Re:A Primer on the Doomsday Argument
by lisper on Monday August 18, 2014 @06:14PM
(#8195010)
Ah, I see. It makes more sense if you forget about cubicles and just call the final outcomes A or B. Call the outcomes of the two coin flips H1/T1 and H2/T2. We have: H1->A, T1,H1->A, T1,T2->B. P(H1|A) is therefore 67% if the coin is fair, but in any event P(H1|A)>P(H1).
So the doomsday argument is actually correct. :-) But it's really nothing more than the (IMO vacuous) observation that (say) half of the people who ever live will have a birth order number greater than the median, and so the odds are 50-50 that fewer people will be born after you than before you. More generally, the odds that N times as many people will be born after you as before you is equal to 1/2N.
So the doomsday argument is actually correct. :-) But it's really nothing more than the (IMO vacuous) observation that (say) half of the people who ever live will have a birth order number greater than the median, and so the odds are 50-50 that fewer people will be born after you than before you. More generally, the odds that N times as many people will be born after you as before you is equal to 1/2N.