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You do not need a black hole for the information loss. Just shout a flashlight into empty space. Any information encoded in photons will be lost from the point

You do not need a black hole for the information loss. Just shout a flashlight into empty space. Any information encoded in photons will be lost from the point of view of the sender. And then the classical notions like information or entropy are not really compatible with General Relativity. Richard Tolman almost 100 years ago proposed interesting extension to the classical thermodynamics that is compatible and can potentially explain apparent paradox of information loss, but it is not known if that extension matches reality.

griffzhowl 1y ago
> Any information encoded in photons will be lost from the point of view of the sender. The crucial difference is "from the point of view of the sender". The black hole information paradox is that the information is lost from any possible receiver (even any possible ensemble of receivers surrounding the black hole). It's not the same thing
- fpoling 1y ago
  The information is not lost from the point of view of receivers inside the black hole horizon. Which again points out that the classical notion of information just does not work in a universe with multiple causally disconnected regions.
  - griffzhowl 1y ago
    What happens when the black hole evaporates then, and there is no more horizon? That's the black hole information paradox
    - butlike 1y ago
      Single point of ~infinite charge?
  - moralestapia 1y ago
    >The information is not lost from the point of view of receivers inside the black hole horizon. Information is lost beyond the event horizon. There is no such thing as "point of view of receivers inside that black hole", everything collapses into a single point or some dimensionless thing or whatever. That's why it is called a singularity.
    - IAmBroom 1y ago
      I do not know of any theories that agree with this. In fact, most admit that "you wouldn't even notice (if somehow still alive) when you crossed the event horizon" - because the only thing that happens is the photons you emit go from taking billions of years to escape, to never escaping. And that's not why it's called a singularity. It is NOT a single point, nor dimensionless. It has a well-defined dimensional size, the Schwarzwald Radius.
      - moralestapia 1y ago
        >I do not know of any theories that agree with this. It shows. You confuse "dimension" with "magnitude", for starters.
        griffzhowl 1y ago
        > It shows. Why be so extravagantly supercilious on the internet? It's ironic because it seems you're not that familiar with general relativity, and confuse the entire region within the event horizon with the singularity. Black holes have a causally connected region within the event horizon which is distinct from the singularity, so there can in fact be observers within the event horizon that are in communication with each other, and they can have a perspective, i.e. receive information. The simplest black hole model would be the Schwarzschild black hole (a static, spherically symmetric spacetime, which is empty apart from the central mass) with the Kruskal-Szekeres coordinates, which smoothly continue over the event horizon. Here's a nice discussion by John Baez about what you might see as you cross the event horizon: https://johncarlosbaez.wordpress.com/2024/11/30/black-hole-puzzle/ https://johncarlosbaez.wordpress.com/2024/11/30/black-hole-p... To some extent though, what really happens within the event horizon remains speculative, because we can't directly verify any of these predictions about what happens there without actually crossing the horizon ("What happens within the event horizon, stays within the event horizon"). We just make inferences based on the structure of our currently most predictive theory for gravitational phenomena outside event horizons (which is general relativity, ofc)

griffzhowl 1y ago

> Any information encoded in photons will be lost from the point of view of the sender. The crucial difference is "from the point of view of the sender". The black hole information paradox is that the information is lost from any possible receiver (even any possible ensemble of receivers surrounding the black hole). It's not the same thing

fpoling 1y ago
The information is not lost from the point of view of receivers inside the black hole horizon. Which again points out that the classical notion of information just does not work in a universe with multiple causally disconnected regions.
- griffzhowl 1y ago
  What happens when the black hole evaporates then, and there is no more horizon? That's the black hole information paradox
  - butlike 1y ago
    Single point of ~infinite charge?
- moralestapia 1y ago
  >The information is not lost from the point of view of receivers inside the black hole horizon. Information is lost beyond the event horizon. There is no such thing as "point of view of receivers inside that black hole", everything collapses into a single point or some dimensionless thing or whatever. That's why it is called a singularity.
  - IAmBroom 1y ago
    I do not know of any theories that agree with this. In fact, most admit that "you wouldn't even notice (if somehow still alive) when you crossed the event horizon" - because the only thing that happens is the photons you emit go from taking billions of years to escape, to never escaping. And that's not why it's called a singularity. It is NOT a single point, nor dimensionless. It has a well-defined dimensional size, the Schwarzwald Radius.
    - moralestapia 1y ago
      >I do not know of any theories that agree with this. It shows. You confuse "dimension" with "magnitude", for starters.
      - griffzhowl 1y ago
        > It shows. Why be so extravagantly supercilious on the internet? It's ironic because it seems you're not that familiar with general relativity, and confuse the entire region within the event horizon with the singularity. Black holes have a causally connected region within the event horizon which is distinct from the singularity, so there can in fact be observers within the event horizon that are in communication with each other, and they can have a perspective, i.e. receive information. The simplest black hole model would be the Schwarzschild black hole (a static, spherically symmetric spacetime, which is empty apart from the central mass) with the Kruskal-Szekeres coordinates, which smoothly continue over the event horizon. Here's a nice discussion by John Baez about what you might see as you cross the event horizon: https://johncarlosbaez.wordpress.com/2024/11/30/black-hole-puzzle/ https://johncarlosbaez.wordpress.com/2024/11/30/black-hole-p... To some extent though, what really happens within the event horizon remains speculative, because we can't directly verify any of these predictions about what happens there without actually crossing the horizon ("What happens within the event horizon, stays within the event horizon"). We just make inferences based on the structure of our currently most predictive theory for gravitational phenomena outside event horizons (which is general relativity, ofc)