Tuesday, November 26, 2013

We Are Alone In the Universe

Speaking in Nairobi
Are we alone in the universe?


I recently ordered a used copy of Arizona State physicist Paul Davies' The Eerie Silence:Renewing Our Search for Alien Intelligence. Davies sums up his thoughts in his nytimes op-ed "Are We Alone In the Universe?" The bullets are:

  • "If a planet is to be inhabited rather than merely habitable, two basic requirements must be met: the planet must first be suitable and then life must emerge on it at some stage."
  • What are the chances of life starting up on a habitable planet? We have no idea. "In spite of intensive research, scientists are still very much in the dark about the mechanism that transformed a nonliving chemical soup into a living cell. But without knowing the process that produced life, the odds of its happening can’t be estimated."
  • "It is irrelevant whether the Milky Way contains 40 billion habitable planets or just a handful." Because even the simplest bacterium at the molecular level is "staggeringly complex." If there is some "complexifying principle" that drives "a chaotic mix of chemicals on a fast track to a primitive microbe" it has not been found. "No hint of such a principle has been found in laboratory experiments to re-create the basic building blocks of life."
  • While we may in the future be able to analyze the atmosphere of extrasolar planets, Davies thinks a good place to look is our own planet. What we would be looking for is "a second sample of life, one that arose from scratch independent of known life." "It could be that intermingled among the seething microbes all around us are some that are so biochemically different they could be descended only from a separate origin." 
I often step outside at night when the skies are clear and look at the stars. I am uninfluenced by science fiction. The facts are that we have no evidence of extra-earth life, and no knowledge of how abiogenesis happened. I gaze clueless into the night sky with the crazy thought that we are, probably, the only member of the set "planets hosting intelligent life."