In 2D for example, warping it only makes sence in a 3D enviorment. In a 2D world, bending 2D would be meaningless. So in GR when we talk about bending 4D ST, is a fifth dimension needed to give ST something to "bend into"? If not, in what sence can we talk about warped ST? I suspect that maybe it warps not in a physical (dimensional - into another dimension) way, but rather the cooardinite system gets messed up and those effects are noticable in 3D. Can someone clarify this please?