6) Faster than light travel is not physically possible, the other civilizations all originated far away, and the other civilizations are all composed of people who don’t like to live in generational spaceships their entire lives.
Your 6 falls under Simon’s category 3: “they exist, but we can’t detect them, and they aren’t beaming an easy to detect advertisement of their existence to places where life might arise”
3.1) Further, they use some crypto-secure or sufficiently low-power RF communication that looks like or is masked by noise. They also don’t leak much distinctive non-communicative RF (no Las Vegas).
3.1.1) They also have no interest (or ability) to create reasonably capable robots who don’t mind the boredom of interstellar travel (either alone, or in an isolated community) as their emissaries
6) Faster than light travel is not physically possible, the other civilizations all originated far away, and the other civilizations are all composed of people who don’t like to live in generational spaceships their entire lives.
Your 6 falls under Simon’s category 3: “they exist, but we can’t detect them, and they aren’t beaming an easy to detect advertisement of their existence to places where life might arise”
3.1) Further, they use some crypto-secure or sufficiently low-power RF communication that looks like or is masked by noise. They also don’t leak much distinctive non-communicative RF (no Las Vegas).
3.1.1) They also have no interest (or ability) to create reasonably capable robots who don’t mind the boredom of interstellar travel (either alone, or in an isolated community) as their emissaries
This is my hypothesis (3c), with an implicit overlay of (3a).
Generation spaceships? No joke...