why don't we see life out there in the
why don't we see life out there in the
why don't we see life out there in the
cosmos you don't need any special
cosmos you don't need any special
cosmos you don't need any special
knowledge to consider this question and
knowledge to consider this question and
knowledge to consider this question and
I've explored it with lots of people and
I've explored it with lots of people and
I've explored it with lots of people and
I found they often frame their thinking
I found they often frame their thinking
I found they often frame their thinking
in terms of the barriers that would need
in terms of the barriers that would need
in terms of the barriers that would need
to be cleared if a planet is to host a
to be cleared if a planet is to host a
to be cleared if a planet is to host a
communicative civilization habitability
communicative civilization habitability
communicative civilization habitability
that's the first barrier we need a
that's the first barrier we need a
that's the first barrier we need a
terrestrial planet in that just right
terrestrial planet in that just right
terrestrial planet in that just right
goldilock Zone where water flows as a
goldilock Zone where water flows as a
goldilock Zone where water flows as a
liquid abiog gelesis the creation of
liquid abiog gelesis the creation of
liquid abiog gelesis the creation of
life from non-life that's a second
life from non-life that's a second
life from non-life that's a second
barrier the ingredients are there we
barrier the ingredients are there we
barrier the ingredients are there we
just don't know how they combine to
just don't know how they combine to
just don't know how they combine to
create life and presumably there'll be
create life and presumably there'll be
create life and presumably there'll be
worlds on which life doesn't start the
worlds on which life doesn't start the
worlds on which life doesn't start the
development of technological
development of technological
development of technological
civilization is a third barrier there'll
civilization is a third barrier there'll
civilization is a third barrier there'll
be worlds where life doesn't give rise
be worlds where life doesn't give rise
be worlds where life doesn't give rise
to Advanced Technology communication
to Advanced Technology communication
to Advanced Technology communication
across space that's a fourth barrier
across space that's a fourth barrier
across space that's a fourth barrier
there'll be worlds where for whatever
there'll be worlds where for whatever
there'll be worlds where for whatever
reason civilizations either stay silent
reason civilizations either stay silent
reason civilizations either stay silent
or don't spend long trying to
or don't spend long trying to
or don't spend long trying to
communicate but for me the Silence of
communicate but for me the Silence of
communicate but for me the Silence of
the universe is shouting we're the
the universe is shouting we're the
the universe is shouting we're the
creatures who got lucky and all those
creatures who got lucky and all those
creatures who got lucky and all those
amazing things dreamed aliens might have
amazing things dreamed aliens might have
amazing things dreamed aliens might have
done in the past that could be our
done in the past that could be our
done in the past that could be our
future