What Happens When You Cross a Black Hole's Event Horizon?

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Discussion Overview

The discussion revolves around the nature of crossing a black hole's event horizon, exploring the experiences of an observer falling into a black hole versus those of an external observer. It touches on concepts from general relativity, Hawking radiation, and the implications of time dilation, with participants questioning and clarifying various aspects of these phenomena.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants assert that an individual crossing the event horizon of a massive black hole will not experience anything special and will do so in finite proper time.
  • Others argue that an external observer will never see the individual reach the event horizon, as this process takes infinite time from their perspective.
  • There is a contention regarding Hawking radiation, with some suggesting that an external observer will see the black hole explode in finite time, while others challenge this by referencing the influence of cosmic background radiation on black hole evaporation.
  • A participant mentions that the temperature of a black hole decreases with increasing mass, suggesting that black holes will eventually lose energy and evaporate, but the timing of this event relative to an observer's fall is debated.
  • Concerns are raised about the implications of time dilation and whether an external observer would see the individual crossing the horizon or merely their image frozen at the event horizon as the black hole evaporates.
  • Some participants express uncertainty about the nature of time and simultaneity in the context of black hole evaporation and the fate of the individual falling in.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the implications of crossing the event horizon, the effects of Hawking radiation, or the nature of time as it relates to observers inside and outside the black hole. Multiple competing views remain, and the discussion is unresolved.

Contextual Notes

Limitations include the dependence on interpretations of general relativity, the unresolved nature of black hole evaporation, and the complexities surrounding the concept of time in relation to different observers.

  • #31
I've been reading these postings, just trying to get a grip on black holes. I am pretty new to this. Something that I have been wondering about... If space traveller A moves directly toward a black hole, into an ever-increasing spacetime compression (while spacetime seeming to decompress as traveller A compresses), would the perceived remaining distance to the black hole decrease at an ever slowing rate, making the trip to the black hole seem endless? From an outside observer, would traveller A seem to assume a spiral path to the black hole, due to spacetime twisting, even though traveller A is moving directly toward it? Also, could it be possible that black holes are actually extremely large (in size, possibly larger than entire galaxies) but distort our perception of themselves by pulling in the space around themselves to a "virtual" singularity. Sorry, don't mean to interrupt a previous discussion, but it seemed liked you guys might have some input. Thanks!
 

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