On 04/10/2018 07:24, Paul Schlyter wrote:
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:

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.

Since the biggest stars burn out the fastest I think that locally a few
places may have been favoured with high metallicity very early on and
you only need enough to make a few planets here and there to get going.

But the early universe was a much more violent place than today and
things closer together so any developing life would be more likely to
get zapped and reset by a close supernova or merging black hole pair.

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.

Some of it ages quite well. When Kubrick flat imaging tablet devices for
watching TV in 2001 the idea was ridiculous but today they are
everywhere likewise for "communicators" in Star Trek. Partly I think
because the engineers and scientists who grew up watching these programs
thought they were cool ideas and tried to make them in reality.

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.

However much you wish to make a wormhole it isn't going to happen
without a heck of a lot of energy and some very exotic matter. And even
if you could make one its stability and unwelcome tendency to spagettify
things near it is an open question.

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.

Chances are that any civilisation that has been around for so long will
be unrecognisable to us - we could even be living inside one of their
computer simulations of universes.

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.

Believing doesn't make it true. It just means that believers will stick
to what they think they know in the face of all evidence to the contrary
(even to the extent of being burnt at the stake as a heretic - popular
with the two most prominent brands of Christianity in the middle ages).

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?

Show me a hyper advanced space faring civilisation or a signal from one
and I will be the first to agree that they exist. Until that time they
are at best a figment of your imagination. I am inclined to think that
the energetics and timescales for interstellar travel are so great that
very few if any civilisations ever expand beyond the confines of their
own solar system. Space is big - really really big. HHGG

http://www.quotationspage.com/quote/33085.html

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.

No they can persist in the face of all the evidence to the contrary.
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.

Dreamers and creative people can think of things but it takes engineers
and scientists to make something that will actually work.

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.

If there was one they would probably be so abstract by now that we
wouldn't recognise them anyway. They would almost certainly have made
the transition to being a self improving AI singularity.

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?

I consider it possible that they exist.
But I'm not expecting to see LGMs shopping in Tesco's any time soon.

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...

I think the evidence is tilting towards the idea that simple life might
be more common than we thought but unless and until we find an
independent occurrence on Mars, Enceledus or Europa there is no evidence
one way or the other. It is all about belief in the absence of evidence.

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.

Chances are they died with their star anyway. Interstellar travel for
life forms is in the seriously too difficult category. Interplanetary
travel for humans is still very very tough with only the moon having
ever been visited (and that was done 50 years ago).

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.

I don't think you can alter the world view of a true believer they have
proved willing to be burnt at the stake for their beliefs in the past.
(often by a rival group of believers in the same "One True God")

Now Mr Galileo do you believe that the Sun goes around the Earth or
would you like more house arrest and a molten lead ear wash?

--
Regards,
Martin Brown