Discussion Overview
The discussion revolves around the implications of Hubble's expansion on the conservation of energy, particularly in relation to the redshift of electromagnetic waves as the universe expands. Participants explore theoretical aspects of energy in the context of General Relativity and the behavior of photons over vast distances.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant suggests that as the universe expands, the wavelength of radiation increases, leading to a decrease in frequency and thus a loss of energy, based on the equation E=hf.
- Another participant argues that the redshift and the velocities of galaxies are due to the expansion of space itself, not the galaxies moving through space, questioning the applicability of the speed limit of light to space expansion.
- A different participant emphasizes that their concern is specifically about the energy of waves, noting that a photon created at a frequency of 100 Hz would lose energy if its frequency drops to 10 Hz due to expansion.
- One participant states that conservation of energy does not apply in General Relativity, indicating that energy is not a well-defined quantity in this framework.
- Another participant reiterates the point about energy conservation in General Relativity, suggesting that it depends on the definitions of "energy" and "conserved."
- A participant shares a link to a resource discussing energy conservation in General Relativity, noting that in special cases energy may be conserved, but generally it is more complex.
- One participant expresses skepticism about the explanation involving pseudo-tensors and gravitational energy, indicating a desire for a more coherent answer regarding energy conservation in the context of General Relativity.
- A participant references a related archived topic and a paper proposing a static universe, expressing skepticism about its credibility due to its unorthodox stance in modern cosmology.
Areas of Agreement / Disagreement
Participants do not reach a consensus on the implications of Hubble's expansion for energy conservation. Multiple competing views are presented regarding the nature of energy in General Relativity and the interpretation of redshift.
Contextual Notes
Participants acknowledge limitations in understanding energy conservation in General Relativity, with some expressing uncertainty about definitions and the applicability of concepts like pseudo-tensors.