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>there is no paradox, because no one person ever sees your clone. Anne only sees one copy of you. You only see one copy of you. You and Anne can never compare n

>there is no paradox, because no one person ever sees your clone. Anne only sees one copy of you. You only see one copy of you. You and Anne can never compare notes. Can't you? Why can't Anne "gather up your ashes" and send them into the black hole, where you can inspect them? Shouldn't that go against the "no cloning theorem"?

kagamine 11y ago
Given the initial split in realities, Anne would create a new parallel universe when she placed your ashes in the black hole, one in which they exist outside the black hole and in a parallel universe where they exist inside the black hole, but this is not the same parallel universe you are experiencing, but a parallel parallel universe. Essentially, 2 instances of the black hole.
- caf 11y ago
  I think this is begging the question.
- repsilat 11y ago
  The theory very explicitly does not posit a "split in realities" or "parallel universes" or anything of the sort. It says there is quantum information both inside the black hole and outside it, and this is ok because they're supposedly causally disconnected from one another.
  - kagamine 11y ago
    > The instant you entered the black hole, reality would split in two. From the 3rd paragraph. However, yes the alternate universe comes into existence when you reach the singularity. Still, if you can exist both inside and outside, then your ashes can exist in both places alongside living you without causing a paradox because you simply will not exist in the same space as you ashes that will arrive very much later anyway as time slows at the edge of the black hole. You are more likely, having read the article, to have a post-life crises knowing that outside the black hole you are dead.
    - repsilat 11y ago
      >> The instant you entered the black hole, reality would split in two. Ah, I'd assumed this meant that "you" would split in two, both copies being "in the same universe". I don't know enough about the physics to know which is meant.
    - logfromblammo 11y ago
      Reality only splits in two in the sense that the observer-dependent reality of the person falling into the black hole and the observer-dependent reality of the person remaining outside of it can no longer exchange information anywhere except inside of the black hole's event horizon. The half of your light cone that extends into the future remains entirely within that event horizon. The outside observer's cone can remain outside of it only as long as she avoids crossing the event horizon. Even if the outside observer decide to jump in just seconds after you, it is possible that the physics inside the event horizon would prevent her from ever catching up with you to compare notes, or even sending you a message. You could send a message with modulated x-rays, and she might pick them up with a VLF antenna. She might reply with a deep infrared laser and accidentally cook your brains with cosmic rays. Assuming a steep spacetime gradient as you approach the singularity, everything sent inward would be severely blueshifted, and everything sent outward severely redshifted. There might even be a sort of Zeno's Paradox inside, where once you cross the event horizon, there's another event horizon beyond that, such that anything that much closer to the singularity than you are can never communicate with you, in the same way that you can never communicate with the universe outside the first event horizon.
      - dragonwriter 11y ago
        > There might even be a sort of Zeno's Paradox inside, where once you cross the event horizon, there's another event horizon beyond that, such that anything that much closer to the singularity than you are can never communicate with you, in the same way that you can never communicate with the universe outside the first event horizon. Isn't every step in from the event horizon effectively an event horizon? If all the mass of a black hole is effectively at the singularity in the center, and escape velocity is the speed of light at the event horizon, won't there be no point within the event horizon where escape velocity is less than the speed of light, such that at any point within the event horizon, no point farther from the event horizon is within the future light cone of that point.
yellowapple 11y ago
Better yet, black holes are known to emit Hawking radiation. If the event-horizon-crosser (let's call him "Matt" to be consistent with the article's "Anne") figured out some way to manipulate how that radiation is emitted (perhaps with some comic-book-esque "freeze ray" to selectively lower temperatures within the black hole with Morse or binary encoding?), Matt could send messages to Anne to the effect of "I AM ALIVE. BLACK HOLES ARE AWESOME.", thus unifying the two realities (or (inclusively) violating one or more models of the universe) if Anne knows to inspect Hawking radiation emissions. Similarly, the black hole will eventually evaporate (unless it indefinitely maintains an intake of matter to counteract evaporation due to the Hawking-radiation-induced loss of mass). While it's highly unlikely that Matt will be emitted in one piece (let alone alive at all), he'll eventually be emitted as Hawking radiation as that evaporation occurs. If Anne's still around when the black hole evaporates, she could then collect and inspect Matt's "ashes" (more like escaped thermal radiation) and possibly get some idea of what happened if she can somehow reconstruct Matt from those emissions.

kagamine 11y ago

Given the initial split in realities, Anne would create a new parallel universe when she placed your ashes in the black hole, one in which they exist outside the black hole and in a parallel universe where they exist inside the black hole, but this is not the same parallel universe you are experiencing, but a parallel parallel universe. Essentially, 2 instances of the black hole.

caf 11y ago
I think this is begging the question.
repsilat 11y ago
The theory very explicitly does not posit a "split in realities" or "parallel universes" or anything of the sort. It says there is quantum information both inside the black hole and outside it, and this is ok because they're supposedly causally disconnected from one another.
- kagamine 11y ago
  > The instant you entered the black hole, reality would split in two. From the 3rd paragraph. However, yes the alternate universe comes into existence when you reach the singularity. Still, if you can exist both inside and outside, then your ashes can exist in both places alongside living you without causing a paradox because you simply will not exist in the same space as you ashes that will arrive very much later anyway as time slows at the edge of the black hole. You are more likely, having read the article, to have a post-life crises knowing that outside the black hole you are dead.
  - repsilat 11y ago
    >> The instant you entered the black hole, reality would split in two. Ah, I'd assumed this meant that "you" would split in two, both copies being "in the same universe". I don't know enough about the physics to know which is meant.
  - logfromblammo 11y ago
    Reality only splits in two in the sense that the observer-dependent reality of the person falling into the black hole and the observer-dependent reality of the person remaining outside of it can no longer exchange information anywhere except inside of the black hole's event horizon. The half of your light cone that extends into the future remains entirely within that event horizon. The outside observer's cone can remain outside of it only as long as she avoids crossing the event horizon. Even if the outside observer decide to jump in just seconds after you, it is possible that the physics inside the event horizon would prevent her from ever catching up with you to compare notes, or even sending you a message. You could send a message with modulated x-rays, and she might pick them up with a VLF antenna. She might reply with a deep infrared laser and accidentally cook your brains with cosmic rays. Assuming a steep spacetime gradient as you approach the singularity, everything sent inward would be severely blueshifted, and everything sent outward severely redshifted. There might even be a sort of Zeno's Paradox inside, where once you cross the event horizon, there's another event horizon beyond that, such that anything that much closer to the singularity than you are can never communicate with you, in the same way that you can never communicate with the universe outside the first event horizon.
    - dragonwriter 11y ago
      > There might even be a sort of Zeno's Paradox inside, where once you cross the event horizon, there's another event horizon beyond that, such that anything that much closer to the singularity than you are can never communicate with you, in the same way that you can never communicate with the universe outside the first event horizon. Isn't every step in from the event horizon effectively an event horizon? If all the mass of a black hole is effectively at the singularity in the center, and escape velocity is the speed of light at the event horizon, won't there be no point within the event horizon where escape velocity is less than the speed of light, such that at any point within the event horizon, no point farther from the event horizon is within the future light cone of that point.

yellowapple 11y ago

Better yet, black holes are known to emit Hawking radiation. If the event-horizon-crosser (let's call him "Matt" to be consistent with the article's "Anne") figured out some way to manipulate how that radiation is emitted (perhaps with some comic-book-esque "freeze ray" to selectively lower temperatures within the black hole with Morse or binary encoding?), Matt could send messages to Anne to the effect of "I AM ALIVE. BLACK HOLES ARE AWESOME.", thus unifying the two realities (or (inclusively) violating one or more models of the universe) if Anne knows to inspect Hawking radiation emissions. Similarly, the black hole will eventually evaporate (unless it indefinitely maintains an intake of matter to counteract evaporation due to the Hawking-radiation-induced loss of mass). While it's highly unlikely that Matt will be emitted in one piece (let alone alive at all), he'll eventually be emitted as Hawking radiation as that evaporation occurs. If Anne's still around when the black hole evaporates, she could then collect and inspect Matt's "ashes" (more like escaped thermal radiation) and possibly get some idea of what happened if she can somehow reconstruct Matt from those emissions.