"The curvature of space is a geometric description of length relationships in spatial coordinates. In mathematics, any geometry has three possible curvatures, so the geometry of the universe has the same three possible curvatures.

Flat (A drawn triangle's angles add up to 180Â° and the Pythagorean theorem holds)

Positively curved (A drawn triangle's angles add up to more than 180Â°)

Negatively curved (A drawn triangle's angles add up to less than 180Â°)"

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I am asking whether two or all three of such spaces can exist as one. I.e., can different curvatures connect continuously? (E.g., saddles to spheres to planes or combinations thereof?)