Difference between revisions of "Homogeneous Universe"
From Universe in Problems
(→Homogeneous and isotropic Universe, Hubble’s law) |
|||
Line 11: | Line 11: | ||
<div id="02003"></div>'''Problem 3.''' There are three cases: three-dimensional plane (zero curvature), sphere (positive curvature) and hyperboloid (negative curvature). | <div id="02003"></div>'''Problem 3.''' There are three cases: three-dimensional plane (zero curvature), sphere (positive curvature) and hyperboloid (negative curvature). | ||
+ | {| class="wikitable collapsible collapsed" | ||
+ | ! Simple collapsible table | ||
+ | |- | ||
+ | | Lorem ipsum dolor sit amet | ||
+ | |} | ||
<div id="02004"></div>'''Problem 4.''' The main qualitative difference from the usual explosion lies in the fact that the explosive charge is usually surrounded by atmospheric air. The expansion is then caused by the difference between the huge pressure of the gaseous products of the explosion and comparatively small pressure of the surrounding air. But when considering the expanding Universe, one assumes that the pressure (according to the cosmological principle) is uniformly distributed too. Therefore there are neither pressure gradients nor forces that could cause or even affect the expansion. The expansion of the Universe itself is the result of initial velocity distribution. | <div id="02004"></div>'''Problem 4.''' The main qualitative difference from the usual explosion lies in the fact that the explosive charge is usually surrounded by atmospheric air. The expansion is then caused by the difference between the huge pressure of the gaseous products of the explosion and comparatively small pressure of the surrounding air. But when considering the expanding Universe, one assumes that the pressure (according to the cosmological principle) is uniformly distributed too. Therefore there are neither pressure gradients nor forces that could cause or even affect the expansion. The expansion of the Universe itself is the result of initial velocity distribution. |
Revision as of 02:33, 17 April 2012
Homogeneous and isotropic Universe, Hubble’s law
Problem 1. A system with constant magnetic field is homogeneous but not isotropic, because the direction along the field and perpendicular to it are not equivalent. On the contrary, a spherically symmetric distribution of electric charges is by construction isotropic, but not, in general, homogeneous.
Simple collapsible table |
---|
Lorem ipsum dolor sit amet |