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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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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World enough and time

Because I'm writing this in the last hours of the Trump presidency, and my other alternative is to become so anxious about what his followers might still do to fuck things up that I chew my fingernails till they bleed, today I'm going to focus on things that are very, very far from planet Earth.

Let's begin with the closest-to-home, three thousand light years away, which seems like it might be almost far enough for safety.

A new study of planetary nebulae -- gas and dust clouds that are what's left of stars that went supernova -- was the subject of a talk at the meeting of the American Astronomical Society last Friday.  Using the Hubble Space Telescope's Wide Field Camera, astronomers were able to photograph these amazing stellar remnants panchromatically (across the frequency spectrum of light).  And what they're learning is changing a lot of what we thought we understood.

Take, for example, NGC 6302, better known as the Butterfly Nebula.  It got its name because of symmetrical "wings" of debris that were thrown out when the central star blew up.  Why it has this strange symmetry is probably due to the magnetic field of the central star, but what's most surprising is that what astronomers thought was the central star doesn't seem to be, but is simply a white dwarf much closer to the Earth that happens to lie between us and the nebula.  Wherever the actual central star is, it's a doozy; from the spectral lines of the nebula, created when light from the star is absorbed and then re-emitted by the dust plumes, its surface is one of the hottest known, at a staggering 250,000 C.  (By comparison, the surface of our own Sun is a paltry 6,000 C or so.)

The Butterfly Nebula [Image is in the Public Domain courtesy of the Hubble Space Telescope and NASA/JPL]

Then there's NGC 7027, the Jewel Bug Nebula, which is also remarkable because of its symmetry -- depending on what feature you're looking at, it shows spherical symmetry (symmetry around the center, like a basketball), axis symmetry (symmetry around a line, like the letter T), or point symmetry (symmetry across a central point, like the letter N).  It's simultaneously one of the brightest planetary nebulae and one of the smallest, and the new study confirms that it's a recently-formed object -- it's only six hundred years old.  (Of course, since it's three thousand light years away, the structure is actually 3,600 years old; but what we're seeing is what it looked like when it was a mere six hundred.)

"We're dissecting [planetary nebulae]," said Joel Kastner, a professor in the Rochester Institute of Technology's Chester F. Carlson Center for Imaging Science and School of Physics and Astronomy.  "We're able to see the effect of the dying central star in how it's shedding and shredding its ejected material.  We're able to see that material that the central star has tossed away is being dominated by ionized gas, where it's dominated by cooler dust, and even how the hot gas is being ionized, whether by the star's UV or by collisions caused by its present, fast winds."

Moving farther afield, another paper presented at the AAS meeting is about a weird object in NGC 253, the Sculptor Galaxy, which is 11.4 million light years away.  It's called a magnetar, and is another stellar remnant, but this one of a supergiant star.  The Fermi Gamma-ray Space Telescope and the Mars Odyssey orbiter both picked up a 140-millisecond-long pulse of gamma rays which seems to have been caused by a starquake on the surface of this object, a cosmic shudder that in one burst released one thousand trillion trillion (10 followed by 27 zeroes) times more energy than the largest recorded earthquake Earth has experienced.  The quake ejected a blob of plasma at nearly the speed of light, and the acceleration is what caused the gamma rays.

The new study gives us a lens into the behavior of some of the oddest structures in the universe, and one that may also be responsible for "fast radio bursts" -- quick pulses of radio waves whose source has been a mystery up until now.  "The apparent frequency of magnetar flares in other galaxies is similar to the frequency of fast radio bursts," said astrophysicist Victoria Kaspi of McGill Space Institute.  "That argues that actually, most or all fast radio bursts could be magnetars."

Last, we go out an astonishing thirteen billion light years, which is only seven hundred million light years shy of the radius of the observable universe.  Another paper at the AAS meeting describes a quasar -- an ancient supermassive black hole that is radiating energy from infalling material, and is one of the brightest objects known -- that lies at the center of a galaxy, and now holds the record for the oldest black hole ever observed.

Like all good scientific discoveries, this one raises almost as many questions as it solves, especially about how such a massive object could have formed so early in the life of the universe.  "A gargantuan seed black hole may have formed through the direct collapse of vast amounts of primordial hydrogen gas," said study co-author Xiaohui Fan, of the University of Arizona in Tucson.  "Or perhaps J0313-1806’s seed started out small, forming through stellar collapse, and black holes can grow a lot faster than scientists think.  Both possibilities exist, but neither is proven.  We have to look much earlier [in the universe] and look for much less massive black holes to see how these things grow."

So that leaves us all the way across the universe, which is a nice comfortable distance to put between myself and the Proud Boys.  It'd be better still to have me stay here and send the Proud Boys out to the farthest reaches of interstellar space, so that their inevitable tweets about what a god-figure Trump is and what a libtard snowflake I am will take thirteen billion years to get here.

But I guess that's not gonna happen.  We all have to stay here and solve our own problems, quasars and magnetars and nebulae notwithstanding.  I'll end with a quote from Doctor Who, which seems apt somehow given the voyage through time and space we just took: "I do think there’s always a way to put things right.  If I didn’t believe that I wouldn’t get out of bed in the morning,  I wouldn’t eat breakfast; I wouldn’t leave the TARDIS ever.  I would never have left home.  There is always something we can do."

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I'm always amazed by the resilience we humans can sometimes show.  Knocked down again and again, in circumstances that "adverse" doesn't even begin to describe, we rise above and move beyond, sometimes accomplishing great things despite catastrophic setbacks.

In Why Fish Don't Exist: A Story of Love, Loss, and the Hidden Order of Life, journalist Lulu Miller looks at the life of David Starr Jordan, a taxonomist whose fascination with aquatic life led him to the discovery of a fifth of the species of fish known in his day.  But to say the man had bad luck is a ridiculous understatement.  He lost his collections, drawings, and notes repeatedly, first to lightning, then to fire, and finally and catastrophically to the 1906 San Francisco Earthquake, which shattered just about every specimen bottle he had.

But Jordan refused to give up.  After the earthquake he set about rebuilding one more time, becoming the founding president of Stanford University and living and working until his death in 1931 at the age of eighty.  Miller's biography of Jordan looks at his scientific achievements and incredible tenacity -- but doesn't shy away from his darker side as an early proponent of eugenics, and the allegations that he might have been complicit in the coverup of a murder.

She paints a picture of a complex, fascinating man, and her vivid writing style brings him and the world he lived in to life.  If you are looking for a wonderful biography, give Why Fish Don't Exist a read.  You won't be able to put it down.

[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!]

The view from afar

One of the strangest phenomena in the universe -- and there's a lot of competition in that regard -- is the neutron star.

This is the ultimate fate of stars of mid-range mass -- between 10 and 29 solar masses.  With stars this size, when they exhaust their hydrogen fuel, the outward pressure from fusion of hydrogen into helium stops, and the core collapses, heating it up catastrophically.  The result is a supernova, in which the outer atmosphere of the star is blown away completely.  The remnant of the core is crushed inward, forcing the electrons into the nuclei of the atoms -- literally squeezing all the space out of the matter inside.  The electrons and protons, presumably present in roughly equal numbers, are smashed together, canceling out their net charge and resulting in a great big ball o' neutrons.

I remember learning about this when I took an astronomy class in college, and asking the professor in some astonishment, "So, neutron stars are basically enormous atomic nuclei?"

He said, "Essentially, yes. They're degenerate matter -- made up entirely of neutrons pushed as close together as possible."

There are a couple of mind-blowing results from this.  One is that because ordinary matter is largely empty space and the degenerate matter in neutron stars isn't, neutron stars are dense beyond what you can imagine.  The estimate is that a matchbox-sized chunk of a neutron star would weigh three billion metric tons.  The other thing that is bizarre about them is that because most -- probably all -- stars spin, as the core collapses into a neutron star, reducing a spinning ball that was on the order of two million kilometers in diameter to one that is ten kilometers across, its spin rate increases.  A lot.  The Law of Conservation of Angular Momentum implies that if a spinning body decreases in radius, it has to increase in rotational rate -- something seen when figure skaters bring in their arms, making them spin faster and faster.

But that increase is peanuts compared to what happens here.  One of the first neutron stars discovered, at the center of the Crab Nebula, is spinning thirty times a second.  This makes it seem to flash off and on at that rate as beams of radiation aligned with its magnetic field sweep across the Earth like the beam from a lighthouse.  This is so hard to imagine that when they were first identified by Jocelyn Bell Burnell in 1967, pulsars -- the name she gave to these flashing stars -- were thought to be signals from an extraterrestrial intelligence, and went by the code name LGM (Little Green Men).

[Image licensed under the Creative Commons ESA/Hubble, Moving heart of the Crab Nebula, CC BY 4.0]

All of this is by way of background for a news story that astronomers have observed, for the second time ever, the merger of two neutron stars.

The first time, you might recall, was almost two years ago, when two neutron stars in tight orbit finally coalesced, resulting in a pulse of gravitational waves that gave powerful support to Einstein's General Theory of Relativity.  This time, the merger was caught on x-ray camera -- as the collision occurred, it caused a shower of x-rays and left behind a single larger neutron star with an unimaginably huge magnetic field -- called a magnetar.

"We’ve found a completely new way to spot a neutron star merger," said Yongquan Xue, astronomer at University of Science and Technology of China and lead author of a paper on the subject that appeared two weeks ago in Nature.  "The behavior of this X-ray source matches what one of our team members predicted for these events."

I haven't told you what's the coolest thing about this.  The colliding neutron stars Xue et al. are studying aren't even in our own galaxy.  What they've done is develop a way to study the collision of two blobs of highly peculiar matter from a distance of six billion light years.

Which is not only an unimaginable distance, but means that the collision happened six billion years ago.  At that point, the Earth hadn't even completely coalesced from the primordial ring of dust and debris that formed it.  Six billion years is just shy of half the time between the Big Bang and now.

So I think you can label my mind blown.

Despite some of the stupid things humans do sometimes, you have to admire our ingenuity.  Sitting on this little speck of rock orbiting an ordinary star in the edge of one arm of an ordinary galaxy, we've found a way to probe the deepest secrets of the cosmos.  Or, as Carl Sagan put it:  "We are a way for the universe to know itself."

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This week's Skeptophilia book recommendation is a classic, and is pure fun: Man Meets Dog by the eminent Austrian zoologist and ethologist Konrad Lorenz.  In it, he looks at every facet of the human/canine relationship, and -- if you're like me -- you'll more than once burst out laughing and say, "Yeah, my dog does that all the time!"

It must be said that (as the book was originally written in 1949) some of what he says about the origins of dogs has been superseded by better information from genetic analysis that was unavailable in Lorenz's time, but most of the rest of his Doggy Psychological Treatise still stands.  And in any case, you'll learn something about how and why your pooches behave the way they do -- and along the way, a bit about human behavior, too.

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