The doomsday argument strikes me as complete and utter misguided bullshit, notwithstanding the fact that smart and careful physicists have worked on it, including J. Richard Gott and Brandon Carter, whose work in actual physics I had used extensively in my research. There are plenty of good reasons for x-risk work, no need to invoke lousy ones. The main issue with the argument is the misuse of probability.
First, the argument assumes a specific distribution (usually uniform) a priory without any justification. Indeed one needs a probability distribution to meaningfully talk about probabilities, but there is no reason to pick one specific distribution over another until you have a useful reference class.
Basically, the Doomsday argument has zero predictive power. Consider a set of civilizations with a fixed number of humans at any given time, each existing for a finite time T, randomly distributed with a distribution function f(T), which does not necessarily have a finite expectation value, standard deviation or any other moments. Now, given a random person from a random civilization at the time t, the Doomsday argument tells them that their civilization will exist for about as long as it had so far. It gives you no clue at all about the shape of f(t) beyond it being non-zero (though maybe measure zero) at t.
Now, shall we lay this nonsense to rest and focus on something productive?
The doomsday argument strikes me as complete and utter misguided bullshit, notwithstanding the fact that smart and careful physicists have worked on it, including J. Richard Gott and Brandon Carter, whose work in actual physics I had used extensively in my research. There are plenty of good reasons for x-risk work, no need to invoke lousy ones. The main issue with the argument is the misuse of probability.
First, the argument assumes a specific distribution (usually uniform) a priory without any justification. Indeed one needs a probability distribution to meaningfully talk about probabilities, but there is no reason to pick one specific distribution over another until you have a useful reference class.
Second, the potential infinite expectation value makes any conclusions from the argument moot.
Basically, the Doomsday argument has zero predictive power. Consider a set of civilizations with a fixed number of humans at any given time, each existing for a finite time T, randomly distributed with a distribution function f(T), which does not necessarily have a finite expectation value, standard deviation or any other moments. Now, given a random person from a random civilization at the time t, the Doomsday argument tells them that their civilization will exist for about as long as it had so far. It gives you no clue at all about the shape of f(t) beyond it being non-zero (though maybe measure zero) at t.
Now, shall we lay this nonsense to rest and focus on something productive?
Nitpick: I was arguing that the Doomsday Argument would actually discourage x-risks related work because “we’re doomed anyway”.
Right. Either way, it’s not a good argument to base one’s decisions on.