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'''Spacetime''' is the 4-dimensional [[vector space]] or [[manifold]]<ref>Often treated as a vector space when working examples, but that isn't really correct because it has no origin.  The more sophisticated term "manifold" is correct.</ref> that simultaneously embodies the concepts of time and 3-dimensional space.  Whether one can ascribe a separate existence to spacetime itself, depends on one's physical intuition.  But that doesn't matter&mdash;"separate existence" or not, physicists working in the field understand spacetime as a useful concept.

'''Spacetime''' is the 4-dimensional [[vector space]] or [[manifold]]<ref>Often treated as a vector space when working examples, but that isn't really correct because it has no origin.  The more sophisticated term "manifold" is correct.</ref> that simultaneously embodies the concepts of time and 3-dimensional space.  Whether one can ascribe a separate existence to spacetime itself, depends on one's physical intuition.  But that doesn't matter&mdash;"separate existence" or not, physicists working in the field understand spacetime as a useful concept.

Under Newtonian/Galilean physics or Newtonian/Galilean relativity at the high-school and general undergraduate level, one typically thinks of time, and the 3 dimensions of space, completely separately.  One can solve many problems of physics with this formulation.

Under Newtonian/Galilean physics or Newtonian/Galilean relativity at the high-school and general undergraduate level, one typically thinks of time, and the 3 dimensions of space, completely separately.  One can solve many problems of physics with this formulation.

The '''curvature of spacetime''' refers to this.  It gives rise to the "fictitious forces" that are perceived as gravity under [[General theory of relativity|General Relativity]].  The Einstein Field Equations explain how that curvature arises from the presence of massive objects like the Earth or the Sun.  Analyzing the resultant gravitational fictitious force arising from massive objects obtains the same result as Newton's law of gravity for non-relativistic objects.

The '''curvature of spacetime''' refers to this.  It gives rise to the "fictitious forces" that are perceived as gravity under [[General theory of relativity|General Relativity]].  The Einstein Field Equations explain how that curvature arises from the presence of massive objects like the Earth or the Sun.  Analyzing the resultant gravitational fictitious force arising from massive objects obtains the same result as Newton's law of gravity for non-relativistic objects.

== References ==

== References ==

[[Category:Astronomy]]

[[Category:Astronomy]]

[[Category:Cosmology]]

[[Category:Cosmology]]

[[Category:Relativty]]

[[Category:Relativity]]

[[Category:Physics]]