Let's say 200 billion (suitable) stars. Let's say 20% of them have planets around them. If our own system is in any way typical, we can say that about 2 of thos

Let's say 200 billion (suitable) stars. Let's say 20% of them have planets around them. If our own system is in any way typical, we can say that about 2 of those planets can sustain life. Let's say life develops maybe 30% of the time and 'intelligence' 5% of that (I think this is extremely generous). Then let's say technology (meaning they can broadcast radio signals) develops out of 10% of those. The last part is pretty crucial, the "lifetime" of these civilizations. What it means for this discussion is the amount of time they are broadcasting unencrypted radio signals. Let's give them 500 years (again, I think this is really generous). That should give us 6 civilizations in the galaxy at any given time. Sorry but you're just not going to find them.