From rgould@cfa.harvard.edu Tue Aug 6 03:28:38 2002 Date: Mon, 5 Aug 2002 10:26:01 -0400 From: Roy Gould To: esp@tapir.caltech.edu, paul.hertz@hq.nasa.gov Cc: dfl@astro.as.utexas.edu Subject: Roadmap and Life Sterl and Paul, I think the SEU theme really does address the deepest mysteries of why life exists in the first place: The physical universe may seem like a remote and forbidding place, but in its every detail it seems to have had the emergence of life in mind -- to put it provocatively. For example: Had the universe expanded just a little slower, all the hydrogen atoms would have been consumed -- and with them, any chances for water and life. Had the universe expanded faster, then galaxies would not have formed and life would not exist. Why is the universe so finely tuned? The neutrino seems like a silly and useless particle, yet in one second of its lifetime it triggers the supernova blast which spreads the chemical elements needed for life. Why should stars be stable for just long enough for intelligent life to evolve? Sure there may be extra dimensions of space -- but for gravity to produce the stable orbits conducive to life demands the three large dimensions we just happen to observe. Galactic ecology seems equally fine tuned -- with regions that are just hot enough and just cold enough for star and planet formation. One could go on... Astrophysicists -- at least at the Center for Astrophysics -- tend to be conservative about these "cosmic coincidences," but I think that's a mistake if the goal is to excite the public. NASA's vision is the grandest in all of science and it surely encompasses the quest to find out -- not just how the universe is put together, but why the universe was put to together to be so wonderfully hospitable to life. Although the roadmap wisely focuses on attainable science goals, the larger questions are implicitly there, and perhaps warrant a sentence to make them explicit? Cheers, esp@tapir.caltech.edu, paul.hertz@hq.nasa.gov Roy