On 26/09/2018 12:11, Gary Harnagel wrote:
On Tuesday, September 25, 2018 at 2:01:11 PM UTC-6, Paul Schlyter wrote:

On Mon, 24 Sep 2018 07:26:36 -0700 (PDT), Gary Harnagel
wrote:

On Sunday, September 23, 2018 at 8:43:48 AM UTC-6, Paul Schlyter
wrote:

Exactly what do you mean with "the universe billions of years older
than our universe"?

The antecedent to "ours" is "civilization" not "universe."

And how do you know that intelligent civilisation will not
self-destruct within a few millennia or so?

Out of MILLIONS of civilizations, all that's needed is ONE to survive.

We don't know of any other ET civilisations though. As yet we haven't
found life arising independently on another planet either although there
may be hints of life having been on Mars back when it had liquid water.
(it may still be there deep in underground rocks or dormant as cysts)

I object to your conclusion "almost certainly" when there are no
known positive cases.

Reject all you want, but that's just your biases and prejudices
speaking. Anyone with a grasp of probability theory and no
preconceived notions would disagree with you.

No, they would disagree with you.

I have a grasp of probability theory and I disagree with YOU.

You have a rather weak grasp of probability theory and an even weaker
grasp of the Drake equation. Planets now appear to be far more common
than was once thought but a lot of them are hot Jupiters tidally locked
to their parent star (a side effect of present experimental methods
which are particularly good at detecting planetary transits and Doppler
shifts as the hefty planet orbits its parent star close in).

Comparatively few have been found in the Goldilocks zone (although that
may be a selection effect of present observational techniques).

You do need a sufficient base of actual data to be able to say anything
about the probability, otherwise you are just guessing.

We have actual data on one civilization. YOU are just guessing about its
longevity, but that's irrelevant because an example of one AND proof that
almost every star has planets (via Kepler), it is a VERY good "guess"
that life has developed elsewhere.

It is certainly possible. But whether or not it is common for life to
evolve beyond the single celled stage is still an open question. One
awkward upper bound on the timescale that a technological civilisation
can operate without having to develop space faring technology is the
time it takes to exhaust the finite resources of their home planet.

You are the one who is biased here, not me,

:-))

since I have not claimed any probability figure about that.

THAT is YOUR bias speaking.

We just know too little to be able to do that reliably.

Just the sheer numbers of planets in the universe shred that assertion.

If intelligent life was really common in our galaxy then there should be
some residual signals for our radio and optical astronomers to see. That
or we would have seen self replicating probes by now a la Fermi paradox.
And why isn't theology an exact science like physics? Why
aren't our most powerful computers running simulations of God?

There, now you have some things to think about...

I thought. You got nuttin'! We don't know enough about how life started
to do believable simulations. We don't even know if it started here.

The chemists and molecular biologists are slowly getting closer to
finding out answers. The tricky step is more likely to be the point
where single celled simple life makes the transition to complex
multicellular organisms. Science is always a step by step refinement
from present knowledge by way of experiments.

https://www.the-scientist.com/featur...-complex-42874

What they find will be way more convincing than a "Just So" story.

--
Regards,
Martin Brown