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Calculations in relation to black holes are solely in consideration of spacetime curvature and its effects. They are in total alienation with respect to the action of inertial agents[external forces].That world lines do not point outwards from a black hole is consistent with the fact that inertial agents are absent. Can the presence of inertial agents change the picture of the world lines? Let's consider the following situation:

An experimenter [source of "external forces" capable of producing non-geodesics] throws some mass into the black hole. Its surface area and volume increase.This is suggestive of outward world lines from the surface, causing the expansion----points on the surface should move outwards.The presence of "external forces" has modified the entire perspective of the situation.

The black hole picture takes into consideration only the blackhole.Right from the outset the black hole is considered in isolation from the rest of the universe. Any type of modification due to the presence of external agents---artificial or natural ones do not figure in the blackhole calculations. Consideration of such factors can modify the picture of the black hole.

Can technology prevent somebody near a black hole from falling into it? Can it remove the apprehensions of what we know to be a graveyard? .

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Do you mean that adding extra stuff makes the black hole reject some matter? Sure--- if you drop some planet into a black hole, you can use the planets' to slingshot out of the black hole. What is the real question exactly? – Ron Maimon May 11 '12 at 8:17
The geometry prescribed by a metric creates certain paths called geodesics. In the presence of inertial interaction it is not mandatory that a body should follow such paths.In Schwarzschild's geometry we have radially inward geodesics.Rockets moving upwards do not follow such paths-------the spacetime path of a rocket[in some planet which has not undergone a collapse] is not a geodesic because of inertial interaction.In the collapsed condition also we have geodesics which point radially inwards.We may think of inertial interaction moving a body against these geodesics – Anamitra Palit May 11 '12 at 8:31
By "inertial interaction" you mean rockets, I suppose. If you attach rockets to things, you can keep them from falling in. Why would the bodies make rockets after the collapse? You need some rockets. In my first comments I should have said "near a black hole, on the way in" instead of "into a black hole", I didn't mean inside the horizon. – Ron Maimon May 11 '12 at 8:58
You may consider the light cones in the following . These cones are "coordinate cones " constructed with the coordinate values of events.They pertain to an "Euclidean Background" viewed from curved spacetime.THe semivertical angles are different from 45 degrees. The coordinate speed of light [which is different from c] has been considered. – Anamitra Palit May 11 '12 at 9:48
Everyone already has this in the head. What is the question here? – Ron Maimon May 11 '12 at 14:37

A Black Hole can be made to misbehave in an artificial manner. It may also "misbehave" due to natural reasons.

An experimenter may project charged mass into a black hole. If the charge [and the mass introduced ] maintain spherical symmetry, we now have the Reissner-Nordstrom metric instead of the Schwarzschild metric. That changes the basic nature of the "erstwhile" Black Hole. It may not remain a Black hole any more. Introduction of charged matter from the external environment may be due to natural reasons also.

The basic aim would be to change the nature of the metric,somehow, any how.

The Black hole is serious but definitely not as serious as as we are inclined to believe in.

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Its twelve minutes since I have posted the answer. It has not shown up in the TOP questions list to be accessed through . The software is quite "resolute" in not posting my answer. – Anamitra Palit May 14 '12 at 15:20

I will address (again as a test of the answer in meta)

Can technology prevent somebody near a black hole from falling into it? Can it remove the apprehensions of what we know to be a graveyard?

In much simpler graveyards, as for example the turbulence raised by the tsunami in Japan, we have seen huge boats falling in the swirl. My advice to anybody going towards a black hole is to better change direction . It is hardly conceivable that a human could leave a black hole if it has attracted him and his rocket, though maybe a calculation could be made with realistic masses to see how close to the horizon a rocket can orbit.

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I had sent a mail at, informing them of the situation that the revised posting did not appear in the TOP question's list. The answer came:Ahh. Chances are you're just seeing a lag in the cache updating. It happens, and it can appear slow. Sometimes a refresh is all that is needed, sometimes it takes a bit more. I assure you, sir, that what you saw was likely perfectly normal." That was 14th May 10:54 AM ,Indian standard time.Later on further queries I was informed by email that low sore questions are not shown.That was 15 May,11:51 PM – Anamitra Palit May 16 '12 at 11:15
Sorry to say that somebody brought your count down to -4 once again, so you are no longer on first page. If you go to the line with PHYSICS and click on QUESTIONS you will see your question. – anna v May 16 '12 at 12:15
I can access my postings from my "user page" by clicking on my name. But the important point is that the persons voting down a question should have some reason for the voting.does this come under any type of moderation? – Anamitra Palit May 16 '12 at 12:24

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