Strange attractors

Dear Readers,

I am going to be taking a short break from Skeptophilia, so this will be my last post for a week and a half.  Lord willin' an' the creek don't rise, as my grandma used to say, I'll be back at it on Monday, January 27.

cheers,

Gordon

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I've always found the concept of the Strong Anthropic Principle wryly amusing.

The idea here is that something (usually a benevolent deity) fine-tuned the universe in just such a way to be hospitable for us -- for having forces perfectly balanced to hold matter together without causing a runaway collapse, for having gravitational pull strong enough to form stars and planets, for having electromagnetic forces of the right magnitude to generate the chemical reactions that ultimately led to organic molecules and life, and so on.

To me, this argument ignores two awkward facts.  First, of course our universe has exactly the right characteristics to generate and support life; if it didn't, we wouldn't be here to consider the question.  (This is called the "Weak Anthropic Principle," for obvious reasons.)  Second, though -- the Strong Anthropic Principle conveniently avoids the fact that a large percentage of the Earth, and damn near one hundred percent of the universe as a whole, is completely and unequivocally hostile to us, and probably to just about any living thing out there.

It's one of those hostile bits that got me thinking about the whole issue today, because astronomers recently observed a phenomenon called a fast radio burst in our own galaxy -- a mere thirty thousand light years away -- and the thing that produces it is not only bizarre in the extreme, but is something that we're very, very lucky not to be any closer to.

The beast that produces this is called a magnetar, and appears to be a rapidly-spinning neutron star, with a mass of two to three times that of the Sun but compressed into a sphere only about twenty kilometers in diameter.  This means that the surface gravitational attraction is astronomical (*rimshot*).  Any irregularities in the topography would be crushed, giving it a smooth surface with a relief less than that of a brand-new billiard ball.

The most bizarre thing about magnetars, however, is the immense magnetic field that gives them their name.  Your typical magnetar has an average magnetic field flux density of ten billion Teslas -- on the order of a quadrillion times the field strength of the Earth.  This is why they are, to put it mildly, really fucking dangerous.  The article in Astronomy about the discovery explained it graphically (if perhaps using slightly more genteel language):

The magnetic field of a magnetar is about a hundred million times stronger than any human-made magnet.  That’s strong enough that a magnetar would horrifically kill you if you got within about 620 miles (1,000 km) of it.  There, its insanely strong magnetic field would pluck electrons from your body’s atoms, essentially dissolving you.

This brought up a question in my mind, though; magnetic fields of any kind are made by moving electrical charges -- so how can a neutron star (made, as one would guess, entirely of neutrons) have any magnetic field at all, much less an "insanely strong" one?   Turns out I'm not the only one to ask this question, as I found out when I did some digging and stumbled on the Q-and-A page belonging to Cole Miller, Professor of Astronomy at the University of Maryland.  Miller says the reason is that not all of the particles in a neutron star are neutrons.  While the structure as a whole is electrically neutral, about ten percent of the total mass is made up of electrons and protons that are free to move.  Take those charged particles and whirl them around hundreds of times per second, and you have a magnetic field that is not only insanely strong, but really fucking dangerous.

This all comes up because of the observation of a thirty-millisecond-long fast radio burst coming from within our galaxy.  All the others that have been detected were in other galaxies, and the distances involved (not to mention how sporadic they are, and how quickly they're over) make them difficult to explain.  But this comparatively nearby one gave us a load of new information -- especially when a second burst came from the same magnetar a few days later.

[Image licensed under the Creative Commons ESO/L. Calçada, Artist’s impression of the magnetar in the extraordinary star cluster Westerlund 1, CC BY 4.0]

Astronomers and astrophysicists are still trying to explain the phenomenon, including odd features of this particular one such as its relative faintness.  As compared to bursts from other galaxies this one was a thousand times less luminous.  Why is still a matter of conjecture.  Is it because bursts this weak occur in other galaxies, but from this distance would be undetectable?  Is it because the distant galaxies are much younger (remember, looking out in space is equivalent to looking back in time), so stronger bursts only happen early in a galaxy's evolution?  At this point, we don't know.  As Yvette Cendes, author of the Astronomy article, put it:

It is far too early to draw a firm conclusion about whether this relatively faint FRB-like signal is the first example of a galactic fast radio burst — making it the smoking gun to unlocking the entire FRB mystery.  And there are also still many preliminary questions left to answer.  For example, how often do these fainter bursts happen?  Are they beamed so not all radiation is equally bright in all directions?  Do they fall on a spectrum of FRBs with varying intensities, or are they something entirely new?  And how are the X-ray data connected?

As usual with science, the more we know, the more questions we have.

In any case, here we have a phenomenon that's cool to observe, but that you wouldn't want to be at all close to.  Not only do we have the magnetic field to worry about, but the burst itself is so energetic that anything nearby would get flash-fried.

So "the universe is fine-tuned to be congenial to us" only works if you add, "... except for the 99.9% of it that is actively trying to kill us."  Not that this makes it any less magnificent, but it does make you feel a little... tiny, doesn't it?  Probably a good thing.  Humans do stupid stuff when they start thinking they're the be-all-end-all.

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NEW!  We've updated our website, and now -- in addition to checking out my books and the amazing art by my wife, Carol Bloomgarden, you can also buy some really cool Skeptophilia-themed gear!  Just go to the website and click on the link at the bottom, where you can support your favorite blog by ordering t-shirts, hoodies, mugs, bumper stickers, and tote bags, all designed by Carol!

Take a look!  Plato would approve.

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A cosmic slide whistle

In 1894, physicist Albert Michelson said, "It seems probable that most of the grand underlying principles [in science] have been firmly established …  An eminent physicist remarked that the future truths of physical science are to be looked for in the sixth place of decimals."

The irony of this statement is twofold.  First, within thirty years, the entire field of physics would be upended twice, by Einstein's Special and General Theories of Relativity, and from the development by Niels Bohr, Louis de Broglie, and Erwin Schrödinger of the Quantum Model.  Second, it was the null result from the experiment Michelson himself performed with Edward Morley that disproved the existence of the luminiferous aether and directly led to Einstein's revolutionary theories about the nature of light and motion.

The fact is, there is still a ton of stuff we don't fully understand, and then there are all the things that we don't even know we don't know.  The universe is full of mystery, and there will be plenty to keep scientists occupied for a very, very long time.

Take, for example, a paper last week in Monthly Notices of the Royal Astronomical Society about a bizarre twist on an already poorly-understood phenomenon -- the fast radio burst.  These sudden explosive blasts in the radio region of the spectrum, lasting between 0.001 and 3 seconds, pack as much energy in that time as the entire Sun emits in three days.  Some are transient, but others -- like the euphoniously-named FRB 180916.J0158+65 -- have a regular periodicity, in this particular case 16.35 days.

[Image licensed under the Creative Commons ESO/M. Kornmesser, Artist’s impression of a fast radio burst traveling through space and reaching Earth, CC BY 4.0]

Since their discovery in 2007, hundreds of fast radio bursts have been observed.  Given their unpredictability and ephemeral nature -- you have to have your radio telescope aimed at exactly the right place in the sky at exactly the right time, and you have a window of under three seconds to see them -- it's probable that they are insanely common, and we just miss 99% of them.  Canadian astrophysicist Victoria Kaspi estimates that over ten thousand fast radio bursts happen somewhere in the sky every single day, so there's potentially a huge amount of data out there to study if we can only figure out a way to observe them.

Explanations for what these things could be are all over the map, and include hitherto-unknown behavior of neutron stars, magnetars, black holes, collapsing/dying supergiant stars, or some combination thereof.

Or an alien intelligence trying to signal us.  Admit it, you knew this had to come up.

The bottom line is the astrophysicists still don't know what causes fast radio bursts, much less why some repeat and some don't.  And the whole thing just got a lot weirder with the discovery by observers at the SETI (Search for Extraterrestrial Intelligence) Institute, who found a fast radio burst that had 35 explosive outbursts -- and each one slid up the frequency scale before it ended, drawing comparisons to an enormous outer space slide whistle.

What could cause a fast radio burst to sweep up the frequency scale in that fashion is, at the moment, beyond guessing.  All we know is that is that what was already a mystery just became a hell of a lot more mysterious.

So I think Michelson may have been a wee bit hasty in proclaiming science to be settled except insofar as calculating things to six decimal places.  I suspect that a closer estimate -- if it were possible to do such a thing -- is that the bits of the universe we understand well are hugely outnumbered by the bits we still haven't a clue about.  I prefer the assessment made by Carl Sagan: "Out there, something incredible is still waiting to be known."

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The celestial lighthouse

Last week I did a piece on three weird astrophysical phenomena -- odd radio circles, high-energy neutrino bursts, and fast blue optical transients -- all of which have thus far defied explanation.  And this week, a paper came out in Nature about a recent discovery adding one more to the list of unexplained celestial curiosities -- one which has the alien intelligence aficionados raising their Spock-like eyebrows in a meaningful manner (although I hasten to point out that there is no evidence that either this one, or the other three I mentioned, have anything to do with you-know-who).

However, the most recent discovery is downright bizarre.  To understand why, a bit of background.

There are many more-or-less understood phenomena in astrophysics that result in a sudden surge in electromagnetic output from an astronomical body.  Some are aperiodic, or at least infrequent, such as fast radio bursts, which were discovered back in 2007 by astrophysicists Duncan Lorimer and David Narkevic.  These are quick, transient pulses in the radio region of the spectrum, and are now thought to be due either to neutron star mergers or starquakes on the surface of magnetars.

Then there are the repeating ones, such as the fast blinking on-and-off of pulsars.  These are the rapidly whirling cores of collapsed massive stars, which funnel out beams of high-energy radiation aligned with the poles of their magnetic fields; because of the star's rotation, the beam appears to pulse, in some cases dozens of times a second.  They were discovered back in 1967 by the brilliant astronomer Jocelyn Bell Burnell, but because no one could figure out what might create a repeating signal that regular, and also because Burnell was a woman in a field almost entirely dominated by men, her discovery was derisively referred to as LGM ("Little Green Men"), and assumed to be from some sort of prosaic terrestrial source.  It was only when more of them were found that astronomers began to take her seriously.  In 1974, the Nobel Prize in Physics was awarded for the development of radio astronomy, and in particular, for the discovery of pulsars...

... to Antony Hewish and Martin Ryle.  Note who wasn't included.  Burnell has graciously stated that she "feels no bitterness toward the Nobel Committee," but in her place, I sure as hell would have.

The paper in Nature, however, describes an object that doesn't seem to fit any of the known types of electromagnetic pulses.  Called GPM J1839-10, it releases energy in the radio region of the spectrum.  But in terms of periodicity, it's somewhere between pulsars (which are so regular they've been proposed as celestial clocks) and fast radio bursts (which are apparently aperiodic).  GPM J1839-10 is slow -- its signal reaches a peak about every twenty-two minutes -- but it's not precisely regular.  The four hundred seconds centering on that twenty-two minute mark is when the peak is most likely to come, but sometimes the window will pass with no peak.  The length of the pulses is also variable, usually between thirty and three hundred seconds in length.  And unlike both fast radio bursts and pulsars, the amplitude of the peak is quite low in energy.

As science writer John Timmer put it in Ars Technica, "The list of known objects that can produce this sort of behavior... consists of precisely zero items."

What's weirdest is that going back through the records of astronomical observations, this object has been doing its thing for three decades, and only just now is attracting attention.  The astrophysicists thus far have no good explanation for what it might be.  It sits out there in space, slowly flashing on and off like some sort of interstellar lighthouse, and the the flat truth is that at the moment, no one has the slightest idea what it might be.

Of course, "We don't know" opens the door for a certain group of people to say "We do!"

As I've said before, no one would be more delighted than me if we did come across evidence of an extraterrestrial signal, but I strongly suspect this ain't it.  For one thing, the semi-regular blips it's putting out don't appear to contain any information; put a different way, the pattern isn't complex.  It could be a beacon, I suppose, but how you'd tell the difference between an alien-built celestial lighthouse and a star of some sort that is sending out pulses of radio waves is beyond me.  With nothing more to go on, by far the greater likelihood is that there is some natural explanation for this slowly-pulsing object -- we just haven't found it yet.

Even so, it's intriguing.  I've always loved a mystery, and this certainly is one.  It's possible that we've missed other objects of this type; the kind of detailed repeated scans of the sky in the radio region of the spectrum that it would take to detect a pulsation this slow have only begun to be done with any kind of thoroughness.  Like with Burnell's discovery of pulsars, it took finding others before astronomers had enough data to start putting together an explanation.

But if no others are found, what then?  It'll be added to the list of astronomical mysteries, of which there are plenty.  It's a big old universe, and filled with wonders, many of which we are only just beginning to understand.

And those are cool enough without the aliens.  Although, of course, I wouldn't object to the aliens as well.

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Flash in the pan

I introduced yesterday's post, about the discovery that a large percentage of the meteorites seem to have come from a single collision event in the distant past, as "a question without an answer."  Today we're going to look at another one; fast radio bursts.

They're pretty much what they sound like; quick, high-energy flashes in the radio region of the electromagnetic spectrum.  What the name doesn't tell you, however, is how quick and high-energy they are.  They have a duration of only a few milliseconds at most; there and gone faster than a camera flash.  And their energy output is enormous -- the average fast radio burst releases as much energy in a few milliseconds as the Sun does in three days.

The trouble with studying these events is that they're over before you can get your radio telescope pointed toward them.  Until recently, there had been no coordinated effort to find fast radio bursts; how can you find them if they come from seemingly random spots in the night sky?  You would have to have the radio telescope pointed in the exactly right direction at exactly the right time in order to know one had even happened.

[Image licensed under the Creative Commons ESO/M. Kornmesser, Artist’s impression of a fast radio burst traveling through space and reaching Earth, CC BY 4.0]

This is why the first ones weren't even observed until 2007, and the number recorded in the fourteen years since was quite small.  But it was just announced this week that CHIME, the Canadian Hydrogen Intensity Mapping Experiment, has recorded 535 fast radio bursts in the one year of its operation -- quadrupling the total number ever detected.

"Before CHIME, there were less than a hundred total discovered FRBs; now, after one year of observation, we've discovered hundreds more," said study contributor Kaitlyn Shin, a graduate student in MIT's Department of Physics.  "With all these sources, we can really start getting a picture of what FRBs look like as a whole, what astrophysics might be driving these events, and how they can be used to study the universe going forward."

Because that's the problem with fast radio bursts; no known astrophysical process could produce such a sudden, short-duration explosion in the radio region of the spectrum.  More interesting still, the CHIME study showed that they seem to fall into two classes; "one-offs" and "repeaters."  So even if we figure out how they happen, we'll still be left with why some of them happen only once, and others seem to be on some kind of regular cycle.

The most perplexing thing about them, though, is how common they appear to be.  For something that is caused by a completely unknown mechanism, they're pretty much everywhere.  "That's kind of the beautiful thing about this field -- FRBs are really hard to see, but they're not uncommon," said Kiyoshi Masui, another study contributor, and a member of MIT's Kavli Institute for Astrophysics and Space Research.  "If your eyes could see radio flashes the way you can see camera flashes, you would see them all the time if you just looked up."

So there you have it; another as-yet unsolved mystery.  It seems like no matter where we look, there are three new conundrums for every one we solve.  It brings to mind the quote from biologist J. B. S. Haldane: "The universe is not only queerer than we imagine, it is queerer than we can imagine."

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I'm in awe of people who are true masters of their craft.  My son is a professional glassblower, making precision scientific equipment, and watching him do what he does has always seemed to me to be a little like watching a magic show.  On a (much) lower level of skill, I'm an amateur potter, and have a great time exploring different kinds of clays, pigments, stains, and glazes used in making functional pottery.

What amazes me, though, is that crafts like these aren't new.  Glassblowing, pottery-making, blacksmithing, and other such endeavors date back to long before we knew anything about the underlying chemistry and physics; the techniques were developed by a long history of trial and error.

This is the subject of Anna Ploszajski's new book Handmade: A Scientist's Search for Meaning Through Making, in which she visits some of the finest craftspeople in the world -- and looks at what each is doing through the lenses of history and science.  It's a fascinating inquiry into the drive to create, and how we've learned to manipulate the materials around us into tools, technology, and fine art.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Strange attractor

I've always found the concept of the Strong Anthropic Principle wryly amusing.

The idea here is that something (usually a benevolent deity) fine-tuned the universe in just such a way to be hospitable for us -- for having forces perfectly balanced to hold matter together without causing a runaway collapse, for having gravitational pull strong enough to form stars and planets, for having electromagnetic forces of the right magnitude to generate the chemical reactions that ultimately led to organic molecules and life, and so on.

To me, this argument ignores two awkward facts.  First, of course our universe has exactly the right characteristics to generate and support life; if it didn't, we wouldn't be here to consider the question.  (This is called the "Weak Anthropic Principle," for obvious reasons.)  Second, though -- the Strong Anthropic Principle conveniently avoids the fact that a large percentage of the Earth, and damn near 100% of the universe as a whole, is completely and unequivocally hostile to us, and probably to just about any living thing out there.

It's one of those hostile bits that got me thinking about the whole issue today, because astronomers just last week observed a phenomenon called a fast radio burst in our own galaxy -- a mere thirty thousand light years away -- and the thing that produces it is not only bizarre in the extreme, but is something that we're very, very lucky not to be any closer to.

The beast that produces this is called a magnetar, and appears to be a rapidly-spinning neutron star, with a mass of two to three times that of the Sun but compressed into a sphere only about twenty kilometers in diameter.  This means that the surface gravitational attraction is astronomical (*rimshot*).  Any irregularities in the topography would be crushed, giving it a smooth surface with a relief less than that of a brand-new billiard ball.

The most bizarre thing about magnetars, however, is the immense magnetic field that gives them their name.  Your typical magnetar has an average magnetic field flux density of ten billion Teslas -- on the order of a quadrillion times the field strength of the Earth.  This is why they are, to put it mildly, really fucking dangerous.  The article in Astronomy about last week's discovery explained it graphically (if perhaps using slightly more genteel language):

The magnetic field of a magnetar is about a hundred million times stronger than any human-made magnet.  That’s strong enough that a magnetar would horrifically kill you if you got within about 620 miles (1,000 km) of it.  There, its insanely strong magnetic field would pluck electrons from your body’s atoms, essentially dissolving you.

This brought up a question in my mind, though; magnetic fields of any kind are made by moving electrical charges -- so how can a neutron star (made, as one would guess, entirely of neutrons) have any magnetic field at all, much less an insanely strong one?  Turns out I'm not the only one to ask this question, as I found out when I did some digging and stumbled on the Q-and-A page belonging to Cole Miller, Professor of Astronomy at the University of Maryland.  Miller says the reason is that not all of the particles in a neutron star are neutrons.  While the structure as a whole is electrically neutral, about ten percent of the total mass is made up of electrons and protons that are free to move.  Take those charged particles and whirl them around hundreds of times per second, and you have a magnetic field that is not only insanely strong, but really fucking dangerous.

This all comes up because of last week's observation of a thirty-millisecond-long fast radio burst coming from within our galaxy.  All the others that have been detected were in other galaxies, and the distances involved (not to mention how sporadic they are, and how quickly they're over) make them difficult to explain.  But this comparatively nearby one gave us a load of new information -- especially when a second burst came from the same magnetar a few days later.

[Image licensed under the Creative Commons ESO/L. Calçada, Artist’s impression of the magnetar in the extraordinary star cluster Westerlund 1, CC BY 4.0]

As this observation was only made last week, astronomers and astrophysicists are still trying to explain it, including odd features such as its relative faintness.  As compared to bursts from other galaxies this one was a thousand times less luminous.  Why is still a matter of conjecture.  Is it because bursts this weak occur in other galaxies, but from this distance would be undetectable?  Is it because the distant galaxies are much younger (remember, looking out in space is equivalent to looking back in time), so stronger bursts only happen early in a galaxy's evolution?  At this point, we don't know.  As Yvette Cendes, author of the Astronomy article, put it:

It is far too early to draw a firm conclusion about whether this relatively faint FRB-like signal is the first example of a galactic fast radio burst — making it the smoking gun to unlocking the entire FRB mystery.  And there are also still many preliminary questions left to answer.  For example, how often do these fainter bursts happen?  Are they beamed so not all radiation is equally bright in all directions?  Do they fall on a spectrum of FRBs with varying intensities, or are they something entirely new?  And how are the X-ray data connected?

As usual with science, the more we know, the more questions we have.

In any case, here we have a phenomenon that's cool to observe, but that you wouldn't want to be at all close to.  Not only do we have the magnetic field to worry about, but the burst itself is so energetic that anything nearby would get flash-fried.

So "the universe is fine-tuned to be congenial to us" only works if you add, "... except for the 99.9% of it that is actively trying to kill us."  Not that this makes it any less magnificent, but it does make you feel a little... tiny, doesn't it?  Probably a good thing.  Humans do stupid stuff when they start thinking they're the be-all-end-all.

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This week's Skeptophilia book recommendation is about a phenomenal achievement; the breathtaking mission New Horizons that gave us our first close-up views of the distant, frozen world of Pluto.

In Alan Stern and David Grinspoon's Chasing New Horizons: Inside the Epic First Mission to Pluto, you follow the lives of the men and women who made this achievement possible, flying nearly five billion kilometers to something that can only be called pinpoint accuracy, then zinging by its target at fifty thousand kilometers per hour while sending back 6.25 gigabytes of data and images to NASA.

The spacecraft still isn't done -- it's currently soaring outward into the Oort Cloud, the vast, diffuse cloud of comets and asteroids that surrounds our Solar System.  What it will see out there and send back to us here on Earth can only be imagined.

The story of how this was accomplished makes for fascinating reading.   If you are interested in astronomy, it's a must-read.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Fermi's Paradox, fast radio bursts, and extraterrestrial intelligence

Just because I believe that science works, and that its methods are sound, doesn't mean that I have to like its conclusions.  And one of my least favorite pieces of sound scientific reasoning is Fermi's Paradox.

Named after the Nobel Prize-winning physicist Enrico Fermi, Fermi's Paradox originally took the form of a succinct response to all of the speculation about life in other star systems.  According to everything we know about stellar evolution, planet formation, biochemistry, and evolutionary biology, life should be common out there.  And just considering the fact that some star systems with planets are likely to be considerably older than ours, it also stands to reason that there should be civilizations out there considerably more advanced than ours.

Upon hearing this sort of argument, Fermi responded with a simple question:  "Where is everybody?"  If life, and intelligent life, is as common as all that, we should be bombarded with signals from extraterrestrials.  And in fact, despite decades of searching the skies, there has never been a single unequivocal transmission found from an intelligent life-form.  (Although the "WOW Signal" might be a contender; it's yet to be explained.)

There are a number of possible explanations for the lack of extraterrestrial communications, and most of them are depressing.  It could be that the likelihood of intelligent life developing on planets is, for some reason, a great deal less likely than we think it is (i.e. we here on Earth were just damn lucky).  It could be that most civilizations destroy themselves shortly after achieving the capacity for long-distance communication.  Some astronomers even think that there are cosmic reset switches -- natural phenomena that periodically wipe the galaxy clean of life, requiring a prolonged reboot, and preventing most life ever from achieving technology.  (For example, consider gamma-ray bursters, but only if you want to spend the next few days worrying about the entire solar system suddenly getting fried.)

Being someone who would love nothing better than to witness the discovery of extraterrestrial intelligence, I find the Fermi Paradox a significant downer.  I do have one possible answer that may still allow for a rich diversity of intelligent life in the galaxy, however; because we are looking for communication in the radio region of the spectrum (the fashion in which we as a species first learned to do long-distance transmission of information), it might be that such discernible, signal-producing modes of communication are quickly superseded by more sophisticated technologies that produce much less in the way of a footprint when observed from light years distant.  In other words; societies might only be detectable during the first few decades of their technological existence, when they're communicating with each other by shouting from the rooftops.  After they learn more efficient means of transmitting information, they seem to go silent.

I hope.  Because otherwise, it's mighty lonely here, you know?

All of this comes up because of a paper published just last week by Michael Hippke, Wilfried Domainko, and John Learned called "Discrete Steps in Dispersion Measures of Fast Radio Bursts."  In this interesting bit of research, an analysis was done of the dispersion measures of microseconds-long pulses in the radio region of the spectrum.  The paper is quite technical -- even with a B.S. in physics, it was over my head -- but insofar as I understand it, the curious thing about the eleven radio pulses thus far detected is that their dispersion measures are all integer multiples of 187.5 parsec/cm3 -- something that admits of no particularly obvious natural explanation.

Carl Sagan, in his wonderful novel (and later movie) Contact, used the idea of encoding a signal with some mathematical pattern as a way of broadcasting a "We're Here" signal into space -- or, conversely, looking for such a signal as a way of detecting life that's out there.  If a radio signal could be encoded with the first ten digits of pi, or (as in Contact) the first few prime numbers, that would be instantly recognizable as an unequivocal signal from an intelligence.  So the discovery of the 187.5 pattern in dispersion measures for FRBs was immediately jumped upon as evidence that the radio bursts originate from some alien civilization.  (The International Business Times, for example, was all a-quiver with the possibility.)

The astrophysicists, of course, are being more circumspect.  All that Hippke, Domainko, and Learned concluded from their research is that the pattern is currently unexplained, if suggestive:

(A)n extragalactic origin would seem unlikely, as high (random) DMs would be added by intergalactic dust.  A more likely option could be a galactic source producing quantized chirped signals, but this seems most surprising.  If both of these options could be excluded, only an artificial source (human or non-human) must be considered, particularly since most bursts have been observed in only one location (Parkes radio telescope)...  In the end we only claim interesting features which further data will verify or refute. 

They also suggest that the FRBs might actually be perytons, signals that appear to originate from space when they actually are entirely terrestrial in origin -- i.e. human-generated signals that are being misinterpreted, or simple radio telescope glitches.

Whatever the explanation is, the FRBs are an interesting phenomenon, and give me hope that there might be an eventual answer to Fermi's Paradox.  I have to be careful about letting my desire for there to be intelligent life elsewhere in the universe get in the way of my objectivity in evaluating the evidence at hand; but even so, the strange mathematical pattern that Hippke et al. have discovered might be the best contender we currently have for an alien civilization saying, "Here we are!"