We must be alone, I mean look at how far our radio broadcasts have gone already, and no aliens have picked up our signals!





As an aside, we are currently searching for alien radio frequencies in single bands, this is ridiculously stupid as it would be an extremely ineffiecent and unsecured way for aliens to communicate. We do the same on earth; when we send data (be it emails, phone calls etc) we do not send on a single band. We break up the data into packets with a "key" that are then "unlocked" and reassembled when they get to the other user. That is what lead the theorectical physicist Kaku to say "We could be in the middle of an intergalactic conversation, and we wouldn't even know."