The more distance along your 4th dimension you allow, the more strange geometric effects you will observe. If you let a 4th dimension be very, very, very small

The more distance along your 4th dimension you allow, the more strange geometric effects you will observe. If you let a 4th dimension be very, very, very small (imagine a 2d universe that actually has a third dimension, it's just subatomic in scale) the geometric effects are negligible.A 3d volume can exist in that 2d + 1 tiny dimension, in the technical sense, but not in any macroscopic sense. Your 3rd dimension curls around to where it started nearly immediately.