necrocat219 wrote:I believe in aliens existing, almost definitely as intelligent as us. But I andwewed no, all forage is lies because
1) I believe it's impossible that we have aliens already attempt to explore earth
2) I believe there are many alien 'human' races. But they are all dead, or yet to exist. In other words, statistically speaking the chance of alien life as intelligent as us living in the same time period of us is 0
+1
The question is in fact "how
intelligent should alien 'human' races be to reach us". You can expect that if any alien civilization once existed somewhere and were as "smart" as we humans are, this civilization did not last long enough to master long range inhabited space flight

.
There has already been earlier civilization on Earth (think about Egyptians for a well-developped and long-lasting one), but it was gone in just a few thousand years. Our "modern" civilization did barely reach.... what ? ... 2 thousand ? Less ? (depends where you place its start)... But can we expect it to last several thousands (I would even say hundreds) of years more without running into such deep shit that space exploration will just be forgotten for ever ?
Sarcasms left aside, the idea is: yes, there must have been intelligent alliens many times, in many places, why not even building nice little fancy space vehicles. But as life and intelligence develops itself (on our own planet for instance), it also can vanish. If you have in mind the tremendous scales (distance and time) involved in this question (flying an UFO from one star system to another one), you see the odds that an intelligent life form breaks this distance barrier during its own existance is really nearly zero.
Same applies to humans : even if we get messages from a distance planet (other star system), we'll probably never reach there. Our civilization will not last long enough, not even speaking about a "closed sub-civilization" that would have to survive for tens, hundreds (or more) years within a spaceship during the journey...