Ask Me Help Desk - Don't understand dimensions

Hi!

I have a difficulty grasping the concept of dimensions. I mean we all know that we live in a multi-dimensional world but when a single dimension is explained separately I just don't understand. Does Pacman 'live' in 2D.Well as far I see- no. The display that we see looks 2d but in an intense closeup it would still be multiD. I mean the particles that account for the display are not 2d.Do electrons or photons have dimensions? They should they do exist in our multiD world. Dimension is not a line nor a dot I think. Those things are multiD. So maybe a direction of movement? But how can we single out one direction without interfering with the other? Can you imagine only one dimension?Can you grasp movement without the object that is moving. Cause whatever direction of movement I think about it appears in all Ds. If the dimension of height was excluded could we see Pacman. How flat should it be to completely remove the height dimension? Wouldn't it seize to exist. Is there anything that can remotely refer to a single dimension? If you can picture something in your mind that's multiD. If I try to pic a dimension out of my thoughts I loose apprehension. So even our thoughts exist in multiD. There is no way(that I know of) to comprehend Anything which is not in all dimensions at once. I hope somebody can explain what dimensions are because if it can't be explained how can we identify what is 1,2,3,4,5.. D.

It might just be gibberish of a seriously hungover guy(had a major party last night :D). But I would definitely appreciate if someone would share their opinion.

Thank you.

Quote:

Originally Posted by Mikis

Hi!

I have a difficulty grasping the concept of dimensions. I mean we all know that we live in a multi-dimensional world but when a single dimension is explained separately I just don't understand. Does Pacman 'live' in 2D.Well as far I see- no. The display that we see looks 2d but in an intense closeup it would still be multiD. I mean the particles that account for the display are not 2d.Do electrons or photons have dimensions? They should they do exist in our multiD world. Dimension is not a line nor a dot I think. Those things are multiD. So maybe a direction of movement? But how can we single out one direction without interfering with the other? Can you imagine only one dimension?Can you grasp movement without the object that is moving. cause whatever direction of movement I think about it appears in all Ds. If the dimension of height was excluded could we see Pacman. How flat should it be to completely remove the height dimension? Wouldn't it seize to exist. Is there anything that can remotely refer to a single dimension? If you can picture something in your mind that's multiD. If i try to pic a dimension out of my thoughts I loose apprehension. So even our thoughts exist in multiD. there is no way(that I know of) to comprehend Anything which is not in all dimensions at once. I hope somebody can explain what dimensions are because if it can't be explained how can we identify what is 1,2,3,4,5..D.

It might just be gibberish of a seriously hungover guy(had a major party last night :D). But I would definitely appreciate if someone would share their opinion.

Thank you.

Hi Mikis,

As I understand it Pacman living in a 2D world is only a thought experiment to draw out distinctions when we come to consider higher dimensions. There is no 2D world as such. You are right, Pacman electronic game is not actually 2D. I think I am right when I say that elementary particles can be considered 3D. Scientists might measure them in terms of one or two dimensions but particles seem to extend themselves over space. In other words, the fundamental forces exert an influence in our 3D world (a scientist might correct me here).

As a thought experiment Pacman is very flat. He is totally unaware of any type of height and it is impossible for him to go over the top of another Pacman. An 'over the top dimension' does not exist. In a similar fashion we would be totally unaware of any dimensions over the 3 we are familiar with.

One dimension is usually reserved for points of measurement. For example, a singularity is often thought of as being of one dimension. This actually means that the point particle is infinitely dense. Because infinities are regarded by some scientists as showing our ignorance about nature string theorists came up with the idea of two dimensional strings in order to rid physics of the troublesome one dimensional particle.

Any dimensions above the 3 we know is mathematically possible. In fact, string theory requires at least 9 dimensions but can go as high as 11 (I think, but I could be corrected).

No one can comprehend what higher dimensions might look like. The nearest we can come to their comprehension can be explored by way of the Calabi-Yau manifold. If you Google Calabi-Yau manifold you can get a look at what multi-dimensions look like in 3 D ( if that makes any sense)

As I said before don't worry about the Pacman 2D world. Its only use is in thought experiments and string theory. It would be equally difficult to imagine what it would be like living in a 2D world as it would be imagining living in 9,10 or 11 dimensional world.

Tut

Hey. Thanks for the reply.

So dimensions are just a mathematical construct. It can't be backed by empirical evidence, nor mental projection and also by any other means of projection. The most problem I had is with 2D examples. Games are a good source because some of them supposedly work in 2D. The problem is when you look at lets say Mario figure he should not EXIST in left and right directions because in 2D they are not there. I say exist not incapable of turning left or right. But you can clearly see that his body has a visual bulk.Witch means at least some particles which make the body extend their influence to the side through the screen. Or exist in 3D+. In short if Mario or any other character was 2D no particles could go left or right hence we would get no visual or other input ( he would not be there for us to see). And if we tried to look at him through the dimension of height ( from above)where he should exist it would have no width (infinitely thin)hence no input whatsoever in our 3D+world.

Quote:

Originally Posted by Mikis

Hey. Thanks for the reply.

so dimensions are just a mathematical construct. It can't be backed by empirical evidence, nor mental projection and also by any other means of projection. The most problem I had is with 2D examples. Games are a good source because some of them supposedly work in 2D. The problem is when you look at lets say Mario figure he should not EXIST in left and right directions because in 2D they are not there. I say exist not incapable of turning left or right. But you can clearly see that his body has a visual bulk.Witch means at least some particles which make the body extend their influence to the side through the screen. Or exist in 3D+. In short if Mario or any other character was 2D no particles could go left or right hence we would get no visual or other input ( he would not be there for us to see). and if we tried to look at him through the dimension of height ( from above)where he should exist it would have no width (infinitely thin)hence no input whatsoever in our 3D+world.

Hi Mikis,

In my limited opinion I would say that some dimensions are mathematical constructs. Laplace's equations probably being useful when applied to 2 D objects. However, I don't think that 3 dimensions plus 1 dimension of time is a problem. The normal 3 plus 1 dimension is something we continually experience. For example, I have to be at 6 First ave, on the third floor at 3PM for a meeting. My EXPERIENCE of the 3 plus 1 dimensions allows me to find this address and arrive at the correct time.

If the meeting information was given to me in anything other than the normal dimensions then I would be lost. In other words, if the information was given to me in the form of 6 dimensional information then I would be totally lost. As Kant might want to say; we only have experience of relational properties of things. We have no knowledge of the intrinsic nature of things.

I can see what you are getting at in relation to Mario games. I can't really comment on this because I have no knowledge of how games are made and developed. Sorry I can't help you there.

In summary I would say the normal dimensions we experience every day are both mathematical and empirical. Any other dimensions we care to talk about can be mathematically explained in relation to the 3 dimensions but ultimately they have a certain intrinsic nature which we cannot explore 'on its own terms' so to speak. In other words, we always have to understand it in terms of 3 dimensions.

If you had a look at the pictures of the Calabi-Yau manifolds you will come to realize that these tiny curled up dimensions do not look like the photographs. The photographs show what they look like from the point of view of humans who can only think in 3 dimensions. The mathematics on the other hand has no problems in dealing with such problems.

This is the best I can come up with. Sorry, but I am no string theorist.

Regards
Tut

Hey Tut!

Nothing to be sorry about. I am satisfied with your answers. At least we came to the conclusion that reflecting on 2D or any compilation of dimensions apart from ours would lead to a distortion of existence beyond our apprehension thus resulting in a incapability to identify such thing or be aware of the changes. If we suddenly turned into 2D beings and somehow have the memory of a different 3D existence we would be incapable of imagining or explaining it. And now imagine if we could in the same circumstances visualize the previous 3D world. Now that would be a torment I think where your mind travels inter-dimensionaly and your body is locked.
Maybe it's a good thing we are unable to perceive different dimensions.

Anyway thank you for supporting this conversation. Not many people take on the task of pondering over such things.

I can't imagine why... :)