Extra dimensions Definition and 74 Threads

This may be a stupid question, but I have been curious about it for awhile. Before string theory, extra dimensions seem not to be taken seriously. But if gravity warps space doesn't it need another dimension to warp into? I saw Brian Green on TV and I thought he suggested that you don't, but he...

I read somewhere that string theory could be disproved if it is found out that the universe expanded at a certain speed as this would cause the extra dimensions to unravel and therefore mean that string theory could not describe our universe. I do not understand why the extra dimensions would...

SU(3) needs to act on a minumum of 4 compact dimensions. SU(2) needs a minimum of 2 dimensions U(1) needs a minumum of 1 dimension Thus SU(3)xSU(2)xU(1) needs 7 extra dimensions. Because of this, string theoretists do not use the extra dimensions to generate the gauge groups, and they use...

Why is it that it is thought that separate dimensions exist, as humans we can only exist in a volume, three so called dimensions, so why do scientists think that these three can be separated when in all probability and experimental AFAIK they can not, length, width and depth are just words to...

I have read about the possibility of more than one time dimension but I never did really understand what the implications of that would be. What is going on in this idea? How can two dimensions of time be explained so that the layman will understand? Here's an example...

Detecting large extra dimensions via "mini black holes"? Occasionally I come across something explaining that one of the possible discoveries at the Large Hadron Collider might be the production of "mini black holes", which if found would demonstrate the existence of large extra dimensions. The...

Scientists and mathematicians speak of extra dimensions that are "curled up" so small that it is impossible to detect them, but what exactly would an extra dimension look like:confused:? I realize that these extra dimensions have been detected mathematically, but the entire concept of something...

I'm confused about the 6 extra curled up dimensions in that they are always portrayed like this: http://people.cs.uchicago.edu/~mbw/astro18200/calabi-yau-grid-small.jpg" But according to that picture it seems there are multiple "extra" dimensions, and that if you move to a different location...

are there any introductory books on the theory behind gravitons and extra dimensions and also the experimental tests that could be done?

Hi, this is my first post. Congratulations to a very interesting forum. The issue, I want to bring up, has probably been discussed already, but hopefully at least not in exactly the same way. I have read the book "Road to Reality" from Roger Penrose, which by the way I found quite interesting...

The attached image file shows the extra dimensions might come from overlapping planes with different energy value. In this model the extra dimensions are very small at the point where they intersect at the parent universe event horizon at the Plank Level (10 Minue 39). This idea suggest the...

Hello, folks - this is my first post here. I am hoping some of you will be kind enough to help me understand something I have struggled with for a long time. A brief background: My lifelong interest in science fiction led me to start reading about relativity and quantum physics around 20...

I heard from a professor at my deparmant that there are some "simple" experiments in searching for extra dimensions. after a research, the only thing that I've found is this: http://www.stanford.edu/group/kgb/Research/gravity.html after checking the experimental procedure, now, i am...

http://www.nature.com/news/2005/050829/full/050829-18.html [PLAIN]http://xxx.arxiv.org/PS_cache/astro-ph/pdf/0508/0508572.pdf[/URL]

http://xxx.arxiv.org/abs/astro-ph/0508572 I like the way the title of this paper captures ones attention. For a minute there I thought they had finally found some evidence for string theory. From what I understand they’re speculating on astronomical observations of dark matter, by...

Im trying to educate myself on relativity with things such as Einstein's Dreams and The Inflationary Universe before i jump into the actual theory. Right now i understand 3 dimenions: 1, 2, and 3 for x, y, and z. I've heard the 4th dimension is time, but i am having a tough time understanding...

OK, this is so unlike me to advertize a theory activity on Supersymmetry, etc. But as a community service, I thought I should point out to those who are interested, that the Argonne Theory Institute will be starting it's Theory Institute 2005 workshop titled "Supersymmetry, Extra Dimensions, and...

Why do extra dimensions have to be "curled up"? This is my first post to this forum. I'll start with a question that has bothered me for a long time. T. Kaluza suggested to Einstein that the equations describing fundamental forces and fields could be simplified if the possibility of real...

are Large Extra Dimensions still acceptable Hi folks, a couple of years ago [in 1998] some people (Arkani-Hamed, Dimopoulos, and Dvali [ADD]) proposed a scenario which uses a string inspired brane world hypothesis. In this model the world that we see is a 3-dimensional brane in a higher...

http://arxiv.org/abs/hep-ph/0404135 Cogitations and comments are welcome! :biggrin:

http://www.gsfc.nasa.gov/topstory/2003/1212einstein.html

I don't know much about physics as you will come to know after reading this. Could some one exsplain to me how an extra dimension can creat gravity? Is it that matter moves into another dimension when it's avablabe (near mass particles or "gravitons")and distorts time-space and pulls most...

I don't know to much about the string theory or loop theory really. I have read a few books on it, but I want to know: Why do scientists think any extra dimensions take the form of strings? Is it that the formula say that is what the strings are, or is it just a way to explain why we can't see...

Hi. I am not a physicist or a mathematician, but I am a Professional Licensed Electrical Engineer with a Masters Degree in EE. I did get through the Quantum Physics class but never pursued the theoretical sciences any further. I say all of this because I have come up with some rather odd ideas...