Just to throw in my two cents on the whole time and aliens thing. I think there are very few aliens in the universe. Like Demis said, we would see signals if they were prevalent. However, I think the main issue is the sheer distance away that life could be. If they are 1 billion light years away and they were equally as sophisticated as us at this exact moment. Then we wouldn't see that progress for 1 billion years. So we may very well not be the first intelligent life but we may not know it for billions of years. Because it will physically take that long for the light to reach us.<br><br>In regards to time. Time itself in my opinion, does not exist. Time is really just a human made concept. Basically defined as the number of times our planet spins around the sun. Or the interactions between specific elemental particles. There really is no such thing as "time". Its really just the relative measure of how matter moves in relation to other matter. However, time as a concept does make things far easier to explain on a lower level.