Discussion Overview
The discussion revolves around the possibility of directly measuring the expansion of the universe by assessing changes in the subtended angles of galaxies over time. Participants explore the implications of the Doppler interpretation of redshift and distance, questioning whether such measurements could provide independent confirmation of universal expansion.
Discussion Character
- Debate/contested
- Exploratory
- Technical explanation
Main Points Raised
- Some participants propose measuring individual galaxy subtended angles over time as a method to assess universal expansion.
- Others question the validity of the expansion of the universe, suggesting that alternative interpretations of redshift exist.
- One participant notes that galaxies do not expand in the same manner as the universe, indicating that gravitationally bound objects do not recede from each other proportionally to distance.
- Concerns are raised about the feasibility of detecting small changes in angular size over short time periods, with calculations suggesting that the expected changes are too minuscule to measure accurately with current technology.
- Participants discuss the limitations of current observational techniques, including the precision required to distinguish very small differences in size of distant galaxies.
Areas of Agreement / Disagreement
Participants express differing views on the validity of measuring galaxy subtended angles as a means to confirm universal expansion. While some acknowledge the theoretical framework for such measurements, others challenge the practicality and the assumptions underlying the expansion model.
Contextual Notes
Participants highlight limitations related to the precision of measurements and the assumptions about galaxy stability over time. The discussion also reflects on the challenges posed by the vast distances involved and the inherent difficulties in measuring angular sizes of galaxies accurately.