Author Topic: Paper states 234 stars signals probably from ETIs  (Read 4945 times)

Offline Star One

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First time I've seen a quantified paper on this particular subject. The results are derived from the Sloan Digital Sky Survey. Please note the paper has been been accepted for publication in PASP. One of the authors has had a distinguished career so at least it's not some nonsense paper.

Discovery of peculiar periodic spectral modulations in a small fraction of solar type stars

Quote
A Fourier transform analysis of 2.5 million spectra in the Sloan Digital Sky Survey was carried out to detect periodic spectral modulations. Signals having the same period were found in only 234 stars overwhelmingly in the F2 to K1 spectral range. The signals cannot be caused by instrumental or data analysis effects because they are present in only a very small fraction of stars within a narrow spectral range and because signal to noise ratio considerations predict that the signal should mostly be detected in the brightest objects, while this is not the case. We consider several possibilities, such as rotational transitions in molecules, rapid pulsations, Fourier transform of spectral lines and signals generated by Extraterrestrial Intelligence (ETI). They cannot be generated by molecules or rapid pulsations. It is highly unlikely that they come from the Fourier transform of spectral lines because too many strong lines located at nearly periodic frequencies are needed. Finally we consider the possibility, predicted in a previous published paper, that the signals are caused by light pulses generated by Extraterrestrial Intelligence to makes us aware of their existence. We find that the detected signals have exactly the shape of an ETI signal predicted in the previous publication and are therefore in agreement with this hypothesis. The fact that they are only found in a very small fraction of stars within a narrow spectral range centered near the spectral type of the sun is also in agreement with the ETI hypothesis. However, at this stage, this hypothesis needs to be confirmed with further work. Although unlikely, there is also a possibility that the signals are due to highly peculiar chemical compositions in a small fraction of galactic halo stars.

https://arxiv.org/abs/1610.03031

Jason Wright linked to this article in his Twitter feed in response to this paper.

http://sites.psu.edu/astrowright/2016/10/11/when-the-press-should-pay-attention-to-a-possible-seti-detection/

SETI Berkeley are to conduct follow up observations.

https://seti.berkeley.edu/bl_sdss_seti_2016.pdf
« Last Edit: 10/12/2016 08:36 AM by Star One »

Offline Star One

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Paper states 234 stars signals probably from ETIs
« Reply #1 on: 10/27/2016 08:31 PM »
Is That An Alien Signal? Please Answer On A Scale Of 1 To 10

Quote
This month, two Canadian astronomers became the latest to claim that they’d found an alien broadcast, and the latest to come under immediate criticism. Astronomer Ermanno Borra and graduate student Eric Trottier of Laval University in Quebec sifted through 2.5 million recordings of stars in the Sloan Digital Sky Survey, looking for periodic variations in starlight. They sought evidence of powerful laser pulses hidden among the stars’ spectral characteristics. They found what they were looking for in 234 cases: variations with “exactly the shape” of light pulses that would not form naturally. They argued that these might have been produced by extraterrestrial intelligence, or ETI. The signals were mostly found in the light of sun-type stars, said Borra, who supervised the work.

“Intuitively, we would expect that if an extraterrestrial civilization exists, it is around a star like the sun,” Borra said.

The light pulses have a period of roughly 1.65 picoseconds — a picosecond is one-trillionth of one second — and Borra said he thinks they are beacons from other worlds. He also says if the signals were caused by an instrumentation or analysis error, they would have shown up in more than 234 stars.

But astronomers publicly criticized his claim on several grounds. Borra and Trottier didn’t double-check their findings with other telescopes, first of all. What’s more, critics argued, they made statistical errors that overstated the probability that the signals are not random. And they did not account for all the ways in which their analysis techniques could have introduced errors, astronomers told me.

“Perhaps there is no discovery you should be more skeptical about than if someone says we have found intelligent life beyond the Earth. That would be the most significant discovery in the history of humanity, in my view,” said Andrew Siemion, the director of the SETI Research Center at the University of California, Berkeley, who is already double-checking Borra and Trottier’s stars.

Astrophysicist Peter Plavchan at Missouri State University initially called the report a “disservice to SETI.” He says the data grouping and analysis required to find these signals is difficult and can introduce errors, which the authors didn’t take into account. He says they should have used more sophisticated statistical techniques, too.

“We’re looking for smaller and smaller signals and going higher in sensitivity than we ever have,” Plavchan told me. “Data volumes are getting bigger and bigger. So we have to rely on robust statistics to get our results. I think if this paper had a different tone to it, which is just acknowledging that the analysis of statistical signals was incomplete, then I think the paper could have been much more well received, rather than saying, ‘We’ve done everything; it’s aliens,’ which is kind of the way the paper reads.”

Like many others, Plavchan said he wishes the authors had independently confirmed their findings using other telescopes or other data. Borra says he hopes other teams will do this; he has already shared his data and analysis code with Siemion.

Borra said that he knows the paper has been criticized and that he thinks the most important thing is to follow up on it. He said he was confident in the work.

“I went through a very systematic analysis to see whether it could be due to other effects, like data interpretation or instrumental effects, and the analysis shows it clearly cannot be the case,” he said.

Borra’s claims followed an announcement in August from Russian astronomers, who initially said they picked up an interesting radio signal emanating from a sunlike star in the constellation Hercules, called HD 164595. That signal came in through the RATAN-600 radio telescope in the southern Russian republic of Karachay-Cherkessia, which is part of a worldwide SETI effort. But as soon as the news hit the internet, SETI Institute and Breakthrough Listen Initiative astronomers double-checked it and found nothing. On the Rio scale, it was a nothingburger.

“The lesson is that when you look for this sort of stuff, you see things all the time,” Wright said.

Siemion said he plugged in Borra’s claims and came up with a Rio scale value of either 0 or 1 (none/insignificant) for the 234 signals. If other astronomers verified the pulses using other telescopes, the δ values would rise, but astronomers would still need to prove the pulses couldn’t be explained by instrumental phenomena or anything else.

Siemion and Wright said the results from Borra and RATAN-600 in Russia show that the Rio scale needs to be updated. Because the scale isn’t standardized, people can come up with different values for the same signals. And there is no database by which people can go back and look at past Rio values for interesting, as-yet-unexplained phenomena, such as the Wow! signal. Siemion adds that it doesn’t account for such passing events as supernovae, which might be worth checking out even if they aren’t aliens. Wright recently tweaked the scale himself to include more detail, such as whether the signals definitely can’t be explained by natural phenomena. On his updated scale, the first discovery of a pulsar, or a spinning neutron star, would have had a Rio value of 8 — “if not aliens, still very interesting” — until we learned about its nature.

Borra and Trottier’s new paper was based on Borra’s efforts of a few years ago, in which he proposed a way to deal with one of SETI’s main challenges: Stars are bright. Alien signals would have to distinguish themselves from their star’s own light, which blazes in every part of the spectrum, from radio to X-ray. In 2012, Borra explained how extraterrestrials could use a laser to do this. Like a cosmic lighthouse, a powerful laser shining ineffably quick pulses could very briefly outshine the star. With the right mathematical analysis, we could see these beacons superimposed on the star’s light.

Borra says we could produce these signals ourselves, and other researchers have also proposed using lasers as cosmic beacons. (Whether we should broadcast them, rather than just look for them, is a separate and controversial question.)

“One would think a civilization which is older than we are by thousands and thousands of years would have even more powerful lasers that could communicate to even more distant locations,” Borra said.

On the phone, Borra stressed that he is a man of science, relying on logic and numbers to back up his claims. But he admits that he hopes his evidence really reveals signs of a distant civilization of intelligent beings.

“Right now, my feeling is there is a very high probability that it is an ETI signal. My emotions would say, ‘Yes, let’s communicate with them, let’s see what they look like,’” he said.

http://fivethirtyeight.com/features/is-that-an-alien-signal-please-answer-on-a-scale-of-1-to-10/
« Last Edit: 10/27/2016 08:36 PM by Star One »

Offline CuddlyRocket

Re: Paper states 234 stars signals probably from ETIs
« Reply #2 on: 10/29/2016 01:10 AM »
Quote
On the phone, Borra stressed that he is a man of science, relying on logic and numbers to back up his claims. But he admits that he hopes his evidence really reveals signs of a distant civilization of intelligent beings.

“Right now, my feeling is there is a very high probability that it is an ETI signal. My emotions would say, ‘Yes, let’s communicate with them, let’s see what they look like,’” he said.

Which should have put him on his guard against seeing what he wants to see.

Offline philw1776

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Re: Paper states 234 stars signals probably from ETIs
« Reply #3 on: 10/29/2016 06:09 PM »
It's basic.
Wait until other telescopes confirm at least some of the pulses.
IF they do, then more rigorous analysis and attempts at natural phenomenon models.
If natural models fail to explain, then the standard more observing time & varied detection approaches follow.

Reminds me very much of the 1st pulsar detections.
“When it looks more like an alien dreadnought, that’s when you know you’ve won.”

Offline Stan-1967

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Re: Paper states 234 stars signals probably from ETIs
« Reply #4 on: 10/29/2016 06:27 PM »
The lesson is that when you look for this sort of stuff, you see things all the time,” Wright said.==> I couldn't have said it better.


I made a first pass read of the paper by Borra & Trottier.   I need to go through it again, but the statistics may be beyond me.   I did find the paper strange in how often it cites the authors previous work as the foundation of credibility for this latest paper.   Both authors are credentialed and respectable persons, but being so reliant on ones own expertise in a small field of study (optical SETI) should lend more modesty to the claims.  It obviously did not.   My takeaway is that he is a "believer", and has separated himself from impartiality.
« Last Edit: 10/29/2016 11:46 PM by Stan-1967 »

Offline as58

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Re: Paper states 234 stars signals probably from ETIs
« Reply #5 on: 10/30/2016 06:56 AM »
Apparently there is some sort of Galactic Empire (or Republic?). Otherwise it'd be hard to explain how ETI signals from a couple of hundreds stars all over the sky and nowhere near each other are using the  same ~1.65 ps modulation. It is also comforting to know the we earthlings are special. Why else would all those aliens beam their signals in our direction, as the authors suggest?


Offline Stan-1967

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Re: Paper states 234 stars signals probably from ETIs
« Reply #6 on: 10/30/2016 10:12 PM »
Apparently there is some sort of Galactic Empire (or Republic?). Otherwise it'd be hard to explain how ETI signals from a couple of hundreds stars all over the sky and nowhere near each other are using the  same ~1.65 ps modulation. It is also comforting to know the we earthlings are special. Why else would all those aliens beam their signals in our direction, as the authors suggest?

In fairness to the authors, I don't think they suggested ETI's were intentionally aiming at Earth civilization.  Earth being in the cone of light of an ETI high powered laser beacon is a chance occurence.   What is apparently unprovable about this claim is that there is no way of knowing if the picosecond pulses are directed or omnidirectional.  That makes a world of difference in the power needed for such a pulse.

Offline meekGee

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Re: Paper states 234 stars signals probably from ETIs
« Reply #7 on: 10/31/2016 01:25 AM »
Apparently there is some sort of Galactic Empire (or Republic?). Otherwise it'd be hard to explain how ETI signals from a couple of hundreds stars all over the sky and nowhere near each other are using the  same ~1.65 ps modulation. It is also comforting to know the we earthlings are special. Why else would all those aliens beam their signals in our direction, as the authors suggest?

In fairness to the authors, I don't think they suggested ETI's were intentionally aiming at Earth civilization.  Earth being in the cone of light of an ETI high powered laser beacon is a chance occurence.   What is apparently unprovable about this claim is that there is no way of knowing if the picosecond pulses are directed or omnidirectional.  That makes a world of difference in the power needed for such a pulse.

And you have to admit - as enormously energetic as these things are, the shortness of the pulse does help reduce the energy bill at the end of the month.
ABCD - Always Be Counting Down

Offline MP99

Re: Paper states 234 stars signals probably from ETIs
« Reply #8 on: 10/31/2016 05:52 AM »
Apparently there is some sort of Galactic Empire (or Republic?). Otherwise it'd be hard to explain how ETI signals from a couple of hundreds stars all over the sky and nowhere near each other are using the  same ~1.65 ps modulation. It is also comforting to know the we earthlings are special. Why else would all those aliens beam their signals in our direction, as the authors suggest?

In fairness to the authors, I don't think they suggested ETI's were intentionally aiming at Earth civilization.  Earth being in the cone of light of an ETI high powered laser beacon is a chance occurence.   What is apparently unprovable about this claim is that there is no way of knowing if the picosecond pulses are directed or omnidirectional.  That makes a world of difference in the power needed for such a pulse.
ISTM the exact opposite.

The only way to explain that the signals come only from stars similar to ours is that ETIs are targeting suns similar to their own.

Cheers, Martin

Offline high road

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Re: Paper states 234 stars signals probably from ETIs
« Reply #9 on: 10/31/2016 06:32 AM »
Apparently there is some sort of Galactic Empire (or Republic?). Otherwise it'd be hard to explain how ETI signals from a couple of hundreds stars all over the sky and nowhere near each other are using the  same ~1.65 ps modulation. It is also comforting to know the we earthlings are special. Why else would all those aliens beam their signals in our direction, as the authors suggest?

In fairness to the authors, I don't think they suggested ETI's were intentionally aiming at Earth civilization.  Earth being in the cone of light of an ETI high powered laser beacon is a chance occurence.   What is apparently unprovable about this claim is that there is no way of knowing if the picosecond pulses are directed or omnidirectional.  That makes a world of difference in the power needed for such a pulse.
ISTM the exact opposite.

The only way to explain that the signals come only from stars similar to ours is that ETIs are targeting suns similar to their own.

Cheers, Martin

Why a galactic empire? Even if it would be hundreds of individual civilizations physically separated by the vastness of space, the fact that they use the same signal would only mean that they communicate amongst each other. Not using the same signal would reduce the chances of the other civilizations interpreting it correctly.

The problems with this paper are summed up in the opening post. No reason to add false dilemmas. Let's leave that to the pro alien intelligence camp.

Edit: inverted meaning of sentence
« Last Edit: 10/31/2016 08:16 AM by high road »

Offline john smith 19

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Re: Paper states 234 stars signals probably from ETIs
« Reply #10 on: 10/31/2016 07:45 AM »
First time I've seen a quantified paper on this particular subject. The results are derived from the Sloan Digital Sky Survey. Please note the paper has been been accepted for publication in PASP. One of the authors has had a distinguished career so at least it's not some nonsense paper.

Discovery of peculiar periodic spectral modulations in a small fraction of solar type stars

https://arxiv.org/abs/1610.03031

Jason Wright linked to this article in his Twitter feed in response to this paper.

http://sites.psu.edu/astrowright/2016/10/11/when-the-press-should-pay-attention-to-a-possible-seti-detection/

SETI Berkeley are to conduct follow up observations.

https://seti.berkeley.edu/bl_sdss_seti_2016.pdf
Obvious questions are
a)Do they all have the same wavelength or different wavelengths?
b)How exhaustive has the search for natural causes been?
c)What is the pattern on them and do all stars show the same pattern? Note that a simple on/off could be natural and an apparently random pattern could simply be the use of a pseudo random number code system.
d) How many of them overlap with the list of stars with known (or suspected) planets?

It looks like something very interesting is happening in the vicinity of 234 stars and should definitely be investigated further.

So a researcher proposes a way ETI's could signal/attract each others attention, goes looking for evidence it's being used and (apparently) finds it.

Odds on bet is some unknown phenomena (or known phenomena operating in a new way) which will tell us something new about stellar or planetary development or (like [pulsars) classes of stars.

Of course that's only the odds on bet while no real evidence of ETI is found.

If that happens everything changes.

But I don't think I'll be worrying about the arrival of aliens just yet.
BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C Apply So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Offline Svetoslav

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Re: Paper states 234 stars signals probably from ETIs
« Reply #11 on: 10/31/2016 03:56 PM »
This is what disturbs me:

http://www.space.com/34541-alien-life-search-possible-seti-signals.html

""" Shostak also said that he knew of six different reviewers who had recommended against publishing the paper, at least without significant revision. However, he did stress that Publications of the Astronomical Society of the Pacific is a reputable journal.""""

If this is true and the reviewers recommended against publishing the paper, why is it published at all? OK, I know that in the end, it's the editor-in-chief who decides whether the paper should be published or not. However I don't think that peer review should only serve a cosmetic purpose. If the reviewer comments were ignored, that would be bad. If I, for example, was a reviewer and someone ignored my comments, I would never again accept to review another paper for the same journal.
« Last Edit: 10/31/2016 03:56 PM by Svetoslav »

Offline as58

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Re: Paper states 234 stars signals probably from ETIs
« Reply #12 on: 10/31/2016 05:00 PM »
This is what disturbs me:

http://www.space.com/34541-alien-life-search-possible-seti-signals.html

""" Shostak also said that he knew of six different reviewers who had recommended against publishing the paper, at least without significant revision. However, he did stress that Publications of the Astronomical Society of the Pacific is a reputable journal.""""

If this is true and the reviewers recommended against publishing the paper, why is it published at all? OK, I know that in the end, it's the editor-in-chief who decides whether the paper should be published or not. However I don't think that peer review should only serve a cosmetic purpose. If the reviewer comments were ignored, that would be bad. If I, for example, was a reviewer and someone ignored my comments, I would never again accept to review another paper for the same journal.

As far as I understand, the paper was rejected by (a) different journal(s) before being accepted by PASP. Maybe some/all of the six reviewers that Shostak mentions weren't reviewing for PASP?

edit: the rumour that the paper has been going around for a long time is also mentioned here:
http://setiathome.berkeley.edu/forum_thread.php?id=80378
« Last Edit: 10/31/2016 05:04 PM by as58 »

Offline Svetoslav

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Re: Paper states 234 stars signals probably from ETIs
« Reply #13 on: 10/31/2016 06:18 PM »
Thanks,    as58!!! This probably explains the long review cycle

Offline Star One

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Paper states 234 stars signals probably from ETIs
« Reply #14 on: 10/31/2016 06:28 PM »
Why didn't they just do as the reviewers suggested.

If there are aliens out there I imagine at least some of them are far more aware we are here than we are of them.
« Last Edit: 10/31/2016 06:36 PM by Star One »

Offline Svetoslav

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Re: Paper states 234 stars signals probably from ETIs
« Reply #15 on: 10/31/2016 06:33 PM »
Why didn't they just do as the reviewers suggested.

They, as authors, reserve the right to resubmit it to another journal as-is :)

I think that that the conclusions will be checked by independent researcher and later refuted.

Offline Star One

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Paper states 234 stars signals probably from ETIs
« Reply #16 on: 10/31/2016 06:38 PM »
Why didn't they just do as the reviewers suggested.

They, as authors, reserve the right to resubmit it to another journal as-is :)

I think that that the conclusions will be checked by independent researcher and later refuted.

I wouldn't go that far, I hate pre-judging stuff like this. If I learnt anything from The Doctor Strange film we should keep an open mind.
« Last Edit: 10/31/2016 06:38 PM by Star One »

Offline baldusi

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Re: Paper states 234 stars signals probably from ETIs
« Reply #17 on: 10/31/2016 07:05 PM »
Science growths thanks to disagreement. If some reputable journal decided to publish it, and most people find it bad science, then many will write papers disproving it. I'm not saying that you should publish anything. But if the Quasicrystals story tells us anything is that some "wackos" are actually right. BTW, I'm making no assertions on this particular paper.

Offline Svetoslav

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Re: Paper states 234 stars signals probably from ETIs
« Reply #18 on: 10/31/2016 07:14 PM »
Science growths thanks to disagreement. If some reputable journal decided to publish it, and most people find it bad science, then many will write papers disproving it.

I also agree with that!

By the way, I'm very much against retraction of "bad" papers (unless there's obvious plagiarism). I think that retractions hurt the  scientific process. If an article turns out to be bad, it should be disproven, not retracted.

Offline baldusi

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Re: Paper states 234 stars signals probably from ETIs
« Reply #19 on: 10/31/2016 07:42 PM »
Science growths thanks to disagreement. If some reputable journal decided to publish it, and most people find it bad science, then many will write papers disproving it.

I also agree with that!

By the way, I'm very much against retraction of "bad" papers (unless there's obvious plagiarism). I think that retractions hurt the  scientific process. If an article turns out to be bad, it should be disproven, not retracted.
I totally concur that shame should be the most powerful incentive not to publish bad papers.

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