### From Pioneer to the Speed of Light

Interesting exchange on Rand Simberg's Transterrestrial Musings. The writer started about the Pioneer Anomaly, but then realized the article he was linking was 2 years old. The Pioneer Anomaly may be old news, but it led to an interesting discussion:
ED MINCHAU: Let’s open up the speed of light can of worms. Rearranging some of the fundamental formulas involving the Planck constant can make h and pi disappear from the equations giving us GM=tc^3. Put another way, if the mass of the universe is a constant and the gravitational constant is a constant and age of the universe is not a constant, then the speed of light cannot be a constant. Alternatively, if c is a constant then one or both of G and M must be a variable function with respect to time.
RYAN: Lots of different ideas have been batted around, personally I like the idea that the speed of light is actually slowing down as a function of time.
c(t)=((GM)^1/3)/(t^1/3)
That is the speed of light is slowing down as the inverse cubed root of the age of the universe. If your meter stick is contracting (the meter is defined by c) then there is an apparent increase in speed. Now days, with t being about 14.5 billion years, that makes that change tiny. However, in the early universe this would have looked different. More like a huge expansion of the universe. From what I can tell this matches the supernova and CMB data better than all that hockus pokus about dark energy/matter. Maybe I just like it because I understand it and I never could understand the dark energy argument. This also answers several other small nitpicking loose ends like, The Dim Young Sun Paradox, and The Receding Moon Paradox. But it would cut all those Dark Energy/Matter grants, so don’t expect this idea to gain a whole lot of big science backing.
ED MINCHAU: I should really read all the comments before posting. Yeah, Ryan, I think Louise Riofrio is on to something with that equation.
JOHNX: I commend these gents for doing all of this data research. However, moving from any old data compilation program to a new one, say C++ is always fraught to errors. I know (moving from Cobol to newer systems — nothing was perfect).
Nevertheless, I think Ryan and Minchau are on to the right idea. Possibly, scientists can remove the idea of “dark energy” and “dark matter” for which there appears to be no answer except for mathematical plugs.
Thank you ED, RYAN and JOHNX! It is always nice to hear that people worldwide are following the equation! There is more reason than ever to believe that someone is "on to something."