Discussion Overview
The discussion revolves around the nature of space in the context of general relativity, specifically whether there is more or less space between two points in curved spacetime near massive objects compared to flat spacetime. Participants explore theoretical implications, the concept of curvature, and related phenomena such as time dilation and the Shapiro delay.
Discussion Character
- Exploratory
- Debate/contested
- Technical explanation
- Mathematical reasoning
Main Points Raised
- Some participants question whether there is more or less space between two points in curved spacetime compared to flat space, suggesting that the intrinsic curvature could imply less space.
- Others argue that space is a frame-dependent concept and that definitions need to be clarified for meaningful comparisons.
- A participant mentions that the diameter through a massive object is greater than the circumference divided by pi, implying more space within the same perimeter if mass is present.
- There is a discussion about the Shapiro delay as an invariant concept that may relate to the question of space and time in curved spacetime.
- Some participants express uncertainty about whether the geodesic path results in more or less time compared to a "straight" path, with references to specific scenarios involving light travel near massive objects.
- Concerns are raised about the meaningfulness of comparing distances in curved spacetime to flat spacetime, with examples such as the distance between New York and London on a flat map versus a spherical Earth.
- One participant seeks confirmation about the constancy of the speed of light as measured by local clocks, even in non-inertial frames, leading to further clarification about coordinate speed versus local measurements.
Areas of Agreement / Disagreement
Participants express differing views on the nature of space in curved versus flat spacetime, with no consensus reached on whether there is more or less space near massive objects. The discussion remains unresolved, with multiple competing perspectives presented.
Contextual Notes
Participants note that the definitions of space and curvature are crucial to the discussion, and the implications of frame-dependence and coordinate systems are acknowledged as limitations in reaching a definitive answer.