4th dimension....can anyone explain it cearly?

[Dory]

Yes, I've seen the Carl Sagan clip. I still don't comprehend how a 4th dimension is possible. Seems very counter-intuitive to me. I need help understanding this concept. Anyone?

[cowiz]

Yeah, it's that one over there. See?

[Azathoth]

Imagine an animation of a cube rotating. The cube has three dimensions and each frame represents a slice of the fourth dimension

[Dory]

Imagine an animation of a cube rotating. The cube has three dimensions and each frame represents a slice of the fourth dimension

Is there some sort of artist rendition of how the world looks like in 4th D? Is it like tons of little 3d cubes?

[Elessarina]

The fourth dimension is time so hen you are watching something move it is moving within the fourth dimension i.e. going through time.


According to string theory there are 11 dimensions...

[Xamonas Chegwé]

The fourth dimension is time so hen you are watching something move it is moving within the fourth dimension i.e. going through time.


According to string theory there are 11 dimensions...

...but most of them are really tiny.

[Elessarina]

It's ok.. just adding another 7 might make Dory implode... I'm still waiting for more drama

[PsychoSerenity]

I used to just think of it mathematically, something to do with calculus, -though I may have been imagining it completely wrong, - but it's been five years since I learnt calculus and in that time I haven't used it once, so I really can't remember how it worked.

This is a 3d representation of a 4d cube, sort of substituting one of the dimensions for time I think:

[Dory]

I see. So, why can't we see it? Is it an evolutionary thing or what? What a puzzling concept!

[Elessarina]

We only see hat we evolved and need to see based on evolving on a particular planet in a particular part of the galaxy and universe. Maybe creatures that have evolved elsewhere can see it if it was an advantage for them to do so..

[Dory]

We only see hat we evolved and need to see based on evolving on a particular planet in a particular part of the galaxy and universe. Maybe creatures that have evolved elsewhere can see it if it was an advantage for them to do so..

Are you sure of what you're saying? Because it sounds like infrared spectrum and ultra violet. We can use devices to see infrared spectrum and ultra violet. Can't we then use devices to see the universe in 4D?

[Horwood Beer-Master]

Yes, I've seen the Carl Sagan clip. I still don't comprehend how a 4th dimension is possible. Seems very counter-intuitive to me. I need help understanding this concept. Anyone?

Well it's bound to be counter-intuitive given that your "intuition" is programmed into you by your evolutionary history and you are descended from three dimensional creatures that had to comprehend a three dimensional universe. Basically a fourth dimension is simply just another "direction" or axis in space in which something could move or exist, which is at right angles to the three we are familiar with, in just the same way as they are at right angles to each other. Only there's no good as a 3D evolved creature trying to visualise in what direction this extra dimension 'goes', anymore then could draw an arrow on a flat piece of paper pointing 'up' off the page or 'down' into the desk.

The only thing you can visualise is what something moving in the fourth dimension would look like from our point of view.

For example, any 3D object that was moved along the fourth dimensional axis would not seem to 'move' at all, it would simply seem to disappear instantly. Even tough it might only be a fraction of a millimetre away, that's still a fraction of a millimetre in a direction we are unable to even look, still less imagine. And yet there would be nothing 'magical' about this disappearance, it's still merely 'movement' in exactly the same sense as as movement in any of the other three dimensions.

Similarly, a four dimensional object moving 'though' our three dimensional 'plane' would appear as a three dimensional object (which is in fact a 'cross section') which will appear to change shape as the four dimensional object moves though. In fact two or more of these three dimensional objects apparently separate from each other, may in fact be part of the same four dimensional object (in much the same way as a 2D cross section midway through a 3D 'doughnut' shape would appear as two separate circles) depending on the 4D shape of the object and the angle at which it is intersecting our 3D plane, you may see several 'blobs' morphing in shape and 'flowing' together and apart from each other, but it's important to remember the overall 4D shape is not changing at all during this process (well actually it could be, but let's assume for the sake of argument we're dealing with a rigid solid shape here) you're merely seeing the changing cross section as it passes through.

[mistermack]

I usually picture it like this.
Imagine a hypothetical universe filled to infinity with a liquid, something like water, that is a perfect electrical conductor.

There is a vast amount of electricity whizzing around in it. Some of it goes in straight lines, some grabs it's own tail, and forms a ball. The balls of electical energy act like particles, and are attracted to other particles, and form "matter", which can move through the liquid. These particles eventually evolve into beings, which can move freely through the liquid, but can't detect it. That's a bit like what we are.

But imagine that alongside the electrical energy and particles, there was light performing in exactly the same way, forming balls of light, that clump together, forming "light matter" and eventually evolving into beings.
And although the two worlds occupy the same space, they don't interract, and can't detect each other, or the medium that supports them.

Then you could have the same again, with "sound energy", another universe in the same place, undetectable by the others.

That's just a mental picture I use, to see how it could happen.
.

[Dory]

It sounds very surreal. Who came up with this idea, and why do we find it believable? It sounds far fetched and very theoretical, but perhaps I'm not thinking hard enough. I can understand and explain 1D to 3D. 1D, that's a plane with a single coordinate. 2D, has two coordinates. 3D, 3 coordinates. 4D.... 4 coordinates? Where do you put the forth one? We really need the guy who came up with the coordinate system (Descartes) to chart up a new one to illustrate the logic in this. Are there organisms who can see 4D, I wonder?...why haven't we been able to create a machine to detect 4D but we triumphs over infrared spectrum, ultra violet, and what not?

[Feck]

Yes read" Moon child" by Crowley .There is an easy explanation in there, it is also nice to note he had the eleven dimensions sorted out long before String theory (sorry esoteric foot-note there )