c is commonly used to represent the speed of light[1]. The commenter was saying that an action sufficiently far away cannot affect you immediately, because the

c is commonly used to represent the speed of light[1]. The commenter was saying that an action sufficiently far away cannot affect you immediately, because the information of that action's occurrence cannot move faster than light. I believe this is generally regarded as true by physicists, although there are some ideas for circumventing this limitation. I think they were making a joke. [1] http://en.wikipedia.org/wiki/Speed_of_light http://en.wikipedia.org/wiki/Speed_of_light