Radiation, microwave background

R. W. Wilson, The cosmic microwave background radiation, pp. 113-33 in I.es Prix Nobel 1978. Almqvist Wiksell International, Stockholm 1979. A. A. Penzias, The origin of the elements, pp. 93-106 in Les Prix Nobel 1978 (also in Science 105, 549-54 (1979)). 

A. A. Penzias and R. W- Wilson (Holm-del) discovery of cosmic microwave background radiation. 

The primordial Li abundance was sought primarily because of its ability to constrain the baryon to photon ratio in the Universe, or equivalently the baryon contribution to the critical density. In this way, Li was able to complement estimates from 4He, the primordial abundance of which varied only slightly with baryon density. Li also made up for the fact that the other primordial isotopes, 2H (i.e. D) and 3He, were at that time difficult to observe and/or interpret. During the late 1990 s, however, measurements of D in damped Lyman alpha systems (high column-density gas believed to be related to galaxy discs) provided more reliable constraints on the baryon density than Li could do (e.g. [19]). Even more recently, the baryon density has been inferred from the angular power spectrum of the cosmic microwave background radiation, for example from the WMAP measurements [26]. We consider the role of Li plateau observations post WMAP. 

Cosmic microwave background radiation Fossil radiation surviving form the Big Bang with a black body temperature of 2.725 K. 

The microwave background radiation has very precisely the spectrum of a black body with a temperature... 

Fig. 4.1. Schematic thermal history of the Universe showing some of the major episodes envisaged in the standard model. GUTs is short for grand unification theories and MWB is short for (the last scattering of) the microwave background radiation. The Universe is dominated by radiation and relativistic particles up to a time a little before that of MWB and by matter (including non-baryonic matter) thereafter, with dark energy eventually taking over.

In consequence, the statistical characteristic temperature of relic radiation is fully determined in terms of relativistic invariant spectrum of the cosmic microwave background radiation and the distribution velocity function of radiating particles, i.e., is described with the following expression (compare with the results of reference (Einstein, 1965))... 

Anisotropic effects of the recorded frequency of cosmic microwave background radiation have been proposed for photon rest mass determination [20]. 

With reference to Table I, the energy usually flows frum higher levels to luwer levels—in a direction such ihut the entropy increases. Thus, cosmic microwave background radiation is defined as the ultimate heai sink. i,e il represents the ultimate in energy degradation with no lower form in which to be convened. 

T. Villela, N. Figueiredo, and C. A. Wuensche, Photon Mass Inferred from Cosmic Microwave Background Radiation Maxwell s Equations in three-Dimensional Space, Instituto Nacional de Pesquisas Espaciais, Brazil, circa 1994, pp. 65-73. 

In 1988, Riis et al. [52] observed a direction-dependent anisotropy of light in the direction of the apex of the 2.7 K microwave background radiation in the universe. These data are consistent with nonzero photon mass. The upper bound on photon mass was estimated as mT 10-65g. A compilation of laboratory data [53] established that the photon mass should not exceed 10-24 eV or even 10 26 eV. 

The isotropic microwave background radiation, observed in the vacuum, has the same wavelength distribution as a black body, which shows that the universe is closed, like a cavity, rather than open and expanding. 

The major selling point of standard cosmology is the observed isotropic microwave background radiation, with black-body spectrum. In a closed universe it needs no explanation. Radiation, which accumulates in any closed cavity, tends, by definition, to an equilibrium wavelength distribution according to Planck s formula (Figure 2.5). 

Bob nods. The Universe is filled with the remnant heat from the Big Bang, the explosion that created our Universe somewhat over 10 billion years ago. The leftover heat we measure today is called the cosmic microwave background radiation. ... 

David Spergel, Gary Hinshaw, and Charles Bennett, NASA, The Cosmic microwave background radiation, http //map.gsfc.nasa.gov/html/cbr.html... 

Cosmic microwave background radiation The uniform background radiation in the microwave region of the spectrum that is observed in all directions in the sky. Its discovery added credence to the big bang model of the universe. 

A second fact that conftonted cosmologists in the 1960s was the discovery of a radiation that permeated the universe. This radiation, called microwave background radiation, had been predicted in 1948, but the prediction attracted little to no attention. In fact. 

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