Theories For The Consequences To The Universe
As the Universe expands, the density of radiation and ordinary and dark matter declines more quickly than the density of dark energy (see equation of state) and, eventually, dark energy dominates. Specifically, when the scale of the universe doubles, the density of matter is reduced by a factor of 8, but the density of dark energy is nearly unchanged (it is exactly constant if the dark energy is a cosmological constant).
Current observations indicate that the dark energy density is already greater than the mass-energy density of radiation and matter (including dark matter). In models where dark energy is a cosmological constant, the universe will expand exponentially with time from now on, coming closer and closer to a de Sitter spacetime. In this scenario the time it takes for the linear size scale of the universe to expand to double its size is approximately 11.4 billion years. Eventually all galaxies beyond our own local supercluster will redshift so far that it will become hard to detect them, and the distant universe will turn dark.
In other models, the density of dark energy changes with time. In quintessence models it decreases, but more slowly than the energy density in ordinary matter and radiation. In phantom energy models it increases with time, leading to a big rip.
Read more about this topic: Accelerating Universe
Famous quotes containing the words theories, consequences and/or universe:
“It takes twenty or so years before a mother can know with any certainty how effective her theories have been—and even then there are surprises. The daily newspapers raise the most frightening questions of all for a mother of sons: Could my once sweet babes ever become violent men? Are my sons really who I think they are?”
—Mary Kay Blakely (20th century)
“Cultivate the habit of thinking ahead, and of anticipating the necessary and immediate consequences of all your actions.... Likewise in your pleasures, ask yourself what such and such an amusement leads to, as it is essential to have an objective in everything you do. Any pastime that contributes nothing to bodily strength or to mental alertness is a totally ridiculous, not to say, idiotic, pleasure.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)
“The kind of scientist who has no room for faith in his universe is rather old-fashioned nowadays.”
—Robert D. Andrews, and Nick Grindé. Dr. John Garth (Boris Karloff)