Alternative explanations of the cosmic microwave background: A historical and an epistemological perspective

Abstract

Abstract:We historically trace various non-conventional explanations for the origin of the cosmic microwave background and discuss their merit, while analyzing the dynamics of their rejection, as well as the relevant physical and methodological reasons for it. It turns out that there have been many such unorthodox interpretations; not only those developed in the context of theories rejecting the relativistic ("Big Bang") paradigm entirely (e.g., by Alfvén, Hoyle and Narlikar) but also those coming from the camp of original thinkers firmly entrenched in the relativistic milieu (e.g., by Rees, Ellis, Rowan-Robinson, Layzer and Hively). In fact, the orthodox interpretation has only incrementally won out against the alternatives over the course of the three decades of its multi-stage development. While on the whole, none of the alternatives to the hot Big Bang scenario is persuasive today, we discuss the epistemic ramifications of establishing orthodoxy and eliminating alternatives in science, an issue recently discussed by philosophers and historians of science for other areas of physics. Finally, we single out some plausible and possibly fruitful ideas offered by the alternatives.

What Is Temperature? Modern Outlook on the Concept of Temperature

“…The fundamental role of the notion of temperature becomes even more pronounced in the context of the effect of the cosmic microwave background [ 50 ]. The discovery and interpretation of the cosmic microwave background in 1965 by Arno Penzias, Robert Wilson, and Robert H. Dicke was a turning point in modern-century cosmology [ 50 ]. The discovery supported the now-well-established cosmological paradigm, broadly known as the Big Bang cosmology [ 51 ].…”

“…The physical picture underlying this prediction is simple: The baryonic number is (at least approximately at timescales comparable to the Hubble time, neglecting effects of the hypothetical proton decay and other very slow processes) a conserved quantity, and the vast majority of photons currently existing in the universe are CMB photons, so the photon-to-baryon ratio today is essentially the same as it was at the time of decoupling, at redshift. Therefore, fixing the photon density per co-moving volume, coupled with limitations on the baryon-to-photon ratio in the early universe (provided by the theory of primordial nucleosynthesis [ 50 , 51 , 52 , 53 ]), gives a unique handle on the total cosmological baryon density.…”

“…This role becomes even more significant when inertia force and gravity are treated as entropic forces [ 25 ]. The fundamental importance of the temperature of the cosmic microwave background in the grounding of basic ideas of modern cosmology is addressed [ 50 ]. The temperature of the CMB has turned out to be one of the most important fundamental physical constants limiting the value of the photon–baryon ratio in the Universe.…”

What Is the Temperature? Modern Outlook on the Concept of Temperature

“…The fundamental role of the notion of temperature becomes even more pronounced in the context of the effect of the cosmic microwave background [46]. The Probably the most significant and most frequently cited consequence of the standard hot Big Bang interpretation of the CMB is the limit the background temperature sets on the fraction of universal density which can be in the form of baryonic matter.…”

“…discovery and interpretation of the cosmic microwave background 1965 by ArnoPenzias, Robert Wilson and Robert H. Dicke was a turning point in the modern century cosmology[46]. The discovery supported the well-established now cosmological paradigm, broadly known as the Big Bang cosmology[47].…”