Does Time have a shape?
147146
My favorite theory is that time is a river.  This takes into account einstiens' equations that have shown time moves at different speeds for different locations (as proven by measuring time in fast moving satellites and comparing it to time on Earth) and yet always moves forward.
113366
The 4th dimension is time. It is essentially equivalent to "flat land" falling through the 3rd dimension.
128617
length, width, depth. Time and space
220861
There are some theoretical models based of GR that allow closed time-like curves. Most working physicists think those models are bunk. To have such curves requires a curves space-time, so is the domain of GR, not SR.\n\nTo see why such a curve would allow time travel, you have to understand what the terms mean. Time-like means that at any point on the curve, the tangent vector is into the future. In other words, someone going along that space-time curve would always be going 'forward in time' in *their* mind. Closed, in this context, means that the curve comes back to the starting point, again *in space-time*. So the traveller would always be going forward in time in *their* mind, but would end up back at the same point in space and time as when they started. Looks like time travel to me. ;)
318179
The shape of things to come
187337
how can something without a boundary, like the universe,  have a center?\nand yes, time is subjective. basically i think it's only a measurement of life.
678785
The basic idea behind space-time comes from Einstein’s General Theory of Relativity, so if you’ll bear with me for a moment… What he proposed was a totally new, geometrical description of space and time that led to a different description of gravity—one that linked space to time and mass to energy in a fundamentally geometrical fashion. In other words, mass(-energy) shapes space(-time) instead of acting like a “force” in the traditional Newtonian sense. This alteration in the fundamental geometry of space-time is often described as the “curvature” or “bending” of space. \n\n(Thus, in Newton’s description of gravity, one would say that all bodies exert an attractive gravitational force on one another; “space” is just the place where it happens. In Einstein’s conception, one would say that all bodies change the underlying geometry of space—and time, too—in a way that causes them to be attracted to one another.)\n\nWhat’s important to note is that, in Einstein’s conception, space and time are linked together in a way that doesn’t allow the two to be considered separately.  So we often talk of space-time being “warped” or “curved” by the presence of mass(-energy). The only we see space-time deformed in the Universe around us is by the presence of a lot of matter—light being bent around the Sun, clocks being affected by Earth’s gravity, that sort of thing.  \n\nThe caveat I feel compelled to add is that curvature or bending really only provides an analogy to what the equations tell us. If you want to imagine the effects of an object on its surrounding space(-time), then you can think of it as changing the shape of space(-time) in its vicinity. The distortion is real—we can measure its effects—but the images that are often presented (of flexible sheets of space-time with bowling balls or marbles rolling around on them) simply present analogous situations.\n\nI guess that’s a lot more than you asked for.  I hope it helps.\n\n\nRyan Wyatt\nRose Center for Earth & Space\nNew York, New York
849985
time is just a dimension. like length, width , and height,\nGod lives in a dimension beyond our scope,\nmuch like an ant maybe only realizes 2 dimensions,\neverything is like a plane to them, although it may be curved, they don't comprehend the curvature,\nas we don't comprehend the curvature of space and time.\nbefore and after is a concept that only applies to those who are constrained by 4 dimensions...\ni think God can put the beginning and end of space and time in one simple (package) concept, and \ni wonder what he will do for an encore?\ni don't know,\ni doubt he was playing solitaire
31234
Einstein said we are living in the past time, that means we have not "now time"!\nSo, nobody can not answer, what time is it! maybe we can ask, what time was it!!
922393
In order to have space one must have time. In fact, I consider time to be the root dimension. Without time in which to percieve the universe, I cannot see how there could be a universe. Time and space are inextricably linked.
465970
It's impossible to describe time because the past can be the present for someone, or the future for another person. The present can be the past for someone and the future for someone. Also, if time is always passing, then there is no stable moment in times passing because it goes down to the most infinently small amount of time in between things happening. As it goes down in infinity, time doesn't really exist, but it has to, otherwise everything would stop.\n\nI suppose that was confusing. Well, it's what I think.
26586
Science currently views the nature of space-time has a 3-D surface which is difficult for us to comprehend since we are accustomed to 2-D surfaces only.  Like all surfaces they have no spatial boundary.  Imagine the surface of a balloon.  If you were confined to move on its surface and travel all over you would not find an edge.  Of course there is a "above and below" but in the context of the universe these are not spatial dimensions but temporal ones.
1119002
Time folds in as much as it is within life.\nThe future exists with the past
1156487
The accurate answer to your second question is "not really".  Our current system for measuring time is based on the movements of our planet & our solar system, which of course did not exist in their current state at the beginning.  Those units, however, have been standardized for convenience & accuracy to reference the cesium atom, so can be back-calculated.\n\nThe answer to your first question is that time began at the instant of the so-called 'big bang'.  Before that there was nothing to reference it again, so the passage of time had no meaning or substance.\n\nWeird, huh?
1180732
Space/time is used to describe our universe as a whole. We live in a 4 dimensional universe. 3 dimensions of space and 1 dimension of time. Think of time like you do any other dimension. Since it is 1 dimension it is linear like a straight line. There is no "width" or "height" to time. To get an idea of time works as a dimension imagine you were a 2 dimensional being. You only see the world in 2 Dimensions. Therefore a sphere (which is 3D) would look like a circle since you can only view a 2D slice of it. Now if someone dropped you and you fell alongside a sphere you will see it start as a point and become a circle that grows in size and then shrinks back down to a point and vanishes. We are 3D beings and can only view our world in 3D. therefore we are seeing only a slice as we move thought time (ie 4th dimension) We don't see past, present and future all at once. Just like a 2D being wouldn't see the entire sphere all at once.\n\nNow when you talk about space/time you are speaking of the universe we live in. Its made of all kinds of matter and energy. some we can see and feel other that we only can see the effects it has on the space around it. No one knows the complete make up of the universe but there are a lot of good theories out there.\n\nsome links\n\nhttp://www.bartleby.com/65/sp/spacetim.html\n\nhttp://www.sciencedaily.com/releases/2005/02/050205074635.htm
90909
Time is a creation. It exists because we keep it. Distance is a constant, something inseparable from the fabric of reality.
341051
time is something that humans have created so, no