1. Established Member
Join Date
Aug 2003
Posts
1,557

Would a 3-D spatial universe and a 4-D spatial universe have a different geometry?

2. ## Re: Quick Question...Need Quick Answer

Originally Posted by Platinum Rhymer
Would a 3-D spatial universe and a 4-D spatial universe have a different geometry?
Yes. It would be similar to the difference between Euclidian geometry and Newtonian. (2D vs. 3D)

There is a book called "Flatland" that does a real good job of explaining 1,2,3&amp;4D space. Try here. It is a very interesting read.

3. Established Member
Join Date
Aug 2003
Posts
1,557
Thanks alot, I am going to check that link out

5. Established Member
Join Date
Apr 2003
Posts
677

PR quote
Would a 3-D spatial universe and a 4-D spatial universe have a different geometry?

IMHO, I would say no. Both spaces would be 3D, but 4D would add motion with the introduction of time. Time would be a 'variable point' added to the 3D dimentions.

6. Established Member
Join Date
Aug 2003
Posts
1,557
I meant spatial dimensions

7. Established Member
Join Date
Aug 2003
Posts
1,557
I would think that they would be different

8. Established Member
Join Date
Jan 2005
Posts
414

## Re: Quick Question...Need Quick Answer

Originally Posted by Platinum Rhymer
Would a 3-D spatial universe and a 4-D spatial universe have a different geometry?
Gravity would reduce by the cube of the distance instead of the square of the distance.

9. Established Member
Join Date
Aug 2003
Posts
1,557
But the problem with the whole inverse cube law thing is that they got the inverse cube law just by adding an additional dimension but applying the same geometry as before, wouldnt you have to do more than that? because 3D geometry and 4D geometry are different from each other

life not being possible in 4D+ universe is just a sad sad thought

10. Like a 2D piece of paper can exist in a 3D universe so, I would have thought could a 3D frame work exist within a 4D universe.

11. Established Member
Join Date
Aug 2003
Posts
1,557
But a 2D piece of paper is not really a 2D universe with laws and such, the 2D paper with 3D laws, I dont think there could be a 2D universe

12. Established Member
Join Date
Jul 2002
Posts
330
A piece of paper is a valid representation of a 2-D universe (ignore the thickness). Take a pencil and try drawing a line ABOVE the paper.
Try a balloon for a closed universe.

13. Established Member
Join Date
Aug 2003
Posts
1,557
Then there certainly could not be any orbits in a 2-D universe

14. Established Member
Join Date
Aug 2003
Posts
1,557
Originally Posted by Frog march
I would have thought could a 3D frame work exist within a 4D universe.
But the 3D frame work would certainly be upgraded

15. Established Member
Join Date
Aug 2003
Posts
1,557
What would happen if you took out one spatial dimension of our universe, expect there to be radical, massive changes

16. if you took out one of the 'rolled up' ones that they keep going on about, perhaps you wouldn't notices any difference.

17. Established Member
Join Date
Aug 2003
Posts
1,557
Probably but there will be effects (if they do exist), but taking out a large macroscopic spatial dimension will result in a completely different universe.

18. Order of Kilopi
Join Date
Nov 2003
Posts
6,197

## Re: Quick Question...Need Quick Answer

Originally Posted by Platinum Rhymer
Would a 3-D spatial universe and a 4-D spatial universe have a different geometry?