Tuesday, I did a class on whether there is life elsewhere in the universe. The students think this is one of the most interesting questions in science.Â
I did it in two chunks.  The first concerns the bit career scientists are involved with: the search for life in our solar system (e.g. Curiosity), the search for Goldilocks planets elsewhere in the Milky Way (e.g. Kepler) and the efforts to listen (e.g. SETI). And of course the Drake equation.
 http://www.youtube.com/watch?v=6AnLznzIjSE
The second chunk is about whether we are being visited: flying saucers, UFOs, Roswell, Alien Abductions and the like. The students are much more interested in this part. I only think about it for this class – and it strains my very being to do so. The main educational benefit is that it helps shape a discussion about what counts as meaningful evidence.Â
There is interesting irony here. Eye witness accounts of alien abduction, deeply believed by the abductees themselves, are deeply disbelieved by almost every credible scientist. Yet in other aspects of life, equally deeply believed eyewitness accounts are enough to put people on death row.
There are other ironies. There is not a jot — not a jot — of evidence there is life elsewhere, but many scientists are spending a lot of money, much of it federal tax dollars, looking for it. In contrast, there are hundreds (?I can’t find a reliable number) of US citizens who say they have been abducted by aliens visiting earth. That’s a lot of evidence.Yet so far as I can tell, there is no credible scientific effort investigating that evidence. Of course, that’s because, by and large, deeply held personal experiences are not very accessible to the rest of us. If I could go see for myself, then the investigation is on. Otherwise, there is nothing. It is just like religious experience: strong evidence to those who have the experience. Nothing to someone with a different experience. That doesn’t make it wrong. It makes it inaccessible.
The final irony struck me during class. I am trying to get the students to think about the nature of evidence, to think decide for themselves what to make of eye witness accounts and grainy shots of strange objects in the sky. Â And the Comment Wall lights up with texts from the students asking what I believe.
As if that matters. Three quarters of the way through semester, and there is still is no right answer folks. You have to think for yourselves.