If you follow a science website, you have a good chance of inform about the Fermi paradox but for those who are not there will be a quick recovery here. Given the high probability that alien life exists in the universe (given the vastness of space and we continue to look for planets in habitable zones), why has not anyone been contacted yet?
If there are many more civilizations to be found, perhaps at a much more advanced stage than ours, how long the universe has been dragging on, will certainly send at least one message or inquiry or do what we are doing: desperate search for signs of life? In addition, if not, cannot we recognize the signs of a galactic colony, if a civilization makes it so that they can spread all over the world? There are many suggested solutions to this question, rang from awful to awful – but let us look at a few weirder.
One solution is that foreign civilizations are there and it is recognizable, but it is still much more primitive to know what to look for. Civilizations may be millennia old before our own, with technology we never imagined is still possible, making it impossible for us to find it. Why they could not communicate with us, physicist Michio Kaku has summed it up nicely by talking to the Daily Grail.
“Imagine walking down the streets of a country and meeting an anthill. Do we go to the ants and say, ‘I brought your trinkets? I brought you beads. I am giving you nuclear power and biotechnology. Your leader took me?” In short, if we do not try to communicate with ants, why would aliens contact us? Beyond that, even if we look directly at them, it is possible that we cannot recognize it as life, just as a head louse does not understand your head.
Another solution that was predicted the notion that we are still more primitive there than in foreign civilizations. In this version, the aliens are fully aware of us but forbid us to communicate and allow us to become isolated. Slightly better than ants, it may be that the aliens think of us as a very intelligent e.g. a dog with which we can leave emails one day if we keep up the work and develop their society.
