Think of a 3D sphere, slice it through the center. You now have a 2D "sphere" which actually looks nothing like a sphere, as your a whole dimension short. What im trying to prove here, is that you need to not get you definitions of words involved when thinking about this, think about it with an open mind. Now lets move to 1D. Essentially, turn a 2D "sphere" sideways. Now you have just a straight line. In a physical sence, a straight line is 2D. But think about it in the true sense, flat with no depth. Now this 3D sphere has entered the 1D space. Still a form of a sphere, just missing 2 dimensions. Now, is this 1D sphere any more obscure than the 2D? Not really. Its just that this image doesn't fit with your traditional thinking of a sphere and how it looks.
Queensland University of Technology