Does a Flat Universe Have an Edge?

AI Thread Summary
The discussion centers on the concept of a flat universe and whether it has edges. While the universe is described as largely flat, this does not imply the presence of physical edges, as a flat universe can be infinite. The analogy of a flat piece of paper is misleading; instead, the universe's flatness refers to its geometric properties without boundaries. The idea is that a flat universe can expand indefinitely without curling back on itself. Ultimately, the lack of edges in a flat universe is a fundamental aspect of its infinite nature.
pivoxa15
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I have read from Universe by Freedman, Kaufmann that our universe is largly flat so it would mean there are edges in our universe. Our universe would be like a flat piece of paper that is continually expanding. A more realistic picture might be a diagram of Einstien's fabric of space time which is a flat sheet with spheres of planets sitting on it. But from the same source they stated that the universe does not possesses an edge. I can see that a spherical universe would not possesses an edge but how does a flat thing not have an edge?
 
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pivoxa15 said:
I can see that a spherical universe would not possesses an edge but how does a flat thing not have an edge?

If it's infinite!
 
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Agreed, Labguy. 'Flat' merely means the universe has no 'edges' that can 'curl' back. It has nothing to do with whether or not the universe is temporally or spatially infinite.
 
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