Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.

Monday, October 24, 2016

Wish upon a star

If I had one wish for something that I will live long enough to see, it'd be incontrovertible evidence of intelligent life on other planets.

I know, when it comes to human problems, feeling alone in the galaxy isn't one of the more pressing ones.  Finding a cure for cancer, finding ways to prevent or treat dementia, developing a universal vaccine for flu and colds and malaria -- those should be up there somewhere.

Oh, and eliminating poverty and ignorance, and having peace on Earth.  Those, too.

But man.  Aliens, you know?  There's something magnetic about the idea of an intelligence that (in C. S. Lewis's words) "floats on a different blood."  So whenever there's a new development in SETI -- the Search for Extraterrestrial Intelligence -- I always read it with great enthusiasm.

And just last week, astronomers found what might be the best candidate yet.

According to a paper published last week at the pre-print site arXiv, Emmano F. Borra and Éric Trottier, two astronomers at Laval University (Québec City), have found 234 stars (out of 2.5 million studied) whose spectra show "peculiar periodic modulations."  The authors write:
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.
When I read this, I said, and I quote, "Holy shit."

That two reputable research astronomers would go out on a limb like this and say, "Yeah, this pretty much looks like ETI" is stunning.  Hell, they didn't even do that with "Tabby's Star" -- the star discovered by Tabetha Boyajian whose brightness profile over time showed some really weird fluctuations.  Boyajian and others said that the change in brightness was strange, and could be consistent with an alien civilization constructing a huge Dyson sphere around the star, but that it was way premature to conclude that this was what was happening.  Further studies have left astronomers still saying "We don't know" -- which is exactly the stance a good scientific skeptic should take when the evidence is insufficient to come to a conclusion.

Here, though, they appear to have eliminated all of the other likely possibilities.  Borra and Trottier are seriously considering the possibility that these odd signals might be signals from extraterrestrial beacons -- and that a civilization who could create pulses this powerful would be significantly beyond us technologically.

It behooves us to recall, however, that when Jocelyn Bell first discovered pulsars, they were nicknamed LGM (Little Green Men) until it turned out that there was a perfectly natural, and non-ETI, explanation for them.  So caution is recommended.  But to me -- and I'm admitting up front I'm not an astronomer, so my opinion probably doesn't count for much -- this seems like the most promising candidate for ETI yet.

So I hope that other astronomers follow up Borra and Trottier's study, because what we need now is more information.  And of course, if it does turn out to be ETI, the question then becomes, "What do we do now?"  Do we signal back "Hey, we're over here?"  The level of terrestrial intelligence sometimes seems to me to be so low that you have to wonder if the aliens would just say, "Oh, man.  This planet is just not worth the trouble."  And in any case, the distances are so great that a two-way conversation wouldn't be possible.

But even so.  Just the idea that we might be looking at the first real evidence of intelligent life beyond our solar system is amazingly cool.  Once in arXiv the paper goes into peer review, and so far it appears to be "generating interest" -- science-ese for "it hasn't been dismissed out of hand."  So we'll watch and wait.

Of course, me, I'm already preparing for the reception committee when they land in my back yard.  I'm not nearly as cool as Zefram Cochrane, but I hope that the Vulcans will still find me an acceptable proxy.


  1. I'm fully with you on hoping for at least a passive, confirmed ID of 'someone, anyone?' out there. And before I 'leave the room'.
    My question, not addressed in the report concerns the '... to makes us aware of their existence. ' assumption. What would be their motivation? Or is that motivation considered to be too 'of course' to mention? These data do suggest, as with Tabby, something currently explainable, and logically consistent with the traces we'd see from intelligent manipulation of a star.
    But I'm wondering how you feel about the unaddressed assumption above.

    1. I think the assumption that the signal is deliberate is a bit premature. The only thing that argues that it is, is its intensity -- it's been compared to a lighthouse beacon. In the case of Tabby's Star, if it is ETI the signal is probably "accidental" -- created as parts of the Dyson sphere cover the star.

  2. A well respected German mathematitian, Eduard Heindl, has created a mathematical model for the most famous KIC8462852 light curve and has come to the conclusion(to a HIGHER DEGREE OF PROBABILITY than that of Borra and Trottier' probability for their 234 stars)that the d792 light curve is NOT NATURAL, and is a result of an ETI STARLIFTING OPERATION! This begs the question: Why doesn't somebody run a Fourier Transform analysis on the spectrum of Boyajian's Star to see if it ALSO pulses in the way rhat the 234 Borra-Trottier stars do?