## Experience Other Dimensions

Has anyone ever experienced the fourth dimension. Sure this is a topic for science fiction novels, new age conspiracy theories and the new Indiana Jones movie. But dimensions past our own experience are having a big impact in theoretical physics.

Flat Land and it's unofficial sequel Flatterland are good books to get a mathematical yet whimsical look into alternative dimensions. The Tesseract from A Wrinkle in Time was a hyper cube as well.

So we go from 0D (a point) to 1D (a line) to 2D (planes) to 3D (solid objects) and then what happens when you pull that plane into an unseen dimension? Well, use your imagination and watch this video:

6d-Hypercube from Tobby Lang on Vimeo.

Why Bother With 4D?

Yours

_BG

*(Corrected, thanks n8mansays)

Flat Land and it's unofficial sequel Flatterland are good books to get a mathematical yet whimsical look into alternative dimensions. The Tesseract from A Wrinkle in Time was a hyper cube as well.

So we go from 0D (a point) to 1D (a line) to 2D (planes) to 3D (solid objects) and then what happens when you pull that plane into an unseen dimension? Well, use your imagination and watch this video:

6d-Hypercube from Tobby Lang on Vimeo.

Why Bother With 4D?

Yours

_BG

*(Corrected, thanks n8mansays)

active| newest | oldestBut the 4th is easy. In fact every object we see is four dimensional. If something had no time aspect it would pass through our experience infinitely quickly and be unperceivable.

Take a photo for example, especially a long exposure. The shutter opens, light from objects hits the film, at some period later the shutter closes. This is a sample of a period of time, and therefore shows four dimensional space.

These photo/videos might help visualising this:

http://www.youtube.com/watch?v=_nOzL8vF4_M

http://www.timetrack.com/samplework/html/lux320.html

~each additional dimension exists perpendicularly to all previous ones. (think the origin with a w axis, still at right angles to eachother) [i guess one could say time is at a right angle, but is there any justification or simulation to represent this?]

~each additional dimension is thought of as the union of an infinite amount of a previous-dimensional-object (lines are infinite points, planes infinite lines, space infinite planes) [this is a contradiction, as time is usually regarded as finite.]

~this is a corollary to the earlier property, but is significant enough to mention. A finite section of a dimension can be completely determined by a finite section of a previous dimension in a tesselation (in the vaguest sense of the word). (a line segment can be bound by points, a 2d shape can be determined with line segments, a 3d shape is defined by 2d shapes, and a 4d shape is defined by 3d shapes.)

{note that 6 cubes arranged around a 7th cube by faces is not defining 4d by cubes. a 4d space would completely cover all 6 faces of x number of cubes, all doing so at right angles. this is impossible to imagine in any ghost of 3d logic, so please do not try.}

that was kind of a behemoth, but well worth an attempt to understand (took me awhile to grasp 4d in this way, but the theory transcends specific dimensions, and can b universally applied to an infinite number of spatial dimensions.)

unfortunately, i didnt understand that calculus (damn slow american education!)

btw, if u know anything about the string theory, can u explain how there are exactly 20something dimensions? seems kinda contradictory to me :o .

1) You probably want to start with an introduction to special relativity so that you understand both the mathematical notation, and the language used to describe it.

2) You seem to be confusing an infinite-dimensional Hilbert space (which is an abstract mathematical construction) with physical spatial dimensions, which observationally form a finite countable set.

3) Depending on which version of string theory you want, it is formulated in an abstract space of either 10 or 11 spatial dimensions. Most of those are "compactified" into a Calabi-Yau manifold, which means that they have finite extent (i.e., they aren't straight lines going off to infinity, but closed curves like lines of latitude).

You need to have a much better grasp of (1) and (2) before you try to throw around concepts from string theory.

anyway, when i read ur comment earlier i was really tired, and the math u wrote was not something ive seen before, so i was all bleh.

thirdly, is there really any proof of #2? dont u have to be in (n-1) dimensions to perceive n dimensions? also, our retinas are 2d, but if time is 4d, then wouldnt we have 3d eyes? we cannot see time, only time's effects

I'm not sure what you mean by "proof." The

factthat physical space is three-dimensional is trivially shown by the fact that three numbers are sufficient to uniquely identify any point in that space. You can use more than three, but by diagonalizing the basis vectors of such a coordinate system, relative to observation, will result in a redundant basis.about observing how 3 numbers define any point in space does not rule out 4d in spatial dimensions. this property only proves that the space that we are capable of perceiving is represented in 3 orthogonal dimensions

assumeyou've taken it before) then he/she has to waste their and everyone else's time by teaching it in class, instead of moving on to the interesting stuff.