Theory on 4th dimension. Do I understand this right?
348301
'Flatland' must be a very exciting story. I wish I have read it.\n--a 2d world surely is a more interesting place compared to a 1d world. Roughly speaking, the added options would be 'left', 'right', 'up', 'down', which are far more entertaining than the 'forward' and 'backward' of the 1d space. \n-- the 3d world easily beats a 2d world and needs few comments. we get 'depth', just to name one thing we would miss in the 2d world. there are many others, no doubt.\n-- a 4d world would be an awesome place. before else, the question is what do we put on the 4th dimension. whatever would be it must have the dimension of space. so it can be time times velocity. let's say we neglect what velocity would mean and just focus on time. now things are going to heat up. what can we do with time, if we are able to use it just as we use the ordinary space? surely we would like to move forward and backward in time. still, I would not think we would be able to see .... ohhh wait a second!! this is really cool! I think I just got your idea of seeing 'inside and out, of every object and event in the entire univers'. yes, it must be this, because we would be able to travel in time, along the 4th direction, and we would be able to see things as they evolve; suddenly appearing in what was before an apparently empty space, turning into real objects and dissapear eventually. hehe I like it
991771
We observe four dimensions everyday, three spatial and time.\nTime is called a dimension because it makes mathematical sense to do so. \nBut...theories such as string theory predict that the space we live in has in fact many more dimensions (frequently 10, 11 or 26), but that the universe measured along these additional dimensions is subatomic in size. As a result, we perceive only the three spatial dimensions that have macroscopic size.\n\nThis is not so strange as it sounds, which I'll show with an example. Imagine you are in an airplane, flying over sea. Seen from a height, the sea looks flat, two-dimensional. But when the plane looses height we start to perceive the waves, that move in a third direction we could see before.\n\nThe universe could be the same. Four macroscopic dimensions and a few more, hidden ones. We can only perceive them for instance, by the small effects their existence might have on subatomic particles.
168520
I believe that the universe is expanding within higher dimensional space. As humans we can only understand this universe in three dimensions because that is all our primitive tools of perception will allow. We are "trapped" in three dimensions. However, the existence of higher dimensions has been proven mathematically time and time again. I'm no expert on the subject but I have done a little reading. I would reccomend reading something by Stephen Hawking such as "Stephen Hawking's Universe" or "A Brief History of Time." Also, "Hyperspace" by Michio Kaku gets a little more in depth with higher dimensional theories. The only way we can understand an expanding universe is through expanding our minds along with it.
606802
Actually, the first two answers are right; but, disregarding time, if we were 4-dimensional beings we would still only cast 2-dimensional shadows.\n\nEven 2-dimensional objects also only cast 2-dimensional shadows.  Anyway, what would your 4th dimension be?\n\nShadows are merely the result of an object being between the shadow and the light source; shadow is merely absence of light.  Shadows are always 2-dimensional.\n\nAnd as far as considering time to be a dimension goes, we are IN the dimension of time, but we are not IN the dimensions of width-height-length.  They are attributes used to describe us; they are part of us, we are not part of them.
1118502
I might be able to answer more fully if you reword your question and put some thought into exactly what it is you're looking for.  For example, string theory predicts extra dimensions beyond the four we experience.  Is that it?  Or are you referring to the Branes explanation, where there are extra dimensions as well as additional universes removed from our own?  Get some additional details and I'll edit.
178542
That's a tough one.\n\nI like this approach: \n\n"This question is based on the ever popular misconception that the\nUniverse is some curved object embedded in a higher dimensional space,\nand that the Universe is expanding into this space.  This\nmisconception is probably fostered by the balloon analogy that shows a\n2-D spherical model of the Universe expanding in a 3-D space.\n\nWhile it is possible to think of the Universe this way, it is not\nnecessary, and---more importantly---there is nothing whatsoever that\nwe have measured or can measure that will show us anything about the\nlarger space.  Everything that we measure is within the Universe, and\nwe see no edge or boundary or center of expansion.  Thus the Universe\nis not expanding into anything that we can see, and this is not a\nprofitable thing to think about.  Just as Dali's Crucifixion is just a\n2-D picture of a 3-D object that represents the surface of a 4-D cube,\nremember that the balloon analogy is just a 2-D picture of a 3-D\nsituation that is supposed to help you think about a curved 3-D space,\nbut it does not mean that there is really a 4-D space that the\nUniverse is expanding into."\n\nAlso, read the wikipedia article!
1009023
The universe that we live in has only three spatial dimensions. We are limited to length, width, and height, and we can only travel along three perpendicular paths. This page attempts to explain the properties of a hypothetical universe with a spatial fourth dimension. While people generally call time the 4th dimension in the universe we live in, time will be the 5th dimension in my hypothetical universe. \n\nMany fascinating possibilities exist when a spatial fourth dimension is present. Several types of wheels are possible, very complex machines can be built, and many more shapes are possible. Objects can pass by each other more easily, but they are harder to break into multiple pieces. Energy reduces much faster with distance than in the 3rd dimension, so both light and sound are weaker. Much more things can be compacted into a small space, but its much easier to get lost. In this page, I will explore these and many other interesting properties of the fourth dimension.
1095974
this is sort of trival, dimensions can be thought of as derivatives, and you can take a formula and make any number of derivatives of the original derivatives and still end up with a line that bends, indicating no limit to the number of dimensions we can really conceive..   \nModern string theory is a bunch of hoo haa,   such a sub-atomic idea makes no sense, the reality we know could not have order if there were "strings".  "strings" have no way of organizing themselves into different sub-atomic particles, the universe would just be a bunch of "strings"
12868
space as we see it has the three dimensions of space and one of it .But if u want to explain everything that is happening around us we have to assume that space is multi-dimensional.I know it is quite hard to imagine and think about a space having dimensions greater than 3 (also caled hyperspace)but there is no way out.A mathematics devised by reinmann is used to study hyperspace .It is easier to write down the equations of hyperspace than to imagine it.Gravity is also defined as the bending of this hyperspace.Many scientist's also believe that hyperspace can give us the answer for an unified field theory.
690773
First of all, you want to come to grips with the fact that you don't really have an appreciation for 1, 2 or even 3 dimensions. We talk about up, down, left and right as if they were things we could grab onto, but cannot really.\n\nBecause we don't have a way to look at dimensions literally, it becomes a matter of concept and deffinition.\n\nConsider the concept of one dimension. It means merely that something can travel in only one of two directions, either foreward or backwards, but that's all.\n\nIn two dimensions, one gets to travel in 4 directions and combinations of those four.\n\nAbout here, you are probably visualizing what I am talking about, but that is a mistake. We want the concept without the visual because the visual will get us into trouble later.\n\nOk, 3 dimensions? Add two new directions which you can combine with the others to make 6 ways to go and the combinations of those 6.\n\n4 dimensions? Add two more for a total of 8.\n\n5 dimensions? Add another two new directions for a total of 10 ways to travel (along with mixtures of the 10).\n\nSo, what shall we call these directions? Traditionally, the first eight are called left and right, up and down, foreward and back, past and future. The next two we can call thither and yon.\n\nNow, notice that if you always just travel left and right, you can't really know if you are in some larger scheme and just using two of the 10 ways to go. That's the status for us in four dimensions and thinking about 5. We travel actually in 7 directions, because we are always going forward in time. \n\nReally, the only thing that makes additional dimensions hard is trying to visualize them. But you don't really visualize time or 'left' anyhow, so if you can just focus on the meanings that will get you over the hump.
830000
Imagine you put a yardstick on the floor facing exactly north and south. That would be the first dimension. Moreover, north and south anywhere in the room would also be the  first dimension. Now, put a second yardstick down on top of the first but facing east and west so they look like a big plus sign. That would be the second dimension. Notice, and this is very important, the two yardsticks are at right angles to each other - 90 degrees. All dimensions must be at right angles to each other. Now, put a third yardstick with the other two but remember, it must be at right angles to BOTH of them. There is only one way it can be oriented - in the center of the plus sign standing straight up and down. This is the third dimension. Take time either to try it or to actually build what I have just described using rulers or pencils and satisfy yourself that all three dimensions are actually 90 degrees to each other. Now go one step further. Can you add another yardstick (or pencil) which is at right angles to ALL THREE of the others? Before you exprience brain burnout I'll answer that for you. No - although you might like to try. You can't do it because we live in three dimensional space. However, many scientists feel that there is a fourth dimension although it can't be drawn or built - just imagined. Remember, it would have to be at right angles to each of the three spatial dimensions. Many scientists think the fourth dimension is time. No matter how we turn or in what direction we face, time is always like a yardstick facing behind us into the past and forward into the future. Remember, this is just a theory, an idea supported by many facts and observations but one which has not yet been proven. Are there more than four dimensions? Possibly. In math we can have as many dimensions as we want but math is strictly a mental exercise. The fact that math so nearly predicts what the actual universe is like is a tribute to the perfection of the universe.
1153435
We observe four dimensions everyday, three spatial and time.\nBut...theories such as string theory predict that the space we live in has in fact many more dimensions (frequently 10, 11 or 26), but that the universe measured along these additional dimensions is subatomic in size. As a result, we perceive only the three spatial dimensions that have macroscopic size.\n\nThis is not so strange as it sounds, which I'll show with an example. Imagine you are in an airplane, flying over sea. Seen from a height, the sea looks flat, two-dimensional. But when the plane looses height we start to perceive the waves, that move in a third direction we could not see before.\n\nThe universe could be the same. Four macroscopic dimensions and a few more, hidden ones. We can only perceive them for instance, by the small effects their existence might have on subatomic particles.
370209
Okay I'm sure that there is more than a four dimensions out of this well known reality (real life).\n\nabout that string theory I have read a little from wikipedia and it says something, that maybe, the Universe was caused or founded pherhaps by a big Crunch.\n\nTo simplifies it for myself, I think that every Dimension is a continuing line. String is a very small thing that exist only in that dimension and not just one string but millions of it, but only that type or kind of string, for example a flashlight in a dark room you can see those particles of dust BUT refering the -strings- are actually those specific Lumens or Lux that are producing light and interacting in a very small subatomic scale, and refering -dimension- are that beam coming out from that flashlight all the way long to the wall.\n\nYou see only those lumens are interacting in the beam which is the well known Dimension, (we live in it) The Universe.\n\nBut there is fourth Dimensions apart that Can not even touch the beam of light wich represent the dimension or universe we are talking about, because the other Dimensions acording to this theory are beams (lines) but not of light for example another dimention could be as a water fall that comes out of spout (sink dishwasher). curiously that flow of wather is very similar to the beam of light.\n\nOkay I'm sure that this a very deep thing to think about it but friendly I advice you to not get more further because we are just humans and those are very Interesting themes or topics that we can not reach or complete understud \n\nI always have thought that the universe is spheric very similar like that crystal spheric snow ball present or souvenir they give you on birthdays maybe like a Marble.\n\nBut serious talking againg about Dimensions. you know, The Book talk about it, a dimension of living creatures and you know the other dimension of people that is not here anymore We can Not interact each other. \n\nLUX OR LUMENS (a Small Portion from Wiki)\nAchieving an illuminance of 500 lux might be possible in a home kitchen with a single fluorescent light fixture with an output of 12000 lumens. Lighting a larger area with the same number of lux requires a larger number of lumens.
1043848
Look at your watch.  That is the 4th dimension.  TIME>
28795
ALL of scientific theories are just "made up" to try to explain observations. All theories are expected to be eventually superceded by something that explains more of the data. \n\nAnd that includes "space time", which is just a shorthand way of saying the 4 dimensional space we live in: 3 space dimensions and 1 time dimension. This concept might very well be eventually replaced as we learn more about what time is, what other dimensions might be, etc. But for now we use it because it is useful. We can make predictions using this concept which we can verify.
1186101
The fourth dimension is loosely known as "time".  But it doesn't stop there.  There are at least ten dimensions at last count.  The easiest explanations are in magazines like Time, Newsweek (when they run articles on this subject, about once a year), and Science.  Check your local library.
436500
I like to add conceptual dimensions like color, (red, green, and blue each get one) temperature, pitch, volume, etc. Then the nine dimensional origin (0,0,0,0,0,0,0,0,0) would be a point located at the center of the 3-D grid colored 50% grey at zero degrees centigrade exhibiting middle C at zero decibels.\n\nI could also imagine extra dimensions represented in the form of trajectories, but more often than not I am thinking in the terms above.