3 ms·

A root fact of my philosophy is the unrefutable claim that I exist, and am alive, so the 1 in 10^22 seems very reasonable.

pfdietz 4y ago
Not 1 in 10^21, or 1 in 10^23? Where exactly is this number coming from? You are implicitly assuming a probability that life can arise. Don't you think that number has to be informed by an actual theory of how life arises, not inferred just from your own existence? And in fact, you can conclude nothing from your own existence. Observer selection bias.
- inanutshellus 4y ago
  This thread comes across as bickering, and detracts from OP's original euphoric "wow" message.
  - mbostleman 4y ago
    Orthogonal and bickering, but I find it interesting. I can keep two thoughts going at once. Sort of.
- ziddoap 4y ago
  What an oddly pedantic comment. 10^21, 10^22 and 10^23... Whichever number, the point that the parent poster was making doesn't change at all. >You are implicitly assuming a probability that life can arise. What are you suggesting? We're all actually not alive? Come on.
  - pfdietz 4y ago
    No, it's not oddly pedantic. It's more an expression of anger, because this sort of argument is common among SETI people. It's a very common error: there's lots of opportunities for life to arise, therefore life must be common in the universe. And this is utter bullshit. Probability does not work that way!
    - haswell 4y ago
      > there's lots of opportunities for life to arise, therefore life must be common in the universe. And this is utter bullshit. Why anger? And will you expand on why this is utter bullshit? In what way does probability not work this way? You are making strong assertions without expanding on why you believe those assertions. Your assertion also goes against some pretty big names in the field; not that big names are automatically trustworthy, but they do seem to carry more weight than a random HN comment (no offense).
      - pfdietz 4y ago
        The argument that gets my goat is basically this: "if N is large enough, then for any probability p > 0, N p > 1." And that's clearly false. The SETI people making this busted argument are implicitly assuming p, the chance that life arises on a suitable world, is not "too small". And there is no basis for making that assumption.
        johnday 4y ago
        On all of the Goldilocks planets we have so far been able to image with the resolution needed to determine the presence of life, we have determined the presence of life. That is not mathematically rigorous, but it is, from the Bayesian perspective, enough to move the needle.
        pfdietz 4y ago
        Observer selection bias blows that argument out of the water. Ask yourself: if life were extremely rare, what would be different here on Earth? Nothing, because life has to have started on Earth for us to be here to be thinking about it.
        thaumasiotes 4y ago
        > That is not mathematically rigorous, but it is, from the Bayesian perspective, enough to move the needle. That is obviously false; zero observations will never cause a Bayesian adjustment.

pfdietz 4y ago

Not 1 in 10^21, or 1 in 10^23? Where exactly is this number coming from? You are implicitly assuming a probability that life can arise. Don't you think that number has to be informed by an actual theory of how life arises, not inferred just from your own existence? And in fact, you can conclude nothing from your own existence. Observer selection bias.

inanutshellus 4y ago
This thread comes across as bickering, and detracts from OP's original euphoric "wow" message.
- mbostleman 4y ago
  Orthogonal and bickering, but I find it interesting. I can keep two thoughts going at once. Sort of.
ziddoap 4y ago
What an oddly pedantic comment. 10^21, 10^22 and 10^23... Whichever number, the point that the parent poster was making doesn't change at all. >You are implicitly assuming a probability that life can arise. What are you suggesting? We're all actually not alive? Come on.
- pfdietz 4y ago
  No, it's not oddly pedantic. It's more an expression of anger, because this sort of argument is common among SETI people. It's a very common error: there's lots of opportunities for life to arise, therefore life must be common in the universe. And this is utter bullshit. Probability does not work that way!
  - haswell 4y ago
    > there's lots of opportunities for life to arise, therefore life must be common in the universe. And this is utter bullshit. Why anger? And will you expand on why this is utter bullshit? In what way does probability not work this way? You are making strong assertions without expanding on why you believe those assertions. Your assertion also goes against some pretty big names in the field; not that big names are automatically trustworthy, but they do seem to carry more weight than a random HN comment (no offense).
    - pfdietz 4y ago
      The argument that gets my goat is basically this: "if N is large enough, then for any probability p > 0, N p > 1." And that's clearly false. The SETI people making this busted argument are implicitly assuming p, the chance that life arises on a suitable world, is not "too small". And there is no basis for making that assumption.
      - johnday 4y ago
        On all of the Goldilocks planets we have so far been able to image with the resolution needed to determine the presence of life, we have determined the presence of life. That is not mathematically rigorous, but it is, from the Bayesian perspective, enough to move the needle.
        pfdietz 4y ago
        Observer selection bias blows that argument out of the water. Ask yourself: if life were extremely rare, what would be different here on Earth? Nothing, because life has to have started on Earth for us to be here to be thinking about it.
        thaumasiotes 4y ago
        > That is not mathematically rigorous, but it is, from the Bayesian perspective, enough to move the needle. That is obviously false; zero observations will never cause a Bayesian adjustment.