Quote Originally Posted by tertius View Post
Well yes and no, yes the many other civilisations increase the probability and of course we are only affected by our own timeline but the timelines of one or more other civilisations need to intersect with ours, so their (presumed) short existence is relevant.

However, the chances of there being “billions” of spacefaring civilisations is I think not large.
Spacefaring maybe so. But looking at the numbers for fun I did a quick google to see how many stars there are, there are approximately 100 Billion Trillion stars ( 1,000,000,000,000,000,000,000) Now if there is a 1 in a million chance of any one of those stars having planets that can sustain life that gives us 1,000,000,000,000,000 planets, if you then say that of those there is a 1 in a million chance of any of those planets having life then you get 1,000,000,000 planets with life in the universe. Now you could argue that half are more advanced and half are not, so there could be half a billion of possible spacefaring civilizations. Or if i'm 1 decimal place out 5 billion

OK so the maths is bollox but it does go to show that realistically there is a high chance of space faring life out there in the universe.

https://scienceline.ucsb.edu/getkey.php?key=3775