Originally Posted by Anon La Ply
The point I (hitherto forlornly) tried to make was that if the galaxies all lie on the surface of a sphere, and we're on the surface of the sphere, then there's got to be something in the middle, doesn't there? There's an outside, there's an inside.
Not really. If a 2D surface is warped into a 3D sphere, there is no "inside" to the sphere for our 2D creatures. We see the three dimensions because we're 3D. It's an imperfect analogy because I don't think we (as 3D people) can really imagine what being 2D is, anymore than we can accurately imagine what being 4D is like. We're saying that their "space" is the sheet and it's warped into a sphere. What we see as the inside of the sphere is not their space. If it was, it would blow apart the whole idea of the big bang-expanding balloon analogy because it implies that the universe is expanding into something
rather than space itself expanding. We humans can do the math but I'm not sure we can ever visualize this on an intuitive level. I fear we are just to tied to our 3D biology. But consider if the universe was negatively curved instead of positively curved. Our 2D sheet universe would wind up looking something like a saddle that extended forever (or think of two U shapes, one up, one down, at right angles to each other). How would we define the "inside" or "outside" in that case? Or think of a Mobius Strip. It's definitely a 3D object yet it only has one side (ignoring the edge, and literally, that's one
edge). But if I'm on "one side" of a Mobius Strip, what space is the "other side"? It's a false question. The "other side" is the side I'm on currently.
"atheist tribal reflex"- never heard that one before but I must admit to a reflex reaction whenever I suspect Cartesian Dualism is about to rear its ugly head!
It is interesting how this thread has evolved. I fear, however, that it is an evolutionary dead end and we have lost all other initial participants. I enjoy discussing philosophy, primarily when it intersects math and science, but I think it puts most people off. Besides, my knowledge of the subject is largely self-taught so it's doubtful I'm going to come up with anything truly insightful. The amateur's technique