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Sat Dec 19, 2020, 02:23 PM

The Milky Way is probably full of dead civilizations

By Rafi Letzter - Staff Writer 5 hours ago



(Image: European Souther Observatory)

Most of the alien civilizations that ever dotted our galaxy have probably killed themselves off already.

That's the takeaway of a new study, published Dec. 14 to the arXiv database, which used modern astronomy and statistical modeling to map the emergence and death of intelligent life in time and space across the Milky Way. Their results amount to a more precise 2020 update of a famous equation that Search for Extraterrestrial Intelligence founder Frank Drake wrote in 1961. The Drake equation, popularized by physicist Carl Sagan in his "Cosmos" miniseries, relied on a number of mystery variables like the prevalence of planets in the universe, then an open question.

This new paper, authored by three Caltech physicists and one high school student, is much more practical. It says where and when life is most likely to occur in the Milky Way, and identifies the most important factor affecting its prevalence: intelligent creatures' tendency toward self-annihilation.

"Since Carl Sagan's time, there's been lots of research," said study co-author Jonathan H. Jiang, an astrophysicist at NASA's Jet Propulsion Laboratory at Caltech. "Especially since the Hubble Space Telescope and Kepler Space Telescope, we have lots of knowledge about the densities [of gas and stars] in the Milky Way galaxy and star formation rates and exoplanet formation ... and the occurrence rate of supernova explosions. We actually know some of the numbers [that were mysteries at the time of the famous 'Cosmos' episode]."

More:
https://www.livescience.com/milky-way-alien-life-map.html?utm_source=notification

16 replies, 1412 views

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Response to Judi Lynn (Original post)

Sat Dec 19, 2020, 02:27 PM

1. What an interesting concept! Bookmarking to read later...

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Response to Judi Lynn (Original post)

Sat Dec 19, 2020, 02:31 PM

2. And we are following their example

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Response to Bayard (Reply #2)

Mon Dec 21, 2020, 09:52 PM

14. Indeed.

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Response to Judi Lynn (Original post)

Sat Dec 19, 2020, 02:32 PM

3. I think Asimov wrote an article on intelligent species prone to offing themselves.

A universal case of getting too big for your britches?

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Response to Judi Lynn (Original post)

Sat Dec 19, 2020, 02:37 PM

4. There's good and bad in this article

The universe probably has seen and will see many civilizations since the universe and space-time appear to be the same everywhere. Life should pop up should the chemistry, biology and physics all align.

However, the authors' suggestion that intelligent creatures have a tendency toward self-annihilation is silly. How could they know? They know of only one species that seems hell-bent on destroying itself: Humans. That doesn't seem like much of a scientific sample from which to draw any conclusions. Additionally, civilizations could disappear for a great many reasons that have nothing to do with self-annihilation: Giant asteroids, tectonic disasters or even just time could be the cause of a civilization's demise.

There are likely two reasons we haven't found life outside of our solar system. First, the distances between star systems and galaxies is just too vast. It's likely that the only way we'll travel to the stars will be when we can transfer our consciousness into something more durable than skin and bones.

The other reason is found in the first part of the article, namely that other civilizations may have formed and died out before humankind evolved. They may form in the future after we're gone.

The universe is really big and really old. Lots of things have happened that we'll never know about.

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Response to PJMcK (Reply #4)

Sat Dec 19, 2020, 02:57 PM

9. The 3rd reason that we may have not discovered life outside the solar system is simple, they (...

outside entities) have a non-interference policy. Kind of like the policy that Star Trek, etc. follow, to not interfere w/ the ongoing development of civilization. Makes sense here too (on earth).

IMHO, I suspect that they (outside solar system (or perhaps sharing this solar system w/ us already)) are here already, watching us/studying us (and why not? Very similar to finding the Incas in Central America and other tribes, when the explorers (English, Portuguese, Spain etc.) discovered them.

The unfortunate thing here that happened here, was Gold and other precious gems were discovered and thus, the race was on to discover and steal/whatever gold and gems could be pried from their dead hands if need be. A terrible shame, who knows what knowledge was lost, what treasures were hidden away prior to being stolen by the Incas and other tribes?

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Response to PJMcK (Reply #4)

Sat Dec 19, 2020, 03:15 PM

10. Even with large number of occurences

The improbability of a particular event can quickly drive down the chance of something actually happening. I personally think technological life is extremely rare, and we are towards the front end of its potential development. Chemistry is a big part of the reason. We need to have a sufficient number of both supernovas as well neutron star collisions to build the heavier elements necessary for life as we understand it.

A big limiting factor is the availability of phosphorus. Our own planet is phosphorus deficient when compared to the composition of life. It appears we live is a nebula that is phosphorus rich when compared to other nebulas.

The evolution of multicellular life is not a given. Also the type of intelligence that will develop technology is also not necessarily driven by evolution. Look at the run that dinosaurs had on this planet. It took an extinction event to reset the game board to allow the emergence of mammals, primates, and humans. Our own emergence was a near thing as well with several keyhole events before we reached this point, and there is no assurance we can maintain and advance our technology.

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Response to Judi Lynn (Original post)

Sat Dec 19, 2020, 02:46 PM

5. Fun, in some ways speculative like the Drake Eq'n, but fewer speculations. The Full Paper...

...is here: A Statistical Estimation of the Occurrence of Extraterrestrial Intelligence in the Milky Way Galaxy

I love the inclusion of a high school student, Xiang Cai, from Santiago High School in Corona, California.

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Response to Judi Lynn (Original post)

Sat Dec 19, 2020, 02:49 PM

6. How many times have Earth inhabitants annihilated themselves?

Then we come back and start the cycle once again.

We are so expert at self destruction, probably not the first time.

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Response to Irish_Dem (Reply #6)

Sat Dec 19, 2020, 04:25 PM

12. I read an interesting article on this concept

The Earth has been habitable for far longer than humans have been around. If there were an intelligent life form on earth before us, what evidence would they leave that we might find? If you go back far enough in time, almost all evidence would have been destroyed. Seismic events, continental shifts, floods, volcanoes, etc. have a tendency to destroy the artifacts one might expect. This becomes more true of they were rendered extinct before developing technically very far.

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Response to zipplewrath (Reply #12)

Sat Dec 19, 2020, 04:29 PM

13. Yes this is my theory exactly. I have never heard anyone else talk about it. nt

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Response to Judi Lynn (Original post)

Sat Dec 19, 2020, 02:51 PM

7. Fun title - makes me look further

'Fun' explanation makes me think a bit

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Response to Judi Lynn (Original post)

Sat Dec 19, 2020, 02:52 PM

8. How the end... always ends...

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Response to Judi Lynn (Original post)

Sat Dec 19, 2020, 03:48 PM

11. Entertaining bullshit. The fact remains that no matter how many "Earth-like" planets we find...

we only know of one which has produced life.

Even the most advanced Bayesian analysis can't get much from that. Especially since we have no idea if there are other, non-carbon, forms of life that have evolved on giant, or tiny, or atmosphere-less, or other types of planets. Or stars themselves.

It is entirely reasonable to guess that in the vastness of the universe some forms of life have evolved, but we have absolutely no way of testing this idea. I would say that it is more probable that there is life out there than not, but I can't check it out.

And about killing ourselves off-- who says evolution has to lead toward species with an amygdala and resulting warlike tendencies? What if trees with brains were the dominant life force? Would they destroy themselves?

Fun, but ultimately pointless speculation.

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Response to TreasonousBastard (Reply #11)

Mon Dec 21, 2020, 11:48 PM

15. Not to be a 'Where are you coming from' but....

What if trees with brains were the dominant life force? Would they destroy themselves?

Fun, but ultimately pointless speculation.



Your words, your question, still pointless speculation on either side.

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Response to Judi Lynn (Original post)

Tue Dec 22, 2020, 01:27 AM

16. Technically all intelligent species will be the cause of their own demise especially if there is

no way for them to actually colonize enough if any star systems in a galaxy before some cataclysm strikes the planet or system they inhabit currently.

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