In the ‘there’s no filter, and colonization bubbles just expand too rapidly for other organisms to get advance warning’ scenario, there’s a fairly small window of time between ‘the first organisms evolve’ and ‘no more organisms evolve ever again’. But in the absence of an early filter, that small window should occur early in the universe’s lifespan, not late. The fact that we live in an old universe suggests that there must be an early filter of some sort (particularly if colonization is easy).
The universe is a big, big place. It also becomes isolated relatively fast due to accelerating inflationary effects. There will probably be many intelligences out there even our most distant descendants will never meet.
Ultimately though you’re making assumptions about the prior distribution of intelligent life which isn’t warranted with a sample size of 1.
In the ‘there’s no filter, and colonization bubbles just expand too rapidly for other organisms to get advance warning’ scenario, there’s a fairly small window of time between ‘the first organisms evolve’ and ‘no more organisms evolve ever again’. But in the absence of an early filter, that small window should occur early in the universe’s lifespan, not late. The fact that we live in an old universe suggests that there must be an early filter of some sort (particularly if colonization is easy).
The universe is a big, big place. It also becomes isolated relatively fast due to accelerating inflationary effects. There will probably be many intelligences out there even our most distant descendants will never meet.
Ultimately though you’re making assumptions about the prior distribution of intelligent life which isn’t warranted with a sample size of 1.
An extremely low prior distribution of life is an early great filter.