Main Question or Discussion Point
Does anyone know what shape the universe is? I.e. a sphere, or an eliptical sphere? and is that the observed shape of the shape after relativity calculation?
I think you're mixing 4D and 3D here and it doesn't work. Its likely that in a 3D sense, the matter forms a sphere, assuming roughly uniform expansion in all directions. If the universe is topologically flat on large scales, this just means that if you head off in one direction, you keep going in that way, you don't wind up back where you started (anyone more familiar with differential geometry or topology can feel free to chime in and correct me if i'm mistaken).jhe1984 said:It doesn't seem like, from a topological perspective, we'd be able to differentiate a smooth, spherically shaped universe from a smooth, flat universe.
I understand the bit about the effect of the cosmological constant, but what perplexes me is why we think the universe is flat versus spherical (although I admit I have no idea what a beyond-3d sphere would look like), especially if there are long distance curves.
How is this different from a purely topologic view of the Earth - where it can be drawn either flat or on a globe, but the spherical globe is the actual shape?