It seems that wherever I go thoughout the web where people are discussing Physics in general and the velocity of light in particular, they seem to always assume that the light they are referring to is relative to an observer on the Earth. But what happens if there were no Earth, and no Sun, and no planets, and no Stars, and no Big Macs, and no.... well, you get my point. Imagine a universe where there is absolutely nothing else except a lonely bundle of photons. Since there is nothing else to reference the light to, how could we know how fast it is moving, and in what direction (ignore the fact that "we" are measuring the light without existing in the same universe along with the light. After all, this is just a thought experiment!)? Does light always move at "C" even if there were nothing else to reference it to? Another question is, does light always have to be moving? And if so, then WHY? Does it continue moving forever, or does it eventually lose all of its energy and finally come to rest? could light ever exist without motion? Thanks!