is time really the fourth dimension? or is it just an effect of it? like smoke being the effect of fire?
597501
Imagine the surface of a two-dimensional sphere. An ant walking on it can go in any direction, without finding a boundary. And he really has no way of perceiving what is outside of his sphere universe.\n\nWe in our Universe, are like the ant but in three dimensions.  We have -for the moment- no way to look outside our 3-dimensional Universe.\n\nTime is often called the 4th dimension because it makes mathematical sense to do so, in Einstein's theory of relativity. \n\nHere is the link to an old but funny book call Flatland, that describes when the world of two dimensional beings suddely is invaded by three-dimensional spheres. \n\nhttp://www.alcyone.com/max/lit/flatland/
335734
I consider humans as being 4 dimensional and existing in a 4d world...unfortunately we cannot fully interact with the 4th dimension (I guess we are temporal retards)......but that aside......\n\nYour 2d and 3d examples are correct because they are both physical dimensions.\n\nHowever, a 4d observer would not be able to touch every molecule of a 3d world which he was observing........this is because the 4th dimension is temporal rather than physical....he would still have physical boundaries.\n\nHe would be able to interact with a 3d world in the same physical way as we would, but he could do it in the past or future....which we cannot unfortunately....we are stuck in our present...moving ever forward in the temporal plane.\n\nPhysically, he would also be able to interact with his 4d world in the same way as a 3d observer interacts with their 3d world (and it would simply appear normal to him).\nTemporally, he could interact with his 4d world in the same way as he could interact with a 3d world...he could travel in time, but would remain constrained by physical barriers.\n\n5d.....well.....what is your definition of the 5th dimension ?\n\nProbably somewhat different to mine !!!
425786
Third dimensional particles (this includes light and electronic data streams) must move through Time (4th Dimension) in a single straight line.  Though you may make them go any direction at any speed within the three dimensions of our reality, time is constant.  The only way to move something in a different direction along Time you would have to get these particles into that dimension and move them along a 5th.\nSo it's just not possible at our current understanding of physics
471213
It all dependend where you are filling time. In an insane intitution there are people who experience 4 ,5 of more dimentions . so far I have heard of 26 dimensions being filled including many dimentions of time.\nSpace and time have the same thing in common they can be filled both at the same instance!
658780
We observe four dimensions everyday, three spatial and time.\n\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.
1045387
GOOD QUESTION: well done! There is not really any such thing as time, it is merely our way of describing a particular abstract concept. If it was a solid physical reality it surely couldn't be relative. Lets all go and read Einstein and try to figure it out!
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.
128525
I don't think that is correct.   I assume you mean fourth spatial dimension, rather than the Minkowski 3 space, 1 time geometry of relativity.  For that, time is actually a dimension, and the question pretty much answers itself.\n\nThe best insight into a spatial fourth dimension is to read the delightful classic little book, "Flatland". Almost any library or bookstore should have it. It works on the analogy of an individual who lives in a two dimensional world - his name is "A. Square" - who learns about three dimensions.\n\nAnother way to insight would be to look up "tesseract" on a search engine. Aside from hits on Madalyn L'engel's misuse of the term in her children's boooks (avoid her description), you should find many discussions on how to represent simple four dimensional objects in three dimensions, just as we represent three dimensional objects on a flat piece of paper with perspective.\n\nFour dimensions would have two directions that are perpendicular to our three dimensional world. They have been given the names "ana" for four dimensional "up" and "kata" for four dimensional "down" with respect to our space. Of course these are just the Greek words for up and down. \n\nSo borrowing a description from Flatland, if a four dimensional sphere were to start anawards of our world and move through it in the kata direction, what we would see, as it intersected our world woild be first a tiny three dimensional sphere (cross section of the four dimensional sphere near its kata pole) which grows in size to a maximum (the "equator" passing through), and then decreases gradually again to its mini size before vanishing, having passed commpletely through our world and out the other side.
321071
There seems to be a lot of confusion on this site as to what a dimension is.  A dimension is not an alternate reality or a parallel universe, or anything like that. A dimension is simply a direction. For instance, the first four dimensions are Length, Heighth, Depth, and Time. Diminsions(directions) beyond these four have been mathmatically postulated, but we cannot perceive them with our senses. We can only percieve time in one direction(Past), so while we "see" only three & 1/2 dimensions, there could, and probably are, others. But they are just other directions, not other worlds. So, if you sent a camera into a black hole, could you see other dimensions-no.  First, nothing we are capable of building could withstand the tidal forces of a black hole's gravitation-it would be destroyed in nano-seconds.  Secondly, no energy can escape a black hole, so we would be unable to receive any signal back-and that includes energy through a cable, folks. Lastly, even if those two obstacles could be overcome(not likely), the effects of relativistic time dialation would be so extreme that we wouldn't get a signal back until the universe ended, at which point the data would be meaningless. So we can realistically count on seeing nothing through a black hole. Be neat if we could though-who knows what we might discover?
1043848
Look at your watch.  That is the 4th dimension.  TIME>
545067
"Time" is not a dimension in the same sense that x,y,z,a,b,c, ..etc are spatial dimensions.\n\nThough the human mind is cabable of imagining muti-dimensional space, and can create clever matematical concepts supporting the idea, there is not one whit of physical evidence to support it.  And there is ample evidence to refute it.  \n\nTake gravity, for example.  Measurments show that gravity decreases as the inverse square of the distance from the source, exactly as it should in three-dimensional space.  If there were more than three spatial dimensions, that wouldn't be the case.  So if you want to postulate there are more than three dimensions, you've got to explain why gravity ignores them!\n\nAlso, take ElectroMagnetic Radiation (EMR), which also behaves the same way - i.e. it decreases as the inverse square of the distance from the source, just as it should in three dimensional space.  So if you postulate more than three dimensions, you've got to explain why EMR doesn't know about it!\n\nAs to string theory, scientists proposing it can't agree whether it requires twenty-six dimensions in order for the math to come out right, or "just" ten!  And they all admit there's no known way to prove or disprove the theory itself. That's makes the theory pretty weak. In fact, it makes it almost science fiction! Great mind exercise, but no eidence of reality!\n\nEinstein's theories provide predictions that can be proved or disproved. That's one reason they are so powerful.\n\nSo the jury's still out on multi-dimensional space - and pobably will be for some time to come.\n\nBut it's fun to speculate!  Just don't bet your food money on it!
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.
912122
You've asked a very good question. When physicists refer to time as the fourth dimension, they don't mean that time is another spatial dimension like the 3 spatial dimension of up/down, right/left, and forwards/backwards.\n\nHowever, it turns out that time and space are intricately linked that Einstein coined the term "spacetime" in his Theory of Special and General Relativity. Also, time is not simply a measure of passage of events, because time and space are NOT absolute in the sense that time is flowing at the same rate everywhere to everyone, or that distance can be mesaured identically the same everywhere to everyone. Einstein discovered that depending on how fast you're moving, time, distance, mass, energy are all affected. This is because the speed of light is invariant no matter where you are and how fast you're moving, and nothing can travel faster than light.\n\nIn addition, Einstein discovered that spacetime forms a 4-dimensional surface that can be warped by the presence of matter and energy. This warping of spacetime fabric is what gravity is. So when you throw an apple up in the air and it falls back down to Earth, you are witnessing the apple following the shortest path possible along the warped spacetime 4-d manifold caused by the presence of the mass of the Earth.
987744
Depending on what you have to use it for I agree whit Answers, but it isn’t as simple as that and it is really a theory, but here goes:\nWe live in a 3-dimensional world, which physics calls "3-space." But there is also spacetime, or 4-space, or the "4th dimension." Then suddenly comes this amazing new knowledge that time itself is actually compressed energy. And it is energy which is compressed by exactly the same factor by which matter is considered compressed energy: the speed-of-light-squared!\nSo we have a new companion to the famous E=mc2. It is now paired with E=tc2 (where t is actually "delta-t," or change in time). Or (amaze your family and friends and) say:\n"E equals em-cee-squared"\nand\n"E equals delta-tee-cee-squared" \nI am not fully up to speed whit all this part of physics but I think this is what you are asking about !
637166
Our existence is defined by 3 spatial dimensions: up-down, left-right, and forward-backward.  Our bodies and senses are only able to conceive these three dimensions.  A fourth dimension really doesn't make sense, because there is absolutely no way we can point in a fourth direction at right angles to these three.\n\n But mathematically, there's no reason why a fourth, fifth, or more dimensions can't exist.  It's quite possible, mathematically, for other dimensions to exist - and it's very probable that, if they did exist, we could never experience them.  NEVER.  That's a bummer, but that's the way it is. \n\n A simple mathmatical 4th dimension mathmatical concept is the tesseract.  Think about these relationships and you may understand what a tesseract is: Line - Square - Cube - Tesseract.  It's a 4-D equivalent to a square (2-D) or cube (3-D).  Google "Tesseract" for more info.\n\n About a hundred years ago a guy named Ed Abbott was asking the same question you've asked.  In order to help him think about what more dimensions are like, why we can't experience them, and what might happen if we could, he wrote a book called "Flatland."  Flatland is a 2-dimensional world, inhabited by shapes like squares and triangles.  They can't comprehend a 3-D world (just like we can't comprehend 4-D)  But interesting things happen when some of those shapes do venture into a third dimension. \n\n Actually I was wrong when I said that humans can't comprehend 4 or more dimensions.  Additional dimensions come in pretty handy in physics.  The most common example of this is time, which lots of scientists treat as a 4th dimension.  But it's a 4th dimension in which we can only move one direction - forward.  By looking at time as a 4th dimension, it's a lot easier to understand most of the principles Einstein came up with in his theory of relativity.  \n\n Another area of science where multiple dimensions are handy is a theory of what everything (atoms, electrons, protons, etc. - the basic building blocks) are made of, called string theory.  It's really complicated, but basically if you think of every basic partical as a string vibrating in 10-dimensional space, then all of relativity and quantum theory works out pretty well.\n \n Finally - to answer your question - do I believe in different dimensions?  Yes.  I think a lot of what we as humans see as spiritual - everything from angels to heaven to how God can do what He does - is a lot more easier to explain if there's a spiritual realm close to us, but separated in a 4th dimension. But that's just my thoughts - it makes sense to me, but I'd have a hard time proving it to anyone.\n\n Great question!  Hopefully these answers help you comprehend it.  And if you're the first person to venture into the fourth dimension, then please come back, look me up, and take me with you!
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.
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.