Tonight's guest, Dr. David Darling, has pondered the idea of life in the universe. Many scientists have found the popular portrayal of humanoid-styled aliens as being statistically unlikely and a case of anthropomorphizing. "Looking at the diversity of life on Earth and thinking about how it has evolved should convince anyone that any aliens will have as much resemblance to us as a doorknob," said Daniel Altshculer, the director of the Arecibo Observatory.
Certainly it's a difficult task to imagine life so dissimilar to ours, that to us it wouldn't even be life. "Our kind of life, biochemical life- needs water...But it wouldn't surprise me at all that we found other kinds of non-water based life. You can find self-replicating vortices in the atmosphere of the sun. There are all sorts of self-reproducing systems in all sorts of environments," said biology expert Dr. Jack Cohen in an interview(1) on ThinkQuest.
One topic that's been batted around in both scientific and science-fiction worlds is what might be an alternative to the carbon-based life forms that we know. Silicon-based life is one of the most frequently conjectured upon, as silicon's crystalline structures are known to grow in a variety of life-like structures. Though it does bear some atomic similarities to carbon, silicon's chemistry appears to be somewhat problematic for carrying out certain biochemical processes. "The complex dance of life requires interlocking chains of reactions. And these reactions can only take place within a narrow range of temperatures and pH levels. Given such constraints, carbon can and silicon can't," Prof. Raymond Dessy wrote in Scientific American.
1. http://library.thinkquest.org/C003763/index.php?page=interview05&tqskip=1