# Why & What extra dimensions in M-theory?

I am not into String or M theory.

Recently I am again reminded that M-theory "requires extra dimensions" beyond the usual string theories, beyond the usual space-time dimensions.

To me, dimensions mean orthogonality - the complete non-overlapping coverage of the field by the components of the field.

Let's look at the statics/dynamics of our awareness
1. 3 orthogonal directions of space.
2. 3 orthogonal directions of rotation.
3. 3 orthogonal directions of compression/rarefaction
Let's throw the monkey at the wrench, without needing to understand 3-D time.
1. 3 orthogonal directions of time.

That makes a total 12 physical mutually orthogonal dimensions easily visualizable by anyone familiar with statics, dynamics (and statistics).

They are mutually orthogonal because, for example
• you could spin all you want, and never traverse any distance
• some states of matter can endure variation in some amount of compressive or rarefactive forces without changing shape, spinning or moving.

Let's visualize time as the passing of events, so that in a repetitive time loop of repetitively sampling the same field of events, you would have at least 2 time dimensions. Where when referencing to a particular point in time, you would have to specify which instance of loop.

Somehow, we will be able to wiggle out 12 mutually orthogonal dimensions that are quite within our human mental grasps.

### Questions

1. Aren't these 12 dimensions sufficient or good 'nuf already? When would you need to manufacture new dimensions that are beyond the grasp of our human minds?

2. If M theory would not consider some of these humanly possible dimensions, then how does the theory treat the existence of these dimensions?

3. Are our humanly imaginable dimensions not compatible with M theory. Or perhaps, these dimensions are indeed considered but perceive with transformed perspectives?

Pls don't get mad at me for trying to understand M theory from the perspectives of statics, dynamics and statistics.

• This is a very difficult topic, i can bet that most string theorists do not have a physical idea of these extra dimensions. These dimensions arise in a sense when the gravitational tensor is taken as a parameter (thus the number of dimensions is increased) and no they are not necessarily orthogonal, these extra dimensions can be correlated with each other and curved in various shapes out of view (for lack of better word) – Nikos M. Sep 30 '14 at 21:21
• – Qmechanic Sep 30 '14 at 21:25