Are we special or unique? Are we, as advanced, thinking beings, at all significant? These and more were powerful questions posed by Dr. Caleb Scharf, director of the Astrobiology Center at Columbia University. Dr. Scharf has a Ph. D from Cambridge University, and has worked with NASA, consulted for the Discovery and Science channels, authored multiple books, and runs the Life, Unbounded blog through Scientific American. His current position at Columbia University entails investigating the possibility of life elsewhere in the universe.
Dr. Scharf’s talk at Stevens took place on Wednesday in Babbio 122, and focused on his new book, The Copernicus Complex. The book explores deep human questions about our existence, including how probable life and humans were. Dr. Scharf opened by saying that this used to be a purely philosophical question, but new science allows us to estimate this.
Dr. Scharf spoke about cosmic mediocrity, which is the principle that the circumstances of life on Earth are not special; therefore, life should be elsewhere in the universe. He claims that there may in fact be evidence to the contrary of this, and that there appear to be some properties “fine-tuned” for life. Through research over the last 20 years, we now know that the universe makes planets in great abundance, and are confident that within 20 light years of the sun, there exists at least one Earth-like planet.
However, planets are extremely diverse, and there are different categories of planets. When we compare our solar system to others to see if we’re ordinary or not, we get interesting results. The answer is actually no; we’re not that ordinary. Fewer than 1 in 100 planetary systems physically resemble our solar system.
So, is complex-celled life on Earth a “rare” occurrence? Dr. Scharf poses an interesting example here that has to do with perspective and the way in which we interpret things after an event. His example is as follows: A friend from high school with whom he hadn’t spoken in years calls him up one morning and they chat for a bit. This friend has tickets to a baseball game in the area, and is wondering if he would like to go. Of course they go together, but on their way, they get stuck in heavy traffic and arrive at the stadium late and in a different section than they should be. So, as they’re making their way to the section they should be in, they stop because a particularly good batter steps up. The batter hits the ball, and it lands right in his hands. So he thinks, “Holy crap! If my friend hadn’t called me and we didn’t get stuck in traffic and we didn’t get here late then I wouldn’t have been in this spot at this moment to catch this ball!”
The reality of it is, of all the spectators in the stadium, one of them had to catch the ball. If he didn’t, someone else would have. So, was it really that special that all those things happened to get him to that point? Probably not. Similarly, our planet is a spectator in a stadium, but we just don’t know if there are any other spectators. We caught the “ball” of life, but there’s nothing to say there aren’t other spectators that caught other balls.
Dr. Scharf closes with just as powerful a statement as that which he opened with. “As unique and special as we are, there seems to be very vast potential for other equally special planets and life to emerge elsewhere. So maybe we’re special, but not exceptional.
Great post & it sounds like an intriguing lecture. For me the wider issue of discussing ‘life elsewhere’ is that, because we have absolute proof of just one life-bearing planet, all our current arguments about life elsewhere rest on induced logic. A debate that has been well entangled with our sense of exceptionalism, certainly at popular level. That, paradoxically, also provokes popular supposition that the ‘aliens’ will be mirrors of ourselves – witness the ‘ufo’ phenomenon in which, every time, the ‘aliens’ are bipedal primates who are the sole intelligent life from their world, often here to show us the error of our ways. This is such a culturally-bound image that these things, very clearly, are actually products of our own thinking.
But I think that the notion of life being ‘like us’ has also coloured the scientific debate, not least in the fact that we have been looking for ‘Earth like’ worlds, despite growing evidence that life might well emerge more commonly in (say) sub-surface oceans such as those on Europa or Enceladus. Debate is, of course, essential – and science obviously begins with a hypothesis; but from there we have to obtain proper data. Therein, of course, is the problem. Ice-drilling probes to Europa (several of them, as we learn from the first experiments and refine our questions), space-borne interferometry telescopes that can resolve Earth-size planets around other systems and so forth are all technically possible, just hideously expensive and many years in the making. And given current attitudes around the world, I can’t see the money being forthcoming. Sigh…