On Tue, 2 Oct 2018 14:09:34 -0700 (PDT), Gary Harnagel
wrote:
On Tuesday, October 2, 2018 at 2:02:36 AM UTC-6, Paul Schlyter
wrote:

On Mon, 1 Oct 2018 18:41:05 -0700 (PDT), Gary Harnagel
wrote:

On Saturday, September 29, 2018 at 3:55:55 AM UTC-6, Paul
Schlyter
wrote:

Back then the galaxies were some 3 times closer to one
another than
today, so the typical intergalactic distance were perhaps
about a
million instead of millions of light years.

But, more importantly, back then there were few if any
population I
stars in existence. All stars back then were population II
stars,
which have very little, if any, elements heavier than H and
He. Those
heavier elements are required to form life. So back then
there was no
life in the universe, that we can say with great certainty.
Back
then, our Sun and our Earth did not even exist. Life, of all
kinds,
formed later.

9 billion years ago there certainly WERE stars with heavy
elements:


http://www.astronomy.com/news/2016/0...rly-galaxies-c

hallenges-star-forming-theory

Although their metallicity was only 20% of stars near us,
that's pretty
good for 11 billion years ago, wouldn't you say?

Lower metallicity means less material from which life can form.

Less, but not zero. You have NO idea how much less prevents life
and neither
do I, so this is just yammering.

Neither do you have any idea about it. So you have no basis
whatsoever to claim it is "almost certain" such civilization will
form and succeed in interstellar travel. It is just fantasies and
wishful thinking from you. The "law of big numbers" doesn't help you
here since there are too many unknown and possibly extremely small
numbers involved.


Such as wormholes? Or did you have something else in your
mind?

Wormholes, Alcubierre=type drives, transit to other branes, and
ways not
even a glimmer in the eyes of theoretical physicists.

Now you've entered the realm of science fiction...

So you believe only scientists can have new ideas? You DO realize
that
some SF authors ARE scientists, don't you?

These are by now quite old ideas. Yes, SF ages too as time passes.
However, wild hypotheses are definitely "almost certain" to be true.
Dream on, and get back if and when solid evidence for the existence
of these phenomena appears. And note that science fiction is not
science fact.


Not by much. Since the big bang happened 13.5 billion years
ago, 5
billion years ago the intergalactic distances already had
about 60%
of their current value.

And maybe there's a way to "wink out" there and "wink in" here
vitually
instantaneously. We haven't had millions of years of scientific
development yet.

More sci-fi...
More lack of vision.

Having vision is easy, you just fantasize. Making it actually happen
is much much harder.


Do you consider one to be a large number? One is the number
of
planets known to have life...

The law of large numbers say that if you repeat an experiment
a large
number of times, the outcome will be very close to the
expected
value. But, in the case of life in the universe, we have no
idea what
the expected value is. So the law of large numbers does not
help us
here.

Sure it does. We don't have to know the expectation value. We
KNOW it
happened ONCE. Given ENOUGH chances, it will happen again.

Sure, but have there been ENOUGH chances? We don't know, we can
only
guess or believe.
I BELIEEEVE!

I know, that's why you also are religious.


Given what we know about planetary systems today, about the
number of
stars in our galaxy, about the number of galaxies in just the
VISIBLE
universe and the tininess of the visible universe, you don't
believe it
hasn't happened MANY times? If so, you are an amazing
pessimist!

You see? All we can do is believe, we don't know. We are getting
to
know the first few factors of the Drake equation, but several
factors
remain unknown to us. And these unknown factors are the hardest
to
get to know. For instance, what is the typical lifetime of a
technologically advanced civilization? Apart from beliefs and
guesswork, hov can we actually get to KNOW that value?

It comes down to how much vision you have vs. how big a pessimist
you are.

And in what way could VISION alone give us knowledge?


That's your guess, and it is a far cry from "absolutely
certain" that
it actually is so.

YOU are the only one talking about "absolute certainty." I'm
talking about
probabilities.

Even if you call it "very high probability' it's really the same
thing. One
thing about extraterrestrial life is that ve cannot be "almost
certain"
about anything.

I am.

Without any solid base, you are. It is easy to get caught up in
wishful thinking. But even a visionary must distinguish what we know
from what we merely believe, or else his visions will at some stage
fall flat to the ground.


You and I are working from different assumptions. Are you
familiar
with Paul Steinhardt's Ekpyrotic theory?

https://arxiv.org/abs/hep-th/0103239

https://en.wikipedia.org/wiki/Ekpyrotic_universe

It posits a cyclic universe. If it has any credence it
means that past
universes existed. If intelligent life is as rare as some
here believe,
it becomes a virtual certainty that it developed in a
previous genesis,
maybe millions of times. If some couldn't find a way to
transport
itself from one genesis to the next, one would have.
Imagine, a
civilization billions of years old appearing on the scene
13 billion
years ago!

But what if it doesn't have any credence? We don't know if it
has, so
we can only guess. And you must do much better than guesswork
to be
able to reliably claim that something is "almost certain".

Don't be such a pessimist! It's bordering on a mania :-)

Don't be such a dreamer...

Why not? Dreamers make reality happen. Pessimists just sit around
moping.

Nope. Realists are those who make reality happen. Dreamers just
dream, and when one dream fails they switch to another dream. To make
things happen you must be careful about distinguish speculation from
knowledge. But regarding extraterrestrial civilizations we humans
cannot make that happen. It either has happened or has not happened
and we cannot do anything about that. Your dreams can never create
extraterrestrial civilizations billions of years into the past.


When you talk about extraterrestrial life, don't you mean real
life in the
real universe and not just your fantasies and wishes?

I believe in ET. Why wouldn't you?


You can fantasize as much as you want, but please stop trying
to
misuse probability to claim something is "almost certain"
when it
actually just is a guess of yours.

Pessimist!

No, I'm a realist.

No, you're a mope-around. And you cannot possibly be a "realist"
since you
admit that we don't know.

The reality **is** that we don't know...


There are no alternatives today that match empirical data so
well.

Irrelevant since we're talking about billion-year-old
civilizations.

You are then talking about something neither you nor anyone else
on
Earth know anything about.

So you admit that calling yourself a realist is just as nonsensical
as my
calling myself a visionary :-))

Calling yourself a visionary is clarifying, since it says you are
talking about your visions, not about reality. And, no, your visions
will never be able to create extraterrestrial civilizations billions
of years into the past.


The discovery of the cosmic background radiation made the
"big bang"
win over the "steady state" cosmology. But note that this is
not
final. If and when a cosmology appears that matches empirical
data
even better, then it will replace the "big bang" as the
standard
cosmological model.

The standard model assumes inflation. There are scientists
that dispute
that.


https://www.wired.com/2008/02/physic...ng-wasnt-the-b

eginning/

There are always people questioning, that's a natural part of the
scientific process. Time will tell who is right.

Indeed. As a human being, however, I want to have a "world view."
It's
important to me. I have developed mine over many years and I'll
hold it
until and if the evidence refutes it.

That's fine, however you should admit that it's just a vision.
Reality itself can be very different.