SUMMARY
This discussion centers on the feasibility of measuring the universe's expansion through the angular size of galaxies over time, specifically questioning the validity of the Doppler interpretation of the redshift/distance relationship. Participants highlight that while the concept of "angular diameter distance" is established in cosmology, the predicted changes in galaxy size are minuscule and currently beyond the precision of existing telescopes. The consensus indicates that while measuring individual galaxy subtended angles over a 5-, 10-, or 20-year period is theoretically interesting, the practical limitations of current technology render such measurements unachievable.
PREREQUISITES
- Understanding of "angular diameter distance" in cosmology
- Familiarity with the Doppler effect and redshift/distance relationship
- Knowledge of Hubble's Law and its implications for galaxy motion
- Basic principles of astronomical measurement and observational limitations
NEXT STEPS
- Research "angular diameter distance" and its role in cosmological models
- Study the implications of Hubble's Law on galaxy motion and expansion
- Explore advancements in telescope technology for measuring distant galaxies
- Investigate alternative theories to the Doppler interpretation of redshift
USEFUL FOR
Astronomers, cosmologists, and astrophysics students interested in the methodologies of measuring cosmic expansion and the implications of redshift interpretations.