Information from a Black Hole
Discussion
It occurred to me that it may be incorrect that no information is released from a Black Hole (Except Hawking radiation)...What about Gravity itself?...If a large enough object was absorbed into the Black Hole it would have a measurable effect on the gravitational waves emanating from the Black Hole itself, allowing us some insight into what happens on the other side of the event horizon?
I.E: If the gravitational pull is a product of the mass creating it so I would presume that the change in gravity (from the increased mass) should be measurable from outside the event horizon, thus allowing information to escape the black hole (something I believe was thought to be impossible (Or at least was last time I looked into it!)...
If the gravitational pull of the black hole and the soon to be engulfed star were measured together it would be interesting to see if the net gravitational pull stayed the same after it entered the event horizon or perhaps even diminished.(Does the star remain as part of our universe or not?)
I.E: If the gravitational pull is a product of the mass creating it so I would presume that the change in gravity (from the increased mass) should be measurable from outside the event horizon, thus allowing information to escape the black hole (something I believe was thought to be impossible (Or at least was last time I looked into it!)...
If the gravitational pull of the black hole and the soon to be engulfed star were measured together it would be interesting to see if the net gravitational pull stayed the same after it entered the event horizon or perhaps even diminished.(Does the star remain as part of our universe or not?)
Nobody knows.
http://en.wikipedia.org/wiki/Black_hole_informatio...
But you've got to love the breadth of possible solutions!
Main approaches to the solution of the paradox
Information is irretrievably lost
Advantage: Seems to be a direct consequence of relatively non-controversial calculation based on semiclassical gravity.
Disadvantage: Violates unitarity, as well as energy conservation or causality.
Information gradually leaks out during the black-hole evaporation
Advantage: Intuitively appealing because it qualitatively resembles information recovery in a classical process of burning.
Disadvantage: Requires a large deviation from classical and semiclassical gravity (which do not allow information to leak out from the black hole) even for macroscopic black holes for which classical and semiclassical approximations are expected to be good approximations.
Information suddenly escapes out during the final stage of black-hole evaporation
Advantage: A significant deviation from classical and semiclassical gravity is needed only in the regime in which the effects of quantum gravity are expected to dominate.
Disadvantage: Just before the sudden escape of information, a very small black hole must be able to store an arbitrary amount of information, which violates the Bekenstein bound.
Information is stored in a Planck-sized remnant
Advantage: No mechanism for information escape is needed.
Disadvantage: To contain the information from any evaporated black hole, the remnants would need to have an infinite number of internal states. It has been argued that it would be possible to produce an infinite amount of pairs of these remnants since they are small and indistinguishable from the perspective of the low-energy effective theory.
Information is stored in a baby universe that separates from our own universe.
Advantage: This scenario is predicted by the Einstein–Cartan theory of gravity which extends general relativity to matter with intrinsic angular momentum (spin). No violation of known general principles of physics is needed.
Disadvantage: It is difficult to test the Einstein–Cartan theory because its predictions are significantly different from general-relativistic ones only at extremely high densities.
Information is encoded in the correlations between future and past
Advantage: Semiclassical gravity is sufficient, i.e., the solution does not depend on details of (still not well understood) quantum gravity.
Disadvantage: Contradicts the intuitive view of nature as an entity that evolves with time.
http://en.wikipedia.org/wiki/Black_hole_informatio...
But you've got to love the breadth of possible solutions!
Main approaches to the solution of the paradox
Information is irretrievably lost
Advantage: Seems to be a direct consequence of relatively non-controversial calculation based on semiclassical gravity.
Disadvantage: Violates unitarity, as well as energy conservation or causality.
Information gradually leaks out during the black-hole evaporation
Advantage: Intuitively appealing because it qualitatively resembles information recovery in a classical process of burning.
Disadvantage: Requires a large deviation from classical and semiclassical gravity (which do not allow information to leak out from the black hole) even for macroscopic black holes for which classical and semiclassical approximations are expected to be good approximations.
Information suddenly escapes out during the final stage of black-hole evaporation
Advantage: A significant deviation from classical and semiclassical gravity is needed only in the regime in which the effects of quantum gravity are expected to dominate.
Disadvantage: Just before the sudden escape of information, a very small black hole must be able to store an arbitrary amount of information, which violates the Bekenstein bound.
Information is stored in a Planck-sized remnant
Advantage: No mechanism for information escape is needed.
Disadvantage: To contain the information from any evaporated black hole, the remnants would need to have an infinite number of internal states. It has been argued that it would be possible to produce an infinite amount of pairs of these remnants since they are small and indistinguishable from the perspective of the low-energy effective theory.
Information is stored in a baby universe that separates from our own universe.
Advantage: This scenario is predicted by the Einstein–Cartan theory of gravity which extends general relativity to matter with intrinsic angular momentum (spin). No violation of known general principles of physics is needed.
Disadvantage: It is difficult to test the Einstein–Cartan theory because its predictions are significantly different from general-relativistic ones only at extremely high densities.
Information is encoded in the correlations between future and past
Advantage: Semiclassical gravity is sufficient, i.e., the solution does not depend on details of (still not well understood) quantum gravity.
Disadvantage: Contradicts the intuitive view of nature as an entity that evolves with time.
Posted this is another topic but can fit in here as well...
Thanks...no worries.....
Here is my idea...There are two travellers...one is going to enter the black hole (1) while the other (2) watches from outside...The first one has a futuristic device that can instantly make a black hole..(don't worry...this is a thought experiment...I just need the traveller to be able to cause a gravity wave)..as traveller 1 enters the black hole he sets of the device which instantly creates a gravity wave that will be felt by traveller 2 however from traveller 2's perspective traveller 1 is still falling into the black hole (time slows down as observed by traveller 2)...therefore gravity itself is moving backwards through time as seen by traveller 2....the gravity waves are felt before they see traveller 1 set of the device..In the real world (but way in the future) it could be a way of sending a probe into a black hole that could communicate to the outside world using gravitational waves....
Hope that makes sense..!
Thanks...no worries.....
Here is my idea...There are two travellers...one is going to enter the black hole (1) while the other (2) watches from outside...The first one has a futuristic device that can instantly make a black hole..(don't worry...this is a thought experiment...I just need the traveller to be able to cause a gravity wave)..as traveller 1 enters the black hole he sets of the device which instantly creates a gravity wave that will be felt by traveller 2 however from traveller 2's perspective traveller 1 is still falling into the black hole (time slows down as observed by traveller 2)...therefore gravity itself is moving backwards through time as seen by traveller 2....the gravity waves are felt before they see traveller 1 set of the device..In the real world (but way in the future) it could be a way of sending a probe into a black hole that could communicate to the outside world using gravitational waves....
Hope that makes sense..!
If gravitons exist (I don't think they do)...then they may travel at the speed of light but would not be bound by lights inability to escape gravity...an event that happens right on the edge of a black hole may take a week to be visible (due to gravity slowing time) but would appear instantaneous when measured by gravity wave...so again gravity travels backwards through an event...
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