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An earlier thread inspired me to imagine the following scenario.
Consider observer A, black hole B and black hole C. A's past and future remains far enough away from any EH so that A is classical. In the past, A and B were stationary relative to each other. C approaches from infinity on a collision course with B. B and C have equal but opposite electric charges, thus forming an electric dipole. In the diagram, the circles represent the event horizons. My description is 100% classical, because it involves only what A sees in A's local frame. [A might get a wild ride from the gravitational waves, but that's not relevant here.]
A can measure his local electric field gradient and divergence. In A's past, he sees only the effects of B, and C is far away. In A's future, B and C will merge and their charges will cancel, leaving net zero charge.
The question involves the time evolution of A's measurements from distant past to distant future. I can plot that as a line plotting A's observations from A's past to A's future. Label t=0 (in A's local time) as the moment when A sees the two EHs first kiss and merge to become one EH. I depict this time evolution as a straight line. But it need not be straight. If B and C orbit each other before merging the line might be corkscrew shaped. My question is not whether the line is straight, but whether it is continuous or discontinuous at t=0. In the illustration below, The solid line is A's past and the dotted line is A's future relative to t=0.
Now for the question. I can think of three arguments. (1) If the BH's charge can be modeled as a point source singularity, the line should be continuous at t=0. A can infer transiently the distribution of charge inside the EH of the merged BH by observing the time evolution of the dotted line until all measurements become zero. (2) The line is not continuous, A sees the net charge becomes zero at t=0. A can infer nothing about the interior of the merged BH. (3) Space time distortions will make it appear to A that the line is continuous but that it intercepts zero net charge at t=0.
The question: are any of these arguments correct?
Consider observer A, black hole B and black hole C. A's past and future remains far enough away from any EH so that A is classical. In the past, A and B were stationary relative to each other. C approaches from infinity on a collision course with B. B and C have equal but opposite electric charges, thus forming an electric dipole. In the diagram, the circles represent the event horizons. My description is 100% classical, because it involves only what A sees in A's local frame. [A might get a wild ride from the gravitational waves, but that's not relevant here.]
The question involves the time evolution of A's measurements from distant past to distant future. I can plot that as a line plotting A's observations from A's past to A's future. Label t=0 (in A's local time) as the moment when A sees the two EHs first kiss and merge to become one EH. I depict this time evolution as a straight line. But it need not be straight. If B and C orbit each other before merging the line might be corkscrew shaped. My question is not whether the line is straight, but whether it is continuous or discontinuous at t=0. In the illustration below, The solid line is A's past and the dotted line is A's future relative to t=0.
Now for the question. I can think of three arguments. (1) If the BH's charge can be modeled as a point source singularity, the line should be continuous at t=0. A can infer transiently the distribution of charge inside the EH of the merged BH by observing the time evolution of the dotted line until all measurements become zero. (2) The line is not continuous, A sees the net charge becomes zero at t=0. A can infer nothing about the interior of the merged BH. (3) Space time distortions will make it appear to A that the line is continuous but that it intercepts zero net charge at t=0.
The question: are any of these arguments correct?