The discussion revolves around the historical prediction of the cosmic microwave background radiation (CMBR) as a blackbody spectrum, specifically focusing on the contributions of Alpher, Herman, and Gamow in 1948. Participants seek to clarify when and how this prediction was made, exploring the context of cosmological theories and historical developments in the field.
Participants do not appear to reach a consensus on the specific historical prediction of the CMBR's blackbody nature, with some focusing on broader cosmological theories and others seeking more precise historical details.
The discussion highlights a gap in historical documentation regarding the prediction of the blackbody spectrum of CMBR, with participants noting the need for clarity on this aspect of cosmological history.
http://en.wikipedia.org/wiki/Discovery_of_cosmic_microwave_background_radiatioDicke and his colleagues reasoned that the Big Bang must have scattered not only the matter that condensed into galaxies but also must have released a tremendous blast of radiation. With the proper instrumentation, this radiation should be detectable.
http://en.wikipedia.org/wiki/Discovery_of_cosmic_microwave_background_radiationAfter 10−6 seconds, the early universe was made up of a hot plasma of photons, electrons, and baryons. The photons were constantly interacting with the plasma through Thomson scattering. As the universe expanded, adiabatic cooling caused the plasma to cool until it became favorable for electrons to combine with protons and form hydrogen atoms. This recombination event happened at around 3000 K or when the universe was approximately 379,000 years old.[8][nb 4] At this point, the photons scattered off the now electrically neutral atoms and began to travel freely through space, resulting in the decoupling of matter and radiation.[9]