
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