Message #1, From: Arcology2
	Wednesday, Jan 19 2000
4:21 p.m. PST	

Question: 
Is time a dimension?

Result: 
47 votes_ 	

	

63% _	
Yes 	

	
12% _	
No 	

	
23% _	
Only in terms of mathematical convention 	

Author's Comment: 
By mathematical convention I mean the way a variable is added to an equation to represent any quantifiable number. To me, a real dimension is an axis (probably either infinite or circular). Real dimensions above the first three would be extremely hard, if not impossible, for us to perceive - except in a theoretical sense.	
Message #14, From: Dr-sociology
To: Bradkin ( Message #13 )	Tuesday, Feb 22 2000
10:33 a.m. PST	

Okay, now, if you remember, I asked you to set aside all human conventions of time. Obviously, you didn't. If you keep holding on to what we have labeled as time, such as feet/second, or miles/hour, then you can never see what I am trying to say. My point is this: an object moves from one place to another because a force acted upon it. Now that this object is in motion, it will move accordingly and affect other objects, thus sending them off on their new courses. Time is not a dimension, it is an ideal, as I said before. We use it for the primary ideal of measurement - sure, it may take four or five seconds for a baseball to leave your hand and come back to the ground, but it still comes back down. If you were to take away all concepts of time, and you threw that ball, it would still go up, because you acted upon it, it would still fall to the ground where it would come to rest, but not before it acted upon the ground and caused minor changes to the grass lawn. 

In the end, I will not say that time is not essential to our lives. I am simply saying that it is more of a convenience than any form of a dimension: Humans have exceedingly short lives, when compared to how long the earth has been around, and therefore humans have had to find ways of being able to measure out the path of earth's orbit around the sun, then break that number down into fitting little blocks, which we call days, and so on. This allows humans to get the most of out their short lives.	
Message #15, From: Arcology2
To: Dr-sociology ( Message #14 )	Tuesday, Feb 22 2000
12:48 p.m. PST	

I think I understand what you're saying - that motion can exist independent of time. But I'm not sure I agree with it. If you define time as a method of measurement, then that is true. And yet, there is a definite sort of 'axis,' or dimension, which allows things to not happen all at once. Again, I'm referring back to time measurement (all at once) - it's very hard to talk about time, or another concrete dimension, without doing so. But, if we don't measure it - does that mean that it suddenly becomes unmeasureable? I guess it's kinda like, "if a tree falls in the middle of the forest, and no one's there to hear it, does it make a sound?" 

If you have ever read Flatland, or Sphereland, then let me explain my theory based on those analogies: I think time is not actually a dimension, but it hints at another dimension. Just as when Mr. Square began to talk about another dimension that could not be sensed, and tried to explain this, the Flatlanders assumed he was describing shading. Shading itself is not the third dimension, but it is the only conception of depth that they have. 

For those of you who have not read these books, let me give a few more examples: A Flatlander is one who lives in a plane. I find it convenient to imagine their world to be a piece of paper. But you have to realize that their eyes and faces do not look up out of the paper. The extent of their field of vision is a line. Their geometry is quite different. For instance, you can draw circles (or any polygons) on a piece of paper, then mark where their eyes would be. Now, from the point of view of the shapes, they see themselves as all closed up, but you see both their insides and exterior simultaneously. Interesting concept. Those little Flatlanders would be quite puzzled, and pained, if you were to touch their internal organs. 

But suppose this paper world we have constructed is merely a plane, and you can put your finger through. Imagine what the Flatlanders would see, if you were to slowly pass your finger throug their world. Shapeshifting! Only you must remember that to them a 'circle' is a line. The varying widths of your finger would appear as a line that changed widths. And, remember that to them, your finger has appeared out of nowhere, and disappears without a trace. 

The interesting thing about such phenomena, is not so much that there is another dimension, but that the Flatlanders are 2D-beings. They cannot perceive that which is ouside their 2D world. However, that is not to say that they don't exist in 3D. Their world has to have some depth, or they would not exist (at least not to us - lol). Yet, their whole land can exist within an infinitely thin sliver of our 3rd dimension. It is also interseting to note that a plane consists of any two geometrical dimensions, therefore the terms 1st, 2nd, 3rd (and greater) dimension are actually meaninful in only a relative sense. For instance, we could have a horizontal Flatland, composed of length and width, or we could have vertical Flatlands, composed of depth and width, or depth and height. In fact, we could even have Flatlands of diagonal dimesions. There could be an infinite number of 'planar universes,' within our own. However, unless they were parallel, they would intersect at some point (assuming we keep this simple and leave out the possibility of non-Euclidean geometry). 

Likewise, our 3D world can only exist within an infinitely small sliver of time at any given point. The fact that time "passes," would suggest that our whole 3D coordinate system is moving along a 4th axis, a bit like movie film for 2D. Time itslef would be a product of motion, but our ability to perceive it, more or less uniformly thoughout the universe (in that as far as we know, the whole universe is experiencing time), stems from somthing else, IMHO. 

Other physical properties, such as density, are debatably dimensions, and can be mathematically represented as such. Density is the only example I can think of, but it is really contained within our 3 dimensions, having to do with how much empty space there is left over after adding in all the necessary protons, neutrons, electrons, etc. in any given atom.
Message #16, From: Bradkin
To: Dr-sociology ( Message #14 )	
Tuesday, Feb 22 2000
5:47 p.m. PST	

I wish to start by saying that I enjoy debate and hope that you see this as only debate and not argument. I am searching only for truth, not to prove you wrong. The following is a quote from "The Elegant Universe" by Brian Greene. Brian Greene is a physicist who graduated from Harvard and Oxford. He now works on super string theory. He too uses human terms in his description, but being that we are human it is difficult to describe a theory without involving us (I'm not saying that the theory doesn't exist without us, only that its description is easier with us)-- this does not invalidate a theory. "We and everything around us are aging, inevitably passing from one moment in time to the next. In fact, the mathematician Hermann Minkowski, and ultimately Einstein as well, advocated thinking about time as another dimension of the universe -- the fourth dimension -- in some ways quite similar to the three spacial dimensions in which we find ourselves immersed. Although it sounds abstract, the notion of time as a dimension is actually concrete. When we want to meet someone, we tell them where "in space" we will expect to see them -- for instance, the 9th floor of the building on the corner of 53rd Street and 7th Avenue. There are three pieces of information here (9th floor, 53rd Street, 7th Avenue) reflecting a particular location in the three spatial dimensions of the universe. Equally important, however, is our specification of when we expect to meet them -- for instance at 3 PM. This piece of information tells us where "in time" our meeting will take place. Events are therefore specified by four pieces of information: three in space and one in time. Such data, it is said, specifies the location of the event in space and in time, or in spacetime, for short. In this sense, time is another dimension." Feel free to offer rebuttal, but I can speak on this subject no more clearly than a physicist and wouldn't try.
Message #17, From: Arcology2
To: Bradkin ( Message #16 )	
Tuesday, Feb 22 2000
7:02 p.m. PST	

Sounds interesting, I started reading that book the other day, but returned it as I was busy with some other reading material and didn't think I'd have time to finish it before my library loan time ran out. I'll probably just buy the 2000 edition that's coming out. 

I agree with what you're saying - but I don't think you quite understood my post. Let my try putting it differently. First of all, I think that calling time the 4th dimension is only half-true, because we have multiple definitions of time (though until recent times we wouldn't have realized this). I don't know what the 4th dimension ought to be called, but "time" invokes irrelevant concepts into the primary concept. The word dimension has a similar problem. 

The prefix 'hyper-' means over, or above. If you consider my earlier analogies, our 3rd dimension rises above the 2nd dimension (it also goes below, but as we know, perfect definitions are a rarity). Likewise, the 4th dimesion can be imagined to rise, somehow (in the instace of Flatlanders, we say up, they think North. What we are speaking of when talking about 4th dimension is not true up, but another sort of up) above the 3rd dimension. For the sake of clarity, let us call the 4th dimension hyperspace. We, our universe, and therefore every evidence we have of our 3 dimensions, could be imagined to be moving along a 4th axis, hyperspace, yet occupying only a sliver of it at a time. All of history lies behind us in hyperspace, all of the future lies before us. The fact that time 'passes,' is the same as saying that hyperspace passes. That sliver of hyperspace that our universe occupies at any given moment passes. However, most people don't think of history, the future, and the present, as being time. To us time is not static, while an axis, relative to itself, is clearly static. What many people actually think of when we say time is the passing, not the axis. Therefore, we can have an hour of time, just as we can have a foot of length. Often people will ask for the dimensions of an object. What they really want is the absolute/non-relative (or at least as close as we can get) measurements of an object within the dimensions it occupies. It would be absurd, or at least irrelevant to us as 3D beings, to ask what the dimensions of an object are, in terms of axis'. 

We are finite in relation to time, and do not perceive its boundlessness in the way the we see everything stretching out in our 3D directions. Otherwise we would be able to 'see' the past and present all at once. Seeing the future would still be another problem as even if 'the future' stretched visible before us, the events of the future would only be in place once they had been caused- i.e. once we got there. Therefore, our verbal and conceptual definition of time is finite, but what we are referring to in the term hypersapce is not subject to the same limits. 'Time' confuses people, at least in introducing the concept, and it is easier to use a word whose definition you can control.	

	
Message #18, From: Dr-sociology
To: Arcology2 ( Message #15 )	Tuesday, Feb 22 2000
8:40 p.m. PST	

I see your point, and it is a very good analogy. I especially liked how you referenced different books - it was a nice touch. Now, I am not going to argue with you. You seem learned enough to be able to see multiple viewpoints on any given subject, so let me say this: would I be wrong to say that time is a property of our three dimensions? As you stated, for multiple happenings to occur at simultaneously, they would need to be established within certain boundaries, and perhaps time is a property afforded by the already existing dimensions of life that allows things to occur at the same moment.	

Later thoughts:
The really peculiar thing to me is that time is not traversable in the same way that other dimensions are. We can’t move around at will in time, whereas we can in the other dimensions. Therefore, time is not a dimension in the same way that the others are dimensions. However, there is something of an analogy if you involve gravity. We really can’t move up and down completely at will, and if we were constantly separated from the Earth we would always be moving down, if the Earth had the mass of a black hole we would never be able to travel up no matter what kind of device we invented (although I guess one should never say never…). So, there seems to be some kind of interconnectivity between time and gravity, though the 4th dimension (not time exactly) still ought to be analogous and interchangeable with the other 3.