Message boards :
SETI@home Staff Blog :
Yet another probable non-detection of ET
Message board moderation
Author | Message |
---|---|
Eric Korpela Send message Joined: 3 Apr 99 Posts: 1382 Credit: 54,506,847 RAC: 60 |
Why do I always have to be the bad guy? A paper was made available on arXiv last night, titled "Discovery of peculiar periodic spectral modulations in a small fraction of solar type stars" In the paper comments from the submitter you can see "Signals probably from Extraterrestrial Intelligence." Here we go again. Another unconfirmed signal from ET. Another author not following the recommended protocols of which they are undoubtedly aware, primarily confirmation before publication. In the paper, the authors have analyzed 2.5 million archival spectra from the Sloan Digital Sky survey using a discrete Fourier transform. In 234 stars, of spectral types G, K they found periodicity which they attribute to broad band pulsations of the stellar signal that have (in nearly all the sources) a period of 1.65 picosecond (1 picosecond=a trillionth of a second). Pulses of such short duration would need to come from an omnidirectional transmitter less than half a millimeter across or they would have to be beamed in our direction. That's typically what we look for in optical SETI, directed pulses, but on nanosecond (a billionth of a second) rather than picosecond timescales. There's lots of math and physical intuition involved in the analysis so I won't describe it all. The authors describe why they think it can't be an instrumental or data analysis effect and then conclude ET is the most likely cause. They conclude there are 234 planets beaming pulses of the same period directly at Earth. A Galactic consortium. What is missing from the analysis? Confirmation, of course. A 1 meter telescope with a low resolution spectrograph would have been able to confirm or refute this in a single night. This paper has been in the review process for more than enough time for a confirming observation at a different telescope to be made. None is mentioned. At any rate, I'm unconvinced that there are 234 stars transmitting pulsations at the same rate toward Earth. My best guess? It's an instrumental or data handling effect. The similar rate seems suspicious. The author list doesn't include a data scientist from the Sloan survey, nor is one acknowledged, so the authors may not have fully understood the data analysis pipeline for Sloan. I'm not an expert on the SDSS pipeline, but I can think of many steps when an oscillatory term could be introduced in an intermittent fashion. For example, if there is a polynomial fit to the wavelength scale that breaks down because of a misdetected calbration line. Or a poor CCD flat field correction, or a polynomial fit to a background or continuum went bad. We'll probably find out more when confirmation attempts are made using different instruments. Of course, Breakthrough Listen is going to take that strategy and look at these stars with the Automated Planet Finder and get high resolution spectra. Prior to confirmation it rates on the Rio Scale as a 1 (out of 10), insignificant. After confirmation it would pop up to a 3-5 (minor to intermediate). To get up to noteworthy (in my estimation) we would have to do more to rule out non-intelligent phenomena. Who knows, maybe we'll get lucky. Jason Wright from Penn State (on sabbatical at UC Berkeley this semester) has penned a blog post about the Rio scale and how it is used in conjunction with announcement of possible discoveries. @SETIEric@qoto.org (Mastodon) |
Gary Charpentier Send message Joined: 25 Dec 00 Posts: 30932 Credit: 53,134,872 RAC: 32 |
Eric, didn't we just have the Nobel's handed out? I theorize there is a connection with the rate of alleged discoveries and the date of the Nobel announcements. :) |
Eric Korpela Send message Joined: 3 Apr 99 Posts: 1382 Credit: 54,506,847 RAC: 60 |
|
JLDun Send message Joined: 21 Apr 06 Posts: 573 Credit: 196,101 RAC: 0 |
Maybe. Gotta get in line for next year. :) So, (jokingly), if You wanted to try for next year's Nobel, when would you want to push those papers? |
Astro Send message Joined: 9 Aug 16 Posts: 9 Credit: 52,370 RAC: 0 |
Well that exact type of Science is not my purview. I wouldn't think many alleged civilizations would want to message us directly, none the less, that many in a synchronized fashion. Assuming that anything is possible, I agree that they should work on conformations before publishing anything that is Scientifically established. Claims to outward are the type of thing that could de-legitimize legitimate ones. With my own research I like to also see what friends and colleagues think, to speculate and criticize. |
JLDun Send message Joined: 21 Apr 06 Posts: 573 Credit: 196,101 RAC: 0 |
"It seems to me" there could be three groups: A.) Finding Chasers: "Hey, we think there's something there! Look at what we found!" B.) Turtles: Gather information, and gather, and gather, until you KNOW... even though you Can't know from here on Earth. C.) True Scientific: "Hey, my information says this - does someone else see it? (By both using my method and maybe an alternative?)" S@H is hopefully a (C.) [But is a (B.) in practice until there is actually information]. Most of the other announcements seem to be an (A.) [And you seem to be a (C.) based on your statement.) |
Michael Watson Send message Joined: 7 Feb 08 Posts: 1386 Credit: 2,098,506 RAC: 5 |
It's particularly interesting that the astronomers involved had previously made a prediction about the characteristics of a SETI signal of this type, and thereafter found that the data they analyzed followed this prediction closely. It's often observed that successful prediction is the 'gold standard' for a scientific hypothesis. Interesting to learn, too, that despite the reservations about these signals' authenticity, they are considered worthwhile enough to be looked for with a very substantial telescope. |
Mike Send message Joined: 17 Feb 01 Posts: 34352 Credit: 79,922,639 RAC: 80 |
I don`t think you are the bad guy Eric. Your detailed explanation is again much appreciated. With each crime and every kindness we birth our future. |
Ray Packham Send message Joined: 30 Sep 13 Posts: 1 Credit: 453,456 RAC: 1 |
Dont these people check with their peers before publishing? and its a shame they don't go through the same vigorous thought processes as your good self , although i note there is still a very slim chance that they may be correct the odds are that they are not as you explain so well. I for one would love to hear from some intelligence in the universe because we are either alone or part of some vast universal seed of life and like Carl Sagan stated the prospect is truly frightening either way. |
George 254 Send message Joined: 25 Jul 99 Posts: 155 Credit: 16,507,264 RAC: 19 |
Eric You the bad guy? Maybe it's another version of that saying "A prophet is without honour in his own country"? Anyway, great article with excellent links - thank you. George |
Chris Send message Joined: 29 Sep 99 Posts: 10 Credit: 1,603,059 RAC: 7 |
Fingers crossed (one set) and I hope it happens I don't know if break a leg or good luck is appropriate. Sounds very exciting now science just needs to invent space folding worm holes or warp drives or all the above and we can go on a intergalactic search. |
jefferson baptiste Send message Joined: 11 Sep 16 Posts: 2 Credit: 1,195,667 RAC: 0 |
[Another author not following the recommended protocols of which they are undoubtedly aware, primarily confirmation before publication.] I blame Thomas Edison's legacy of theft for that. i expect publication to often precede confirmation because of that history. |
jefferson baptiste Send message Joined: 11 Sep 16 Posts: 2 Credit: 1,195,667 RAC: 0 |
We already are on a spaceship with a nuclear engine (with no steering).All we need in science now is to be able to turn energy into matter and scientific research is over.I wonder if we are going at the speed of light, would we know it? like the fly flying inside a jar inside a car, traveling at 100 miles/hour? |
Eric Korpela Send message Joined: 3 Apr 99 Posts: 1382 Credit: 54,506,847 RAC: 60 |
Don't these people check with their peers before publishing? and its a shame they don't go through the same vigorous thought processes as your good self , although i note there is still a very slim chance that they may be correct the odds are that they are not as you explain so well. My understanding (through the grapevine) is that the paper was in the peer review process for several years and was rejected by several different reviewers at at least one other journal. But nothing prevents authors from resubmitting a paper unchanged to many different journals until they find a reviewer who lets it through. A drawback of the anonymity of the peer review process is that journal editors can't talk to each other about which papers have been rejected. It also may be a shortcoming of the typical Astronomy peer review process which is conducted by a single reviewer rather than the two or three that may be typical in other fields. The assumption is that every reviewer is equally competent, which is not necessarily true. @SETIEric@qoto.org (Mastodon) |
Raistmer Send message Joined: 16 Jun 01 Posts: 6325 Credit: 106,370,077 RAC: 121 |
hehe, you got citation at least :D Korpela et al. (2011) SETI apps news We're not gonna fight them. We're gonna transcend them. |
Regans PC Send message Joined: 22 Nov 99 Posts: 2 Credit: 2,398,239 RAC: 17 |
They're simply waiting for us to visit. They're not as fortunate as we, with our gas/oil/coal/nuclear power that still isn't enough, and their suns produce more of a benign power that cannot be used for more than frying eggs. Worm holes? Not in their neighbourhood, but perhaps we can find and use them in ours to travel to meet them. I'm doing my job in looking for them. Anyone else? |
Bill Hail 1958 Send message Joined: 9 Sep 16 Posts: 1 Credit: 373,939 RAC: 0 |
Definitely not a bad guy at all! Interesting post. Well stated. |
Walter Kraslawsky Send message Joined: 6 Jun 02 Posts: 8 Credit: 1,024,102 RAC: 0 |
I would certainly reject any explanation that all sources are beaming directly towards Earth. However, can you elaborate a little on the "omnidirectional" alternative explanation? |
chuckivie Send message Joined: 15 Dec 04 Posts: 2 Credit: 313,206 RAC: 0 |
I was working as a radio astronomer at Cal Tech when pulsars were detected. It was some time before we realized that the signals had a natural source. Now we have added SNR's to the astrophysical zoo and our knowledge of cosmological phenomena has been enhanced. As much as I would like to believe in LGM's I suspect that the signals are, as you suspect, instrumental error or something new that will further enrich our understanding. Very cool if confirmed. |
chuckivie Send message Joined: 15 Dec 04 Posts: 2 Credit: 313,206 RAC: 0 |
An "omnidirectional" source requires vastly more energy than a tightly beamed one simply because, by definition, it radiates energy over a full sphere rather than a narrow beam. The pulse width sets an upper limit on the size of the source if it is omnidirectional because of speed of light limitations. A phased array beamed directly at earth can be of any size and still deliver a coherent signal but an isotropic source must be small and very powerful. |
©2024 University of California
SETI@home and Astropulse are funded by grants from the National Science Foundation, NASA, and donations from SETI@home volunteers. AstroPulse is funded in part by the NSF through grant AST-0307956.