Discussion Overview
The discussion revolves around the relationship between redshift (##z##) and the scale factor (##a(t_e)##) in cosmology, particularly focusing on what these concepts imply about the size of the universe at different epochs. Participants explore theoretical implications, numerical examples, and the limits of redshift values.
Discussion Character
- Exploratory
- Debate/contested
- Technical explanation
Main Points Raised
- One participant defines the relationship between redshift and scale factor, suggesting that a redshift of ##z=2## implies the universe was ##\frac{1}{3}## times its current size.
- Another participant questions the assumption that there should be a significant difference between redshifts of ##z=2## and ##z=6##.
- A different participant proposes that at a maximum redshift of ##z=10##, the universe would have been significantly smaller, estimating a current scale of 45 billion light years compared to a much smaller size in the past.
- Some participants assert that the maximum value of redshift is not limited to 10, referencing the Cosmic Microwave Background Radiation (CMBR) which has a redshift of ##z=1089##.
- One participant cites external sources that suggest redshift can be as high as 10, but another counters that this does not preclude the existence of higher redshifts.
- There is mention of the evolution of galaxies and the observation limitations regarding high redshift values, indicating that while redshifts larger than 10 may exist, they are not commonly observed.
Areas of Agreement / Disagreement
Participants express differing views on the maximum possible value of redshift, with some asserting it can exceed 10 while others believe it is capped at that number. The discussion remains unresolved regarding the implications of redshift values on the size of the universe.
Contextual Notes
Participants reference various sources and numerical examples, but there are uncertainties regarding the assumptions made about redshift and the corresponding scale factors. The discussion includes speculative reasoning about the implications of redshift on cosmic size.
Who May Find This Useful
This discussion may be of interest to those studying cosmology, astrophysics, or anyone curious about the implications of redshift in understanding the universe's expansion and size at different epochs.