Inflationary multiverse is essentially infinite. But as you take a slice through (a part of) the multiverse, there is way more young universes. The proportion of universes of given age is inversely (exponentially, as in memoryless distribution) proportional to the age. This resolves the doomsday paradox (because our universe is very young relative to its lifespan). http://youtu.be/qbwcrEfQDHU?t=32m10s
Another argument to similar effect would be to consider a measure over possible indices. Indices pointing into old times would be less probable—by needing more bits to encode—than indices pointing to young times.
Our universe might be very old on this picture (relative to the measure), so the conclusion regarding Fermi paradox is to update towards the “great filter in the past” hypothesis. (It’s more probable to be the first observer-philosopher having these considerations in one’s corner of a universe.)
Inflationary multiverse is essentially infinite. But as you take a slice through (a part of) the multiverse, there is way more young universes. The proportion of universes of given age is inversely (exponentially, as in memoryless distribution) proportional to the age. This resolves the doomsday paradox (because our universe is very young relative to its lifespan). http://youtu.be/qbwcrEfQDHU?t=32m10s
Another argument to similar effect would be to consider a measure over possible indices. Indices pointing into old times would be less probable—by needing more bits to encode—than indices pointing to young times.
Our universe might be very old on this picture (relative to the measure), so the conclusion regarding Fermi paradox is to update towards the “great filter in the past” hypothesis. (It’s more probable to be the first observer-philosopher having these considerations in one’s corner of a universe.)
See also http://www.youtube.com/watch?v=jhnKBKZvb_U