Yes I have, and they both only have three spatial dimensions. There are other dimensions in them, they are not spatial dimensions though. Furthermore, YOU make the claim there IS a 4th spatial dimension, it's up to YOU to prove it.
No, string theory advocates that gravity can penestrate 3D spaces. Actually, close-ended strings are on dimensional spaces planes while close-ended strings can travel through spaces.
Why should I prove it for you. You will experience it yourself anyway. By that time, you will know how your soul will function and perceive.
Edited by Hawkins, : No reason given.