An avalanche of fire

One of the most utterly terrifying phenomena on Earth is called a pyroclastic flow.

Pyroclastic flows are explosive eruptions of volcanoes that release not molten rock, but finely pulverized debris and hot gases that then flow downhill at an astonishing rate -- in some cases, forming a cloud at a temperature of 1000 C moving at an almost unimaginable 700 kilometers per hour.  Pompeii and Herculaneum were destroyed by pyroclastic flows from Mount Vesuvius on August 24, 79 C.E., which killed everyone in their path and buried the cities under layers of ash, where they remained for centuries until being unearthed by archaeologists.

If you're not too prone to freak-out over such things, I strongly recommend this ten-minute animation that recreates the destruction of Pompeii:

More recently, a 1902 eruption of Mount Pelée on the island of Martinique triggered a pyroclastic flow that obliterated the city of Saint Pierre, killing 30,000 people in an estimated five minutes.  There were only three survivors -- Louis-Auguste Cyparis, who was lucky enough to be in an underground dungeon; Léon Compère-Léandre, who lived on the edge of town and still suffered severe burns; and Havivra Da Ifrile, who was on the beach when the eruption started and had the presence of mind to jump in a rowboat, where she was later found, unconscious and adrift, three kilometers offshore.

Saint Pierre before the eruption...

... and after:

[Images are in the Public Domain]

What has long been a mystery to volcanologists is how pyroclastic flows achieve the speeds they do, which, after all, is the key to their deadliness.  Lava flows, while they can do tremendous damage to houses and land, rarely cause loss of life because they can almost always be outrun (or in some cases, outwalked).  The fastest pyroclastic flows, on the other hand, are moving so rapidly that even if you had warning, you couldn't move quickly enough to escape.

But a paper last week in Nature describes how a team from three universities in New Zealand (Massey University, the University of Auckland, and the University of Otago) and one in the United States (the University of Oregon) created a model of pyroclastic flows, and found that the reason they travel so quickly is basically the principle of air hockey -- the cloud is suspended on a cushion of superheated air, reducing the friction to nearly zero.

In "Generation of Air Lubrication Within Pyroclastic Density Currents," by Gert Lube, Eric C. P. Breard, Jim Jones, Luke Fullard, Josef Dufek, Shane J. Cronin, and Ting Wang, we find out about a series of experiments that are not only cool but must have been extremely fun to carry out.  They built a twelve-meter-long chute, mined some volcanic particles (deposited in the 232 C.E. eruption of New Zealand's Mount Taupo), heated it up to 130 C, and sent 1000 kilograms of it at a time barreling down the chute, all the while filming it with an ultrafast camera.

As Michelle Starr, writing for Science Alert, describes the results:

[W]ithin the flow there were extremely high shear rates - the rate at which layers in a fluid flow past each other.  When shear increases, so does air pressure; and when shear rates are at their highest, that pressure produces a cushion of air just above the ground, pushing particles away from each other, with denser volcanic dust layers sliding over the top of it.

The result is that the flow keeps moving downhill at higher and higher rates until it hits an obstacle, dissipates, or cools enough that the effect diminishes and the particles slow down.

This makes me glad I live in such a benign part of the world.  Here in upstate New York, the worst we have to worry about is the occasional snowstorm, and the fact that the summers are distressingly short.  (This year, summer is scheduled for the second Thursday in July.)  But compared to living near an active volcano, or a hurricane zone, or Tornado Alley, or near a seismic fault line -- I'd say we're pretty damn fortunate.

But of all the natural disasters the Earth is capable of creating, I don't think there's anything quite as terrifying as these avalanches of fire -- unpredictable, lightning-fast, and capable of destroying everything in their path.  Compared to that, I'd choose our long, cold winters in half a heartbeat.

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

This week's Skeptophilia book recommendation is a fun one; Atlas Obscura by Joshua Foer, Dylan Thuras, and Ella Morton.  The book is based upon a website of the same name that looks at curious, beautiful, bizarre, frightening, or fascinating places in the world -- the sorts of off-the-beaten-path destinations that you might pass by without ever knowing they exist.  (Recent entries are an astronomical observatory in Zweibrücken, Germany that has been painted to look like R2-D2; the town of Story, Indiana that is for sale for a cool $3.8 million; and the Michelin-rated kitchen run by Lewis Georgiades -- at the British Antarctic Survey’s Rothera Research Station, which only gets a food delivery once a year.)

This book collects the best of the Atlas Obscura sites, organizes them by continent, and tells you about their history.  It's a must-read for anyone who likes to travel -- preferably before you plan your next vacation.

(If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!)

The black heart of M87

It's awfully easy to get discouraged lately.

The news seems to go from bad to worse every day.  Government corruption, terrorist attacks both here and overseas, every other news story a testament of the amazing ability of Homo sapiens to treat each other horribly.

So when we have a triumph, we should celebrate it.  Because as Max Ehrmann put it, in his classic poem "Desiderata:" "Many persons strive for high ideals; and everywhere life is full of heroism...  With all its sham, drudgery, and broken dreams, it is still a beautiful world."

We got a lovely example of that a couple of days ago, with the revelation that scientists had amassed enough data from the Event Horizon Telescope project to produce the first-ever photograph of a black hole.  It's at the heart of the massive elliptical galaxy M87, in the constellation of Virgo, and is about 54 million light years away.  With no further ado, here's the photo:

I think the left-hand one -- with less magnification -- is even more amazing, because it shows the black hole in context with its surroundings.  It looks more "real."  But in either case, they're stunning.  The glow comes from matter being sucked into the black hole, being heated up to the point of producing x-rays as a sort of electromagnetic death scream before dropping forever beyond the event horizon.  For the very first time, we're seeing an actual image of one of the most bizarre phenomena in nature -- an object so massive that it warps space into a closed curve, so that even light can't escape.

But even this isn't my favorite image that has come out of this study.

This is:

This is Katie Bouman, the MIT postdoc (soon to be starting as an assistant professor at CalTech) whose algorithm made the black hole image a reality.  Bouman responded to her sudden fame with modesty.  "No one of us could've done it alone," she said.  "It came together because of lots of different people from many backgrounds."

Which may well be, but no one is questioning her pivotal role in this groundbreaking achievement.  And what I love about the photograph above is that it perfectly captures the joy of doing science -- what Nobel Prize-winning physicist Richard Feynman called "the pleasure of finding things out."  We now have a window into a piece of the universe that was invisible to us before, and that ineffable feeling is clearly captured in her expression.

There have already been six papers written about this accomplishment, and that's only the beginning.  I find myself wondering what other obscure and fascinating astronomical phenomena Bouman's algorithm could be used to photograph -- and what we might learn from seeing them for real for the first time.  I also wonder what effect that will have on us ordinary laypeople.  The physicists may be comfortable living in the world of their mathematical models (I heard one physicist friend say, "The models are the reality; everything else is just pretty pictures"), but the rest of us need to be more grounded in order to understand.  So what if we were to see more than an artist's conception of things like pulsars, quasars, gamma-ray bursters, type 1-A supernovae?

Kind of a surfeit of wonder, that would be.  But what a way to be overwhelmed, yes?

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

This week's Skeptophilia book recommendation is a fun one; Atlas Obscura by Joshua Foer, Dylan Thuras, and Ella Morton.  The book is based upon a website of the same name that looks at curious, beautiful, bizarre, frightening, or fascinating places in the world -- the sorts of off-the-beaten-path destinations that you might pass by without ever knowing they exist.  (Recent entries are an astronomical observatory in Zweibrücken, Germany that has been painted to look like R2-D2; the town of Story, Indiana that is for sale for a cool $3.8 million; and the Michelin-rated kitchen run by Lewis Georgiades -- at the British Antarctic Survey’s Rothera Research Station, which only gets a food delivery once a year.)

This book collects the best of the Atlas Obscura sites, organizes them by continent, and tells you about their history.  It's a must-read for anyone who likes to travel -- preferably before you plan your next vacation.

(If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!)

The dangers of pseudoarchaeology

One of my ongoing peeves is that so many people put more faith in popular media claims than in what the scientists themselves are saying.

This can take many forms.  We have the straw-man approach, usually done with some agenda in mind, where someone will completely mischaracterize the science in order to convince people of a particular claim, and for some reason said people never think to find out what the scientists actually have to say on the matter.  (One example that especially sets my teeth on edge is the young-Earth creationists who say that the Big Bang model means "nothing exploded and created everything" and forthwith dismiss it as nonsense.)

An even more common form this takes is the current passion many people have for shows like Monster Quest and Ancient Aliens and Ghost Hunters, which aim to convince viewers that there is strong evidence for claims when there is actually little or none at all.  This kind of thing is remarkably hard to fight; when you have a charismatic figure who is trying to convince you that the Norse gods were actually superpowerful extraterrestrial visitors, and supporting that claim with evidence that is cherry-picked at best and entirely fabricated at worst, non-scientists can be suckered remarkably easily.

But "hard to fight" doesn't mean "give up," at least to archaeologist David Anderson of Radford University (Virginia).  Because he has absolutely had it with goofy claims that misrepresent the actual evidence, and is publicly calling out the people who do it.

Anderson's quest started in February, when a claim was made on The Joe Rogan Experience that a famous piece of Mayan art, from the sarcophagus of Mayan King K’inich Janaab’ Pakal, who died in 683 C.E., showed him ascending into the skies in a spaceship:

It's one of the favorite pieces of evidence from the "Ancient Aliens" crowd.  But the problem is, it's wrong -- not only from the standpoint that there almost certainly were no "Ancient Aliens."  They evidently never bothered to ask an actual expert in Mayan archaeology, because that's not even what the art is trying to depict. Anderson was infuriated enough that he responded to Rogan in a tweet: "Dear @joerogan… [the piece of Mayan art you mentioned] depicts [Pakal] falling into the underworld at the moment of his death."  The "rocket" beneath the king's body, Anderson explains, is a depiction of the underworld, and the rest of the "spaceship" is a "world tree" -- a common image in Mayan art, not to mention art from other cultures.

Rogan, to his credit, thanked Anderson for the correction, but some of his fans weren't so thrilled, and railed against Anderson as being a "mainstream archaeologist" (because that's bad, apparently) who was actively trying to suppress the truth about ancient aliens for some reason.  Anderson, for his part, is adamant that archaeologists and other scientists need to be better at calling out pseudoscience and the people who are promoting it.  He cites a study done at Chapman University (California) showing that 57% of Americans polled in 2018 believe in Atlantis (up from 40% in 2016) and 41% believe that aliens visited the Earth in antiquity and made contact with early human civilizations (up from 27%).

Anderson says, and I agree, that this is a serious problem, not only because of how high the raw numbers are, but because of the trend.  I know it's not really a scientist's job to make sure the public understands his/her research, but given the amount of bullshit out there (not to mention the general anti-science bent of the current administration), it's increasingly important.

You may wonder why I'm so passionate about this, and be thinking, "Okay, I see the problem with people doubting climate science, but what's the harm of people believing in ancient aliens?  It's harmless."  Which is true, up to a point.  But the problem is, once you've decided that evidence -- and the amount and quality thereof -- is no longer the sine qua non for support of a claim, you've gone onto some seriously thin ice.  Taking a leap into pseudoscience in one realm makes it all that much easier to jump into other unsupported craziness.  Consider, for example, the study that came out of the University of Queensland that found a strong correlation between being an anti-vaxxer and accepting conspiracy theories such as the ones surrounding the JFK assassination.

So learning some science and critical thinking are insulation against being suckered by counterfactual nonsense of all kinds.  Which is why yes, I do care that people are making false claims about a piece of Mayan artwork... and so should you.

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

This week's Skeptophilia book recommendation is a fun one; Atlas Obscura by Joshua Foer, Dylan Thuras, and Ella Morton.  The book is based upon a website of the same name that looks at curious, beautiful, bizarre, frightening, or fascinating places in the world -- the sorts of off-the-beaten-path destinations that you might pass by without ever knowing they exist.  (Recent entries are an astronomical observatory in Zweibrücken, Germany that has been painted to look like R2-D2; the town of Story, Indiana that is for sale for a cool $3.8 million; and the Michelin-rated kitchen run by Lewis Georgiades -- at the British Antarctic Survey’s Rothera Research Station, which only gets a food delivery once a year.)

This book collects the best of the Atlas Obscura sites, organizes them by continent, and tells you about their history.  It's a must-read for anyone who likes to travel -- preferably before you plan your next vacation.

(If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!)

The library of possibilities

In the brilliant Doctor Who episode "Turn Left," the Doctor's companion Donna Noble finds out that a single decision she made on a single day -- whether to turn right or left at an intersection -- creates two possible futures, one of them absolutely horrific.

It's a common trope in science fiction (although in my opinion, it's seldom been done as well, nor as poignantly, as in "Turn Left"), to look at how our futures could have been significantly different than they are.  I even riffed on this in one of my own novels -- Lock & Key -- in which there are not only multiple possible outcomes for each decision, there's a library (and a remarkably grumpy Head Librarian) that keeps track of not only what has happened, but what could have happened.  For every human being who ever existed, or who ever might have existed.

If you want to know how I handled the idea, you'll just have to read the book.

In reality, of course, the number of possible outcomes for even a simple series of choices increases exponentially with each successive decision, so in any realistic situation the possibilities are about as close to infinite as you can get.  Which makes a paper that came out in Nature last week even more extraordinary.

In order to see how amazing it is, a brief lesson in quantum mechanics for the non-physics-types in the studio audience.

One of the basic concepts in quantum physics is superposition: any measurable property of a wave (or subatomic particle) exists in multiple states at the same time.  The distribution of these states -- more specifically, the probability that the particle is in a specific state -- can be described by its wave function.  And the completely counterintuitive outcome of this model is that prior to observation, the particle is in all possible states at once, and only drops into a particular one (in a process called "collapsing the wave function") when it's observed.  (Regular readers of Skeptophilia may recall that I did a post on a particular part of this theory, Wigner's paradox, a few weeks ago.)

So that's amazing enough.  Particles and waves exist as a multitude of present possibilities, all at the same time.  But now, a collaboration between physicists at Griffith University (Queensland, Australia) and Nanyang Technological University (Singapore) have gone a step further:

They have developed a prototype device that generates a quantum state embodying all of the particle's future states simultaneously.

 My first thought was, "That can't possibly mean what it sounds like."  But yes, that turns out to be exactly what it means.  "When we think about the future, we are confronted by a vast array of possibilities," said Mile Gu of Nanyang Technological University, who led the study.  "These possibilities grow exponentially as we go deeper into the future. For instance, even if we have only two possibilities to choose from each minute, in less than half an hour there are 14 million possible futures.  In less than a day, the number exceeds the number of atoms in the universe."

So having even a simple system that generates all possible futures at the same time is somewhere beyond amazing, and into the realm of the nearly incomprehensible.

"Our approach is to synthesize a quantum superposition of all possible futures for each bias," said Farzad Ghafari, of Griffith University.  "By interfering these superpositions with each other, we can completely avoid looking at each possible future individually.  In fact, many current artificial intelligence (AI) algorithms learn by seeing how small changes in their behavior can lead to different future outcomes, so our techniques may enable quantum enhanced AIs to learn the effect of their actions much more efficiently."

"The functioning of this device is inspired by the Nobel Laureate Richard Feynman," added Dr Jayne Thompson, a member of the Singapore team.  "When Feynman started studying quantum physics, he realized that when a particle travels from point A to point B, it does not necessarily follow a single path.  Instead, it simultaneously transverses all possible paths connecting the points.  Our work extends this phenomenon and harnesses it for modeling statistical futures."

So I'm sitting here, trying to wrap my brain around the implication of this research.  Quantum indeterminacy indicates that we don't live in a completely deterministic universe; there's always some uncertainty, built into the actual fabric of the universe.  But the idea that we could, even in principle, create a system from which we could analyze all of the possible futures is stunning.

As Maggie Carmichael, the Assistant Librarian in Lock & Key, puts it:

All of our actions, even the smallest ones, make a difference.  Most of us never find out what that difference is.  All choices have consequences, however insignificant they seem at the time.  However, the truth of that statement is only evident here in the Library, where we can see what would have happened if we had acted otherwise.  Without that information, what happens simply… happens.

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

This week's Skeptophilia book recommendation is a fun one; Atlas Obscura by Joshua Foer, Dylan Thuras, and Ella Morton.  The book is based upon a website of the same name that looks at curious, beautiful, bizarre, frightening, or fascinating places in the world -- the sorts of off-the-beaten-path destinations that you might pass by without ever knowing they exist.  (Recent entries are an astronomical observatory in Zweibrücken, Germany that has been painted to look like R2-D2; the town of Story, Indiana that is for sale for a cool $3.8 million; and the Michelin-rated kitchen run by Lewis Georgiades -- at the British Antarctic Survey’s Rothera Research Station, which only gets a food delivery once a year.)

This book collects the best of the Atlas Obscura sites, organizes them by continent, and tells you about their history.  It's a must-read for anyone who likes to travel -- preferably before you plan your next vacation.

(If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!)

Whales, fossils, and the limitations of commons sense

One of my favorite things about science is its ability to jolt us out of our preconceived notions.

We all have common-sensical ideas about how the universe works, and they allow us to function pretty well most days.  The problem is, some of them are correct and some of them are wildly wrong, and how do you tell which is which?  As physicist Sean Carroll eloquently puts it, in his wonderful book The Particle at the End of the Universe:

It's only because the data force us into corners that we are inspired to create the highly counterintuitive structures that form the basis for modern physics...  Imagine that a person in the ancient world was wondering what made the sun shine.  It's not really credible to imagine that they would think about it for a while and decide, "I bet most of the sun is made up of particles that can bump into one another and stick together, with one of them converting into a different kind of particle by emitting yet a third particle, which would be massless if it wasn't for the existence of a field that fills space and breaks the symmetry that is responsible for the associated force, and that fusion of the original two particles releases energy, which we ultimately see as sunlight."  But that's exactly what happens.  It took many decades to put this story together, and it never would have happened if our hands weren't forced by the demands of observation and experiment at every step.

That's why I find it frustrating when someone says, "Oh, that can't be right, it sounds ridiculous," and forthwith stops thinking about it.  We've seen over and over that "sounding ridiculous" is not a reliable indicator of the truth of a claim.  The only acceptable criterion is hard evidence -- as long as you've got that, what your claim sounds like is entirely irrelevant.

This point comes up every year in my AP Biology class when we talk about the evolutionary history of whales.  The fossil record for whales was pretty lousy, because being marine mammals their skeletons are mostly destroyed by scavengers and degraded by seawater, not to mention the fact that many of them end up in the abyssal regions of the ocean floor.  After that, we'd only find them if those deep oceanic sediments get scooped up by the movement of tectonic plates and thrust up onto land -- something that (1) doesn't happen that often, and (2) results in significant deformation of the rocks formed, thus completely destroying any fossils that were present.

It wasn't until a fossil bed was discovered in Pakistan in the early 1980s that we actually got any data on what the ancestors of today's whales looked like.  The northern parts of Pakistan and India -- i.e., the Himalayas -- were formed in exactly the way I've described above.  We lucked out, though, because at least one rock formation not only has ancestral whale fossils, but ones that survived in reasonably good condition.

Now, here's the counterintuitive part; the fossils found in Pakistan and India have conclusively shown that the nearest living non-cetacean relatives of whales are hippos...

... and artiodactylid ruminants.  For example, cattle, sheep, goats, deer, and antelopes.

This is the point where people look at a picture of a blue whale and a white-tailed deer and say, "Hang on a moment.  That can't be right."  But it is -- as confirmed not only from the fossil record, but from extensive genetic studies.

We just got further confirmation of this relationship from an entirely different fossil bed -- this one from mid-Eocene (i.e., about forty million years old) rocks in Peru.  A team led by paleontologist Olivier Lambert, of the Institut Royal des Sciences Naturelles de Belgique, has discovered not only a new species but an entirely new genus of proto-cetaceans.  Called Peregocetus pacificus, it catches whale evolution right in the middle between the terrestrial ancestors and their aquatic descendants.

The authors write:

[T]his unique four-limbed whale bore caudal vertebrae with bifurcated and anteroposteriorly expanded transverse processes, like those of beavers and otters, suggesting a significant contribution of the tail during swimming.  The fore- and hind-limb proportions roughly similar to geologically older quadrupedal whales from India and Pakistan, the pelvis being firmly attached to the sacrum, an insertion fossa for the round ligament on the femur, and the retention of small hooves with a flat anteroventral tip at fingers and toes indicate that Peregocetus was still capable of standing and even walking on land.  This new record from the southeastern Pacific demonstrates that early quadrupedal whales crossed the South Atlantic and nearly attained a circum-equatorial distribution with a combination of terrestrial and aquatic locomotion abilities less than 10 million years after their origin and probably before a northward dispersal toward higher North American latitudes.

So that's kind of amazing.  It also illustrates why we can't rely on "that sounds reasonable" to determine what's true.  This is just one example of how science has come up with a result that we never would have arrived at using common sense -- as helpful as that is in most ordinary situations.

Reconstruction of ancestral cetacean Pakicetus inachus [Image licensed under the Creative Commons Nobu Tamura (http://spinops.blogspot.com), Pakicetus BW, CC BY 3.0]

Myself, I like the capacity of science to astonish us.  It would be incredibly boring if the universe turned out to work exactly the way we thought, that our minds are perfect little windows through which we perceive everything right the first time.

Much better to be reminded of our limitations -- and to have such a powerful tool to check our guesses, and correct us when we're wrong.

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

This week's Skeptophilia book recommendation is a fun one; Atlas Obscura by Joshua Foer, Dylan Thuras, and Ella Morton.  The book is based upon a website of the same name that looks at curious, beautiful, bizarre, frightening, or fascinating places in the world -- the sorts of off-the-beaten-path destinations that you might pass by without ever knowing they exist.  (Recent entries are an astronomical observatory in Zweibrücken, Germany that has been painted to look like R2-D2; the town of Story, Indiana that is for sale for a cool $3.8 million; and the Michelin-rated kitchen run by Lewis Georgiades -- at the British Antarctic Survey’s Rothera Research Station, which only gets a food delivery once a year.)

This book collects the best of the Atlas Obscura sites, organizes them by continent, and tells you about their history.  It's a must-read for anyone who likes to travel -- preferably before you plan your next vacation.

(If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!)

Whispers, tingles, and brain orgasms

My wife sent me a link to an article a couple of days ago about a phenomenon that I'd heard a bit about, but never really researched.

It's called an "Autonomous Sensory Meridian Response," ASMR for short.  The nickname, though, is more telling; people call it a "brain orgasm."

Of course, on some level, all orgasms are about what happen in the brain.  fMRI studies of people during orgasm show that during arousal and climax people experience a surge of neurotransmitters like dopamine and endorphin, as well as the "cuddle hormone" oxytocin (explaining why most of us feel snuggly after doing the deed, not to mention sleepy).  Without a brain response, there's no arousal, and I think just about everyone can think of times when what was going on in their brains -- worry, fatigue, frustration, anger -- interfered with their desire, or even ability, to have sex.

Gustav Klimt, The Kiss (1908) [Image is in the Public Domain]

It brings up the question, however, of who is volunteering for those studies.  I mean, I'm as comfortable in my skin as the next guy, and in fact in my twenties would have been voted the captain of the co-ed skinnydipping team.  But doing a solo performance while hooked up to a fMRI, with lots of people wearing white lab jackets and holding clipboards and peering at me and taking notes, gives new meaning to the phrase, "no way, José."  I mean, if getting off with an audience turns you on, more power to you, but even with a significant cash incentive I don't think I'd participate.

But I digress.

Anyhow, my point is, there have been a good many studies of the neurochemistry of the human sexual response, so this ASMR thing is interesting because apparently for some people, hearing certain noises (or, less commonly, seeing particular images) triggers a brain response that is very similar to orgasm but without the involvement of your naughty bits.  Here's how one person describes it:

While watching videos of space... a tingling spreads through my scalp as the camera pulls back to show the marble of the earth.  It comes in a wave, like a warm effervescence, making its way down the length of my spine and leaving behind a sense of gratitude and wholeness.

The similarity to an actual orgasm is obvious.  But why was it happening?

Turns out, we don't know.  Also unknown is why the people who experience ASMR are (1) nearly all female, and (2) have particular triggers that are specific to them.  The article in the New York Times (linked above) said that there are five hundred new ASMR-inducing videos uploaded to YouTube every day, which I suppose is understandable given what they can allegedly do to you.  Most of them are some combination of people whispering, rubbing fabric or combs or the like across microphones, stroking rough surfaces with fingernails, crunching paper, brushing hair, or chewing food.

This last one was a little puzzling right from the get-go.  A lot of people hate the sound of others chewing.  My older son, for example, was as a teenager really sensitive to sounds like that, and became nearly homicidal when he was around someone eating Doritos.  But apparently not everyone responds that way, and some people feel exactly the opposite.

So I was intrigued, and got onto YouTube and checked out a couple of the videos.  Here's a typical one:

 I went into it figuring I wouldn't respond, given that I'm male, also was a little dubious from the outset, and...

... sure enough, nothing, or at least nothing positive.  In fact, I found the noises intensely annoying.  Not only was I not soothed or tingly, after about 45 seconds I wanted to climb out of my skin.  So if you watched the video and had a brain orgasm or whatever, I'm happy for you, but that was certainly not my experience.

It does bring up the fascinating question of how the same stimuli can provoke entirely different responses in different people.  And this applies outside of the realm of listening to people brush their hair, or even what specific things are a sexual turn-on; consider how unique people's reactions are to music.  My wife and I, for example, both love music, but what particular pieces of music grab us are completely different.  When I find a piece of music I love, it definitely gives me chills, and has been known to bring me to actual tears.  The first time I heard Vaughan Williams's Fantasia on a Theme by Thomas Tallis, for example, I ended up sobbing, and couldn't have explained why.

Now there's something I'd be willing to do while hooked up to a fMRI machine.

My point, though, is that these kinds of emotional and physical reactions are pretty common in humans, as is the fact that what specifically triggers them is highly personal.  I think we're a long, long way from figuring out why that is, though, even on the level of being able to comprehend as individuals why a particular trigger is a turn-on for us.

In any case, the whole ASMR thing is curious enough that it deserves more research.  It's understandable that scientists have been reluctant to do so, I suppose; both the variability of response, and the general oddity of the phenomenon, probably pushes researchers to look into phenomena that are more likely to get grant approval.  (In fact, the New York Times article said that there have only been ten academic papers addressing ASMR ever published.)

But given the popularity of the videos, there has to be something to it, and it'd be cool to find out what that something is.  So even if the sound of someone whispering or twisting bubble wrap or chewing gum doesn't turn me on, I'd sure like to know why it has that effect on others.

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

This week's Skeptophilia book recommendation is a fun one; Atlas Obscura by Joshua Foer, Dylan Thuras, and Ella Morton.  The book is based upon a website of the same name that looks at curious, beautiful, bizarre, frightening, or fascinating places in the world -- the sorts of off-the-beaten-path destinations that you might pass by without ever knowing they exist.  (Recent entries are an astronomical observatory in Zweibrücken, Germany that has been painted to look like R2-D2; the town of Story, Indiana that is for sale for a cool $3.8 million; and the Michelin-rated kitchen run by Lewis Georgiades -- at the British Antarctic Survey’s Rothera Research Station, which only gets a food delivery once a year.)

This book collects the best of the Atlas Obscura sites, organizes them by continent, and tells you about their history.  It's a must-read for anyone who likes to travel -- preferably before you plan your next vacation.

(If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!)

Tales from a white dwarf

This week we've focused on some cool scientific discoveries, which is, honestly, my happy place.  So we'll round out the week with a new piece of research that is kind of a double-edged sword.  It is (1) fascinating, but (2) tells us about how the Earth is going to be destroyed.  So while it's interesting, cheerful it isn't.

Of course, the upside is that the Earth isn't going to be destroyed for another few billion years.  So even in the best-case scenario, I won't be around when it happens.

The research was led by Christopher Manser of the University of Warwick, and is based on observations done of a white dwarf star at the 10.4-meter Gran Telescopio Canarias on La Palma in the Canary Islands.  White dwarfs are the remnants of stellar cores for stars smaller than about 10 times the mass of the Sun.  At the end of their lives, stars in this range exhaust the hydrogen fuel in their cores, and switch to burning helium -- this gives an added kick to the core temperature, and the outer atmosphere balloons out into what's called a red giant.  But eventually, it becomes a nova -- it exhausts the helium as well, the core collapses and heats up (dramatically), and that blows the outer atmosphere away (forming what's called a planetary nebula), in an expanding cloud of gas and dust surrounding the exposed core -- the white dwarf star.

[Image licensed under the Creative Commons, ESA/Hubble, Artist’s impression of debris around a white dwarf star, CC BY 4.0]

It was long thought that a star that becomes a white dwarf will in the process completely destroy any planets that happen to be orbiting around it.  When the Sun becomes a red giant, for example, it's believed that its outer edges will be somewhere between the orbits of Mars and Jupiter.  So where you are sitting right now will be inside the Sun.

I like it warm, but that's a bit toasty even my my standards.

So it was quite a shock when Manser et al. found that the white dwarf they were studying, the euphoniously named SDSS J122859.93+104032.9, had a planet orbiting it.

The fact that they could even tell that is pretty extraordinary.  As I explained in a previous post, the two most common ways of detecting planets are by occlusion (the star dimming because the planet has passed in front of it) or by Doppler spectroscopy (seeing shifts in the frequency of light from the star because it's being pulled around by the planet as it orbits).  Both of these work better when the planet is massive -- so for a little planet around a littler star, it's kind of amazing they even figured out it was there.

What they found was that there was light coming from the star system that was consistent with the emission spectrum of calcium, but oddly, the calcium spectral lines were split in two -- and the two lines oscillated back and forth with a period of almost exactly two hours.  The best explanation, say Manser et al, is that there is a planetesimal -- probably the iron-rich core of a planet that once orbited the star prior to its demise -- that is dragging around a cloud of calcium-rich gas that is being Doppler shifted first one way and then the other every time the planet circles the star.

As Luca Fossati, writing for Science magazine, describes the research:

The method of Manser et al. has revealed the presence of planetesimals without the need for the particular orbital geometry that is required by the transit method.  It could therefore be used to identify the presence of planetesimals orbiting other polluted white dwarfs and advance the study of the planetary systems evolution.  Furthermore, because planetesimals orbiting white dwarfs are believed to be the remnant cores of shattered planets, studying the spectra of polluted white dwarfs known to be surrounded by planetesimals enables one to gain information about the chemical composition and metal abundances of the infalling material—that is, planetary cores.

The most awe-inspiring part of this research is that this will be the likely fate of the Earth -- assuming that the red giant and nova phases of the Sun don't destroy it completely.  All that will be left is the remnant core of the Sun and the remnant core of the Earth, circling each other and gradually cooling, becoming a whirling pair of cinders forever spinning in the infinite dark, cold vacuum of space.

Have a nice day.

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

This week's Skeptophilia book recommendation combines science with biography and high drama.  It's the story of the discovery of oxygen, through the work of the sometimes friends, sometimes bitter rivals Joseph Priestley and Antoine Lavoisier.   A World on Fire: A Heretic, an Aristocrat, and the Race to Discover Oxygen is a fascinating read, both for the science and for the very different personalities of the two men involved.  Priestley was determined, serious, and a bit of a recluse; Lavoisier a pampered nobleman who was as often making the rounds of the social upper-crust in 18th century Paris as he was in his laboratory.  But despite their differences, their contributions were both essential -- and each of them ended up running afoul of the conventional powers-that-be, with tragic results.

The story of how their combined efforts led to a complete overturning of our understanding of that most ubiquitous of substances -- air -- will keep you engaged until the very last page.

[Note:  If you purchase this book by clicking on the image/link below, part of the proceeds will go to support Skeptophilia!]