Nature of The Absolute Horizon
The definition of an absolute horizon is sometimes referred to as teleological, meaning that it cannot be known where the absolute horizon is without knowing the entire evolution of the universe, including the future. This is both an advantage and a disadvantage. The advantage is that this notion of a horizon is very geometrical, and does not depend on the observer, unlike apparent horizons, for example. The disadvantage is that it requires the full history (all the way into the future) of the spacetime to be known. In the case of numerical relativity, where a spacetime is simply being evolved into the future, only a finite portion of the spacetime can be known.
Read more about this topic: Absolute Horizon
Famous quotes containing the words nature, absolute and/or horizon:
“One of the most significant effects of age-segregation in our society has been the isolation of children from the world of work. Whereas in the past children not only saw what their parents did for a living but even shared substantially in the task, many children nowadays have only a vague notion of the nature of the parent’s job, and have had little or no opportunity to observe the parent, or for that matter any other adult, when he is fully engaged in his work.”
—Urie Bronfenbrenner (b. 1917)
“In our science and philosophy, even, there is commonly no true and absolute account of things. The spirit of sect and bigotry has planted its hoof amid the stars. You have only to discuss the problem, whether the stars are inhabited or not, in order to discover it.”
—Henry David Thoreau (1817–1862)
“The whole world of thought lay unexplored before me,—a world of which I had already caught large and tempting glimpses, and I did not like to feel the horizon shutting me in, even to so pleasant a corner as this.”
—Lucy Larcom (1824–1893)