The lack of solid proofs are due to the equipments used by NASA and other space organizations or scientists.
We've been using telescopes, a ridiculous method, and lately, with SETI, some few radio frequencies. Not unreasonable, given that aliens are like us... but why should that be true?
Suppose we found out how to increase head size, or produce more efficient folding, or better, connect ourselves to our computers? Where would our intelligence go then? In the latter case, the practical limits would be... well, I certainly can't even begin to envision it. Now, given that we could be, let us conservatively say, 100 times more intelligent than now, how would we signal... what indeed would our picture of the universe be, our physics, our electronics? We are not now 100 times smarter than dogs. How would our physics compare with our present idea of physics? Etc. You see my point? To aliens, if they notice us at all, we are, until we can consciously increase our intelligence, merely another species of animal on this planet. So why should they want to contact us, any more than we would want to contact those dogs? And how would we notice or understand it, if they did, any more than dogs could conceive, build, and use a radio set?
Lets take another theoretical case...
Now, if I were an alien civilization faced with that possibility, vs. living in the cold, hard, limited real universe, hey, why not? So the second theory is that we can't contact them because when a civilization gets advanced to that stage, they just all move into their computers and live happily ever after, in a virtual heaven of their own design, with the computer protected behind layers of armor and powered by something reasonably perpetual. When that happens, why in the world should they explore?
Last edited by PotterManiac on Fri Oct 02, 2009 9:20 am; edited 1 time in total (Reason for editing : Title Change)