Dimensions

[Richie Stan]

Height, width, length, time.

These I take to be the 4 dimensions.

But some scientists think there are more; can anyone explain just one of these other dimensions?

[ugly_bob]

unfortunately, there is no way to explain any further dimensions really. I've only ever come across them in a purely theoretical situation in mathematical eqautions.

[Buenchico]

You can artificially create as many dimensions as you like. For example, something on a 2-dimensional graph has dimensions which can be expressed by the coordinates (x,y). Something in three dimensional space can be identified with coordinates (x,y,z). If the object only has those coordinates at a specific moment in time, then we need to refine the coordinates to (x,y,z, t). However, several objects could be at that position, at that time, but each one could be emitting radiation of a different frequency, so we need coordinates such as (x, y, z, t, f). But there might be several objects at (x, y, z, t, f), with each one having a different Kelvin temperature, so we now need (x,y,z, t, f, k).
This can be continued ad infinitum.

Physicists might argue that the '5th and 6th dimensions', which I've suggested, don't meet the true criteria for 'dimensions' but mathematicians still make use of these concepts within modelling techniques, both for 'real-life' physical situations and to aid the theoretical physicists.

At university (when I studied mathematics) I taught myself to think in terms of 'n-dimensional space' where n didn't even have to be a rational number (e.g. pi-dimensional space) but alas, with the passing years, I'm now happier to stick with 3 or 4 dimensions :-)

Chris

[fo3nix]

'length' is not a dimension. x,y,z; or height, width, depth are the three spatial dimensions. time is the extra one.

Kaluza-Klein theories are those with more dimensions. They were originally thought about (in the non sci-fi sense) because with extra dimensions forces and other things unify and thus simplify much more. Many physicists like this because they like things to be pretty and beautiful.

Ever played those early video games where you had a screen and if you went off the edge of the screen on the right you came straight back on the left? Well, imagine something like that, but really small (smaller than we can detect). That way, by just swinging our arms round we're travelling through this other dimension many, many times; we just can't detect it.

It's all very theoretical though, and much of it is tied to string theory which is a sinking ship in many ways anyway.

From this and your previous question on special relativity, you should find The Elegant Universe by Brian Greene a good read. For the first half of the book, anyway.

[fo3nix]

Sorry, I typed that answer before there were any other answers, but AB wasn't liking it.