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Einstein's static universe, aka the Einstein universe or the Einstein static eternal universe, is a relativistic model of the universe proposed by Albert Einstein in 1917. [ 1 ] [ 2 ] Shortly after completing the general theory of relativity , Einstein applied his new theory of gravity to the universe as a whole.
Albert Einstein, physicist, 1879-1955, Graphic: Heikenwaelder Hugo,1999. Special relativity is a theory of the structure of spacetime. It was introduced in Einstein's 1905 paper "On the Electrodynamics of Moving Bodies" (for the contributions of many other physicists and mathematicians, see History of special relativity).
Einstein's static universe is closed (i.e. has hyperspherical topology and positive spatial curvature), and contains uniform dust and a positive cosmological constant with value precisely = /, where is Newtonian gravitational constant, is the energy density of the matter in the universe and is the speed of light.
In physics, the special theory of relativity, or special relativity for short, is a scientific theory of the relationship between space and time.In Albert Einstein's 1905 paper, On the Electrodynamics of Moving Bodies, the theory is presented as being based on just two postulates: [p 1] [1] [2]
The field equations of general relativity are not parameterized by time but formulated in terms of spacetime. Many of the issues related to the problem of time exist within general relativity. At the cosmic scale, general relativity shows a closed universe with no external time. These two very different roles of time are incompatible. [4]
1905 – Albert Einstein publishes the Special Theory of Relativity, positing that space and time are not separate continua, and demonstrating that mass and energy are interchangeable. 1912 – Henrietta Leavitt discovers the period-luminosity law for Cepheid variable stars, which becomes a crucial step in measuring distances to other galaxies.
"The Unreality of Time" is the best-known philosophical work of University of Cambridge idealist J. M. E. McTaggart (1866–1925). In the argument, first published as a journal article in Mind in 1908, McTaggart argues that time is unreal because our descriptions of time are either contradictory, circular, or insufficient.
The same experimental data shows that time as measured by clocks in a gravitational field—proper time, to give the technical term—does not follow the rules of special relativity. In the language of spacetime geometry, it is not measured by the Minkowski metric. As in the Newtonian case, this is suggestive of a more general geometry.