5 ms·
That is interesting, and it changes my math a bit, though not to your favor; >Based on the survey, scientists predict that there should be 1 billion Earth-size
by cortic 6y ago
That is interesting, and it changes my math a bit, though not to your favor;
>Based on the survey, scientists predict that there should be 1 billion Earth-sized worlds in the Milky Way galaxy at present, a good portion of them presumed to be rocky. That estimate skyrockets when you include the other 100 billion galaxies in the observable universe.
So for us to be near the first, near enough not to trip on Fermi's paradox, and allowing a short 5 billions years for these planets to have existed on average; we are (1000 billion X 5 billion) to 1. Which still needs one hell of a filter to explain.
- drichel 6y agoWell actually you are starting to convince me of the opposite. My horizon is limited to the galaxy. The hypothesis here is that the Earth is an early bloomer in the Milky Way. Then we are dealing with 1 billion Earth-sized planets, only a fraction of which is orbiting stars capable of sustaining life, only a fraction of which in the habitable hone around their stars... They also need to be in the right region of the galaxy in which heavy stars were formed and died with the right conditions to produce heavy elements. Candidate planets also need to be far enough from sources of gamma ray bursts. And finally, even if they have life, it still needs to develop in the right direction for it to be complex enough and interested in reaching out and colonizing the galaxy. So, the odds are a billion times a tiny fraction to one, a sustainable hypothesis as far as I am concerned. I believe I saw a model somewhere, predicting that most habitable planets are yet to form in our galaxy, but I did not bother to look hard enough for references.