[Nepharski]

The universe has no perception of what classifies as a "waste of space", therefore it is not inclined to create life elsewhere just so that you don't get lonely on your spacefaring adventures.

Really, if for some reason people find that they reach a mental brick wall when attempting to comprehend the possibility that there is no life in the universe except for on Earth, then perhaps they need to consider the possibility that they might just be refusing to accept the possibility of a lifeless universe because they don't want it to be true. People who claim to be scientific about it and make outrageous claims like "it's impossible for life NOT to exist elsewhere in the universe" are no more scientific than your average christian.

The real truth is, that nobody knows for certain how life is made, so nobody knows what the chances of it occuring are, but it's looking like life itself is either the work of a creator, or it's so complicated that the chances of it occuring elsewhere are so remote that the universe is not big enough for it to occur elsewhere. As much as we understand about how a single cell works (it's essentially a very advanced self replicating, self sustaining biological nanobot) we still cannot even come close to replicating it in the laboratory - now, if we can't do it in the laboratory with all our advanced tools and such, then what do you think the chances are of life magically occuring on a bunch of big rocks in the night sky?

Thank you, Mr. Overly-Serious-Commentator. I have no real idea if there is life out there. However, "Sometimes I think the surest indicator of other intelligent life in the universe, is that none of it has tried to contact us."