dimensions?

Question

I understand that the second dimension is x & y, third is x & y & z, but I've heard there are so many other dimensions.

What exactly is the fourth dimension and what are some of the other dimensions available and how are they defined?

Answer 1

Here you see the sum of 4-dim vectors:
(3 , 0 , -7 , 8) + ( -5 , 6 , 0 , -2) = ( -2 , 6 , -7 , 6)
In statistical physiscs 6N-dim spaces are used.
N = Avogadro's number = 6 x 10^23.

Th

Answer 2

in terms of math / high-level physics / imagination, you could have as many dimensions as you want.

in our daily lives we only experience three physical dimensions (front-back, left-right, low-high) so imagining anything beyond this is a bit tricky. One example: you know when you draw a wire-frame model of a cube? And depending how it is drawn, it can seem that it is the bottom left part which is at the front, and then at other moments it seems that it is the upper right part which is at the front? Well, a cube could be transformed from one to the other, by a rotation IN THE 4th DIMENSION, and AROUND A PLANE. With a bit of exercise you can kind of visualise this.

How is a 4th physical dimension defined? It would have to be PERPENDICULAR to the other three. I'm afraid we don't know how to do that.

Now what about the real reality? Based on Einstein's equations, spacetime, i.e. the 3 dimensions of space, plus time as a 4th dimension, gets curved by the presence of mass, which implies higher dimensions. But this is only at scales far larger than us humans so we'd not see it in our daily lives.

In math in general, some problems will use spaces with many dimensions, but this are not physical spaces at all.

Hope this helps a bit

a

Answer 3

In mathematics, a 'dimension' is any measurement which cannot be derived from all of the other measurements. (More formally, that is 'linearly independent'.) For example, height, weight, age, hair color, eye color, and gender are all 'dimensions' that could be used to 'measure' a person. But there is simply no way that you could figure out a persons hair color even if you knew all of their other measurements.

In Physics, time is generally considered a 'dimension' in the sense that no matter how much you know about length, width, and height you have no information about time that can be computed from knowing them.

Other (quantum) characteristics are things such as charge, spin, color, flavor, strangeness, and charm.


Doug

Answer 4

string theory postulates a number of dimensions. the most widely used model predicts 11 dimensions; height, width, depth, time, and several others, including a number of small curled up dimensions which do not really interact with our own in any really direct or obvious ways. wierd but kinda cool to think about.

Answer 5

Logically and practically as seen, there are 4 dimension only.
x, y, z and t.

The last one is the time. All these 4 dimensions is the most practical of the creation of the world.

But, theorectically and under imagination term (sometimes we need to), they are n-th dimension. In actual fact, n-th dimension will lead to no where at the end.

Answer 6

this is theoretical stuff, but it has been argued that the fourth dimension is time itself