>The main thing the speed of light prevents is a single civilization staying together as a galaxy sized empire. It seems to me that, in principle, a ruling cla

>The main thing the speed of light prevents is a single civilization staying together as a galaxy sized empire. It seems to me that, in principle, a ruling class could set itself apart from humanity and conduct the business of a galactic government -- ahem, a galactic enlightened dictatorship, with its own timing. For example, Alice and Bob live on Trantor, and are employees of the Galactic Federation. They constantly travel [at the same fractions of the speed of light] to clusters located in different galactic hemispheres, and, thanks to almost identical rates of time dilation in their [perhaps carefully chosen] travels, they meet every weekend of their proper time. They live happily as a family in the headquarters of the government, to the rhythm of the passing of countless generations on the myriad planets of the federation.