By contrast, Newton's cosmology was homogeneous, hence manifestly non-fractal. |
In the 1930s, the assumption of spatial homogeniety was joined with spatial isotropy to form the Cosmological Principle. |
The Cosmological Principle asserts that on very large scales all parts of the universe are more-or-less the same, and every direction looks the same. |
Perhaps in part this is a reaction to centuries of believing the earth is the center of the universe. |
While this "we're nothing special" certainly conflicted with Newton's theology, it seems appropriate to modern world views. |
An additional motivation in relativistic cosmology is that Einstein's equations are much easier to solve under the assumptions of homogenietry and isotropy. |
Yet stars are organized into galaxies, and galaxies into cluseters of galaxies, so any homogeniety must occur at a very large scale. |
Einstein's cosmological model takes as hypothesis that the universe is homogeneous and isotropic in space. |
Homogeneity is generally regarded as essential for Hubble's law, that the velocity of recession of galaxies is proportional to their distance. |
Return to Large-Scale Distribution of Galaxies.