A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Research
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

A quasar, too heavy to be true



 
 
Thread Tools Display Modes
  #31  
Old January 2nd 18, 08:54 AM posted to sci.astro.research
Eric Flesch
external usenet poster
 
Posts: 321
Default A quasar, too heavy to be true

On 01 Jan 2018, Gary Harnagel wrote:
G-type stars that are gone now
but the intelligent species "hatched" by them have migrated to a younger
star. At only 0.1% the speed of light, generation ships could cross the
entire galaxy in a mere 0.1 billion years.


But they never came here, to Earth. And yet they would have spread
out over the galaxy, the same as yeast in a Petri dish. What part of
the Petri dish escapes the yeast? None. There is your evidence that
no such alien civilizations exist.

  #32  
Old January 2nd 18, 09:04 AM posted to sci.astro.research
Phillip Helbig
external usenet poster
 
Posts: 38
Default A quasar, too heavy to be true

In article , (Eric
Flesch) writes:

On 01 Jan 2018, Gary Harnagel wrote:
G-type stars that are gone now
but the intelligent species "hatched" by them have migrated to a younger
star. At only 0.1% the speed of light, generation ships could cross the
entire galaxy in a mere 0.1 billion years.


But they never came here, to Earth. And yet they would have spread
out over the galaxy, the same as yeast in a Petri dish. What part of
the Petri dish escapes the yeast? None. There is your evidence that
no such alien civilizations exist.


Not really. Of course, technically, one can never prove the
non-existence of something; at most, one can accumulate evidence for it.
(Similarly, one is not asked to prove one's innocence in court; rather,
the accuser must prove one's guilt.) Even so, you are making two
assumptions: that an alien civilization would want to colonize the
galaxy, and that they would have no reason to avoid us. The latter is
known as the "zoo hypothesis". With regard to the former, remember
that an alien civilization is ALIEN. They might have very different
motivations. (Even so, since it requires just ONE alien civilization,
or actually just one (sufficiently powerful) individual, it doesn't seem
unlikely that such colonization would take place. However, the zoo
hypothesis does seem to make sense.)

  #33  
Old January 3rd 18, 10:41 AM posted to sci.astro.research
Gary Harnagel
external usenet poster
 
Posts: 659
Default A quasar, too heavy to be true

On Tuesday, January 2, 2018 at 12:54:07 AM UTC-7, Eric Flesch wrote:

On 01 Jan 2018, Gary Harnagel wrote:

G-type stars that are gone now
but the intelligent species "hatched" by them have migrated to a younger
star. At only 0.1% the speed of light, generation ships could cross the
entire galaxy in a mere 0.1 billion years.


But they never came here, to Earth.
And yet they would have spread
out over the galaxy, the same as yeast in a Petri dish. What part of
the Petri dish escapes the yeast? None. There is your evidence that
no such alien civilizations exist.


OTOH, brute-force interstellar travel (i.e., space ships) may be too
difficult for civilizations a few thousand years beyond ours, given
cosmic radiation and the possibility of collisions with Oort cloud
objects. Interstellar travel might have to wait hundreds of thousands
of years.

I try to imagine what a mature civilization 100,000 years ahead of ours
would have as goals. For one thing, they wouldn't be like Captain Kirk,
but they may have the Federations non-interference mandate. In any
case, they wouldn't be yeast. They would be:

There may be millions of inhabited worlds circling other suns, harboring
beings who to us would seem godlike, with civilizations and cultures
beyond our wildest dreams. --- Arthur C. Clarke

  #34  
Old January 3rd 18, 11:39 AM posted to sci.astro.research
Eric Flesch
external usenet poster
 
Posts: 321
Default A quasar, too heavy to be true

On 03 Jan 2018, Gary Harnagel wrote:
On Tuesday, January 2, 2018 at 12:54:07 AM UTC-7, Eric Flesch wrote:
But they never came here, to Earth. And yet they would have spread
out over the galaxy, the same as yeast in a Petri dish. What part of
the Petri dish escapes the yeast? None. There is your evidence that
no such alien civilizations exist.


OTOH, brute-force interstellar travel (i.e., space ships) may be too
difficult for civilizations a few thousand years beyond ours, given
cosmic radiation and the possibility of collisions with Oort cloud
objects. Interstellar travel might have to wait hundreds of thousands
of years.


Well, given that you previously said: "It seems to me that we should
be arguing intelligent life developed long ago in the universe until
refuted by evidence to the contrary", and you've now shortened that
time frame to "a few thousand years beyond ours", it's good to see
that you're considering the evidence.

I would also point out that there's no operational difference between
being the first ones, and being the only ones.

  #35  
Old January 4th 18, 11:34 AM posted to sci.astro.research
Gary Harnagel
external usenet poster
 
Posts: 659
Default A quasar, too heavy to be true

On Wednesday, January 3, 2018 at 3:39:03 AM UTC-7, Eric Flesch wrote:

On 03 Jan 2018, Gary Harnagel wrote:
On Tuesday, January 2, 2018 at 12:54:07 AM UTC-7, Eric Flesch wrote:
But they never came here, to Earth. And yet they would have spread
out over the galaxy, the same as yeast in a Petri dish. What part of
the Petri dish escapes the yeast? None. There is your evidence that
no such alien civilizations exist.


OTOH, brute-force interstellar travel (i.e., space ships) may be too
difficult for civilizations a few thousand years beyond ours, given
cosmic radiation and the possibility of collisions with Oort cloud
objects. Interstellar travel might have to wait hundreds of thousands
of years.


Well, given that you previously said: "It seems to me that we should
be arguing intelligent life developed long ago in the universe until
refuted by evidence to the contrary", and you've now shortened that
time frame to "a few thousand years beyond ours", it's good to see
that you're considering the evidence.


Actually, I haven't. It's just easier to imagine a civilization a
thousand years older than ours as to one that's a billion years older.

I would also point out that there's no operational difference between
being the first ones, and being the only ones.


That depends upon whether the development of intelligent life is common
and nearly coexistent (as is commonly presented in SF novels).

And your assertion might be correct if WE are the first or only, but it
seems much more likely to me that intelligence arose billions of years
ago. Someone else was the first, has the galaxy (or universe) organized
and under control while we are Johnny-come-latelies.

  #36  
Old January 4th 18, 11:35 AM posted to sci.astro.research
jacobnavia
external usenet poster
 
Posts: 105
Default Observational evidence for life elsewhere

Le 31/12/2017 à 21:48, Phillip Helbig (undress to reply) a écrit :

Whether it is likely that we are the first, and whether it is likely
that we are not alone, are other questions.


It would be nice if we would argue not just by opinions but opinions
based on actual observations.

Here is a small overview of "life elsewhere" evidence.

A) Mars

Mars life has strong observational evidence.

1) "Silica deposits on Mars with features resembling hot spring
biosignatures at El Tatio in Chile"
Nature communications, Nov 17th 2016

2) Ancient Sedimentary Structures in the 3.7 Ga Gillespie Lake Member,
Mars, That Resemble Macroscopic Morphology, Spatial Associations, and
Temporal Succession in Terrestrial Microbialites.
Astrobiology February 2015, Vol. 15, No. 2: 169-192

3) The Allan Hills meteorite from Mars is peppered with tiny magnetic
crystals that on our planet are made only by bacteria.
https://science.nasa.gov/science-new...000/ast20dec_1

4) NASA Rover Finds Active and Ancient Organic Chemistry on Mars
https://www.jpl.nasa.gov/news/news.php?feature=4413

There are MANY other hints for life in Mars.

B) Meteorites:
1) Bacteria in the Tatahouine meteorite: nanometric-scale life in
rocks.
Earth and Planetary Science Letters 175 (2000) 161^167

C) Bacteria can survive in space without much damage
Pete Conrad, the Apollo 12 Commander, took samples of the Surveyor 3
camera and brought samples of "Streptococcus mitis" fropm the
moon. The bacteria survived in the moon during 3 years.
Pete Conrad said:
"I always thought the most significant thing that we ever found on the
whole...Moon was that little bacteria who came back and lived and
nobody ever said [anything] about it."

D) Titan
1) Biologically Enhanced Energy and Carbon Cycling on Titan?
Astrobiology. 2005 Aug;5(4):560-7.
(https://arxiv.org/pdf/physics/0501068.pdf)
2) Organic Materials Spotted High Above Titan's Surface

https://saturn.jpl.nasa.gov/news/232...itans-surface/

E) Encedalus
Enceladus's hot, gritty core may cook up ingredients for life

https://www.newscientist.com/article...ents-for-life/
The Possible Origin and Persistence of Life on Enceladus and
Detection of Biomarkers in the Plume
Astrobiology Volume: 8 Issue 5: December 23, 2008

F) Europa
1) Unmasking Europa: The Search for Life on Jupiter's Ocean Moon
by Richard Greenberg
Praxis/Springer: 2008. 278 pp. £17.50/$27.50 9780387479361
Reviewed in natu https://www.nature.com/articles/457384a

G) Venus
1) COULD DARK STREAKS IN VENUS' CLOUDS BE MICROBIAL LIFE?
https://www.astrobio.net/venus/dark-...icrobial-life/

  #37  
Old January 7th 18, 04:52 PM posted to sci.astro.research
Martin Brown[_3_]
external usenet poster
 
Posts: 189
Default A quasar, too heavy to be true

On 01/01/2018 16:09, Eric Flesch wrote:
On 31 Dec 2017, Phillip Helbig wrote:
... Could an intelligent but non-technological
species at a level of intelligence similar to humans have arisen
sometime in the past but left no fossil or other record?


About 40 years ago the "Planetary Report" magazine carried an article
about how, about a million years before the dinosaurs vanished, a new
human-sized upright-walking dinosaur appeared with stereoscopic vision
(I don't have the exact reference, sorry). When reading it, I


Sounds like one of the T. Rex walks like a kangaroo claims from before
the time when they realised that it used its tail for balance and walked
more like a modern day bird with a long tail (eg pheasant). Footprint
tracks show no signs of it dragging its tail like a kangaroo would...

couldn't help but wonder if they'd built a civilization and then
immolated themselves -- that would thus be the true cause of the
dinosaurs' disappearance. That may sound absurd, but if we vanished
tomorrow, what trace of our civilization would survive 66 million
years later? Not a nail.


I suspect slabs of refined gold in bulk storage repositories and nuclear
waste would easily survive for that long in a form where they would be
easily recognisable as technological artefacts. Some of the better
grades of stainless steel might also last that long once covered by mud.

--
Regards,
Martin Brown

  #38  
Old January 10th 18, 10:08 PM posted to sci.astro.research
jacobnavia
external usenet poster
 
Posts: 105
Default A quasar, too heavy to be true

Le 01/01/2018 Ã* 17:09, Eric Flesch a écritÂ*:
but if we vanished
tomorrow


That's one way of seeing the future.

Personally, I do not think that we will vanish tomorrow.

Why would we?

The history of homo sapiens is relatively new in human history, millions
of years old.

We discovered fire, and with it cooking. That allowed us to eat better,
pre-digesting food and hence enlarging the amount of food available to us.

Then, we grew, and population growth made old methods unpracticable.

We figured out a symbiosis with certain kinds of plants we choose.

We settled down and developed agriculture.

We constructed a symbiosis with certain kinds of animals that provided
meat easier and better than hunting around for meat.

We used a bit our brains. That's what they are for, anyway.

Use your brain. Sapiens knows that.

Because we grew, and population growth makes old methods unpracticable.

We expanded through the whole planet and we constructed a human
environment. We setup fields of plants we planted, and our work made
more food available.

And we built cities, developed writing, started to look at the stars.

And we started to fly.

Humans are too heavy to fly. That's why they build machines heavier than
the air that fly. In this manner, Sapiens has been able to start flying.

Higher and faster than ever a bird would dream of.

I like being born in the suburbs. Unlike downtown, where all stars are
so near each other, from here we have a much better view of the Way,
spinning like a gigantic inclined wheel, right in front of you. What a
nice view!

The problem of suburbs, as everybody knows, is that there is no
transportation.

Downtown, since the distances between the stars are smaller and the
stars older, life has solved the transportation problem eons ago.

Not in the suburbs, way countryside like here. To meet the others, we
have to develop our own transportation.

But I think that using our brains we will develop transportation,
eventually.

An essential part in the development of transport, is the fact that we
see the stars, we see the Way.

Astronomy.

It motivates Sapiens.

  #39  
Old January 10th 18, 10:10 PM posted to sci.astro.research
Steve Willner
external usenet poster
 
Posts: 1,172
Default A quasar, too heavy to be true

In article ,
Martin Brown writes:
I suspect slabs of refined gold in bulk storage repositories and nuclear
waste would easily survive [60 Myr] in a form where they would be
easily recognisable as technological artefacts. Some of the better
grades of stainless steel might also last that long once covered by mud.


I was thinking of glass. Suitable conditions would be required for
any specific object to be preserved, but if fossilized bones could
survive, then I'd expect anything not chemically reactive to survive
if conditions were right.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

  #40  
Old January 10th 18, 10:15 PM posted to sci.astro.research
Jonathan Thornburg [remove -animal to reply][_3_]
external usenet poster
 
Posts: 137
Default scientific proof and disproof (was: A quasar, too heavy to be true)

Phillip Helbig (undress to reply) wrote:
Of course, technically, one can never prove the
non-existence of something;


On the contrary, one can indeed prove the non-existence of some things.
For example, I am currently in a room which is approximately 2.5 meters
by 5 meters by 2.5 meters in size. Given the known size of adult elephants,
I can prove the non-existence of adult elephants in this room by looking
around and not seeing any adult elephants.

Abstracting a bit, for propositions X and Y,
(a) if X implies Y, and
(b) we observe not-Y, then
(c) we have proven not-X.

In the above example, X = "there is an adult elephant in this room"
and Y = "I can see an adult elephant when I look around in this room".

In the same way, one can prove the non-existence of (for example)
hitherto-unknown Jupiter-mass planets orbiting within 10 astronomical
units of the Sun: if such a planet or planets existed, they would cause
substantial gravitational perturbations to the orbits of other planets.
But we observe that there are no (unexplained) substantial gravitational
perturbations to the orbits of the known planets in our solar system.

Here we are taking X = "there is a hitherto-unknown Jupiter-mass planet
orbiting within 10 astronomical units of the Sun" and Y = "there are
substantial unexplained gravitational perturbations to the orbits of
other (known) planets in our solar system".

--
-- "Jonathan Thornburg [remove -animal to reply]"
Dept of Astronomy & IUCSS, Indiana University, Bloomington, Indiana, USA
currently visiting Max-Plack-Institute fuer Gravitationsphysik
(Albert-Einstein-Institut), Potsdam-Golm, Germany
"There was of course no way of knowing whether you were being watched
at any given moment. How often, or on what system, the Thought Police
plugged in on any individual wire was guesswork. It was even conceivable
that they watched everybody all the time." -- George Orwell, "1984"

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Could Delta IV Heavy use the same technique as Falcon Heavy Alan Erskine[_3_] Space Shuttle 1 May 20th 11 07:56 AM
Whoa, it can't be true, it can't be true, William Shatner knows,he'll protect us LIBERATOR[_3_] History 2 March 24th 09 06:28 PM
Heavy H = Lots of Heavy Compounds G=EMC^2 Glazier Misc 3 November 12th 05 07:12 PM
Since Boeing and LM are partnering 50/50 and Boeing already has Delta IV Heavy does that mean we'll never see the Atlas V Heavy? D. Scott Ferrin History 5 May 6th 05 05:34 PM
Delta IV Heavy: Heavy Enough for Mars Damon Hill Policy 1 December 22nd 04 08:39 PM


All times are GMT +1. The time now is 05:11 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.