(May 9, 2019 at 12:13 pm)vulcanlogician Wrote:(May 9, 2019 at 11:18 am)Anomalocaris Wrote: The third is entirely relevant to the thesis. Even if we exhaustively eliminated any possibility of any technological civilization from every part of the entire universe whence any indication of any technological civilization can even be theoretically be accessible to us, we would have ruled out the presence of technological civilization from just a few % of the volume of the observable universe, and just for one single conical slice of time. But we are so far from having exhaustively ruled that out, that to first, second and third degree of approximation we can say we are 0% of the way there.
In other words, we are not in, and has no prospect of ever being in, any position to observationally contradict the probabilistic assessment that other technological civilization likely exist in some numbers elsewhere in the universe.
Even if the average distance between any technological civilization that ever arise is 1 billion light years when they arise, there can still be >10,000 technological civilizations that arose within the observable volume of universe.
Finding a second data point is crucial to making any determination as to how common life is in the universe. As it stands now, the size of the universe cannot tell us a thing. In order to make any claims about the abundance of life in the universe (or lack thereof) we need:
1) To find another example of life. (We haven't found one yet.)
OR
2) Figure out the probability of abiogenesis. (We have no clue how probable abiogenesis is.)
As for technological civilizations and/or advanced life on other planets, we can assume that IF abiogenesis is fairly common, advanced lifeforms in the universe will also be very common. If advanced life forms are common, then it seems plausible that other technological civilizations exist somewhere out there.
The issue discussed in the video is that (for all we know) the chance of abiogenesis could be so infinitesimally small that even in an area many times the size of our observable patch of the universe, it may be unlikely for it to happen more than once.
If this is true, then it is useless to speculate about other technological civilizations because (without abiogenesis) such civilizations won't even have a chance to emerge.
Second data point as in a second independent abiogenesis as you conceive it is not the only way to constrain deductions based on current understanding of possible chemical process of abiogenesis. We actually do have a an alternative data point. That is how long did it take for abiogenesis to occur in the one instance where it is known to have occurred, after conditions can reasonably be said to have allowed it.
The answer is very quickly. That is a strong data point, as strong as discovering several independent occurrence of abiogenesis on other planets, for the contention that abiogenesis is a easy process to facilitate on a time scale of hundred million years in geological and chemical conditions prevalent on early earth.
