To: TimF who wrote (380 ) 3/22/2005 9:14:12 PM From: ManyMoose Read Replies (1) | Respond to of 725 Mind you I'm just a forester, but I'm used to dealing with big numbers. I cranked up Excel and did the following thumbnail analysis with my arbitrary guesses as to numbers and probabilities. It's my version of the Drake equation, I suppose--same idea, but completely off the cuff for me. The end result I get is still a minuscule 1000 habitable planets in the universe. This is my first iteration, and I did not fudge any guesses to get the answer I show. If you factor in time, the probability that there is intelligent life at the goldilocks state of development for communication, we are it. I read a number of critiques of The Privileged Planet, and was astonished that they attacked the theory as an attempt to justify God, which I do not believe that it did although religious entities seem to have accepted and incorporated it. It looked to me like the critics were desperate to prove that there is no God and were frantic that this book might prove them wrong. Number of stars in a galaxy 1.E+10 (ten billion) Number of galaxies in the universe 1.E+10 (ten billion) Number of stars in the universe 1.E+20 (Huge number) Average number of planets per star 1.E+01 (ten) Number of planets in the universe 1.E+21 (gargantuan number) Probability that a star is the goldilocks distance from the galactic center 0.000001 (one in a million = 10,000 stars per galaxy) Probability that a star has the goldilocks mass 0.1 (one in ten) Probability that a planet is in the goldilocks orbit 0.01 (One in a hundred) Probability that a planet has the goldilocks mass for habitable gravity 0.01 (one in a hundred) Probability that a planet has an iron core for a magnetic field to deflect harmful radiation 0.01 (one in a hundred) Probability that a planet has plate tektonics to recycle and mix constuents for life 0.1 (One in ten) Probability that a planet has a moon of the correct size to stabiliize earth's axis and rotation 0.1 (One in ten) Probability that large gas planets are available to intercept comets 0.1 (one in ten) Probability that a planet has the correct element mix 0.1 (one in ten) Probability that a planet has a nitrogen-oxygen atmosphere 0.1 (one in ten) Combined probability of habitability 1.00E-18 (0.000000000000000001--very small number) Estimated number of habitable planets 1,000