Discussion Overview
The discussion centers on the question of where photon energy goes during the expansion of the universe, particularly in the context of cosmology and general relativity. Participants explore the implications of photon energy loss over long distances and the theoretical frameworks that address this phenomenon.
Discussion Character
- Debate/contested
- Technical explanation
- Conceptual clarification
Main Points Raised
- One participant asserts that photons lose energy when traveling long distances and questions where that energy goes, seeking theoretical explanations.
- Another participant claims that energy is simply lost and notes that there is no global conservation of energy in general relativity, referencing an external article for support.
- A different viewpoint challenges the notion of photons losing energy, suggesting that this description is dubious and relates to discredited theories like 'tired light.' They argue that energy conservation does not apply to the universe as a whole and that observations can be explained without assuming photon energy loss.
- A later reply highlights that while some cosmologists believe photons lose energy, this loss is not necessarily due to long-distance travel, which they associate with outdated theories.
Areas of Agreement / Disagreement
Participants express multiple competing views regarding the energy of photons in the context of cosmic expansion. There is no consensus on whether photons lose energy or how to interpret the implications of energy conservation in general relativity.
Contextual Notes
The discussion reflects differing interpretations of energy conservation in cosmological contexts and the validity of various theories related to photon behavior over cosmic distances. Some assumptions regarding the nature of energy loss and the applicability of certain theories remain unresolved.