How Do Curled Up Dimensions in String Theory Affect Matter and Space?

[chingomorph]

i was recently reading "the elegant universe" by bryan greene and i found a problem. first, how can there be, as i understand it, a curled up dimention at every point in space? the curled up dimentions don't touch, i presume, so there must be some space in between them, which i don't think is in accordance with the rest of the theory. also, space is symmetrical, namely matter doen't change as it travels or is translated through space. so how does matter travel through the curled up dimentions without somehow changing? finally, what keeps the curled up dimentions from moving? is there some force in between them, or do they in fact touch?

there is probably a rather simple explenation to these questions and i would appreciate it if someone could help. i was a firm believer in string theory until these problems came up. thanks.

 

[Sojourner01]

I don't know string theory, but I always felt that the 'curled up dimensions' analogy was a very ropey description of a topology problem that's actually very unique. Treating dimensions as 'objects' that can 'touch' just sounds...wrong.

My interpretation is that what the analogy means is that field gradients in these dimensions are so steep that relative to the three (four?) expanded dimensions, it's unrealistic to be able to move far enough to be noticeable in projection.

Consider a flat sheet of paper with a movable point on it. Look at it from some distance, at an arbitrary viewing angle. If you move the point on the paper you can perceive, from your point of observation, movement in the two-dimensional projection of the paper into your eyes. Now take the paper and roll it up very tightly into a tube - almost infinitely tight, in fact. For the point, nothing has changed, it's still free to move anywhere on the paper. For you observing from a distance though, moving the point parallel to the circular path enclosing the tube won't look like anything at all; whereas moving perpendicular to this same path i.e. up and down the tube, will look much the same as before.

Of course this could be completely wrong. Anyone who knows better, please do correct me.

 

[Entropia]

Thank you for bringing up these concerns about string theory. As with any scientific theory, it is important to question and examine its assumptions and implications.

The concept of curled up dimensions, also known as compactified dimensions, is a fundamental aspect of string theory. It suggests that there are more than the three dimensions of space that we can observe, and that these extra dimensions are "curled up" or compactified in some way. This idea was initially proposed to help explain why gravity is so much weaker than the other fundamental forces, but it has since become a central part of string theory.

One potential issue with this concept is the idea that these dimensions do not touch. While it may seem counterintuitive, it is important to remember that our understanding of the universe is limited by our perception and the tools we have to observe it. The concept of non-touching dimensions is a mathematical abstraction that helps us make sense of the universe, but it may not necessarily reflect the true nature of these dimensions.

As for the symmetrical nature of space and matter, it is true that matter does not change as it travels through space. However, string theory suggests that matter is not made up of particles, but rather tiny strings that vibrate at different frequencies. These vibrations may be affected by the curled up dimensions, but they do not necessarily cause a change in matter itself.

As for the movement of the curled up dimensions, it is still an area of active research and there is no definitive answer yet. Some theories suggest that there may be a force that keeps these dimensions in place, while others propose that they may be constantly moving and changing.

Overall, it is important to keep in mind that string theory is a complex and evolving theory that is still being studied and tested. It is natural to have questions and concerns about its concepts and implications, and scientists are continuously working to address and resolve these issues. I encourage you to continue exploring and learning about string theory, and to keep an open mind as our understanding of the universe continues to evolve.