Re: Intelligent alien life
To Dr. Crank.
Sure, there may be intelligent species sitting at home and playing philosopher. However, it seems to be a law of nature that every species has a drive to disperse. An intelligent species would have individuals willing and keen to explore outside what we consider to be the norm. Humans certainly have enough individuals willing to put their lives at risk to go somewhere no-one else has ever been.
It seems to me that, while a few species might be happy stay-at-homes, others will be expansionist. If there have been more than a tiny number of intelligent species in our galaxy, over 6 billion years, it would be strange if some had not explored and colonised widely. With a maximum of 10 million years to fully populate the entire galaxy, we should have no problem seeing signs of those beings.