The twin paradox and black holes

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Discussion Overview

The discussion revolves around the twin paradox in the context of black holes and varying gravitational fields. Participants explore the implications of general relativity on time dilation effects experienced by observers in different states of motion and gravitational influences, particularly focusing on scenarios involving black holes.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • Some participants question whether the twin paradox applies in the vicinity of a black hole, suggesting that the scenario may differ from that in weaker gravitational fields like Earth's.
  • Others argue that it is possible to find pairs of timelike worldlines between the same two points that have different elapsed times in any spacetime, including around black holes.
  • A participant mentions a specific example involving freely falling observers and the potential for them to meet again after one accelerates away.
  • There is discussion about the ability of observers to compare clock readings at a common event, regardless of their relative velocities.
  • Some participants explore the implications of resetting clocks at a common event and the conditions under which they would keep time relative to each other afterward.
  • One participant suggests that the twin paradox can be modeled in a spaceship falling into a black hole, indicating that different paths taken could lead to different clock readings.
  • There is a mention of Feynman's thoughts on time passed for freely falling objects versus those brought to a common event through forced means, referencing the Hafele-Keating experiment as a related example.

Areas of Agreement / Disagreement

Participants express differing views on the applicability of the twin paradox in strong gravitational fields, particularly around black holes. The discussion remains unresolved, with multiple competing perspectives on the nature of time dilation and clock synchronization in these contexts.

Contextual Notes

Participants highlight the complexity of the scenarios discussed, noting that the specifics of the paths taken by observers can significantly influence the outcomes. There are also references to the need for careful consideration of the definitions and assumptions involved in the discussion.

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