Deadly fireworks

I've always thought it would be amazingly cool to witness a supernova.

Imagine it.  Within a few hours, a dim, ordinary-looking star increases in luminosity until it outshines every other astronomical object in the sky except the Sun and Moon.  It's visible during the day and you can read by its light at night.  It's not a blink-and-you'll-miss-it phenomenon, either; the light from the massive explosion peaks rapidly but declines slowly.  Most supernovae will be visible for months, before dimming to near-invisibility, ending as neutron stars or black holes.

There are lots of candidates for what could be the next supernova, although don't get your hopes up; most of these fall into the "some time in the next million years" category.  Yeah, it could happen tomorrow, but I wouldn't put money on it.  Still, the list is sizable, and here are five of the best possibilities:

• Betelgeuse (720 light years away, in the constellation Orion).  This one got some serious press a few months ago because it suddenly started to decrease in brightness, and astronomers wondered if this was a prelude to an explosion.  What appears to have happened is that there was turbulence in the star's core that blew a cloud of dust from its surface, obscuring the star and making it appear to dim.  So we're still waiting for this red supergiant to explode, and probably will be for a while.
• IK Pegasi (154 light years away, in the constellation Pegasus).  IK Pegasi isn't well known because at an apparent magnitude of 6, it's not visible to the naked eye, but it bears mention as the nearest serious supernova candidate.  It's a double star -- a main-sequence star and a massive white dwarf orbiting a common center of mass.  As the main-sequence star evolves, it will become a red giant, with a radius large enough that its white dwarf companion will start suctioning matter from its surface.  When the white dwarf reaches what's called the Chandrasekhar Limit -- 1.4 solar masses -- it will explode cataclysmically as a Type 1a supernova.  This will not only be spectacular but potentially dangerous -- a topic we will revisit shortly.
• VY Canis Majoris (3,820 light years away, in the constellation Canis Major).  Another star not visible to the naked eye, VY Canis Majoris is a lot more spectacular than you'd think to look at it.  It's the largest star known, with a mass fifteen times that of the Sun, and a radius so large that if you put it where the Sun is, its surface would be about at the orbit of Jupiter (so we'd be inside the star).  This "hypergiant" is one of the most luminous stars in the Milky Way, and is only dim because it's so far away.  This one is certain to go supernova, probably some time in the next 100,000 years, and the remnants will collapse into a black hole.
• Eta Carinae (7,500 light years away, in the constellation Carina).  Eta Carinae is another huge star, with a radius twenty times that of the Sun, but what makes this one stand out is its bizarre behavior.  In 1837 it suddenly brightened to being one of the five brightest stars in the night sky, then over the next sixty years faded to the point that it was only visible in binoculars.  Detailed observations have shown that it blew out a huge cloud of material in "The Great Eruption," which is now the Homunculus Nebula.  It's a unique object, which makes it hard to predict its future behavior.  What seems certain is that it'll eventually explode, but there's no telling when that might occur.

The consensus amongst astronomers, however, is that the next likely supernova probably isn't on the list -- that it will be a previously-unknown white dwarf or an unremarkable-looking red giant.  We know so little about supernovas that it's impossible to predict them with any kind of accuracy.  And while this is an exciting prospect, we'd better hope that the next supernova isn't too close.

The Homunculus Nebula with Eta Carinae at the center [Image licensed under the Creative Commons ESA/Hubble, Cosmic Fireworks in Ultraviolet Eta Carinae Nebula, CC BY 4.0]

Not only do supernovas produce a lot of light, they generate a tremendous amount of radiation of other kinds, including cosmic rays.  A close supernova could produce enough cosmic rays to wipe out the ozone layer -- leading to a huge influx of ultraviolet light from the Sun, with devastating effects.

Scarily, this may have already happened in Earth's history.  One of the lesser-known mass extinctions occurred at the end of the Devonian Period, 359 million years ago.  Because it is poorly understood, and was dwarfed by the cataclysmic Permian-Triassic Extinction a little over a hundred million years later, it's not one you tend to read about in the paleontology-for-the-layperson books.  Even so, it was pretty significant, wiping out 19% of known families and 50% of known genera, including placoderms (armored fish), cystoids (a relative of the starfish), and graptolites (colonial animals not closely related to any living species).  Most striking were the collapse of reef-forming corals -- reefs didn't begin to form again on any significant scale until the Mesozoic Era, almost two hundred million years later -- and the near-complete wipeout of vertebrates.  The latter left no vertebrate species over a meter long (most of them were under ten centimeters), and again, it was millions of years before any kind of recovery took place.

Fortunately for us, it eventually did, because we're talking about our ancestors, here.

The cause of this catastrophe has been a matter of speculation, but a team led by Brian Fields, astrophysicist at the University of Illinois, may have found a smoking gun.  In a paper this week in Proceedings of the National Academy of Sciences, we find out that the most likely cause for the End-Devonian Extinction is a nearby supernova that caused the collapse of the ozone layer, leading to the Earth's surface being scorched by ultraviolet light.  This triggered a massive die-off of plants -- which had only recently colonized the land -- and worldwide anoxia.  

The result?  A mass extinction that hit just about every taxon known.

The idea that a supernova might have been to blame for the End-Devonian Extinction came from the presence of hundreds of thousands of plant spores in sedimentary rock layers that showed evidence of what appeared to be radiation damage.  This isn't conclusive, of course; the Fields et al. team is up front that this is only a working hypothesis.  What they'll be looking for next is isotopes of elements in those same rock layers that are only produced by bombardment with radiation, such as plutonium-244 and samarium-146.  "When you see green bananas in Illinois, you know they are fresh, and you know they did not grow here," Fields said, in an interview in Science Daily.  "Like bananas, Pu-244 and Sm-146 decay over time.  So if we find these radioisotopes on Earth today, we know they are fresh and not from here -- the green bananas of the isotope world -- and thus the smoking guns of a nearby supernova."

So as much as I'd love to witness a supernova in my lifetime, it'd be nice if it was one well outside of the terrifyingly-named "kill zone" (thought to be about 25 light years or so).  And chances are, there's nothing inside that radius we need to worry about.  If any of the known supernova candidates explode, we'll almost certainly be able to enjoy the fireworks from a safe distance.

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Fan of true crime stories?  This week's Skeptophilia book recommendation of the week is for you.

In The Poisoner's Handbook:Murder and the Birth of Forensic Medicine in Jazz Age New York, by Deborah Blum, you'll find out about how forensic science got off the ground -- through the efforts of two scientists, Charles Norris and Alexander Gettler, who took on the corruption-ridden law enforcement offices of Tammany Hall in order to stop people from literally getting away with murder.

In a book that reads more like a crime thriller than it does history, Blum takes us along with Norris and Gettler as they turned crime detection into a true science, resulting in hundreds of people being brought to justice for what would otherwise have been unsolved murders.  In Blum's hands, it's a fast, brilliant read -- if you're a fan of CSI, Forensics Files, and Bones, get a copy of The Poisoner's Handbook, 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!]

Of rhinos and puppies

You're not alone if you immediately think "Africa" when you hear the word "rhinoceros."  The two largest and best-known species -- the black (Diceros bicornis) and white (Ceratotherium simum) rhinos -- are both native to the southern parts of Africa.  There are three additional extant species in southern Asia, however; the Indian (Rhinoceros unicornis), Javan (Rhinoceros sondaicus), and Sumatran (Dicerorhinus sumatrensis) rhinos.  The latter two are amongst the most endangered mammals in the world, with only about 60 and 245 individuals left, respectively.

Rhinos, though, used to be much more diverse, and much more common.  One of the most remarkable fossils ever discovered is the Blue Lake rhino, a fifteen-million-year-old cast of an extinct rhinoceros species called Diceratherium in what is now eastern Washington state.  The "remarkable" part is that it's fossilized in igneous rock, which isn't supposed to happen -- fossils are supposed to all be in sedimentary rock, right?  But what happened is there was a colossal eruption fifteen million years ago that produced the Columbia River Flood Basalts, releasing an estimated 174,000 cubic kilometers of lava, an amount that's hard to fathom.  Anyhow, this poor rhino was peacefully grazing, minding its own business, and suddenly BAM, it gets hit by a fast-moving, highly liquid lava flow, its body entombed then burned away.  Fast forward to 1935, when a fossil hunter named Haakon Friele discovered a strange cave in a basalt formation, crawled inside with a flashlight, and somehow thought, "Hey, this hole is shaped just like a rhino."  A bit later, a crew of paleontologists from the University of California - Berkeley were called in, and they made a plaster cast of the interior -- and sure enough, it's a cast of a very surprised-looking rhino who was very much in the wrong place at the wrong time.

There were other rhino species more recently, however.  The woolly rhinoceros (Coelodonta antiquitatis) was an ice-age species that lived pretty much everywhere in what is now Asia and Europe, but started declining in population about forty thousand years ago, dwindling until only a remnant population was left in Siberia.  The last ones died fourteen thousand years ago, give or take.

[Image licensed under the Creative Commons ДиБгд, Wooly Rhino15, CC BY-SA 4.0]

The blame for the woolly rhino's demise has been attributed to overhunting by early humans, but recent research suggests the cause was actually climate change.  In the paper, "Pre-Extinction Demographic Stability and Genomic Signatures in the Woolly Rhinoceros," by a team led by Edana Lord of the Swedish Museum of Natural History, we read the following:

Ancient DNA has significantly improved our understanding of the evolution and population history of extinct megafauna.  However, few studies have used complete ancient genomes to examine species responses to climate change prior to extinction.  The woolly rhinoceros (Coelodonta antiquitatis) was a cold-adapted megaherbivore widely distributed across northern Eurasia during the Late Pleistocene and became extinct approximately 14 thousand years before present (ka BP).  While humans and climate change have been proposed as potential causes of extinction, knowledge is limited on how the woolly rhinoceros was impacted by human arrival and climatic fluctuations.  Here, we use one complete nuclear genome and 14 mitogenomes to investigate the demographic history of woolly rhinoceros leading up to its extinction.  Unlike other northern megafauna, the effective population size of woolly rhinoceros likely increased at 29.7 ka BP and subsequently remained stable until close to the species’ extinction.  Analysis of the nuclear genome from a ∼18.5-ka-old specimen did not indicate any increased inbreeding or reduced genetic diversity, suggesting that the population size remained steady for more than 13 ka following the arrival of humans.  The population contraction leading to extinction of the woolly rhinoceros may have thus been sudden and mostly driven by rapid warming in the Bølling-Allerød interstadial.

So at least that's one calamity we're not responsible for.

On the other hand, another recent discovery shows that we might not have doomed the woolly rhino, but our best friends might have had a hand -- um, a paw -- in it.  A friend and long-time loyal reader of Skeptophilia sent me a link to an article about a mummified body of a dog found in Siberia that, when analyzed, was found to have bits of meat from a woolly rhino it its stomach.  "This puppy, we know already, has been dated to roughly 14,000 years ago," said researcher Love Dalén, also of the Swedish Museum of Natural History.  "We also know that the woolly rhinoceros goes extinct 14,000 years ago.  So, potentially, this puppy has eaten one of the last remaining woolly rhinos."

Dogs: Eating Stuff They Shouldn't Eat For the Past Fourteen Thousand Years.

So that's today's excursion into weird cul-de-sacs of zoology.  And honestly, I'm just as glad the temperate-area rhino species are gone, cool as they undoubtedly were.  We have enough trouble keeping the groundhogs and rabbits out of the vegetable garden, I can't imagine how we'd deal with rhinos tromping around the place.

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Fan of true crime stories?  This week's Skeptophilia book recommendation of the week is for you.

In The Poisoner's Handbook:Murder and the Birth of Forensic Medicine in Jazz Age New York, by Deborah Blum, you'll find out about how forensic science got off the ground -- through the efforts of two scientists, Charles Norris and Alexander Gettler, who took on the corruption-ridden law enforcement offices of Tammany Hall in order to stop people from literally getting away with murder.

In a book that reads more like a crime thriller than it does history, Blum takes us along with Norris and Gettler as they turned crime detection into a true science, resulting in hundreds of people being brought to justice for what would otherwise have been unsolved murders.  In Blum's hands, it's a fast, brilliant read -- if you're a fan of CSI, Forensics Files, and Bones, get a copy of The Poisoner's Handbook, 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!]

Scooting past the reviewers

If there's one piece of advice I have for anyone trying to stay informed, it is: check your sources.

Unfortunately, these days, that takes more than just a quick look, or a recommendation from someone with authority.  After all, just two days ago Donald Trump tweeted that Fox News wasn't right-wing enough for him, that all of his faithful MAGA followers should troop on over to OANN (One America News Network),  that it was the only news source that was "fair and balanced."  Of course, this was transparent enough; in Trump-speak, "fair and balanced" means "willing to kiss Trump's ass on a daily basis."  OANN is a far-right outlet allied to sites like Breitbart -- and let's face it, anything to the right of Fox News isn't even within hailing distance of unbiased.

So "sounds like a reliable source" is itself unreliable.  As an example, take the paper that appeared last week, authored by Mathieu Edouard Rebeaud (University of Lausanne), Valentin Ruggeri (University of Grenoble), Michaël Rochoy (University of Lille). and Florian Cova (University of Geneva).  I won't tell you the title, but leap right in with an excerpt:

As the number of push-scooters has been rising in France, so has the number of push-scooters accidents.  Some of these accidents have proven to be deadly and previous YouTube™ and Dropbox© studies have warned against the deadly potential of push-scooters [1].  For a comparison, only three Chinese people had died from the novel coronavirus SARS-CoV-2 at the end of 2019 [2].  It is therefore important to reflect on the use of push-scooters through an accurate and ethical cost-benefit analysis.

Use and promotion of push-scooters have been advocated on the basis that they would contribute to the reduction and slowing of global warming.  In fact, the French scientific elite has been working on the subject and has recently argued that there was no proof of global warming, as he could not see the ice cap melt on his computer [3].  So, even if global warming was real, there are serious reasons to think that France is not affected, as global warming clearly stopped at the closed border [4].  Unfortunately, the debate is being polluted by bots, trolls and so-called experts funded by Big Trottinette to spread misinformation. Indeed, an independent study (in press on the third author’s Google Drive®) found a positive correlation between experts’ positive advocacy of push-scooters and the amount of money they received from Decathlon® (r = 3.14).  The fact that push-scooters are now a ‘generic’ means of locomotion that can be produced by anyone for a cheap price might lead people to the conclusion that no private interest is involved, but we’re not fooled, we know the truth [5].  So, it is important to diminish the increasing number of push-scooter drivers who are sacrificed on a daily basis.

The authors then go on to show that the way to combat the deadly push-scooter accident surge is through doses of hydroxychloroquine, which also shows promise in dealing with the Israeli-Palestinian conflict.  (Well, most of their research supported this.  They didn't have so much luck with Study 2.  "Study 2 was excluded from analysis and from this paper," the authors write, "as it did not provide informative results (i.e. the results we wanted)."

[Image licensed under the Creative Commons Alex Genz, Female rider on Egret One eScooter, CC BY-SA 4.0]

Also notable is that besides the four actual authors, there are also additional co-authors listed as belonging to places like "The Institute of Quick and Dirty Science of Neuneuchâtel, Switzerland" and the "Institute of Chiropteran Studies of East Timor," and one is called a "General Practitioner and Independent Seeker of Science" from Ankh-Morpork, France.

You may be thinking that this must have appeared in some kind of science spoof site like the brilliant Journal of Irreproducible Results.

You may be wrong.

This paper, titled, "SARS-CoV-2 Was Unexpectedly Deadlier than Push-scooters: Could Hydroxychloroquine be the Unique Solution?", was published in the Asian Journal of Medicine and Health.

(If you want to read it -- which I highly recommend -- you should do it soon.  My guess is that it'll be taken down before long.)

Sounds like a legitimate source, doesn't it?  You might be clued in that something was wrong if you noticed that the paper was submitted on July 24, accepted on August 11, and published on August 15 -- I say that notwithstanding the obviously goofy content from the title on, because most of the papers in the AJMH aren't blatantly off.  But if you look at stuff like this -- dates that make it clear that there was zero peer review involved -- there's no doubt left that this is one of those predatory pay-to-play journals, that will publish damn near anything if you give 'em some money.

Which, of course, was the point of the Rebeaud et al. paper.  It wasn't just to give us all a good laugh -- although it did that as well -- it was to shed some light on the way that predatory journals muddy the waters for everyone.

So back to where we started: CHECK.  YOUR.  SOURCES.  Which doesn't just mean a cursory "okay, it's a 'journal of medicine and health,' it must be reliable."  Take five minutes to do a quick search to see if there are any reviews or commentary on the journal itself.  The best thing is to find good sources that you know you can always rely on -- top-flight research journals like Science, Nature, Cell, Proceedings of the National Academy of Science, and PLOS-One, to name five -- as well as research-for-the-layperson journals like Scientific American and Discover.

If you get outside of those realms, though, caveat lector.  You never know what kind of lunacy you'll find, up to and including recommendations for taking hydroxychloroquine to prevent push-scooter accidents.

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Fan of true crime stories?  This week's Skeptophilia book recommendation of the week is for you.

In The Poisoner's Handbook:Murder and the Birth of Forensic Medicine in Jazz Age New York, by Deborah Blum, you'll find out about how forensic science got off the ground -- through the efforts of two scientists, Charles Norris and Alexander Gettler, who took on the corruption-ridden law enforcement offices of Tammany Hall in order to stop people from literally getting away with murder.

In a book that reads more like a crime thriller than it does history, Blum takes us along with Norris and Gettler as they turned crime detection into a true science, resulting in hundreds of people being brought to justice for what would otherwise have been unsolved murders.  In Blum's hands, it's a fast, brilliant read -- if you're a fan of CSI, Forensics Files, and Bones, get a copy of The Poisoner's Handbook, 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!]

The power of ritual

I was raised in a devoutly Roman Catholic home, but after spending my teenage years feeling question after question bubbling up inside me, I left Catholicism, never to return.  In my twenties I tried more than once to find a faith community that seemed right -- that made sense of the universe for me -- attending first a Quaker meeting, then a Unitarian church, and finally a Methodist church, and each time I ended up faced with the same questions I'd had, questions that no one seemed to be able to answer.

The prime question was "How do you know all this is true?"  In other realms, that question was usually easy to answer.  Science, of course, was cut-and-dried; factual truth in science is measurable, quantifiable, observable.  But even with situations that aren't exactly rational, there's usually a way to approach the question.  How do I know that my family and friends love me?  Because they demonstrate it in a tangible way, every day.

But the claims of religion seemed to me to be outside even of that, and I never was able to get answers that satisfied.  Most of them boiled down to "I've had a personal experience of God" or "the existence of God gives meaning to my day-to-day experience," neither of which was particularly convincing for me.  I have never had anything like a transcendent, spiritual experience of an omnipresent deity.  And something imbuing meaning into your life doesn't make it true.  I'd read plenty of meaningful fiction, after all.  And as far as my wanting it to be true, if there was one thing I'd learned by that point, it was that the universe is under no compulsion to behave in a way that makes me comfortable.

So ultimately, I left religion behind entirely.  I have no quarrels with anyone who has found a spiritual home that works for them, as long as they're not forcing it on anyone else; in fact, I've sometimes envied people who can find reason to believe, wholeheartedly, in a greater power.  I just never seemed to be able to manage it myself.

That's not to say I'm unhappy as an atheist.  Perhaps I can't access the reassurance and comfort that someone has who is deeply religious, but there are a lot of the petty rules and pointless, often harmful, restrictions that I wish I'd abandoned many years earlier.  (The chief of which is my years of shame over my bisexuality.  The damage done to the queer community by the largely religiously-motivated bigotry of our society is staggering, and heartbreaking.)

But there's something about being part of a religion that I do miss, and it isn't just the sense of community.  You can find community in a book group or weekly sewing night or runners' club, after all.  What I find I miss most, strangely enough, is the ritual.

There's something compelling about the ritual of religion.  The Roman Catholicism of my youth is one of the most thoroughly ritualistic religions I know of; the idea is that any believer should be able to walk into any Catholic church in the world on Sunday morning and know what to do and what to say.  (Giving rise to the old joke, "How do you recognize a Catholic Star Wars fan?"  "If you say to them, 'May the Force be with you,' they respond, 'And also with you.'")  The vestments of the priests, the statuary and stained glass windows, the incense and candles and hymns and organ music -- it all comes together into something that, to the believer, is balm to the soul, leaving them connected to other believers around the world and back, literally millennia, in time.

Window in the Church of St. Oswald, Durham, England [Image licensed under the Creative Commons Tom Parnell, Church of St Oswald - stained glass window, CC BY-SA 4.0]

What got me thinking about this topic was a fascinating look in Science News at the effect that COVID-19 has had on rituals, and how that's affected individuals and society as a whole.  Not just religious rituals, of course; the pandemic has also put the kibosh on rituals like graduations, baby showers, weddings, funerals, secular holiday celebrations, sporting events, even personal ones like birthday parties and anniversaries.  All this has left a lot of us feeling unmoored.  What's taken their place -- Skyping, virtual get-togethers, Zoom meetings -- hasn't proven to be a replacement emotionally, even for non-religious people like myself.

Why humans are so attracted to rituals is an interesting question in and of itself, and one which the article looks at in some depth.  What interests me is not the obvious answer -- creating an in-group, a way to recognize our tribe.  There's a lot more to it than that.  It seems like humans are so wired into ritualistic behavior that it doesn't even matter what the context is.  One experiment the article cites took volunteers and separated them into two groups.  Each group was given a list of one-syllable words to read.  Members of the first group took turns, each participant reading aloud one column of words, then another participant moving on to the next, and so on.  The second group, though, did something different -- they recited the words together to the beat of a metronome.

The researchers gave the volunteers a standard "cooperation game" to play afterward.  The way it works is that you have two choices, X or Y.  If you choose X, you get seven dollars.  If you choose Y, you get ten dollars -- but if and only if every other member of the group also chooses Y.  If anyone chooses X, the ones who chose Y get nothing.

In the group who had recited the words in sequence, only 21% took the risk of cooperation and chose Y.  In the group who had chanted the words together, almost three times as many -- 62% of participants -- chose Y.

We bond to each other through rituals, even if it's something as silly as chanting a list of random words together.

Given that the pandemic is showing no signs of waning -- here in the United States, at least, where for some people wearing a mask to protect yourself and others is considered a fundamental infringement on your liberties -- my guess is that our rituals won't be returning to normalcy for a long time.  What's certain is that our desire for those rituals is very deeply wired into our brains, and their loss has hit a lot of people hard.  It remains to be seen whether we'll find alternate ways to exercise this drive, at least until there's an effective vaccine for COVID-19.

What long-term effect this will have on society -- on cohesion, connection, cooperation, even rates of depression and anxiety -- is unknown.

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Fan of true crime stories?  This week's Skeptophilia book recommendation of the week is for you.

In The Poisoner's Handbook:Murder and the Birth of Forensic Medicine in Jazz Age New York, by Deborah Blum, you'll find out about how forensic science got off the ground -- through the efforts of two scientists, Charles Norris and Alexander Gettler, who took on the corruption-ridden law enforcement offices of Tammany Hall in order to stop people from literally getting away with murder.

In a book that reads more like a crime thriller than it does history, Blum takes us along with Norris and Gettler as they turned crime detection into a true science, resulting in hundreds of people being brought to justice for what would otherwise have been unsolved murders.  In Blum's hands, it's a fast, brilliant read -- if you're a fan of CSI, Forensics Files, and Bones, get a copy of The Poisoner's Handbook, 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!]

Tuning in and tuning out

Mexican free-tailed bats (Tadarida brasiliensis) are remarkable animals.  They live in staggeringly huge colonies.  The largest known, in Bracken Cave in Comal County north of San Antonio, Texas, has twenty million bats.  I got to see a smaller (but still impressive) colony, in Carlsbad Caverns National Park, New Mexico, when I was a kid, and I'll never forget the sight of the thousands and thousands of bats streaming out of the cave mouth at dusk.

Free-tailed bats echolocate, which you probably already knew; they navigate in the dark by vocalizing and then listening for the echoes, creating a "sonic landscape" of their surroundings accurate enough to snag an insect out of the air in pitch darkness.  But this engenders two problems, which I honestly never though of until they were brought up by the professor of my Vertebrate Zoology course when I was in graduate school:

1. If these bats live in groups of millions of individuals, how do they tune in to the echoes of their own voices, distinguishing them from the cacophony of their friends and family all vocalizing at the same time?
2. In order to echolocate, they must have exquisitely sensitive hearing.  They're picking up the faint echoes of their own calls with an accuracy that allows them to detect the contours and motion (if any) of the object they're sensing.  To create an audible echo, they have to vocalize really loudly.  So how does the original vocalization not deafen those sensitive ears?

The answer to the first was discovered by some research at the University of Tübingen back in 2009.  Using recordings, scientists found that bats are sensitive not only to the echoes themselves, but can pick out from those echoes enough information about the sonic waveform that they can recognize their own voices.  Each bat's voice has a distinct, if not unique, sonic "fingerprint" -- much like human voices.

The answer to the second is, if anything, even more astonishing.  Just as humans do, bats have three tiny sound-conducting bones in their middle ear -- the malleus, incus, and stapes (commonly known as the hammer, anvil, and stirrup) -- that transmit sound from the eardrum into the cochlea (the organ of hearing).  Bats have a tiny muscle attached to the malleus, and when they open their mouths to vocalize, the muscle contracts, pulling the malleus away from the incus.  Result: dramatically decreased sound transmission.  But even more amazing, as soon as they stop vocalizing, the muscle relaxes -- fast enough to bring the malleus back in contact with the incus in time to pick up the echo.

Bats, it turns out, aren't the only animals to experience these sorts of problems.  The reason this whole topic comes up is because of some research that was published last week in The Journal of Neuroscience.  In a paper called "Signal Diversification is Associated with Corollary Discharge Evolution in Weakly Electric Fish," by Matasaburo Fukutomi and Bruce Carlson of Washington University, we learn about a group of fish called mormyrids (elephant fish) that have, in effect, the opposite problem from bats; they have to find a way to tune out their own communication so they can sense that of their neighbors.

Long-nosed elephant fish (Gnathonemus petersii)  [Image licensed under the Creative Commons spinola, Elefantenrüsselfisch, CC BY-SA 3.0]

Mormyrids communicate by electrical signals; the long "trunk" is actually an exquisitely-sensitive electrical sensor.  They not only use it to pick up electrical signals given off the nerves and muscles of the insect larva prey they feed on, they use it to pick up those sent by other members of their own species.  In effect, they talk using voltage.

Here, though, they have to be able to ignore the voltage shifts in the water around them given off by their own bodies.  It's as if you were in a conversation with a friend, and instead of doing what most civilized friends do -- taking turns talking -- you both babble continuously, and your brain simply stops paying attention to your own voice.

They do this using a corollary discharge, an inhibitory signal that blocks the higher parts of the brain from responding to the signal.  The researchers found that corollary discharges only occurred in response to voltage changes from the individual itself, and not to those from other individuals.

In other words, just like the bats, mormyrid fish can recognize their own communications.  "Despite the complexity of sensory and motor systems working together to deal with the problem of separating self-generated from external signals, it seems like the principle is very simple," said study co-author Bruce Carlson, in an interview with Science Daily.  "The systems talk to each other.  Somehow, they adjust to even widespread, dramatic changes in signals over short periods of evolutionary time."

So there you have it.  Another natural phenomenon to be impressed by.  It reminds me of the wonderful TED talk by David Eagleman called, "Can We Develop New Senses for Humans?" that talks about an animal's umwelt -- in essence, how it perceives the world.  What must the world seem like to a fish that gathers most of its information from electrical signals?

Staggers the imagination, doesn't it?

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Fan of true crime stories?  This week's Skeptophilia book recommendation of the week is for you.

In The Poisoner's Handbook:Murder and the Birth of Forensic Medicine in Jazz Age New York, by Deborah Blum, you'll find out about how forensic science got off the ground -- through the efforts of two scientists, Charles Norris and Alexander Gettler, who took on the corruption-ridden law enforcement offices of Tammany Hall in order to stop people from literally getting away with murder.

In a book that reads more like a crime thriller than it does history, Blum takes us along with Norris and Gettler as they turned crime detection into a true science, resulting in hundreds of people being brought to justice for what would otherwise have been unsolved murders.  In Blum's hands, it's a fast, brilliant read -- if you're a fan of CSI, Forensics Files, and Bones, get a copy of The Poisoner's Handbook, 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!]

Wings over North Carolina

Rounding out Paleontology Week is a story courtesy of my friend and long-time loyal reader of Skeptophilia, the brilliant novelist Tyler Tork (whose new book The Deep End is a must-read for anyone who likes speculative fiction and magical realism).  And, I might add, it is completely on-brand for 2020.

So today we have: pterodactyl sightings are on the increase in the United States.

Pteranodon by Heinrich Harder (1916)  {Image is in the Public Domain]

Myself, I would have thought that one pterodactyl sighting would be an increase given that the number of currently-living pterodactyls is zero, but apparently I'm incorrect.  Evidently North Carolina is a hotspot of pterodactyl activity, where people are seeing big flying things with crests and a diamond-shaped rudder on the tail.  This sounds to me like my favorite pterodactyloid, Rhamphorhynchus:

[Image is in the Public Domain]

Now, I hasten to add that I don't really believe there are pterodactyls flying around Charlotte.  To me, there's the same problem with this as with all the Bigfoot claims; lots of anecdotal stories of sightings, and not a single unequivocal piece of hard evidence.  You'd think if these things were still around, someone would have run across a body or a skull or something.  Or even a fossil of one that isn't older than 66 million years.

But that doesn't stop the true believers.  Over at the sight LivePterosaurs.com (of course there's a website called "LivePterosaurs.com") you can read dozens of eyewitness accounts.  And much to my surprise, my home state of New York is not far behind North Carolina, according to this map:

So I think I better keep my eyes open.  Although even with my fairly lousy eyesight, it's hard to imagine how I could miss something that (according to one witness) "had an enormous pointed beak, and a pointed top of its head...  The wingspan was probably about 5-6 feet wide with bony wing structure ending in points (almost like sails) and what looked like small claws on the middle of wing."

Anyhow, after reading this article I made the mistake of looking at the "comments" section.  (This is, in fact, always a mistake.)  The comments seemed to be half "of course pterodactyls are still alive, I've seen one" and half "whatever you've been smoking, can I have some?"  But my favorite comment was from the woman who wrote (spelling and grammar are as written): "Wit all the ice melting.  Who knows what was frozen.  Or.  Wilderness caves where anything could hide."

So here we have yet another downside of global climate change; thawing out all the pterodactyls who have been encased in ice in the frozen wasteland of North Carolina for 66 million years.

In any case, if you had "pterodactyls" on your 2020 Apocalypse Bingo Card, you can check that box off.  And frankly, I'd take pterodactyls over murder hornets.  Have you ever seen a photograph of one of those things?  They are huge, and have a stinger like a fucking harpoon.  So I say: bring on the pterodactyls.

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This week's Skeptophilia book recommendation of the week is by the brilliant Dutch animal behaviorist Frans de Waal, whose work with capuchin monkeys and chimps has elucidated not only their behavior, but the origins of a lot of our own.  (For a taste of his work, watch the brilliant TED talk he did called "Moral Behavior in Animals.")

In his book Mama's Last Hug: Animal Emotions and What They Tell Us About Ourselves, de Waal looks at this topic in more detail, telling riveting stories about the emotions animals experience, and showing that their inner world is more like ours than we usually realize.  Our feelings of love, hate, jealousy, empathy, disgust, fear, and joy are not unique to humans, but have their roots in our distant ancestry -- and are shared by many, if not most, mammalian species.

If you're interested in animal behavior, Mama's Last Hug is a must-read.  In it, you'll find out that non-human animals have a rich emotional life, and one that resembles our own to a startling degree.  In looking at other animals, we are holding up a mirror to ourselves.

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

The English dinosaurs

Continuing with the paleontological bent we've been on all week, today we have: bones of a previously-unknown tyrannosaur on a beach in England.

As unlikely as it sounds, beaches in southern England are great places to find dinosaur bones.  One of the founders of the science of paleontology, Mary Anning, did most of her work in the Lyme Regis region of the Dorsetshire coast during the first half of the nineteenth century, and her discovery of complete skeletons of Jurassic-era ichthyosaurs and plesiosaurs on walks with her faithful dog has become the stuff of legends.  (Sadly, her dog was killed in a landslide when a cliffside collapsed -- Anning missed sharing his fate because she was only a couple of feet ahead of him.)

The new find comes from Cretaceous sedimentary rocks on the coast of the Isle of Wight, where paleontologists from the University of Southampton have identified some fossilized bones as belonging to a new species that has been christened Vectaerovenator inopinatus (the name translates roughly to "unexpected air-filled hunter").  It got its name from the presence of air sacs in and around the bones.  This adaptation is also found in modern birds, re-emphasizing the relationship between predatory theropods and chickadees.

Vectaerovenator was a big guy -- an estimated four meters long -- but was astonishingly light-built.  "We were struck by just how hollow this animal was - it's riddled with air spaces," said Christopher Barker, who was lead author of the study.  "Parts of its skeleton must have been rather delicate.  The record of theropod dinosaurs from the 'mid' Cretaceous Period in Europe isn't that great, so it's been really exciting to be able to increase our understanding of the diversity of dinosaur species from this time...  You don't usually find dinosaurs in the deposits at Shanklin as they were laid down in a marine habitat.  You're much more likely to find fossil oysters or driftwood, so this is a rare find indeed."

The fossils were found in marine sedimentary rocks, and surmise is that the dinosaur they belonged to fell into a river (whether before or after it died is, of course, impossible to tell) and its body washed out into the shallow sea, where it was covered up and preserved.

Artist Trudie Wilson's impression of the final moments of the Shanklin Ventaerovenator inopinatus  [Image courtesy of the University of Southampton]

The bones were found by three amateur fossil-hunters.  Robin Ward of Stratford-upon-Avon, was walking on the beach with his family and found the first ones.  "The joy of finding the bones we discovered was absolutely fantastic," Ward said.  "I thought they were special and so took them along when we visited Dinosaur Isle Museum.  They immediately knew these were something rare and asked if we could donate them to the museum to be fully researched."

"It looked different from marine reptile vertebrae I have come across in the past," said James Lockyer, of Spalding, Lincolnshire, who found additional pieces of the skeleton.  "I was searching a spot at Shanklin and had been told and read that I wouldn't find much there.  However, I always make sure I search the areas others do not, and on this occasion it paid off."

Paul Farrell, an Isle of Wight native, contributed further pieces to the discovery.  "I was walking along the beach, kicking stones and came across what looked like a bone from a dinosaur," Farrell said.  "I was really shocked to find out it could be a new species."

All three agreed to donate their finds to the Dinosaur Isle Museum at Sandown.

What this highlights to me is the degree to which interested amateurs can contribute to science.  In fact, Mary Anning herself had no training in paleontology, or in fact, in any kind of science; to call opportunities for women in science in the early nineteenth century "limited" is a vast understatement.  Anning's descriptions of her extraordinary discoveries were turned down for publication by the Magazine of Natural History, and she was denied entry to the Geological Society of London purely because of her gender.

So it's a double-edged sword, isn't it?  Talented amateurs can make incredible contributions, but only if the often hidebound powers-that-be will allow them.  Sometimes it's an uphill struggle just to gain a small amount of credibility, and in Anning's case, even that never happened.  Shortly before her death from breast cancer at the age of 47, she wrote, "The world has used me so unkindly, I fear it has made me suspicious of everyone."

Fortunately, that isn't the case here, and the amateurs and the scientists are happily collaborating.  With luck and persistence, we will continue to learn about the prehistoric landscape of England as it was 115 million years ago, when dinosaurs like Ventaerovenator were prowling the shores.

***********************************

This week's Skeptophilia book recommendation of the week is by the brilliant Dutch animal behaviorist Frans de Waal, whose work with capuchin monkeys and chimps has elucidated not only their behavior, but the origins of a lot of our own.  (For a taste of his work, watch the brilliant TED talk he did called "Moral Behavior in Animals.")

In his book Mama's Last Hug: Animal Emotions and What They Tell Us About Ourselves, de Waal looks at this topic in more detail, telling riveting stories about the emotions animals experience, and showing that their inner world is more like ours than we usually realize.  Our feelings of love, hate, jealousy, empathy, disgust, fear, and joy are not unique to humans, but have their roots in our distant ancestry -- and are shared by many, if not most, mammalian species.

If you're interested in animal behavior, Mama's Last Hug is a must-read.  In it, you'll find out that non-human animals have a rich emotional life, and one that resembles our own to a startling degree.  In looking at other animals, we are holding up a mirror to ourselves.

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