Evidence of 6 Dimensions or More? 277
shelflife writes "Nature.com is reporting that there may be evidence of 6 dimensions. Galaxies seem to behave as there were more matter in them than is actually visible. 'One explanation, they say, is that three extra dimensions, in addition to the three spatial ones to which we are accustomed, are altering the effects of gravity over very short distances of about a nanometre.'" Update by J : Like most of string theory, this is acknowledged by its authors to be "extremely speculative."
One can dream (Score:5, Funny)
Re:One can dream (Score:4, Funny)
Re:One can dream (Score:2)
> when talking to her, then?
I...
[X] bathe regularly
[X] can make eye contact with a woman when talking to her
[ ] do have a girlfriend
So please, what did you leave out?
Re:One can dream (Score:3, Funny)
Re:One can dream (Score:3, Interesting)
String theory has come a long way and has the power\simplicity to explain a lot of things in the universe which simply wasnt possible before. AFAIK, other theories, forumlas and phenomenon emerge naturally out of the theory (i.e. if we only knew string theory, the rest wou
Re:One can dream (Score:3, Insightful)
Re:One can dream (Score:3, Insightful)
ObTime Cube (Score:5, Funny)
This is clearly false and evil. The Time Cube has exactly 4 dimensions.
An open mind is a slop bucket, "THINK CUBIC [timecube.com]".
Re:ObTime Cube (Score:2)
Please repost your TimeCube comment again below, with more vitriol this time.
ObGame Cube (Score:2)
Sony fandom is a lie, "PLAY CUBIC" [fateback.com].
Re:ObTime Cube (Score:5, Funny)
Re:ObTime Cube (Score:2)
So if we can't see it, it's in another dimension? (Score:5, Interesting)
But then again, if they do manage to actually find solid evidence (not just its apparent invisibility in our traditional 3 or 4 dimensions) of matter in an unexpected dimension, I will be extremely impressed. It's an interesting theory at any rate, and worth looking into.
Re:So if we can't see it, it's in another dimensio (Score:5, Informative)
Someone came up with a model called string theory that includes systems with multiple "hidden" dimensions.
The dark matter they're talking about in the article is behaving in a way predicted by one of the current string theory models, which doesn't fit the more traditional models, thus the assertion that it must be 6 dimensions at work.
Re:So if we can't see it, it's in another dimensio (Score:5, Interesting)
One of the things they had us do in college, and it is interesting IMO, is to take a sport you know nothing about and observe it. Try to formulate the rules of game based on observation (that is, create the model). Then look the actual rules up and compare them.
It's not a perfect experiment - there are things common amongst nearly all games that we simply just know, but it was interesting how correct you would normally get some things and how wrong others (this is even more true because we *do* have correct preconcieved notions, it gets worse when going blind into something). It's also interesting how you can be correct and wrong at the same time - accuratly predict the outcome but for totally incorrect reasons. And, in some sense, it raises the question of if it really matters if the path to get to the correct point is wrong. If you are correct 100% of the time that it is "pass interference" (in American Football) does it matter that you definition of "pass interference" is wrong?
In really really complicated scenarios I always wonder which side is thier model on (though, of course, it's a sliding scale not just an absolute two sides). Especially given the magnitude that some of the models will evnetually have in our lifes.
Of course, this is what makes these fields so interesting to me, the combination of "right or wrong" with the amount of "feel" and "intuition" in the system.
Re:So if we can't see it, it's in another dimensio (Score:2, Interesting)
Dangerous? (Score:2)
Re:Dangerous? (Score:2)
Re:So if we can't see it, it's in another dimensio (Score:4, Informative)
That IS the scientific method - you start with a 'conjecture' which IS a made up explanation and look for ways to prove or disprove it. If you think it's done by fairies at the bottom of the garden you race down there and start looking under leaves. "God did it"? start looking for gods to photograph and measure. Extra dimensions? start looking for evidence of them
How dimensions wrap themselves up (Score:5, Informative)
The thought experiment was similar to the following. Imagine a sheet of paper with a line crossing from one edge to the opposite edge. You can see that the line exists when viewing the sheet in two dimensions. However, imagine if you rolled the sheet of paper up tightly with the line not directly aligned with the roll. Now you would have instead of a line a single dot or a series of evenly-spaced dots. The line hasn't gone anywhere, it has simply been rolled onto itself so that it seems to have become small and barely detectable.
Now extend that idea to multiple spatial dimensions beyond just two or three. Since we humans can only perceive three spatial dimensions, it is hard to imagine what multiple extra dimensions would be like. However, if we can take the extra dimensions and "roll" them into themselves, we can make a little more sense of the concept.
Re:How dimensions wrap themselves up (Score:2)
Just rambling, but this makes some sense to me (Score:2)
Some of the more recent discoveries, like quantum action at a distance stuff makes sense from the Occams Razor point of view. On one hand, we have these bizzare behaviors that involve unseen forces, etc... On the other, our 4 dimensional universe is really a function of a multi-dimensional one, with the interactions in the other dimensions embodied as complex behavior here in our 4 dimensional world.
The latter makes more sense than the former does to me, be
Re:How dimensions wrap themselves up (Score:2, Interesting)
Re:How dimensions wrap themselves up (Score:2)
Re:How dimensions wrap themselves up (Score:3, Interesting)
Re:How dimensions wrap themselves up (Score:3, Informative)
Re:How dimensions wrap themselves up (Score:2)
There couldn't be anything on the other side, so we tend to assume the universe has no boundary, of either kind. Interestingly, however, some recent results suggest our universe may be ever so slighly hyperbolic. If so, it could be a sphere, and everything shrinks the closer you go to the boundary. So you can ne
Re:How dimensions wrap themselves up (Score:2)
Re:How dimensions wrap themselves up (Score:2)
Great! (Score:3, Funny)
dotted... (Score:5, Funny)
To keep the traffic flow normal, mirrors have been provided on the seventh, eighth, and ninth dimensions for the earthlings...
Well i thought it was at least 11 (Score:4, Insightful)
Re:Well i thought it was at least 11 (Score:2)
The most popular versions of string theory suggest that there are as many as eight extra dimensions, not just three. But thankfully this needn't be a problem. There's no reason why, in addition to the three large extra dimensions predicted by Silk and colleagues, there might not be several other small ones too.
Re:Well i thought it was at least 11 (Score:3, Interesting)
The most popular versions of string theory suggest that there are as many as eight extra dimensions, not just three.
Yes, exactly. Three space dimensions we know exist plus eight extra (including time) equals eleven total dimensions. So apparently, there's no inconsistency between this research and current string theory.
Re:Well i thought it was at least 11 (Score:5, Interesting)
This has been worked on for a while, and the equations are getting there. If you think about it though, a fifth dimension can be easily produced from the equations of general relativity, and maxwells equations of electro-mag produce yet another micro-dimension to govern the electromagnetic force.
So this isn't that surprising, the problem is the math for 11 dimensions doesn't work well yet, because it's freaking hard to do energy waveform equations in 11 dimensions, when you don't even know how those 11 dimensions are laid out.
The next breakthrough in physics will be a model for at least some of the underlying dimensional geometry, leading to a final m-theory, likely the long sought theory of everything.
I just like the fact that the standard model is showing it's flaws, trying to write theory to fit your experiments is never as good as trying to understand the underlying causes and drawing conclusions from the emergent properties of the basic model.
Re:Well i thought it was at least 11 (Score:2)
You mean like they do in Chemistry?
Nope, won't believe this... until... (Score:4, Funny)
Round and Round (Score:5, Informative)
Greene's Elegant Universe [pbs.org]
The Mechanical Universe [learner.org]
Last book I enjoyed, Three Roads to Quantum Gravity [amazon.com] by L. Smolin... ya, ya, I know, nothing fits, is, isn't, yo momma... no yo momma... can, can't... I'm not touching you!
This is way old news (Score:3, Funny)
Re:This is way old news (Score:2)
string theory? (Score:5, Interesting)
The only problem is that when the calculation is done, the universe's dimensionality is not four as one may expect (three axes of space and one of time), but twenty-six. More precisely, bosonic string theories are 26-dimensional, while superstring and M-theories turn out to involve 10 or 11 dimensions.
somewhere to start (Score:2, Informative)
PBS Nova: The Elegant Universe (Score:3, Interesting)
I watched this DVD [shoppbs.org] and it gave me a really good introduction to Relativity, String Theory and Quantum Mechanics. I'm no physicist, but I am able to understand the key ideas through the video.
Or you may prefer to visit their homepage here [pbs.org].
For the actual reference (Score:5, Informative)
Observational Evidence for Extra Dimensions from Dark Matter [arxiv.org]
(It's actually a draft of a paper submitted to Physical Review Letters, not yet approved.)
It's a nice phenomenology paper without any heavy math that puts together a bunch of theoretical ideas floating around. Even better, it has testable hypotheses! (unlike many papers these days)
- Gravity should deviate from the inverse-square law at the nanometer scale.
- Dark matter should be composed of a particle with mass 3e-16 GeV/c^2. (For comparison, mass of electron is 5e-4 GeV/c^2.)
- The large extra dimensions assumptions all this is based on would require us to see all sorts of quantum gravity interactions at the LHC.
Now short-range gravity experiments are just approaching the micron scale, so we're 3 orders of magnitude away from testing hypothesis #1. I doubt anyone has an idea how to close that gap right now.Checking hypothesis #2 would require some independent way of determining the mass of dark matter particles. I don't know what the sensitivity range of the various dark matter experiments running or planned are. Maybe they would be able to see something this light.
#3 however is going to start running in 2 years, and then we'll get some good information either way.
Re:For the actual reference (Score:3, Interesting)
This probably requires a number of astronomical surveys (mainly Sunyaev-Zeldovich effect surveys for galaxy clusters at microwave/mm-wave frequencies, and optical and radio surveys for galaxy dynamics) to give large datasets from which the statistical prop
Re:For the actual reference (Score:2)
Looks like the astrophysical observations will have to save the day. :)
Simplest explanation? (Score:3, Funny)
From TFA (Score:2)
On atomic scale, 1/100 mm is still pretty huge and I understand science itself has progressed enough to have the means to make such measurements. So before speculating any further, it seems it would make sense to start doing that first then, wouldn't it?
...and if you call before the dupe is posted... (Score:4, Funny)
(*old people in korea need not apply)
Higher Dimensions and Fermions (Score:3, Interesting)
And I quoth:
Re:Higher Dimensions and Fermions (Score:2)
Dimension is just a definition (Score:2, Interesting)
Whatever happened to Occam's Razor? (Score:4, Insightful)
Re:Whatever happened to Occam's Razor? (Score:3, Interesting)
To compare it with the situation of 3 vs 2 dimensions, most people couldn't plot a path from the surface of the Earth to the moon in 3+1(time) dimensions, so it's not like things suddenly get completely easy just because fewer dimensions are involved.
Re:Whatever happened to Occam's Razor? (Score:2, Insightful)
Everyone abuses Occam's razor (Score:5, Informative)
Parent asserted;
Occam's Razor, which is a basic tenent of modern scientific thought says that the simplest explanation is the best.
This is an abuse of the version of Occham's Razor used in modern scientific thought, though an oft repeated misinterpretation.
A better way of phrasing the desire for elegance in modern science is; "Given two identically predictive models, choose the one which requires the fewest assumptions." Reducing the number of assumptions is not always the same as 'simplifying' the problem.
Also, remember that the purpose of science is to generate predictive value. If one of those models is more complex but also more predictive, then it is ALWAYS the better model, no matter how complex.
The original version of Occam's Razor, as correctly expressed in the Wiki article, is "Entities should not be multiplied beyond necessity" where 'necessity' equates to generating the maximum level of predictive value.
Check out the following link, which gives a better summation of the role of Occham's razor in science than the wiki article does.
http://www.physics.adelaide.edu.au/~dkoks/Faq/Gen
Re:Whatever happened to Occam's Razor? (Score:3)
Science is about explaining the observations by whatever means necessary. Occam's Razor means yes, we assume space doesn't have 6 dimensions as long as that has equal explanatory power to assuming it does. When we come across something that can't be explained by "normal" theories, at least without making them more complex than assuming 6 dimensions, we assu
Re:Whatever happened to Occam's Razor? (Score:2)
Re:Whatever happened to Occam's Razor? (Score:5, Interesting)
- "When multiple explanations are available for a phenomenon, the simplest version is preferred"
Occam's Razor is a tool to, when faced with multiple explanations for the same situation, help one choose the best one.
It is not some sort of philosophical statement on how there should be a simple explanation for everything.
Although i too feel unconfortable with the increasing complexity of scientificy theories (and judging from the current moderation on your post i suspect many others also yearn for simplicity), i cannot stand by and see you missuse Occam's Razor (one of the first things i learned in philosophy).
PS: At the risk of spoiling this post, i have to state a theory of mine: I suspect one of the things that turns some scientific minds to the belief on a "higher power" (aka almighty) is a yearning for simplicity and/or an inability/unwillingness to accept complex explanations to the mind-bogling complexity of the world.
The real meaning of Occam's Razor (Score:2)
A better way of thinking of Occam's Razor is as a rule of thumb for ordering the universe of possible hypotheses for investigation. Simple theories have fewer free variables, which generally makes
Re:Whatever happened to Occam's Razor? (Score:3)
Science is full of theor
Re:Whatever happened to Occam's Razor? (Score:2)
Well, you have to have a hypothesis before you can test it; and if nothing simpler comes to your mind, you can try all kinds of mathematical tricks to form a hypothesis that will actually fit the observations.
But you're right, in this case the tricks feel like the spinning and circling crystal balls in the skies on which the planets were located.
Re:Whatever happened to Occam's Razor? (Score:2)
The string theory may be not in the great shape just now, but there is no better alternative(well, there is the loop quantum gravity, but it's not much better) The biggest problem of the modern theoretical physics is that it is proven that general relativity and modern quantum mechanics contradict each other. They can not both be exactly right in the same universe. Both theory verified experimentally. So if theoretical physics want to remain s
Occam was a 13-14th century monk. . . (Score:2)
It's a rule of thumb to help order one's already biased thinking. Nothing more.
-FL
Re:Whatever happened to Occam's Razor? (Score:2)
That is not elegant as I understand the word!
Trying to explain real-world phenomena and physical properties such as (for example) vibration and tension using microscopic strings (the 2D aspect of M-Theory) which themselves are supposed to experience vibration and tension is kind of pointless[sic] and circular to me...
Re:Whatever happened to Occam's Razor? (Score:2)
I realise it isn't really circular; I was using the fact one vibration is eventually defined in terms of another to illustrate a point - that string theory does not seem much like a fundamental theory, as there are still things that need to be explained - what are these 'strings', and why do they 'vibrate' and experience 'tension'?
I could
Re:Whatever happened to Occam's Razor? (Score:2)
Atoms aren't considered to be fundamental.
IANAP, but I think that the additional mental effort, required to think of theoretial entities as nonexistent-prohections-of-math is unnecessery: phisics and math pe
The idea of extra dimensions is... (Score:3, Interesting)
Re:The idea of extra dimensions is... (Score:2)
Re:The idea of extra dimensions is... (Score:2)
A simple proof (Score:2)
The result is of course wrong, but it (or its equivalent) is actually used for renormalizing [wikipedia.org] quantum field theories to get rid of ugly infinities. Don't ask me what's happening here, I just use the results :-)
Maybe? (Score:2)
Not an expert (Score:2)
It seems that sometimes fanciful theories pop up that seem to just shoot wildly in the dark for lack of observable/obtainable info.
At least it's not a human-centric nonfalsiable unlimited paralell universes or time travel can't alter history theory........
Re:Not an expert (Score:3, Insightful)
So, right now, we have GR. Which needs undiscovered "dark" matter to explain why galaxies are rotating faster than expected. And extra dimensions to solve the problem of different-sized galaxies. And "dark" energy to explain why these ga
Then again... (Score:2)
Re:Then again... (Score:3, Funny)
Unfortunately, they still have problems figuring out how to exchange the twenty million AA batteries powering it once it's in space.
explaination (Score:2, Informative)
http://www.pbs.org/wgbh/nova/elegant/ [pbs.org]
dimensions (Score:2)
Known Dimensions (Score:2)
Some of these are actually measureable:
- time
- X axis
- Y axis
- Z axis
- female perception of reality (this is the "Q" axis that will never be understood due to constantly changing parameters)
And, yes, I've had sex with females before, they are quite squishy and nice.
Why Gravity Gets Weaker With More Dimensions (Score:2)
The pattern continues as the number of dimensions incr
Diamond-Nanotube fabric as nanogravity sensor (Score:2)
1) It sounds like the diamond-nanotube composite material mentioned in a separate slashdot article today would include nanoscale diamond chunks, nice hard, heavy things, nanoiron seeds, and conductive nanotubes. Would this not be an interesting candidate for use in the testing of this theory of how gravity works at the nanometer scale?
2) I don't really understand the idea of a dimension only a nanometer wide, or the idea of dimensions being rolled u
Sheldon Glashow doesn't believe in strings (Score:2, Informative)
Holy men knew it before (Score:2)
Re:String Theory is a joke (Score:5, Funny)
This is why the theory of relativity is a joke. Whenever they run into a problem, they throw in more gammas or some other kludge, like gravitation being the same as acceleration.
This is why Newtonian physics is a joke. Whenever they run into a problem, they throw in more integrals or some other kludge, like momentum being preserved.
This is why bakery is a joke. Whenever they run into a problem, they throw in more meal or some other kludge, like lowering the temperatur of the oven.
Re:String Theory is a joke (Score:2)
Re:String Theory is a joke (Score:3, Insightful)
The meme "string theory" means something because a few brilliant people continue to believe the math involved is actually applicable to modeling reality. It may yet be dismissed as luminiferous aether. In the meantime it serves as a possibility that can be studied. Does this status justify ridicule? Certainly not from me.
Re:String Theory is a joke (Score:2)
Its very popular and has many followers in physics. Einstien himself came up with the field of relativity by mathmatics as well.
Re:String Theory is a joke (Score:2)
They are studied because they are 'elegant', before Newton, circular orbit was the way to go because circles are 'elegant'..
Note that I don't say that studying string theory is bunk, just that being popular means nothing until actual predictions can be verified.
Re:String Theory is a joke (Score:2)
gravitons leaking out of the universe... part of the attempted quantum gravity reconciliation?
string theory isn't done yet, so it's hard to say it's all being added as a kludge, you want to see a kludge, look at the damn standard model sometime, half the particles are "uhh, we don't know what happens here, so we have particle q come in and take care of whatever exchange is happening" and none of the underlying problems a
Re:String Theory is a joke (Score:2)
Given that is is already quite hard to think in just four dimensions, I consider it not at all surprising that thinking in 11 or more dimensions is even harder.
Re:String Theory is a joke (Score:2, Funny)
Re:String Theory is a joke (Score:2)
Save the Gravitons!!!
Re:String Theory is a joke (Score:2)
I agree - it is a valid point of view.
How many people could be provoked into a flamewar over string theory?
Pretty easily in my experience! String Theory is highly controversial in some ways. For many physicists it is the way forward in explaining just about everything. For other scientists (like me) it looks like nothing more than mathematical games, playing about with weird ideas at energy scales so high that it is unlikely they can ever be tested.
Re:String Theory is a joke (Score:2)
Pardon me, but you must have forgotten what site you're reading. This is Slashdot.
Re:You know the drill... (Score:2)
Re:Excuse the lunatic fringe rant, but... (Score:2)
If a certain german math teacher hadn't started doing that we wouldn't have much of modern physics.
Re:Excuse the lunatic fringe rant, but... (Score:2, Interesting)
For all of the extra dimensions, predictions of superstrings, dark matter (and the associated WIMPS, MACHOs etc.), dark energy
Re:dark matter? (Score:2)
I guess I'm just too uneducated to properly understand the mathematics behind recursive mass.
Re:dark matter? (Score:2)
Re:dark matter? (Score:2)