How many dimensions are there, really?

[Ductaper]

i've seen talk jof 4d, 5d, 10d, and even 26d space when talking about string theory. Have any experiments been conducted to show those extra dimensions exist, or are the extra dimensions just theoretical; just the best explanation for the behaviors of particles and strings we've observed in these three dimensions?

 

[meteor]

Have any experiments been conducted to show those extra dimensions exist,

Not to date, but there are conjectures that if you give enough kinetic energy to a string, then it can "leap" to another dimension. Imagine that you have a bubble chamber, where you follow the trace of a particle. If this trace suddenly stops, then the particle is not there anymore, if this can be observed in future experiments, it can be an evidence of other dimensions

 

[setAI]

probably infinite- [but it must be understood that space's dimension is-as-it-is and is not quantized into integers of axes- although “larger” <unquantized> dimensions are possible- the concepts of fractal dimensionality seem to be closer to nature ]


and I think that it is reasonable to say that extra dimensional spaces are proven becasue there are many discovered/invented "stable" universe simulations in higher dimensions- therefore it is possible to build virtual/artificial/digital universes with higher dimensionality- if a viable hyperdimensional space can be programed- then complex natural process somewhere in the universe should have already allowed such universes to emerge- also if something is created by an intelligence ultimately it is just as natural as anything else that forms- the only difference is that part of the emergent dynamics includes the operation of intelligent systems- a nest is a natural thing built by birds .'. an hyperdimensional continuum is a natural thing built by sophonts

in fact there is an argument that it is more likely that our universe is an alien artifact/simulation than natural based on anthropic reasoning/ Bekenstein's ideas/ and the seemingly digital discreteness of the Planck-scale

"One thing which struck me recently, and I found it a really disconcerting concept, was that once we accept all that, we get into a very deep set of questions about the nature of physical reality. That's because even in our universe, and certainly in some of the others, there'd be the potential for life to develop far beyond the level it's reached on Earth today. We are probably not the culmination of evolution on earth; the time lying ahead for the Earth is as long as the time it's elapsed to get from single-celled organisms to us, and so life could spread in a post-human phase far beyond the earth. In other universes there may be an even richer potentiality for life and complexity.

Now life and complexity means information-processing power; the most complex conceivable entities may not be organic life, but some sort of hyper-computers. But once you accept that our universe, or even other universes, may allow the emergence within them of immense complexity, far beyond our human brains, far beyond the kind of computers we can conceive, perhaps almost at the level of the limits that Seth Lloyd discusses for computers—then you get a rather extraordinary conclusion. These super or hyper-computers would have the capacity to simulate not just a simple part of reality, but a large fraction of an entire universe.

And then of course the question arises: if these simulations exist in far larger numbers than the universe themselves, could we be in one of them? Could we ourselves not be part of what we think of as bedrock physical reality? Could we be ideas in the mind of some supreme being, as it were, who's running a simulation? Indeed, if the simulations outnumber the universes, as they would if one universe contained many computers making many simulations, then the likelihood is that we are 'artificial life' in this sense. This concept opens up the possibility of a new kind of 'virtual time travel', because the advanced beings creating the simulation can, in effect, rerun the past. It's not a time-loop in a traditional sense: it's a reconstruction of the past, allowing advanced beings to explore their history."

-Sir Martin Rees

___________________________

/:set\AI transmedia laboratories

http://setai-transmedia.com

 

[marcus]

----quote from the recent AJL paper, page 2----
...This may be seen as a particular case of a more general truth, not always appreciated, that in any nonperturbative theory of quantum gravity
"dimension" will become a dynamical quantity, along with other aspects of geometry.
----end quote----

might interest participants in this thread
the paper is
http://arxiv.org/hep-th/0404156

 

[marcus]

"dynamical quantity" means you don't get to pick what the dimension of spacetime (observed at macroscopic scale) is going to be at the outset

the number of spacetime dimensions is one of those aspects of geometry that emerge by running the model---in a computer simulation or in solving the equation that say how the univese evolves

they use a simplicial quantum gravity model which they implement in a computer to generate universes with various spacetime geometries
and the universes have been tending to come out 4 dimensional
as they report in their paper:

"Emergence of a 4D world from Causal Quantum Gravity"

 

[marcus]

another quote from hep-th/0404156

----AJL paper, page 3----

In what follows we will report on the outcome of the first ever Monte Carlo simulations of four-dimensional causal dynamical triangulation...We will present strong evidence that the Lorentzian framework produces a quantum geometry which is both extended and effectively four-dimensional. This is to our knowledge the first example of a theory of quantum gravity that generates a quantum spacetime with such properties dynamically.

--------end quote-----

 

[MathematicalPhysicist]

Not to date, but there are conjectures that if you give enough kinetic energy to a string, then it can "leap" to another dimension. Imagine that you have a bubble chamber, where you follow the trace of a particle. If this trace suddenly stops, then the particle is not there anymore, if this can be observed in future experiments, it can be an evidence of other dimensions

and then those who watched "sliders" can say: "we told you so".

 

[sol2]

another quote from hep-th/0404156

----AJL paper, page 3----

In what follows we will report on the outcome of the first ever Monte Carlo simulations of four-dimensional causal dynamical triangulation...We will present strong evidence that the Lorentzian framework produces a quantum geometry which is both extended and effectively four-dimensional. This is to our knowledge the first example of a theory of quantum gravity that generates a quantum spacetime with such properties dynamically.

--------end quote-----

Marcus I wanted to add http://wc0.worldcrossing.com/WebX?14@39.MKVVcs64cFw.0@.1ddeda81/5 ( just click on page and scroll down immediately, bypassing heading) here because of the issues in regards to triangulation, in terms of the model gravitationally built in the Monte Carlo effect. It's a bit of artistic addition, but I think you will see some significance here?

I hope you can see that I can switch back and forth between M and LQG in terms of the issues of discreteness and continuity. I think both sides exemplify one of these stance repsectively? Would you agree or disagree?

It would be as important as distinquishing back ground versus back ground independance?

 

[marcus]

the 1911 painting "Le gouter" (teatime) is pretty
even in the reduced size version.
I never saw it before

who is the person in the blue baseball hat?
it doesn't say

 

[sol2]

who is the person in the blue baseball hat?
it doesn't say

http://www.edge.org/3rd_culture/bios/hauser.html

 

[setAI]

and then those who watched "sliders" can say: "we told you so".

Sliders was awesome! they mentioned M-theory on the show less than six months after Ed Witten gave his famous talk and introduced it to the world-

___________________________

/:set\AI transmedia laboratories

http://setai-transmedia.com

 

[RAD4921]

The origin of dimensions

Astrophysicist Paul Davies once wisely asked if mathematics was built into nature or just a concept of man. More than likely dimensions along with geometry in general are just abstraction of thought and are not reality itself.
Mathematics and geometry are like topographical maps in that they are depictions but are not reality itself, like a photograph of your family. The photograph is a picture of your family but not actually your family.
I tend to lean towards a holographical model of the universe. If this is so, then it is likely that in real sense the universe is dimensionless.

 

[Ductaper]

Back to SetAI in post #3

I'm not asking how many dimensions we have thought about, I'm asking how many dimensions have been proven to exist scientifically. You can think about all the dimensions you want, but if only four dimensions really exist, what good is all your guesswork?

The vanishing path-bubble chamber in post #2 is an excellent example. Two questions about it though. Can we observe strings in bubble chambers? and Assuming we can observe strings in bubble chambers, has there ever been a bubble chamber experiment wherein one trace simply vanished, suggesting the guilty particle leapt to another dimension?

 

[meteor]

Yet another possible testing of extra dimensions:
http://www.pbs.org/wgbh/nova/elegant/greene.html

"What the theory also predicts -- not necessarily but possibly -- is that energy can escape from our known dimensions and leak into these extra dimensions under appropriate circumstances. Those appropriate circumstances might be generated in high-energy collisions that will take place at the new atom smasher, the Large Hadron Collider.

So it's possible that through these high-energy collisions we will find that there is less energy at the end of the collision than there was at the start. If the energy loss is of just the right sort, it could be very strong evidence that the energy has seeped off into these extra dimensions. If that were true, if that were the best explanation we could find, that would be strong evidence that the extra dimensions are real, and that in turn would be strong evidence that the framework of string theory is correct."

By Brian Greene

 

[setAI]

Back to SetAI in post #3

I'm not asking how many dimensions we have thought about, I'm asking how many dimensions have been proven to exist scientifically. You can think about all the dimensions you want, but if only four dimensions really exist, what good is all your guesswork?

I didn't really address whether there are "naturally" occurring hyperdimensional objects/spaces- [becasue we don't have enough information to even GUESS yet ]- but I would say "probably" that dimension is emergent from fundamantal relational physics- and completely arbitrary- so universes of unlimited dimension surely exist in a classical sense [ but I often change my mind about this!] it seems to me unavoidable that if a hyperdimensional space can be made either artificially or as a virtual simulation- that you have in ANOTHER WAY proven extra-dimensions- as you say- "really exist": by creating them instead of finding them-

my conjecture is more of an ancillary bit of reasoning that deals with the more fundamental issue of what does intelligence DO from a cosmic/ontological perspective and what can be said to "exist"- does a nest or a beehive exist in nature? if so then you must also agree that any possible artificial/virtual univeres must also exist in nature- becasue having been made by some natural being does not invalidate it's existence- in fact there is no consistant way to separate a natural process like a big bang or the birth of a star from another natural process like an advanced intelligence building an artificial universe with 67 dimensions- big bangs and artificial universes both result from complex dynamics- the only difference is that some of the dynamics involved int the synthesis of an artificial universe are also processes that we have identified as being intrinsic to intelligence- if a virtual universe works- then it is just as natural and real as any world- our current computer science has shown that we can build stable "simulations" of universes of any/every euclidian [and non-euclidean] dimension- this would seem to be very solid circumstantial evidence for other-dimensional worlds "out there in Nature" becasue even if there aren't worlds with extra-dimensions "naturally" occurring- there are still the universes that were made by someone else which can have any dimension that the builder wishes


it isn't guesswork-it's an unnavoidable conclusion of intelligence: when an intelligent agent "thinks about" something- in many respects this is an act of creation- anything that we can build exists as much as any other thing exists-

I'm in no way a mathematical platonist nor do I believe that our notions of mathematics are actually fundemental- but I do recognize the full implications of intelligent systems- when Man thinks a thing or builds a thing- that thing has become manifest in Existence- it becomes real and part of the natural forms in the Cosmos

___________________________

/:set\AI transmedia laboratories

http://setai-transmedia.com

 

[sol2]

http://www-glast.sonoma.edu/resources/cubeimages/glastallskysm.jpg

The questions about dimension are important ones from what I see.

What happened for me knowing full well that GR and Qm have been joined in the complexity of the "information," wondering if it could speak to the dynamcial nature of reality? Is it that gravity had now formed as an carrier particle(thanks to wittens contribution here) as its discriptor(much like the "photon" as a Em disciptor).

But now, if we engaged in interactions here, how would we describe dimension in relation to the graviton?

Lets just say for a minute, even Peter Woit in his strong consideration of strings was to answer this question above? Would it not have come from some formulation that such a question could arise, where all other attempts have been limited from particpating in such a question?

We have created a question in regards to the energy levels for consideration and an scaling consideration having been now introduced? So what then would help us see these interections, if not in context of the issue of photons having fully been recognized, that em consideration and gravity have been joined? What is the result?

We needed a viable means for consideration of quantum geometry, arising out of quantum gravity. Is this feasible as a direction considering the energy values assigned to the string windings and the KK tower for consideration?

The complex turns in the Calabi Yau would be very difficult to discern in a compacted universe of dimenisons, yet such "energies," have pointed out the twists and turns in that string? This would have to become a scalable feature in relation to dimension?

Fermions and bosons then become figures in a choreograph dance of maxwell equations with the eqaution of GR. How woud one then see this new geometry arise with the graviton? Brane realizations then move these considerations to the bulk, and the gravitons ability to roam?

 

[Tom McCurdy]

Dimensions in Universe 0-infitie

my 3 top choices
1. 4
2. 11
3. 3

 

[Netme]

So we exist within a 4 dimension+ universe? How can this be if we can only function viewing the universe in 3d. Wouldnt functioning be impossible?

 

[techwonder]

Talking dimensions like this, i.e. as if the number of dimensions might be (locally?) variable. Is there anybody who have analysed the possibility of this? It seems that our nice inverse square laws puts strict limits to such schemes, no?

 

[sol2]

Talking dimensions like this, i.e. as if the number of dimensions might be (locally?) variable. Is there anybody who have analysed the possibility of this? It seems that our nice inverse square laws puts strict limits to such schemes, no?

If inverse square law in regards to gravity is being considered, how would we contain the wave equivalants to gravitons and not call them representation of dimensions? There had to be a energy value considered, and as in the quantum harmonic oscillator, zero point vibration limitation to all points of view?

If we can change the way we see the nature of all particles as in their windings, then what signatures could we have given any element? Is it not universal then?

 

[Olias]

how many dimensions are there, really?

There are only Three Dimensions, any more and Proton Decay would make everybody's life a nightmare!

One can see that dimensional make-up follows in three-fold steps.

Third Dimension.
The proton occupies the most stable Dimension, the third, this is why every combination of Quark interactions and existence occurs in THREE'S, and why all matter is in Phase across this dimensional domain.

Second Dimension.
Preceeds the first in all aspects Proton(MATTER) construction, and is by definition a Field. Matter can exist within a Field, but a field cannot exist within a Particle(Proton for instance), so theoretically 2-D fields surround matter at all times. Try and think of any field that is internal/inside matter?..you will arrive at a duality.

First Dimension.
The singularity where all 2-D components are separated into base 'mono-space', 'everything' is everything else. Anti-Matter is Matter and Matter is Anti-Matter, everything is ONE.

 

[sol2]

how many dimensions are there, really?

There are only Three Dimensions, any more and Proton Decay would make everybody's life a nightmare!

One can see that dimensional make-up follows in three-fold steps.

Third Dimension.
The proton occupies the most stable Dimension, the third, this is why every combination of Quark interactions and existence occurs in THREE'S, and why all matter is in Phase across this dimensional domain.

Second Dimension.
Preceeds the first in all aspects Proton(MATTER) construction, and is by definition a Field. Matter can exist within a Field, but a field cannot exist within a Particle(Proton for instance), so theoretically 2-D fields surround matter at all times. Try and think of any field that is internal/inside matter?..you will arrive at a duality.

First Dimension.
The singularity where all 2-D components are separated into base 'mono-space', 'everything' is everything else. Anti-Matter is Matter and Matter is Anti-Matter, everything is ONE.

There is no doubt about the ultimate question where everything is one. Pierre Ramond place this out there, front and centre in his graphed analyst for introspection. Yet on this realization, it points us in a direction about the early universe and its formation, even at the quantum level. So the classical discription of GR has revealled in the cosmo, needs a frame work at the supersymmetrical levels of this universe where such ideas spoken too, as you speak, also to two facets of reality that shoud become joined.

There are a couple of images that are immediately triggered in my mind to support my post above yours, yet something in what you said also triggerred another image.


http://www.auriga.lnl.infn.it/auriga/guy_wave.jpg

https://www.physicsforums.com/showpost.php?p=245983&postcount=6

Think of the graviton as the fellow? How would your assessment in dimenison speak to this unfolding?


http://www.cerncourier.com/objects/2003/cerndesy1_4-03.jpg

The host of quarks, antiquarks and gluons inside a proton all have intrinsic spin, but their constant movement also creates orbital angular momentum. Understanding how these individual angular momenta together yield the total spin of the proton is still proving to be a challenge. (DESY Hamburg.)

http://www.cerncourier.com/main/article/43/3/15/1

Your attempts at such a model discrption is something that I have also done from a "string persepctive" ( an attempt to geometrical map the movement of each particle) in regards to the "immediate" morphing of the circle into the length of the string. From a energy standpoint this has to identify the partciles nature and the only way that I know to do this is identify its energy counterpart. I should be corrected here if this is wrong?

 

[agnostikos]

String theory has afforded mankind an incalculable benefit. It has been such a brashly sexy field that it has doubtless kept stringmeisters off of Wall Street. Can you imagine some mathwhiz inventing an "exotic financial instrument" to suck liquidity out of parallel universes? And such a thing succeding, causing inflation so astronomical that the Planckdollar is the new currency---

 

[chrispb]

What you and I observe on a day-to-day basis is described as a (3+1=4)d universe. When people were first doing (bosonic (i.e. no fermions)) string theory, they discovered that there had to be extra dimensions that were compactified (curled up on themselves) with a small radius. In order to prevent a technical problem (known as anomalies) from happening in the theory, it was discovered that there had to be exactly 26 dimensions. When the same calculations were repeated with superstring theory (which DOES allow for a description of fermions), that number was found to be 10. It was later discovered that the various kinds of string theory were a particular limit of what's come to be known as M-theory, which is still ill-defined and poorly understood. However, it IS known that M-theory lives in a 11d spacetime. I don't know what the status of anomaly cancellation in 11d is.

Now, the extra dimension that's added in M-theory is (I think) taken to be decently larger than the other 6 added for string theory. Thus, in energy scales where you can't probe the 6 of string theory but you CAN probe the extra one of M-theory, you'd end up doing well for yourself with an approximately 5d description of the universe. Sometimes you see models like that around as well.

 

[czes]

Astrophysicist Paul Davies once wisely asked if mathematics was built into nature or just a concept of man. More than likely dimensions along with geometry in general are just abstraction of thought and are not reality itself.
Mathematics and geometry are like topographical maps in that they are depictions but are not reality itself, like a photograph of your family. The photograph is a picture of your family but not actually your family.
I tend to lean towards a holographical model of the universe. If this is so, then it is likely that in real sense the universe is dimensionless.

Yes, how many dimensions are in a CD containing a Star Treck video or another game ?
If the Holographic Universe is right our dimensions are the illusion.

 

[Gokul43201]

Since this old thread has been revived, I suppose it wouldn't be inappropriate to insert a little humor that appeared elsewhere recently:

http://xkcd.com/848/

 

[PhilKravitz]

Physical experimental data says 3 spatial dimensions and 1 time dimension. There are folks exploring math ideas about higher dimension universes. There is currently no experimental data to back any of them up.

 

[Dr_Zinj]

I think Paul Davies was actually begging the question. If there is order, then it can be mathematically described. But due to the randomness of nature, you can't always say that something exists here and now.

Netme: "So we exist within a 4 dimension+ universe? How can this be if we can only function viewing the universe in 3d. Wouldnt functioning be impossible?"

I function quite nicely viewing the universe in 4 dimensions. While my ability to interact is limited to the present, and to a limited extent, the future; I can view the entire past that intersects with my 4 dimensional personal space within the space-time continuum. It's called memory.

Referring back to meteor's comment, a particle would not be able to "leap" to another dimension if it exists in all dimensions simultaneously. Which would also pose a problem with Heim Theory conjecture that an object could phase into a higher dimension to travel faster than light. I'm not sure of the math, but I think what it would look like on paper is a drop in all 3 physical dimensions to zero, becoming a "dimensionless" point; but to balance the equation, the other, "non-physical" dimensions would have to change. Can a dimensionless point move within our space-time continuum at faster than light speeds? I suppose it could if it has zero mass. But if an object's dimensions approached zero, it's density would approach infinity. At some point, it would become a black hole, with an event horizon. Can a black hole shrink in size? And can an event horizon move at FLT speeds?

 

[raynicolle]

there has to be some kind of "friction point" where 'stuff' from other dimensions interact with our 3 dimesional Observable Universe. If there is no "friction point" then why do we care about these mathematical creations called dimensions? They don't have an effect on us. If they do have an effect on us...where is that "friction point". A simple example to me would be showing me how the 4th dimension called time actually interfaces with my 3D world. I see the results of "time" but never observe it itself. That makes it very easy to say that dimensions are imaginary, vaguely useful, and easily ignored. Trodding down the multi-dimensional path could lead to madness...lol.