# Gigantic dimensions ?

1. Apr 2, 2006

### oldtobor

From what I read of string theories and such, they always talk about the other dimensions being very small. Has anyone ever thought about making them very large instead to see where the theory leads ? Like a hidden dimension trillions of times the size of the universe etc. Just interesting as another thread talked about the following:

"Thinking about reductionism, it may be that there is no absolute size. The universe may be made in such a way that as we get to smaller and smaller items at a certain point we get to (maybe at 10^-100 cm) back to the universe all over again. Like if we look inside an imaginary microscope and get past a small enough size limit we start to see our whole universe all over again. Then going smaller we see our galaxy, sun, earth, ourselves all the way down again recursively forever. At that given size limit where the smallest item corresponds to the entire universe is where "meatphysical entities" lie, or our mind, or minds or god's mind or mathematical objects lie. That ultimate item doesn't respect mathematics in the sense that the smallest size is equal to the largest, so it lies outside this universe and logic and yet it is the interface between mind and matter. A mathematics where 3 is equal to 3^100 may even be possible to construct.

The point is that if size is infinitely recursive in this sense, then there is no absolute size or measurement, they are only relative to each other within a certain range. The universe would seem to lie outside of any mathematical description or maybe even any logical description. We have no extension and our mind is the ULTIMATE ELEMENTARY PARTICLE AND COMPLETE UNIVERSE AT THE SAME TIME.

One way to imagine a universe with all items having a "constant size" is imagining them decreasing their size in some dimensions of an n-dimensional space and increasing their extension in the hidden dimensions such as their volume is always constant. So the item of size 10^-100 cm will have a length in the hidden dimension of 10^100 cm so as the total volume is always constant. And when the size reaches the "mind as elementary particle" limit it just switches dimensions and starts all over again. I mean a universe and mathematics where the electron (or planck size item) is equal in size to the universe is conceivable and developable, surely by much smarter mathematicians then myself.

Interesting. Then what would happen if the universe was an INFINITE DIMENSIONAL UNIVERSE ? Then the big bang could be seen as some small items in a set of hidden dimensions reaching their limits and all of a sudden start expanding in our 3 dimensional universe. Or maybe the dimensions are constantly being created to accomodate ever expanding sizes of items. Or maybe at certain size limits new dimensions come into being to keep the volumes constant.

Maybe the extra dimensions introduced in string theories and such should be gigantic dimensions instead of microscopic dimensions. An infinite dimensional universe is even more odd then a universe that has small sizes equal to large sizes. "

2. Apr 2, 2006

### Hurkyl

Staff Emeritus
Then it wouldn't be very well hidden!

3. Apr 2, 2006

### DaveC426913

No?

We can't see outside the visible universe. That's pretty well hidden.

Consider a world that exists entirely within the tiny, curled up 6 dimensions that string theory proposes. Wouldn't they have a lot of difficulty seeing our dimensions?

4. Apr 2, 2006

### Hurkyl

Staff Emeritus
AFAIK, string theory say we live in a 10-dimensional universe. It does not say that we live in a 4-dimensional slice of a 10-dimensional universe. (And it certainly doesn't say that dimensions are like boxes in which we live!)

The 6 hidden dimensions aren't hidden because we're constrained to live in our 4-dimensional slice and simply cannot access them...

The 6 hidden dimensions are hidden because they're so incredibly small that we are currently unable to distinguish displacements along those directions.

I would imagine that a civilization that is on the spatial scale of those 6 hidden dimensions would be living in a rich 9-dimensional space, in which they see 6 of those dimensions curling back upon themselves, and the other three not doing so.

(Ignoring, of course, that in ST it probably doesn't even make sense to talk about anything but a handful of strings on those distance scales)

Last edited: Apr 2, 2006
5. Apr 2, 2006

### nrqed

Just a quick comment: I think that by now the consensus if on 11 dimensions. And in the "brane" models, some of these extra dimensions *are* large, not curled up. And we perceive 4 dimensions because we are constrained to a 4-dimensional slice (except for gravity which "leaks" out in the other dimensions, explaining why it is much weaker than the other forces).

6. Apr 2, 2006

### Intuitive

If Life does exist at higher Dimensions wouldn't it be just as difficult for say someone in the 10 dimension trying to see us in the 3rd Dimension as it would be for us to see them?

Where we would have to look into a very small throat to see the 10th Dimension and anyone in the 10th Dimension would need a Special Telescope to see us here in the 3rd since we would be so big when compared. It would be like looking at a Painting that had no seeable end to size and that you could not see the picture until you were far enough away from it otherwise it would just appear as some extremely large smear of particles before them in the 10 Dimension.

Last edited: Apr 2, 2006