“Where is Everybody?” asked Enrico Fermi.
‘The Zoo Hypothesis, proposed by the MIT radio astronomer John A. Ball in 1973, says that aliens may be avoiding contact with us on purpose, so as not to interfere with our evolution and the development of our societies. The human civilization could be essentially living in a “zoo” or a space wildlife sanctuary, where others populating the cosmos dare not go. By staying clear of us, they avoid interplanetary contamination.
Perhaps the aliens are waiting for us to reach a certain technological or moral point before they will talk to us. Or they may be simply trying to protect us and themselves. You’ve seen “Independence Day” – there may be a similar movie made thousands of light years away about us….’
Via Big Think