Hi Ethan, I know you have said that traveling at light speed, only 6% of the universe is currently reachable. That is really an amazing number. But if we assume a more realistic speed, like 10% of light speed, then what percent of the universe is currently reachable? I assume this same problem would be true for any alien civilizations. It seems like this calculation alone slams the door on the concept of aliens ever visiting Earth, or visa versa? Thanks for your comments . . .