Some people think that it is probable that there is intelligent life somewhere else in the universe. I count myself among these people. And some people believe that the earth has been visited by aliens. And that they are grayish, with strange oblong heads, huge craniums and squinting eyes. And furthermore, they believe that the U.S. government has evidence of these visits, but is deliberately covering up these facts. I do not identify with this group of people.
But that brings up an interesting question. I am not alone in thinking there might be intelligent life somewhere else in the universe. Many reputable scientists feel the same way. (Just look at the SETI program.)
So what would these alien life forms look like? Obviously, they would probably vary from planet to planet. But would they share anything in common–like bipedal locomotion, for example? Can science tell us anything about this hypothetical area of biology? Are there somethings that they don’t know–and may never know, about what alien life forms might look like?