The analogy I’ve heard associated with Gott’s argument is this: You’re presented with a box of pingpong balls (you can’t quite see how large the box is - maybe one side of it is embedded in a wall, so you don’t know how far back it goes) and you’re told that the balls are numbered from 1 to the total number of balls, and thoroughly mixed. Poke a hole in the box, and grab one ball at random. Its number is 12. How many balls are likely to be in the box? Or the first balls’ number is 4,515,271,009 - how many balls are likely to be in the box? For the first case, you’d expect a number greater than 12 (obviously), but pretty small - it would be very unlikely that if there were 10 million balls, you happened to pull out #12. Likewise for the 4,515,271,009 case, it would be very unlikely that there were only 4515,271,010 balls and you happened to pick the one with the second highest number. Gott applies that reasoning to the human race - if the human race lasting for another 10,000 years would mean that there could be 100 trillion humans in all of history, it’s weird that you and I (the 100 billionth and 100 billionth (and one)) humans were randomly selected to be alive now - far more likely that we’re middle of the road folks in a human race that lasts only 200 years more and had only 172 billion people in total. All his calculations have a lot of assumptions - are we really picked at random from the total population of hypothetical humanity? Are possible human futures all equally likely? (no to that one, certainly), so I don’t sweat about that issue much. But for certain things, it’s a reasonable calculation to do - my house has existed since 1980, so the odds that it will collapse immediately are pretty small (but the odds tthat it will last 150 years are also pretty small).
(2 minutes later - house is still here)
Previous discussion Refute The Carter Hypothesis (Statistics & Probability)