Comments by "belstar" (@belstar1128) on "Crowded or Lonely? The Statistics of Alien Life" video.

  1. ok if we look at the history of life on earth we know that complex multicellular life has existed for about 1/8 of the time that life existed on earth at all so far so good if there are planets with bacterial life there will definitely be some with multicellular life too. but it sees like civilization is a very rare fluke there seems to have been nothing as intelligent as humans. so in in the last 100.000 years could there have been a civilization so that makes for about a roughly 1in 40.000 chance for intelligent life but we were hunter gathers for most of our existence. the first civilizations came around 5000 years ago so that reduces it to 1 in 800.000 but these were pre industrial civilizations and we can't communicate with them. the industrial revolution started about 250 years ago but i am going to skip the early industrial revolution because we want a civilization that has discovered radio so we can communicate and is on par or slightly less advanced or more than us. so i am just going to round it off to 100 years or or about 1in 40 million .we have no idea how many stars have a habitable planet i am going to be generous and say 1% so by my very lazy amateurish Hypothesis about 1 in 4 billion stars have a civilization on par with us and as far as civilizations that can do interstellar travel and are way more advanced nobody knows and ofcourse on other planets life can be very different.
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