The Cosmological Principle says that the universe is homogenous and isotropic. Doesn't this imply that our universe cannot be in finite size, but is finiteless? If it has a boundary, how can then the cosmological principle still be true for those heavenly bodies residing at the boundary of the universe? If the universe has no boundary, how can we have R(t), where R is the radius of the universe in the Robertson-Walker metric? Or even in determining the future of our universe, for the different k values, 0, 1, and -1, eg, expanding forever, or Big Crunch etc.?