sfgate.comAre we alone? Scientists revisit the question of aliens before National UFO Day(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.) Kevin Knuth, University at Albany, State University of New York (THE CONVERSATION) Are we alone? Unfortunately, neither of the answers feel satisfactory. To be alone in this vast universe is a lonely prospect. On the other hand, if we are not alone and there is someone or something more powerful out there, that too is terrifying. As a NASA research scientist and now a professor of physics, I attended the 2002 NASA Contact Conference, which focused on serious speculation about extraterrestrials.