Quote:
Originally Posted by Cpl. Shrike
If love and god are equal then one is redundant...
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somehow I love this humour or whatever it is
@Stefan: I don't agree with your definition of "dimension". I think it is incorrect for there are much more things than a "dimension" which you can receive, interpret, and react upon. A dimension, strictly speaking, is the whole range of coordinates in which you pick an number in order to help you pinpoint an occurence (event, point in space, entity) on a certain referential. For example, ! - Let's consider the instant where I pressed this exclamation point. I can characterize this event as a point in a 4 dimension referential: x, y, z, t. The latitude, longitude, altitude and time relatively to the center of the Universe and the beginning of Time where in my life, a balance of forces located at a certain point under my finger triggered the "!" key. These are the 4 dimensions I need to characterize this event in its uniquety. If I miss the t component, I can't pinpoint this event among all the ! keypresses I will make in my whole life (provided my computer doesn't move). If I miss the z component, I can't tell how high I was located when I pressed this key (was it in a particular floor of a building where all the floors would be identical ?). If I miss the x or y component, I miss the exact location of my computer. It may slide 10cm left or forward on the table, or 400km further - well, assuming the origin of the Universe is the center of planet Earth, but as usuals with maths I'm free to choose my own referential.
Imagine the Universe would be a fixed point. That would be an universe with 0 dimension. Everything that would fit in this universe would need 0 dimension to be described accurately. Why can we comprehend and represent a point in its entirety ? Because we live, our plane of existence happens, among 4 dimensions. 4 > 0. On the contrary, an inhabitant of the "point" universe would not be able to represent his own world.
Now imagine the Universe would be a line. That would be an universe with 1 dimension. You only need 1 dimension (that's to say, "x"), to locate a point in this universe. Why can we represent ourselves a line in its entirety ? Because our plane of existence happens in a space with a greater number of dimensions (4 > 1). This "overview" allow us, for example, to tell that a point, which is a space with 0 dimension, is the intersection of two lines, which are spaces with 1 dimension. And how did we figure out that ? Because we moved two of these lines in a
plane, which is a space with 2 dimensions.
Now imagine the Universe would be a plane. That would be an universe with 2 dimensions. Because you only need 2 dimensions (x and y) to represent accurately a point in such a space. And how come we can represent it accurately anyway ? Because we live in an universe which has a greater number of dimensions (4 > 2). And this allows us, for example, to tell that a plane (x and y, like a sheet of paper), is the intersection of two volumes (like spheres, or like bubbles of soap glued together : in the middle they make a visible plane). How did we figure out that ? Because we moved these volumes (3 dimensions) in space until they met together. And we saw their intersection makes a plane: 2 dimensions. We can still represent this in our mind, even if it becomes more and more tricky as we're adding dimensions.
Now imagine the Universe would be some sort of big sphere, with a center somewhere, and planets and galaxies inside (this is how many people still represent themselves our Universe, even nowadays). That is a space with 3 dimensions. We
can make a mental picture of such an Universe ; how come ? you'll say, because that's the Universe where we're living, right ? How come we can manage to represent it ? Wait: NO - this is NOT the Universe you're living in. Not anymore. It is the Universe you
were living in at time T. But at time T plus one second, things happened in the world already, and that's simply not the same Universe anymore. It's trickier to represent ourselves a 3D thing in our mind, such as a volume. Even, some people cannot "think in space". Most of us can, though. Why can we ? We can represent ourselves a 3 dimensions universe, because we live through a 4th one:
time. At time T, you were
inside the Universe you're now trying to represent, hence
unable to represent it yet. At time T+1, you moved
outside of it so that you could "see" it, in your mind, and from that instant you have been able to represent it
like it was. You moved forth on the time plane. You couldn't help it anyway, that's the way we live. Now, try to represent yourself what a 3 dimension space is the intersection of ? Haha, here it becomes tricky. But still, 4 > 3 so we
should manage to figure it out. Think about a sphere. A sphere is a 3D thing. Now take this sphere, and make it
move smoothly around in your mind. That is a sphere moving with time. That is a space with 4 dimensions (3+1). We added one dimension to that 3D thingy, much like we added the width dimension to the length dimension of a single line to get a plane. With this sphere moving around, you have now a space with 4 dimensions. Don't lose it. Take
another sphere, and make it move around in your mind too. You see them ? Now make them meet together and "cross" each other. What happens when they're confused with each other ? When they're confused with each other we're at time T, we must
stop the time so that this event lasts, and we see
one sphere. We get one fixed sphere out of 2 spheres moving.
We got a 3 dimension space at the intersection of two 4 dimension spaces.
Now one pack of beer to the guy who tells me what a 4 dimension space (our Universe), is the intersection of.
We can't, and why can't we ? Because that's the Universe we're
living in, and that's
all that we know of it, these 4 dimensions. We can't represent it completely in our mind,
because we're unable to reach the next dimension in order to look behind us and have an overview of it all. It is possible, to represent the universe, but only at a time T, like a "screenshot", but can you represent the whole Universe with its 4 dimensions, entirely, including the way it was back in the limbos of Time and the way it will be in thousand of billions years ? That's impossible. We know 4 dimensions in our Universe, and we're able to represent ourselves only 3.
All that's beyond, we can't do much but calling it "void".
So yes, in a sense, void is something man invented. But to invent it was the only thing he could do about it
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*edit*
Quote:
Originally Posted by Cpl. Shrike
But it more puzzeling if one could represent him self in only 1 or 2 dimensions. To me that would seem impossible.
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lad, when you take a photograph, don't you represent the world in 2 dimensions ?