On the Spontaneous Genesis of Photons in an Expanding Universe
G.R.Dixon, February 5, 2007
In 1964 Penzias and Wilson discovered universal, isotropic radiant noise corresponding to black body thermal radiation at approximately 3 K. This radiation is presumed to be an artifact of the big bang expansion. The idea is that, as a consequence of the big bang, the universe’s radius has expanded by a factor S. Concurrently the mean wavelength of any photons, present in the initial fireball (and since absorbed and re-emitted), has presumably increased by the same factor S. Since a photon’s energy is hc/l, the mean photon energy has evidently decreased by the factor 1/S.
Let us say that (a) the total energy has been conserved, and (b) f, the fraction of the total energy tied up in radiation, has not changed. Let l be the initial average photon wavelength, and l’ be the present wavelength. If the initial total number of photons was N, then Nhc/l = fE. If the present number of photons is N’, then N’hc/l’ = Nhc/l, and N’ = (l’/l)N = SN.
Based on assumptions (a) and (b) above, the total number of photons has not remained constant (as is sometimes suggested). Hypothetically, as the universe expands there is a more or less spontaneous genesis of additional photons at ever-increasing wavelengths. A similar "stimulated" genesis is discussed in another article on this site, entitled "The Stimulated Genesis of Radiant Energy from Electromagnetic Field Energy."