How The Life Begin

The  curvature  is a quantity describing how the geometry of a space differs locally from the one of the  flat space . The curvature of any locally  isotropic space  (and hence of a locally isotropic universe) falls into one of the three following cases: Zero curvature (flat); a drawn triangle's angles add up to 180° and the  Pythagorean theorem  holds; such 3-dimensional space is locally modeled by  Euclidean space  E 3 .Positive curvature; a drawn triangle's angles add up to more than 180°; such 3-dimensional space is locally modeled by a region of a  3-sphere  S 3 .Negative curvature; a drawn triangle's angles add up to less than 180°; such 3-dimensional space is locally modeled by a region of a  hyperbolic space  H 3 . Curved geometries are in the domain of  Non-Euclidean geometry . An example of a positively curved space would be the surface of a sphere such as the Earth. A triangle drawn from th...