Mortal Monkey on 9/7/2006 at 00:16
Well if you had been paying attention (something I don't blame you for not doing), you'd have known that it's the universe that is curved, not a line inside it. You could argue that everything inside the universe is also curved, but seeing as everything is relative that doesn't have much merit.
Ko0K on 9/7/2006 at 01:19
Pick and choose your definition, I suppose:
Quote Posted by dictionary.reference.com
di·men·sion
n.
* A measure of spatial extent, especially width, height, or length
* Extent or magnitude; scope. Often used in the plural: a problem of alarming dimensions
* Aspect; element: “He's a good newsman, and he has that extra dimension” (William S. Paley)
* Mathematics.
1. The least number of independent coordinates required to specify uniquely the points in a space
2. The range of such a coordinate
* Physics. A physical property, such as mass, length, time, or a combination thereof, regarded as a fundamental measure or as one of a set of fundamental measures of a physical quantity: Velocity has the dimensions of length divided by time
Pyrian on 9/7/2006 at 04:02
Mortal Monkey, you're conveniently switching definitions of "universe" to suit your purpose. If you define "universe" in its old-school meaning of "literally everything" then of course you can't have a dimension outside of the universe - but that's only by definition and tells us nothing about what may exist outside of what is more readily perceived. So far, I'm seeing an argument based purely on the abuse of semantics rather than one having any actual meaning or merit.
You do not get to have your own unique definition of dimension. That's retarded. Discuss spatial dimensions if you must, but realize that to the best of our knowledge spatial dimensions are curved by the temporal dimension - and by their contents.
Deep Qantas on 9/7/2006 at 04:49
Quote Posted by Mortal Monkey
* It is
not a 3D geometric shape, as 3D geometric shapes tend to either have a volume greater than 0, or not exist. And it's a universe anyway, not a curled newspaper. Trust me, there
is a difference.
Sure. Universe we perceive is a 3D space.
A piece of paper is a shape in 3D world and is also a valid representation of 2D surface. And a 2D surface is a valid representation of a world perceived by that 2D flatlander. Do you disagree on any particular point?
Quote Posted by Mortal Monkey
* Distances can only exist within the universe, and so everything remains in the same relative place within the universe even after curving it. If you thought you could prove anything by drawing a line from A to B on the 3D representation and then measure it with a ruler, you are sadly mistaken.
You're still arguing that travelling across the 2D universe/world and ending back to where you started from is
irrelevant? Seriously, what is up with that?
Quote Posted by Mortal Monkey
* And even if you could, any given point on the universe in the 3D representation can still be represented by only two values - Y and Rotation (unlike in a polar coordinate system where you also have Distance). Rotation is directly proportional to X in the original universe. Somehow I fail to see where the perpedicularity lies.
Describe the point (100, 100, 100) - that's X, Y and Z - with only two values.
Hint:
The point is not necessarily on the paper.
mopgoblin on 9/7/2006 at 05:43
Quote Posted by dj_ivocha
If you can't explain a straight line meeting itself in your 2d universe, then your knowledge of it is insufficient and it actually has 3 dimensions, about which you can theoretize but not prove.
I can see that working if you live on the surface of a hypersphere or torus or something else that fits nicely into a Euclidean space with enough dimensions, but what would you conclude if you lived in a universe with the geometry of a hyperbolic or elliptic plane?
Agent Monkeysee on 9/7/2006 at 05:50
Quote Posted by Stitch
yeah what the hell monkeysee why's it always got to be about
your definitions :mad:
I always forget these arguments are easier to win when you make up your own goalposts.
Quote Posted by Mortal Monkey
And how do
you explain how a spatial dimension can exist outside the universe itself?
It doesn't exist outside the Universe, it's just that you don't perceive the whole Universe. The Universe is more than its extent spatial dimensions. There are other spatial dimensions with a different sort of topology.
Quote Posted by Mortal Monkey
They explained your meets-itself conundrum fairly well in the flash - you pop out of existence here and into existence there. If this applies to
all the smallest building blocks of the universe, the trasnition is seamless. Does it necessarily have anything to do with the circle they used for demonstrational purposes?
They explained it using higher dimensional curvature which is what I've been doing :confused:
Quote Posted by Mortal Monkey
Besides, a circle (or any curvature for that matter) is in itself 2D. If what you are saying actually had merit, the universe would be 4D, not 3D.
Yeah, that's what I'm saying. Actually according to String Theory the Universe is 10D.
Quote Posted by Mortal Monkey
Now I'll say this one last time.
My definition of a dimension is something that is perpendicular to all the other dimensions. How on earth can a dimension be perpendicular to the others if it's not even inside the universe?
Your definition of dimension is too simplistic. Perpendicularity as you're using it only makes sense if you're considering 2 or 3 dimensions in a Cartesan coordinate system which is a really specific case and is not really relevant to any of this stuff. Strictly speaking you can talk of perpendicularity in the general hyperspace equation I've been giving (the WXYZ one), it's just you can't draw it. But not being able to draw something is completely irrelevant to its usefulness or expressiveness or in its applicability to real-world problems.
Have you ever done any higher level calculus or anything? You work with higher dimensions in some of that stuff, as well as in linear algebra and some differential equations. Higher dimensions are pretty standard fair in advanced mathematics and there's not even anything particularly notable or interesting about them. This stuff has found application in reconciling QM and GR, which tantalizingly suggests that higher spatial dimensions actually exist but they have a different topology than the extant 3 dimensions, which is why we don't perceive them.
Gingerbread Man on 9/7/2006 at 06:41
monkeysee
ur awesome
Agent Monkeysee on 9/7/2006 at 06:49
so r u bebe :cool:
descenterace on 9/7/2006 at 09:26
This reminds me of a thread on another BB about using electromagnets to make a vehicle hover a variable distance (up to about 300m) off the ground. The proponent of this idea has no clue at all how much power would be necessary for this, but idiots never let the facts get in the way.
MM, you've been arguing based on semantics and a common-sense view of the world. Neither are particularly useful in this field of science. Give it up.
JACKofTrades on 9/7/2006 at 14:47
Quote Posted by Agent Monkeysee
You... just add it. A point in a plane aX + bY = c becomes a point in a volume aX + bY + cZ = d.
Shouldn't that be a point in a
line aX + bY = c becomes a point in a
plane aX + bY + cZ = d. Or am I missing something?
Quote Posted by Agent Monkeysee
You have a piece of evidence: straight lines eventually meet themselves. This is not describable using the 2 dimensions the Flatlanders have access to so they propose their 2d Universe is actually curved in the 3rd dimension, and further that it's a closed curvature. This model of the Universe explains why straight lines meet themselves.
The higher dimensions proposed in String Theory more or less work this way, though instead of describing the behavior of straight paths they're used to describe the behavior of quantum particles. The particles behave a certain way or have certain properties that aren't easily reconcilable with a 3-dimensional universe. But you add higher dimensions and the behaviors and properties suddenly make sense.
Isn't this similar to the situation where Maxwell's equations suggested that light was a form of electromagnetic radiation but there were no experimental means to verify it at the time? Similar in that the math says it must be true, so therefore it must be true.
