The issue of light-speed in the early cosmos is one which has received some attention recently in several peer-reviewed journals. Starting in December 1987, the Russian physicist V. S. Troitskii from the Radiophysical Research Institute in Gorky published a twenty-two page analysis in Astrophysics and Space Science regarding the problems cosmologists faced with the early universe. He looked at a possible solution if it was accepted that light-speed continuously decreased over the lifetime of the cosmos, and the associated atomic constants varied synchronously. He suggested that, at the origin of the cosmos, light may have travelled at 1010 times its current speed. He concluded that the cosmos was static and not expanding.
In 1993, J. W. Moffat of the University of Toronto, Canada, had two articles published in the International Journal of Modern Physics D (see also ). He suggested that there was a high value for 'c' during the earliest moments of the formation of the cosmos, following which it rapidly dropped to its present value. Then, in January 1999, a paper in Physical Review D by Andreas Albrecht and Joao Magueijo, entitled "A Time Varying Speed Of Light As A Solution To Cosmological Puzzles" received a great deal of attention. These authors demonstrated that a number of serious problems facing cosmologists could be solved by a very high initial speed of light.
Like Moffat before them, Albrecht and Magueijo isolated their high initial light-speed and its proposed dramatic drop to the current speed to a very limited time during the formation of the cosmos. However, in the same issue of Physical Review D there appeared a paper by John D. Barrow, Professor of Mathematical Sciences at the University of Cambridge. He took this concept one step further by proposing that the speed of light has dropped from the value proposed by Albrecht and Magueijo down to its current value over the lifetime of the universe.
An article in New Scientist for July 24, 1999, summarised these proposals in the first sentence. "Call it heresy, but all the big cosmological problems will simply melt away, if you break one rule, says John D. Barrow - the rule that says the speed of light never varies." Interestingly, the initial speed of light proposed by Albrecht, Magueijo and Barrow is 1060 times its current speed. In contrast, the redshift data give a far less dramatic result. The most distant object seen in the Hubble Space Telescope has a redshift, 'z', of 14. This indicates light-speed was about 9 ( 108 greater than now. At the origin of the cosmos this rises to about 2.5 ( 1010 times the current value of c, more in line with Troitskii's proposal, and considerably more conservative than the Barrow, Albrecht and Magueijo estimate. This lower, more conservative estimate is also in line with the 1987 Norman-Setterfield Report. (Barry Setterfield, January 24, 2000)