Raumflotte I Astrodome Artwork by Fred Freeman Many of the navigational instruments might be mounted inside an "astrodome", which is a blister dome of some strong but transparent material used with a manual sextant as a back-up to the periscope.
Note the gravitational lensing effect, which produces two enlarged but highly distorted views of the Cloud. Across the top, the Milky Way disk appears distorted into an arc.
The idea of a body so massive that even light could not escape was briefly proposed by astronomical pioneer and English clergyman John Michell in a letter published in November Michell's simplistic calculations assumed that such a body might have the same density as the Sun, and concluded that such a body would form when a star's diameter exceeds the Sun's by a factor ofand the surface escape velocity exceeds the usual speed of light.
Michell correctly noted that such supermassive but non-radiating bodies might be detectable through their gravitational effects on nearby visible bodies.
Only a few months later, Karl Schwarzschild found a solution to the Einstein field equationswhich describes the gravitational field of a point mass and a spherical mass. The nature of this surface was not quite understood at the time.
Firstly, the force of gravitation would be so great that light would be unable to escape from it, the rays falling back to the star like a stone to the earth. Secondly, the red shift of the spectral lines would be so great that the spectrum would be shifted out of existence.
Thirdly, the mass would produce so much curvature of the space-time metric that space would close up around the star, leaving us outside i.
But inRobert Oppenheimer and others predicted that neutron stars above another limit the Tolman—Oppenheimer—Volkoff limit would collapse further for the reasons presented by Chandrasekhar, and concluded that no law of physics was likely to intervene and stop at least some stars from collapsing to black holes.
This is a valid point of view for external observers, but not for infalling observers. Because of this property, the collapsed stars were called "frozen stars", because an outside observer would see the surface of the star frozen in time at the instant where its collapse takes it to the Schwarzschild radius.
History of general relativity InDavid Finkelstein identified the Schwarzschild surface as an event horizon"a perfect unidirectional membrane: Finkelstein's solution extended the Schwarzschild solution for the future of observers falling into a black hole.
A complete extension had already been found by Martin Kruskalwho was urged to publish it. This process was helped by the discovery of pulsars in  which, bywere shown to be rapidly rotating neutron stars.
InRoy Kerr found the exact solution for a rotating black hole. Two years later, Ezra Newman found the axisymmetric solution for a black hole that is both rotating and electrically charged.
This view was held in particular by Vladimir BelinskyIsaak Khalatnikovand Evgeny Lifshitzwho tried to prove that no singularities appear in generic solutions. However, in the late s Roger Penrose  and Stephen Hawking used global techniques to prove that singularities appear generically.
The analogy was completed when Hawking, inshowed that quantum field theory predicts that black holes should radiate like a black body with a temperature proportional to the surface gravity of the black hole. Science writer Marcia Bartusiak traces the term "black hole" to physicist Robert H.
Dickewho in the early s reportedly compared the phenomenon to the Black Hole of Calcuttanotorious as a prison where people entered but never left alive.
If the conjecture is true, any two black holes that share the same values for these properties, or parameters, are indistinguishable from one another. The degree to which the conjecture is true for real black holes under the laws of modern physics, is currently an unsolved problem. For example, a charged black hole repels other like charges just like any other charged object.
Similarly, the total mass inside a sphere containing a black hole can be found by using the gravitational analog of Gauss's lawthe ADM massfar away from the black hole.
The behavior of the horizon in this situation is a dissipative system that is closely analogous to that of a conductive stretchy membrane with friction and electrical resistance —the membrane paradigm.in a black hole the stars matter continues to contract until original volume becomes a fantastically dense point a galaxy is an extremely large collection of stars bound together.
by mutual gravitational attraction fundamental components for structure of universe.
General relativity (GR, also known as the general theory of relativity or GTR) is the geometric theory of gravitation published by Albert Einstein in and the current description of gravitation in modern leslutinsduphoenix.coml relativity generalizes special relativity and Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time.
Dec 15, · Any object that is smaller than its Schwarzschild radius is a black hole – in other words, anything with an escape velocity greater than the speed of light is a black hole. For something the mass of our sun would need to be squeezed into a volume with a radius of about 3 km.
A very luminous, starlike object that generates energy at a high rate; quasars are thought to be the most distant objects in the universe.
cosmology The study of the origin, properties, processes, and evolution of the universe. Apr 20, · What all of this suggests is a pretty stunning conclusion: Maybe we’ve been thinking about political ideology in very much the wrong way.
It seems to . Black Holes Black holes are objects so dense that not even light can escape their gravity, and since nothing can travel faster than light, nothing can escape from inside a black hole.
Loosely speaking, a black hole is a region of space that has so much mass concentrated in it that there is no way for a nearby object to escape its gravitational.