# VIsualizing the 4th Spacial Demension

#### Zantra

Hello people. I'm relatively knew here. I've posted already but consider this a formal introduction. That being said...

I'm having quite a hard time visualizing a 4th spatial demension. I mean I've seen a model of a tesseract, but still the concept escapes me. It's basically as if our 3 demensions were turned on thier sides as a piece of paper, and a 4th demensional object was passed through it. I guess I need a better frame of reference. Anyone know of a better way to eplain this or visualize it?

Or do I already have the concept down and I'm overthinking this?

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#### Eh

It's logically impossible to visually imagine a 4D object. That's because we can only ever see any given volume of space one 2D slice at a time.

If it helps, try to visual with analogies using lower dimensions.

#### Zantra

So you're saying that even though we can percieve a 3 demensional object we're still seeing it in 2 demensions? could not our mind then make the leap to visualize 4 demensions in much the same way? So then if a 4th demensional object were to protrude into 3 demensional space much like the ball through the piece of paper, would it then seem to come "out of thin air"?

#### Funkee

Indeed that is the case. To visualize a 4d cube, a hypercube as it is known would require totally different brains. We see 2D cross-sections, including 2D cross-sections of a wireframe hypercube which is easily found online. To visualize it properly we would need to be able to see 3D cross-sections, meaning a full 3d object in one view without rotation. Impossible it is for us to visualize that making it impossible to visualize a hypercube.

#### Zantra

It could be done holographically or on a computer 3 modeler, though it would seem odd.. At least I think...

#### maximus

Originally posted by Zantra
It could be done holographically or on a computer 3 modeler, though it would seem odd.. At least I think...
but computers are programed by people, who are unable to visualize a fourth spacial demension.

#### Zantra

Actually I think it's already been done on a rudimentary level. If it can be concieved, it can be visualize, though maybe not easily Not saying it was a true representation, but I do know an attempt was made. I'll have to look for it

#### neutroncount

Originally posted by Zantra
Actually I think it's already been done on a rudimentary level. If it can be concieved, it can be visualize, though maybe not easily Not saying it was a true representation, but I do know an attempt was made. I'll have to look for it
If you've gone through your whole life looking at the world in 2D and visualizing 3D, then how do you go about looking at the world in 3D and visualizing 4D? The brain doesn't work that way. We have limits to our perception and it's not exactly easy to 'trick' our brains into thinking any differently.

#### Zantra

There is indeed no way to see a true and accurate representation of the 4th demension, however you could view it much as you would view a 3D demensional object on a screen.

#### maximus

i don't think it's possible Zantra. the best we can do is to sacrifice a lower deminsion (say, z) and then have in its place a represtantion of the higher dimension. you still have to stretch your imagination a bit, but that's the way it's done.

#### Eh

Originally posted by Zantra
So you're saying that even though we can percieve a 3 demensional object we're still seeing it in 2 demensions?
No we aren't. We live in a 3D world, but can only see it one 2D slice at a time. Light travels off a surface to your eye, and the geometric pattern that strikes your retina is 2D. Thus, the image in your brain is going to be 2D as well. That is part of the reason why you can't see through objects. If light was not limited to 3 dimensions and could travel in a straight line towards you eyes off every sigle point on a 3D volume, you could then at least imagine it. But then, you would have to be a 4 dimensional being yourself, with a retina with a 3D volume for recording data.

It helps to use lower dimensions for analogy. Imagine a 2D stick person, and observe that light in a 2D universe can only move along the x,y axis. Now imagine a 2D persons retina. Since it is 2D, the "surface" in this case is really a 1D edge, and the geometric pattern from light striking it will be 1D as well. So this poor 2D person will only be able to view his 2D universe one 1D slice at a time.

In order for him to see the full 2D, two things must happen. First, he must become 3D, so that his retina goes from being an edge to a surface. 2nd, light must be able to move along the x,y,z axis, so that it might strike all points of the surface, giving a 2D geometric pattern. That is a similar analogy for a 3D universe. We would need to be 4D people living in a 4D universe in order to imagine a 4D object, in the same way that depth perception works from a 2D image.

#### maximus

by the way, i'm familiar with the four dimensions (x,y,x,t), but what is the fourth spacial demension. is it one of the ones that they thought would be curled up very small in another deminsion?

#### Zantra

Going by the M-theory, yes. Or you could just think of it as the 5th demension, or whatnot.

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