There’s no center of the surface of the balloon (approximating the balloon as a sphere and ignoring the nipple).
If you are standing on the earth, there is no center of the surface of the earth. The actual center of the earth requires movement in the 3rd dimension, but the surface is 2 dimensional.
If our universe is hyper spherical, the “center” would be something unreachable; it would require moving in the 4th spacial dimension.
Yeah I get that, but there is no evidence of a 4th spacial dimension, so it’s really just creative writing at this point.
Yes, but just because the discrete distance between 3D points isn’t constant does not mean a 4D space exists that allows for what is being proposed.