What is the ''FOURTH DIMENSION''??
357568
We live in a 3 demensional world, which means you can jump / move up and down (one demension), right and left (one demension) and forward and backwards (one demension)...which totals three. The fourth demension is considered to be time, because you can 'move' in time as well...which means you can not 'move' in space from Point A to Point B without spending 'time' doing that. In other words, you can not move in space without moving in time as well (It took me 9 seconds to move from my chair to the refrigerator and back)...therefore, time is the fourth demension.
79119
Our universe has 4 dimensions of space-time, and the domain of these domains is finite.  However, the expansion of that is in a larger dimensional space--meaning more than our four dimensions, with higher dimensions orthogonal to our four.\n\nThink of the 2-D surface of a balloon.  If you were a 2-D being on the surface on that balloon, you'd have no concept of the 3-D space inside and outside the balloon--your entire existence wouldbe contained on that 2-D surface.  But if the balloon inflated, you 2-D reality would grow in the context of the larger 3-D reality which was beyond you.
182923
Yes. But, it's just a personal assumption, although it is an assumption held by the majority of people.\nThe most well known 4 dimensions are best described as width, length, depth and time. The order you list them does not matter, and there could be more - but humans have difficulty relating to more than these 4 (apart from imagining what they are like). The easist way to explain what a dimension is, is to say that you need all 4 to describe where an object is located.... eg, as a real world example I could tell you that I am located in a building at a certain cross-street (=length+width), a certain floor (=height) and at a certain time. You need all 4 dimensional descriptions to find me.\nTime is definitely the hardest of the 4 to properly comprehend. It's hard to think of time as being similar to length or width or height. It is special for sure to us humans, but that is only because our brain operates as a function of time... which means we are fooled into the perception that time 'moves'. Time does not move, no more than 'length' moves. You mind changes with time, just like the slope of a hill changes with height, but there is nothing to suggest that there is a certain special moment called 'now' that is somehow different to 'the future' or 'the past'. Read any scientific article on the topic if you really want to find out more about this 'special' dimension (see source link for an excellent read).
187814
The 4th dimension is time and the 5th dimension is quantum probability, where every possibility occurs in an infinite number of "parallel universes."
662178
Any line you can make in this physical Universe is 3-dimensional.  A drawing has a 3rd dimension - no surface is ideal, and there has to be something beyond this surface.\nIf you draw a line, it is also 3-dimensional (otherwise, you would not see it - it would be infinitely thin, and if it is not, it is a rectangle on an uneven surface).\n\nIf you ask whether truly 1-D or 2-D objects can exist in our Universe, there is an answer: no and yes.\n\nNO for macroscopic objects: the reason is that there is a minimum unit of space: Planck length. Therefore, you may think of all non-elementary objects in this Universe as being at least 1 Planck length thick in all 3 dimensions.  \nhttp://en.wikipedia.org/wiki/Planck_length\n\nYES for elementary particles. They are viewed either as zero-dimension (points) or one-dimension (strings, with the size of - I think you guessed it - Planck length).\nhttp://en.wikipedia.org/wiki/String_theory
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.
910873
The fourth dimension is referred to as time because of 3d charting.\n\nSay you have a 3d chart of two airplanes traveling through the sky, and they both cross through the point x,y,z. That is a measure of depth, height and width on a coordinate map.\nNow, that would mean that the planes crash at that point. But they don't necessarily crash because there is another dimension involved, time. The way real world events are charted involves length width height and time when. That means its XYZ time. that makes time the 4th dimension.\n\nIf you are talking about another direction being the 4th dimension, then when we discover how to move in that direction, time will be the 5th dimension.\n\nALSO: Look at the animation by clicking on the helix at the right side of this website, it should help you.\n\nHope that helps.
1155114
We live in a universe of observable/measurable quantities. For example, length, width, height, time, mass, etc.  If different quantities cannot be expressed in terms of the other quantities, they are "orthogonal" to each other - you can think of them as being separate dimensions. For example, on an X-Y graph, the x-dimension is independent of the y-dimension because you cannot express a "y" quantity as a combination of "x" quantities. \n\nSpace has 3 dimensions (length, width, height); time is a fourth dimension that cannot be expressed in terms of the other three.\n\nAn n-dimensional space is just a space that is characterized by "n" orthogonal quantities - quantities that cannot be expressed in terms of each other. To completely define the space/universe, you only need to specify "n" values - any more than that would be superfluous because the other values would be some combination of the other orthogonal quantities.\n\nExample: if we lived in a 4-dimensional space characterized by length, width, height, and time, all you need to do is specify those 4 quantities to uniquely determine any point in that space.  If we add another quantity (such as temperature) that cannot be expressed in terms of the other 4, we now have a 5-dimensional space that requires 5 quantities to be specified.
886
Classical physics theories describe three physical dimensions: from a particular point in space, the basic directions in which we can move are up/down, left/right, and forward/backward. Movement in any other direction can be expressed in terms of just these three.\n\nTime is often referred to as the "fourth dimension". It is, in essence, one way to measure physical change. It is perceived differently from the three spatial dimensions in that there is only one of it, and that movement seems to occur at a fixed rate and in one direction. The equations used by physics to model reality often do not treat time in the same way that humans perceive it.\n\nTheories 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.
255954
I will take a shot at it.\n\nWe are all very familiar with 3 dimensional space, up down, left right, forward backward. To describe the location of an object in space we have to use those three dimensions. BUT. Nothing is actually fixed in space. Everything is moving. So in order to describe the location of an object in space you must also describe at what time that object was at that location or will be at that location. That is why time is called the 4th dimension. \n\nNow here is the really bizaar part. Some scientists think there are more than 4 dimensions. Some propose 10 dimensions and some 26 dimensions. It is called string theory and it is all over my head.
158992
sorry i must really correct the first answer before i continue;living in a 10 dimensional world is just a theory,known as string theory,and that is all it is,there is no proof\n\n(and the theory ACTULLY states that there are 11 dimensions)\n\na 2d object could not even physically exist because even if you had the smallest possible object that could exist indepdantly(an atom) it still has dimensions of length width and height,however small it may be it is not 2d\n\nIn writing the answer im kinda curious as to Could you theoretically stack and infinate number of 2d objects on top of each other and it still remain 2d?? anyone know?
705451
If your legs lived in, say, the 4th Dimension - how would your brain be aware of them since it exists only in 3 Dimensions? We are physically in 3 dimensions (time is an illusion made to mark the difference between one state and another) - we can comprehend of separate parts of our bodies being in different dimensions as much as a stick man drawn on a piece of paper can imagine moving freely around the room in 3 dimensions.  We can only visualise higher dimensions using tricks such as looking at the shadows cast when a 4 dimensional object is illuminated inside a computer program.  What would it matter how big the sock was to be pan dimensional? Good question though.
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.
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.
83422
Scientist belive there are several dimesions.  Remember dimensions are based on measurement.  Length width height, 3 dimesions so we are in the third dimension.  A showdow for example only has length and width so it is the 2nd dimseion.  We cannot comprehend other demensions because we live in a 3d world where only LWH exist.  It is like asking your shadow what is tall, he would know because he lives in the 2nd demsiond.  So there are other dimensions yes and we can dicipher them though the wonders of mathmatics and physics.\n\nGravity works likes a bowling ball on a bed.  Think of the bed as the fabric of space.  If you put a tennis ball on the bed it would "gravitate" towards the bowling ball.  This is the theory of realtivity.  A worm hole forms when a really heavy mass punches through that space fabric.  If you had a million pound bowling ball it would go right though the bed.  The same things happens in space that heavy mass punches right though to the other side forming a worm hole.
1172936
1 dimensions is a line    width, but no height or depth\n\nif you lived in one dimension you might know the person or thing on each side of you, but you could never pass them, there is no way to go around or over them because there is just the one dimension, back and fourth\n\n2 dimensions is a plane    width and depth but no height\n\neverything in a two dimensional world is flat, you could go over or under something you met but not around because there is no around, you are flat and so is everything else\n\n3 dimensions   is like our spatial universe width, depth and height\n\nthings have volume\n\nsome constructs use time as a 4th dimesion but that is really a different deal, there are only 3 spatial dimensions that we can percieve.  it is hard to imagine what another spatial dimension might be like
572522
dimensions used to explain the behavior of strings and subatomic particles in String Theory.\n\nbut to give you a basic understanding of what another dimension can be like, think about this for a moment, we live in a world limited to and guided by four dimensions, now they are \n1:up/down \n2:left/right \n3:backwards/forward\n4:time\nnow go outside take a look at an electrical feeder cable, from the ground it looks like a solid line, but if you get closer to it you'll notice that there is a line wrapping around the wire where the wire is braided, now imagine if you are an ant crawling on the wire, these braids will be a dimension to you, because you have to follow their path otherwise you'll fall off. that's a perfect example of what another dimension besides the four that you are familiar with can be like. now in string theory, in order to explain the very complex movements and behavior of the strings and of other subatomic particles, mathematics will include those  additional dimensions in the theory, the only problem is that its very hard to understand much less visualize these additional dimensions, because they can be extremely complex and twisted around all over the place.\n\nthe new M-theory includes as many as 11+1(that's 11 space dimensions and one of time)dimensions.