2006-09-17 05:12:53 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
In models of spacetime, it is possible for distances in the 'spatial' part not to obey the euclidean distance formula. One other possibility is that it obeys an analog of the distance formula on the sphere. Another is that it obey an analog of the distance formula on a hyperboloid of revolution. In the latter case, we say that the universe is hyperbolic. Another term often heard is 'positive' and 'negative' curvature. The sphere is 'positively curved' and the hyperbola is 'negatively curved'. In models without the cosmological constant, positively curved universes experience a 'big crunch' eventually, while negatively curved universes expand forever.
2006-09-17 10:29:21 · answer #1 · answered by mathematician 7 · 1⤊ 0⤋
This refers to the type of curvature that dominates.
2006-09-17 05:15:04 · answer #2 · answered by bruinfan 7 · 0⤊ 1⤋