as the GEO600. The holographic principle, if borne out, could help distinguish among competing theories of quantum gravity, but "We think it's at least a year too early to get excited," the lead GEO600 scientist said.
Re:Plato (Score:2, Interesting)
Anti-science (Score:2, Interesting)
Does this sound to anyone a little like the argument for intelligent design? "We can't explain why animals are the way they are because an intelligent creator that we don't understand has made them this way," to me sounds a lot like "We've gotten to the highest possible resolution of the nanoscale universe, because it's a hologram and that's it's highest resolution. It's okay that we can't see what we want to see, because it's not actually there."
I'm not a physicist so I might be missing the real testable hypothesis here, and I don't think the thought should be suppressed just because it's not scientific, but I think it's important to keep in mind that we're departing the realm of science here and moving towards a cop-out.
Re:Plato (Score:2, Interesting)
Actually this isn't a bad tie in.
Plato wasn't discussing human perception as in each person's perception is different but that we only see a shadow of truth.
If we're living 'in a hologram' where we are unable to perceive an extra dimension that exists and affects us, then is it really that different from Plato's example?
Re:Okay... (Score:5, Interesting)
That sounds like a credible description of Quantum Gravity, or rather the big question of quantum gravity, namely, IS gravity a continuous force or is it quantized? Nobody knows if "gravitons" exist.
The issue in this article is that these discontinuous "blurry" fluctuations are much (much much much) larger than a planck length, and this agrees with the assumptions of the so-called holographic principle, and this experiment may not be picking up gravitons so much as it's detecting the blurryness you would expect from a 2-dimensional hologram projected into 3-space. Since the 2-dimensional "horizon" of the universe can only encode information on the scale of a planck length, thus the projection in 3-space within is going to have a much lower information density. I think. I'm not a physicist...
This is all, of course, impossible. [wikipedia.org]
Don't panic (Score:5, Interesting)
I hear Nvidia is updating the universes GPU and soon we will get less grains. Mac Users will be able to switch between GPU, one with faster performance and shorter lifespan and one grainier but longer lasting.
it is interesting to note that the universe is mainly built out of second order laws. This means that in many cases there are a small number of poles or zeros that can control macroscopic behaviour and often analytic solutions exist. This would be how a desiginer would do it. given a choice one chooses a qaudradic over a 6th order polynomial since an anytic solution to the zeros exits.
Likewise when things in a game are not observed you don't keep maintaining them. You just recreate them when needed. That is you keep the wireframe but don't texturize it till it is on screen. This is analgous to the way in QM the details are not predictcable till you look, and when you do the details of other things not simultaneously observed can change at a distance.
simmilarly in optics resolution behaves the way it does in video games. pixelation means that the farther something is away the less resolved it appears. There is constant angular resoltuion not spatial.
Perhaps the ancients had it right ... (Score:4, Interesting)
I, for one, welcome our new Matrix overlords, and will be on the holodeck if you need me.
Re:Flatland! (Score:3, Interesting)
Indeed! while Flatland turns out to be more of a social commentary than a scientific one (as many good sci-fi books eventually mature into), the physical concept that Spaceland is merely a 3D projection of 2D information is very interesting.
This is not the first time noise in an experiment [wikipedia.org] led to a groundbreaking discovery (if this indeed turns out to be one). Kudos to the scientists - often times the compulsive search for signal obscures the importance of noise.
Re:Don't panic (Score:1, Interesting)
Careful, you mention a designer, it's still not a given that there is one even if the universe is a computer.
Black holes (Score:3, Interesting)
This theory was stimulated by research suggesting the information about a collapsed star is stored in quantum fluctuations of the black hole's horizon. However, when applied to the universe as a whole, to quote the NewScientist article: "the cosmos has a horizon too - the boundary from beyond which light has not had time to reach us in the 13.7-billion-year lifespan of the universe." I had some questions resulting from my own dim understanding of black holes and having read only the NewScientist article, not the published paper.
Matter that falls into a black hole, from the perspective of a faraway observer at rest w/ respect to the black hole, appears to slow down and the light reflected becomes redshifted - the object appears to be almost frozen in time just before the redshifting becomes so great that the object becomes invisible. The object never appears to actually go in but is stuck forever at the event horizon. This suggests to me that information about infalling matter is also stored in the black hole's horizon. So what I'd like to know - is the surface area of all the black holes within the visible universe included in their calculations along with the surface area of the visible universe? If not, are even black holes simply holograms of the visible universe's surface area, thus making the information encoded in the black hole horizons redundant? Would including the black hole surface area significantly change the expected frequency of the holographic noise?
Re:Plato (Score:3, Interesting)
Science starts with the axiom that something objectively exists to observe. It further presupposes both causality and (except for some of the most out-there interpretations of the quantum world) locality.
Try as you might to avoid it, you need axioms. Without a few basic assumptions about our world, you end up with solipsism.
10^(-16) meters? (Score:4, Interesting)
The article states that the uncertaintly at the Planck scale at the (hypothetical) border could translate to something like 10^(-16)m scale in "our world"? But some 10 years ago when I was at some research facility near Padua, they had a gravitational wave detector which they claimed could detect movement on the scale of 10^(-21)m so that would suggest we can already make much more precise measurements. How would that be possible?
(Disclaimer if I'm missing something obvious: I'm not a physicist)
Re:Plato (Score:3, Interesting)
The Universe As Cellular Automaton? (Score:2, Interesting)
This makes me take a second look at this guy's ideas:
http://en.wikipedia.org/wiki/Edward_Fredkin
Re:Don't panic (Score:5, Interesting)
This is analgous to the way in QM the details are not predictcable till you look, and when you do the details of other things not simultaneously observed can change at a distance.
See http://www.overcomingbias.com/2008/05/collapse-postul.html [overcomingbias.com]
Back when people didn't know about macroscopic decoherence aka many-worlds - before it occurred to anyone that the laws deduced with such precision for microscopic physics, might apply universally at all levels - what did people think was going on?
The initial reasoning seems to have gone something like:
to
to
Read literally, this implies that knowledge itself - or even conscious awareness - causes the collapse. Which was in fact the form of the theory put forth by Werner Heisenberg!
[...]
If collapse actually worked the way its adherents say it does, it would be:
Re:Let's see if it's true... (Score:5, Interesting)
You know what would have been awesome? If we had discovered that the universe is really a holodeck simulation when the actor playing Moriarty in that episode said the line "Computer, arch" and an arch really did appear there in the studio. It just would have been so meta.
Re:Anti-science (Score:5, Interesting)
The deeper we look the more layers we find. It's like finding out that your Commodore-64 is really an 8086-PC emulating the C64, but that the 8086 is really a 286 emulating the 8086. But the 286 is really a 386 emulating a 286, which is really a Pentium emulating a 386 emulating a 286 emulating a 8086 emulating a C64, and new evidence suggests that the Pentium is being emulated also.
God, knock it off already! It's not funny anymore.
Heim Theory (Score:4, Interesting)
I wonder if there is any relation at all to the "grains" and Heim's "metrons".
A single elementary particle is characterized not only by and the limiting distances R+- of its gravitational field, but also by its Compton wavelength. R- vanishes in empty space when the mass of the field source approaches zero, while R+, , and the Compton wavelength all diverge. However, since the smallest geometrical unit must be a real number and a property of empty space its value has to remain finite. As shown in [1], only a single product having this property can be formed from the 4 characteristic lengths above. The result is an area, , bounded on all sides by geodesics, whose present numerical value is = ca. 6.15x10-70 m2. This quantity, called a metron, represents the smallest area existing in empty space and requires the differential calculus to be replaced by a calculus of finite areas. Accordingly, a whole chapter in [1] is devoted to the development of a difference calculus considering the finite area of . This enables any differential expression to be metronized. It follows that in any subspace Rn, whose dimensionality n is divisible by 2, the geometrical continuum is replaced by a metronic lattice formed by n-dimensional volumes bounded on all sides by metrons. Thus, R6 and R12 are 6-dimensional and 12-dimensional metronic lattices, respectively. Since all dimensions are metronized, even time proceeds in finite, calculable steps. By the use of a difference calculus it becomes possible to consider in the nonlinear system of geometric structures in R6. - Bastic Thoughts of Heim's Theory [engon.de]
Wonderful Book (Score:3, Interesting)
I highly recommend "The Holographic Universe" by Michael Talbot, which talks a great deal on the topic. It takes the work of physicist David Bohm and neurophysiologist Karl Pribram, and goes on to explain how the holographic model can easily explain paranormal and psychic phenomenon. I've studied mysticism, spirituality, physics, and neuroscience for ten years, and the holographic model fits perfectly with what people experience during waking life, in dreams, at near-death, and during other mystical experiences.
I realize that most Slashdot readers will look upon this with skepticism, but after all these years of research and study, I can honestly say that if this isn't the way the universe works, it's the way it should work.
Comment removed (Score:2, Interesting)
Re:Black holes (Score:3, Interesting)
So the answer to the frequency question might be this. Because the information contained on a closed surface must be the same as the information contained in side a closed surface must be the same, this implies that the size of the fundamental unit inside the surface must vary, assuming that we are assuming the plank length to the fundamental unit on the surface. Assume, for instance, that our closed surface is a sphere. Assume further that the radius of the that sphere is r plank length units long. That means that the surface area of the sphere is 4 pi r^2 and the area is 4/3 pi r^3. This means that each square planck unit of the surface encodes r/3 units of volume. If we assume this volume is a cube, then the length of fundamental cube encoded in the closed surface in the a square of plank length the cube root of r, where r is the radius of closed surface, or so it seems.
To me this seems kind of neat because it show that information is compressed in a black hole, as the radius of the black is smaller than the radius of the universe. It also shows that as the universe expands, the amount of information held in a cube also is reduced, but at a much smaller rate. This would imply that the frequency would change in a black hole, and also over time as the universe expanded. This side length must have grown very rapidly in the early universe, and now must be a very small change, which would only be observed when matter is compressed to a black hole.
However, if the universe continues to expand indefinitely, the size fo the smallest volumes outside fo the black hole will be huge compared to those inside of the black hole.
Re:Flatland! (Score:3, Interesting)
I've often expressed this theory myself (Score:2, Interesting)
Here's a simple thought experiment. It isn't proof of anything, but it's interesting.
Let's say that we wanted to simulate the universe on a supercomputer.
The laws of physics and information theory seem to dictate that it's impossible to store that much information on a supercomputer, because you would need as much information as contained in the entire universe to do it accurately.
But what if you just simulated it roughly, unless you detected intelligence (decreased entropy) in your model? Whenever the intelligent things tried to study your model, you'd give them better and better information as they looked at smaller, and farther away things.
Eventually, though, you'd run out of information to give them, and you'd basically have to turn your pockets inside out.
For example, if they figured out how to change a texture in their world, they would notice that textures changed all over the place, seemingly randomly, because you're reusing them all over the place.
That the universe is a figment of someone's (or some THING's) imagination, to me, seems the simplest theory, not at all far out.
Re:They found the Matrix? (Score:3, Interesting)
Having said that, allow me to point out that if the universe has a resolution limit, then it is effectively "pixellated". One thing that produces pixellation effects is digitization. Therefore it is possible that the pixellation we observe in the universe is caused because it is digital in nature.
Actually, anytime you record anything it becomes "pixelated", although sometimes other terms are used. The exception of course being when you know the actual formula and inputs used to generate the original in which case you can merely store the formula and inputs and then recreate the original at any point from that.
Take for instance a picture of something (for now assume we're using a traditional film camera and not a digital one). Generally we don't notice because our senses aren't that fine, but even a film camera will cause a certain amount of "pixelation" or to use the more accurate term, grain, to appear in both the negative and the final print. The quality of the image is dependent on how fine the crystal structure of the film used to take the picture is. There's nothing that makes digital information special in this regard, it's merely that the way more traditional analog information is stored and played tends to flatten out artifacts so that they're less noticeable in the reproduction.
As another example take sound recordings. No recording is ever a perfect 100% reproduction of the sounds at the point it was produced. That's not really a problem though, as we don't care about all the sounds, or even most of the sounds, so the lack of them in the final recording does not detract from its purpose. Further quite a bit of the sound we can't even perceive, so even if it was recorded we wouldn't know about it (its beyond the limits of our hearing).
Re:Okay... (Score:3, Interesting)
GR works great at the macroscopic level, but is lousy at the subatomic level, which is pretty much what you'd expect whether space/time was quantized or continuous. The scale of GR is so fantastically large compared to the granularity, that everything is essentially continuous. In GR, space/time is indeed curved and one of the huge problems with QM gravity is that it cannot be reconciled with GR gravity at the present time. The reconciliation of the two is considered essential for a Grand Unified Theory to exist, and a fair chunk of modern physics only works if you assume a GUT does exist. If the GUT's existance is falsified, that's going to cause a lot of headaches.
So far, that's "textbook" stuff. The next question is whether GR precludes quantized space/time in some other way. The answer is probably no. The equation for relativistic mass is M'=M/(1-sqrt(V^2/C^2)). Both rest mass and relativistic mass are quantized, since mass is supplied in quantized units in the form of the Higg's Boson. The only way you can force M' to hold discrete values is if V also can only hold discrete values. V=S/T (S being the symbol used for displacement, which leads me to believe physicists haven't yet grasped the Latin alphabet quite as well as the Greek one), which in turn means S and T must be constrained, or V would be infinitely variable. If V were infinitely variable, you could convert a mass to energy (E=MC^2) where that energy could NOT be converted back into a mass, because you'd have some non-zero amount of energy left over that did not correspond to a valid Higg's Boson.
(The above paragraph makes the assumption that the Higg's Boson does indeed exist. Iff it does not, GR could permit a totally continuous state.)
Now, can GR's gravity be discrete, using just the notion of curvature in space/time? Perhaps. If I had the answer to that one, I'd be 9/10ths of the way to solving the GUT problem and becoming a celebrity. The odds of this happening are (infinity-1):1 against.
Re:Don't panic (Score:2, Interesting)
What we have is that classical mechanics is a particular approximation of general relativity, at one end of the scale, and of quantum mechanics, at the other.
Not quite, they describe different things, so you can put them on the same scale. Classical mechanics is a framework for describing the dynamics of a system once you specify the forces. QM is a different framework. But GR is a theory for describing a particular force, gravity.
A wonderful example iirc is the spinning top. In classical mechanics, the top cannot be solved exactly. But in general relativity, the top can be solved exactly in about one page
This doesn't make any sense IMO, unless you can come up with something to back it up. If you mean the precession of a top in the presence of gravity, then sure it can be solved analytically in classical mechanics, but the general two body problem has no analytical solution in GR, and I doubt the restriction to a top simplifies it enough to allow a closed form solution. But I can give you valid examples that suggest the opposite. In classical mechanics, the dynamics under a linear potential (constant force) is very simple: constant acceleration in one direction. But try solving that in quantum mechanics, and what you get are hideous Airy functions to describe the position of the particle.
The designer, then, still has the last laugh, until there is a TOE, if there ever is.
Not even then. I don't know what it means among laypeople, but for a physicist TOE means a quantum field theory that describes gravity, electroweak and strong force. I can guarantee that we will have such a theory in 100 years, and probably a lot less. I can also guarantee that this TOE will eventually be superseded by a more accurate theory.
Re:Don't panic (Score:2, Interesting)
Oh it is. Until you understand what is going on, of course. Though there is nothing "fuzzy and indistinct" about reality, a particle can't have definite momentum and position. It's a not that we can't figure it out, or somehow our measuring it always destroys it. This idea from classical physics simply doesn't transfer.
Here's a bad example that kind of illustrates the point:
Suppose you have a purple shirt. You ask the question "is the shirt pure blue, or does it have no blue in it?" The answer is neither: there is some blue, but it isn't pure blue.
The idea of a particle having definite momentum requires it to have different positions in the same way that being purple requires both blue and non blue colors.
You're forgiven for saying this: it's the same thing Einstein believed. Check out the EPR paradox. The issue is not a question of limiting our knowledge. QM is much weirder than you think.