Discussion Overview
The discussion revolves around the concept of treating the speed of light (c) as a dimensionless constant in the context of spacetime. Participants explore the implications of different unit systems, particularly natural units versus SI units, and the philosophical and practical considerations of defining time and space measurements.
Discussion Character
- Exploratory
- Technical explanation
- Conceptual clarification
- Debate/contested
Main Points Raised
- Some participants propose that c can be viewed as a dimensionless ratio between time and space in a unified measurement system, rather than as a ratio of different units.
- Others argue that the treatment of c as dimensionless is fundamentally a matter of unit choice and convention, emphasizing that different systems of units can lead to different interpretations of dimensionality.
- A participant references Bernhard Schutz's work, suggesting that measuring time in meters could lead to c being dimensionless, but questions whether this truly resolves the issue of differing units.
- There is a discussion about the utility of natural units, which unify time and space dimensions, making the geometric nature of spacetime more evident.
- Some participants highlight the distinction between timelike and spacelike intervals, asserting that this distinction remains regardless of the unit system employed.
- Concerns are raised about the implications of defining new units for events or spacetime, questioning whether these must adhere to existing definitions of time or space.
Areas of Agreement / Disagreement
Participants express a mix of agreement and disagreement. While there is acknowledgment of the validity of treating c as dimensionless under certain conventions, there remains contention regarding the implications of unit choice and the fundamental distinctions between time and space.
Contextual Notes
Limitations include the reliance on specific definitions of units and the unresolved nature of how different conventions affect the interpretation of physical dimensions.