Discussion Overview
The discussion centers on the history and prediction of cosmic microwave background (CMB) temperature variations, specifically the measurement of anisotropies at a level of 1 part in 100,000. Participants explore the origins of these predictions, the contributions of various scientists, and the theoretical frameworks involved.
Discussion Character
- Historical
- Exploratory
- Technical explanation
Main Points Raised
- One participant notes that variations in the CMB were first measured by COBE and questions whether this value was predicted and what the estimates were prior to measurement.
- Another participant discusses Robert Dicke's contributions to the prediction of the CMB while developing radar receivers, highlighting his encouragement of the Bell Labs team that first detected the CMB radiation.
- It is mentioned that Dicke, along with Jim Peebles, re-derived the prediction of the CMB in the early 1960s, although he may have overlooked earlier predictions by George Gamow and others.
- A participant references a paper by Steven Weinberg discussing expected thermal variations in the CMB based on Brans-Dicke theory, suggesting that Weinberg predicted anisotropies at the level of 10^-5, but seeks to confirm the relevant texts and publication dates.
- Another participant shares a link to a paper discussing contributions by Sunyaev and Zel'dovich, and Peebles and Yu, from 1970, which may provide additional context.
- There is mention of revisions to Weinberg's cosmology primer that include discussions on CMB anisotropies, but it is noted that these are not peer-reviewed publications specifically making predictive claims.
- A later post references a specific paper by Weinberg that offers a method for calculating CMB anisotropies, but does not clarify whether it includes predictive elements.
Areas of Agreement / Disagreement
Participants express various viewpoints regarding the history and prediction of the CMB, with no clear consensus on the precedence of predictions or the specific contributions of different scientists. The discussion remains unresolved regarding the exact nature of the predictions and their historical context.
Contextual Notes
Some limitations include the potential for missing assumptions in the historical accounts, the dependence on specific definitions of predictions, and unresolved details regarding the publication dates of relevant works.