So was watching [ame=http://www.youtube.com/watch?v=NA-ZJNKfNZo&feature=BFa&list=PL0F9D6331E42A5778]Neil deGrasse Tyson: "Adventures of an Astrophysicist" [4/11] - YouTube[/ame] and I had the thought, if space is expanding (because of dark energy) then shouldn't there be a point we can look at that would be right at the point where galaxies are passing from "just close enough for us to see" to "expanding too fast for us to ever see" kinda like we can look at the point that light was able to travel (wmap image) I wonder if 1) the universe is old enough for galaxies to have reached that far, they would have to be very old even compared to the universe we know now (14? bil years old) 2) if it isn't how old would that galaxy have to be to reach whatever age it would take
Im sorry i cant watch the video since im using an old cellphone right now. Anyway, is your question in relation to the universe expanding more rapidly than in the past? If that be the case, i think you have a point. As far as the math inolved to figure out how old they would have to be.... I cant offer anything there