Right after the 1965 discovery of the CMB, F. Hoyle and his student J.N. Narlikar constructed a new version of the steady-state model, starting with Hoyle’s matter creation scalar field, and this model is the focus of the chapter. The creation of matter in the pockets near massive objects violated earlier adherence to inhomogeneity. The 1972 version of the model introduced an intriguing explanation of the CMB as a radiating of the boundary between the regions of the universe with positive and negative mass: any amount of matter entering such a boundary will act as a perfect thermalizer, with radiation of 3 kelvin reaching us from all directions. It was perhaps the first worked out model of the multi-universe. Hoyle and Narlikar argued for perfect thermalization, implying a black body spectrum. In this, their model was unlike many other unorthodoxies motivated by the erroneous measurements of 1979 indicating disagreement with the shape of the spectrum.

Keywords: The steady-state theory of Bondi, Gold, and Hoyle of the late 1940s was very much alive at the time of the CMB discovery, and the discovery prompted new variants and reformulations. The chapter argues that the theory was motivated by the fear of the untenable changing of physical laws that the evolving universe enabled. This fear resulted in adherence to a “perfect cosmological principle” ensuring the homogeneity and isotropy of the universe at all times. Bondi and Gold’s version was a theoretical framework within Newtonian universes, while Hoyle’s was developed within the General Theory of Relativity without cosmic constant while introducing a universal scalar for (constant) creation of matter. The theory faced observational obstacles (especially with the newly discovered quasars), and thus required reworking. Reworking continued after the 1965 discovery of the CMB. Other radical unorthodoxies like plasma cosmologies and the closed stationary state cosmological model were not as original, but they too have a place – they ensure we understand that current rebels against allegedly outlandish inflationary cosmology had earlier counterparts.

Narlikar and Wickramasinghe’s 1968 version of steady state theory made use of the dust grains hypothesis, while arguing that the precise measurements of the CMB spectral shape deviate from the black body shape. As critics pointed out, an unrealistic consequence of the model (CMB exceeding visible radiation by a factor of 100) was Wickramasinghe’s 1975 version; it included a very detailed account of elongated whiskers as thermalizers that compose cosmic dust. The 1990s version of steady state constructed by a larger group of authors – the usual proponents of the steady state – introduced the discrete creation of matter (“mini bangs”) in the cellular form of observed galactic structures. The motivation was to eliminate the epistemically problematic singularity of the Hot Big Bang, explain creation of matter as an inherent feature of physical laws, and introduce strong gravitational fields of galactic nuclei as the sites of synthesis of atomic nuclei (with a detailed description of the mechanisms of nucleosynthesis). The chapter discusses a number of combinations of steady state, Population III as sources, and dust grain thermalizers devised until early 2000.