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

Monday, September 20, 2021

Hot times

In today's contribution from the Completely Useless Advice department: if you own property in southern Africa, you might want to consider selling it some time in the next ten million years or so.

The reason I say this is because of a paper published a couple of months ago in Nature Geoscience that was once again thrown my way by my pal Gil Miller, who seems to have an inordinate talent at ferreting out truly fascinating stuff I hadn't heard about.  The paper is entitled "A Tree of Indo-African Mantle Plumes Imaged by Seismic Tomography," by Maria Tsekhmistrenko, Karin Sigloch, and Kasra Hosseini (of Oxford University), and Guilhem Barruol (of the Université de Paris), and describes the structure of the mysterious "hotspots" -- upwelling of extremely hot magma from deep in the mantle -- that are responsible for such volcanically-active regions as Hawaii, Yellowstone, and Réunion Island.

These hotspots have long puzzled geologists, because they are quite distant from tectonic plate boundaries, where most of the world's seismic and volcanic activity occurs.  Hawaii is the best-studied hotspot; it was one of the most powerful pieces of evidence of plate movement, back in the 1960s when the theory of plate tectonics was first being studied.  The Big Island of Hawaii is just the easternmost point in a chain that extends way beyond what we usually think of as the Hawaiian Islands; even the westernmost island that pokes up above sea level, Kure Atoll, isn't the end of it.  It continues into the Emperor Seamount Chain, which extends underwater all the way to the Kamchatka Peninsula of Siberia. 

My long-ago geology professor described it as being like pulling a piece of fabric (the Pacific Plate) through an upside-down sewing machine (the Hawaiian Hotspot); the needle of the sewing machine punches regular holes upward through the fabric as it moves through, but the sewing machine itself stays in the same place.  The plates are moving; the hotspot isn't.  (And the angle in the chain of seamounts indicates that at some point in the past, the Pacific Plate changed direction, probably because of jostling against other plates.)

The Pacific Ocean floor, showing the Hawaiian-Emperor Seamount Chain [Image is in the Public Domain courtesy of NOAA]

What is still mysterious about hotspots is why they happen at all.  We have a pretty decent idea of why the activity along plate margins occurs -- strike-slip faults like the famous San Andreas, where two plates are moving along each other in opposite directions; trenches/subduction zones like Indonesia, where you get both powerful quakes and huge volcanoes; and mid-ocean ridges/divergent zones like the Mid-Atlantic Ridge, where plates are moving apart and new magma upwells to fill the gaps.  But why would there be a persistent chain of volcanoes out in the middle of a stable plate?

The current paper describes blobs of extremely hot magma originating from the lower parts of the mantle, which rise and then diverge into branches.  The authors write:
Mantle plumes were conceived as thin, vertical conduits in which buoyant, hot rock from the lowermost mantle rises to Earth’s surface, manifesting as hotspot-type volcanism far from plate boundaries.  Spatially correlated with hotspots are two vast provinces of slow seismic wave propagation in the lowermost mantle, probably representing the heat reservoirs that feed plumes...  Using seismic waves that sample the deepest mantle extensively, we show that mantle upwellings are arranged in a tree-like structure.  From a central, compact trunk below ~1,500 km depth, three branches tilt outwards and up towards various Indo-Austral hotspots.  We propose that each tilting branch represents an alignment of vertically rising blobs or proto-plumes, which detached in a linear staggered sequence from their underlying low-velocity corridor at the core–mantle boundary.  Once a blob reaches the viscosity discontinuity between lower and upper mantle, it spawns a ‘classical’ plume-head/plume-tail sequence.
So the Réunion Hotspot is apparently connected to the East African Rift Zone, three-thousand-odd kilometers away.  The EARZ is a developing rift that is ultimately going to shear off the "Horn of Africa," opening a new ocean and creating a new "microcontinent" made up Somalia and bits of Ethiopia, Kenya, and Tanzania.  (As an aside, it's also the site of Olduvai Gorge, where some of the earliest hominin fossils were found.)

[Image is in the Public Domain courtesy of the USGS]

"From looking at the core-mantle boundary, you can maybe predict where the oceans will open,” said study co-author Karin Sigloch.  "If the new models are accurate, a few tens of millions of years from now, you may not want to be in South Africa — or, perhaps, on planet Earth at all."

The reason Sigloch says this is that the team's analysis of the "tree" of magma that underlies both Réunion and the EARZ suggests that it's in the process of forming another branch -- another mantle plume -- that will ultimately end up underneath what is now South Africa.  "In tens of millions of years, a blob of nightmarishly gargantuan proportions will pinch off from the central cusp," Sigloch said, in an interview with Quanta magazine.  "This would produce cataclysmic eruptions.  The Deccan Traps [one of the largest volcanic eruptions ever, and which probably contributed to the extinction of the non-avian dinosaurs 66 million years ago] were caused by what we would think of as a solitary mantle plume.  This future mega-blob, though, would be capable of producing volcanism so prolific and extensive that the Deccan Traps would be a firecracker in comparison."

Pretty scary.  But like I said, if you want to visit South Africa, or if you live there, you still have a ten-million-year window to take care of business.  What's interesting from a geological perspective is that up till now, South Africa has been very stable tectonically.  The majority of the country is made of extremely old rock, what geologists call a "craton" -- a chunk of some of the oldest continents on Earth.  A massive flood basalt eruption, like the Deccan Traps, the Columbia River Flood Basalts, and the largest of them all -- the Siberian Traps, implicated in the cataclysmic Permian-Triassic Extinction -- would (literally) overturn three billion years of stable geology, with catastrophic results for the entire planet.

So yeah.  That's cheerful.  But since we have ten million years before we have anything serious to worry about, it'd be better if to turn your attention to more pressing concerns, even if you live in Johannesburg.  Like what we're doing to destroy the global ecosystem our own selves by our seeming commitment to burn every last gallon of fossil fuels out there, damn the climate, full speed ahead, and which could make the Earth pretty close to uninhabitable a great deal sooner. 

Which now that I think of it, isn't all that reassuring.

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

Like graphic novels?  Like bizarre and mind-blowing ideas from subatomic physics?

Have I got a book for you.

Described as "Tintin meets Brian Cox," Mysteries of the Quantum Universe is a graphic novel about the explorations of a researcher, Bob, and his dog Rick, as they investigate some of the weirdest corners of quantum physics -- and present it at a level that is accessible (and extremely entertaining) to the layperson.  The author Thibault Damour is a theoretical physicist, so his expertise in the cutting edge of physics, coupled with delightful illustrations by artist Mathieu Burniat, make for delightful reading.  This one should be in every science aficionado's to-read stack!

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


Saturday, September 18, 2021

The reawakening of Merlin

A couple of weeks ago I wrote a post about a site in Hertfordshire, England called "Arthur's Seat" that has long been associated with the famous (but possibly mythical) sixth-century king, but which dates from Neolithic times -- over four millennia earlier.

The difficulty with teasing out fact from fiction, when there are scant contemporaneous written records of any reliability, is apparent.  A good many historians think that Arthur is based on a real person, who was a Celtic (or Celto-Roman) chieftain and fought against the first invasions of the Saxons, but the phrase "based upon" is being used in the loosest possible sense.  How many of the other figures in the Arthurian Legend cycle -- Guinevere, Lancelot, Galahad, Gawain, the Knights Who Say "Ni" -- were even within hailing distance of reality is unknown, and probably unknowable.

Of course, there are always new discoveries being made, even in an extensively-researched place like England.  The most recent, and the reason the topic of Arthur comes up (again), is a manuscript found in an archive in Bristol, which I found out about because of my friend Gil Miller, who is a frequent contributor to Skeptophilia

The manuscript dates from the middle of the thirteenth century, and has a few interesting features.  The text is very similar to known copies of the Lancelot-Grail Cycle, which formed the basis of Thomas Malory's famous Le Morte d'Arthur.  It has a few curious differences, though, particularly surrounding the relationship between Merlin and Viviane (also called Nimué) -- the Lady of the Lake.

A piece of the Bristol manuscript

In most copies of the Lancelot-Grail Cycle, Viviane writes magic words on her groin, and this binds Merlin to her will, inducing him to have sex with her and teach her all of his knowledge.  Once she's had her way with him as much as she wants and has learned everything she can from him, she puts him into a charmed sleep -- this prevents him from assisting King Arthur in his fight at the Battle of Camlann against his villainous nephew Mordred (or Modred or Medraut), resulting in the deaths of both Arthur and Mordred.  Afterward, Merlin is fated to sleep "until Britain needs him again," at which he'll awaken and use his magic to save the day and make up for allowing Arthur to die.

Merlin, from Howard Pyle's illustrations for The Story of King Arthur and His Knights (1903) [Image is in the Public Domain]

The new version takes out some of the more risqué bits.  Viviane inscribes the magic words on a ring instead of on her skin, and Merlin is simply bewitched rather than doing the deed with her.  The outcome is the same -- Merlin gets put into a charmed sleep -- but otherwise, the Bristol fragments have been cleaned up a bit by the prudish sorts.  Here's the passage from one of the standard sources:

And the girl [Viviane] made Merlin lie down in her lap, and she started to ask him questions.  She moved around him, and seduced him again and again until he was sick with love for her.  And then she asked him to teach her how to put a man to sleep.  And he knew very well what she was planning, but nevertheless, he could not prevent himself from teaching her this skill, and many others as well, because Our Lord God wanted it this way.  And he taught her three names, which she inscribed on a ring every time that she had to speak to him.  These words were so powerful that when they were imprinted on her, they prevented anyone from speaking to her.  She put all of this down in writing, and from then on, she manipulated Merlin every time that he came to talk to her, so that he had no power over her.  And that is why the proverbs say that women have one more trick than the devil.

What I find interesting about the new manuscripts is that from handwriting analysis, they were written in northern France -- but an annotation in the margin has been identified as an English script style used in the early fourteenth century, so the manuscript somehow made its way to England only a few decades after it was written.

Interesting as it is, it doesn't improve our knowledge from a historical perspective.  The Bristol manuscripts were still written a good seven centuries after Arthur's time, and don't add anything much to the legend, unless you count whether or not Merlin had sex with Viviane.  Back in the British "Dark Ages" -- between the exit of Rome in the fourth century and the consolidation of the Saxon kingdoms in southern and eastern England in the seventh century -- there were damn few records of any kind being kept, and whatever there was didn't survive.  We're relying on folk histories (which intermingle history with legend and mythology) and records that were written way after the fact.

So the sad truth is, we'll probably never know which bits of the story were true and which were not.

But it's still a cool discovery.  I had no idea how much handwriting analysis tells scholars; I didn't realize that it was distinct enough as to time and place that you could confidently say "this was written in northern France in around 1250."

But all I can say is, if Merlin is still in his magical sleep, it's probably time for him to wake up.  I know a few places other than Britain that could use some help from a powerful benevolent wizard.  So if Viviane reads this, allow me to say: Enough already.

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

London in the nineteenth century was a seriously disgusting place to live, especially for the lower classes.  Sewage was dumped into gutters along the street; it then ran down into the ground -- the same ground from which residents pumped their drinking water.  The smell can only be imagined, but the prevalence of infectious water-borne diseases is a matter of record.

In 1854 there was a horrible epidemic of cholera hit central London, ultimately killing over six hundred people.  Because the most obvious unsanitary thing about the place was the smell, the leading thinkers of the time thought that cholera came from bad air -- the "miasmal model" of contagion.  But a doctor named John Snow thought it was water-borne, and through his tireless work, he was able to trace the entire epidemic to one hand-pumped well.  Finally, after weeks and months of argument, the city planners agreed to remove the handle of the well, and the epidemic ended only a few days afterward.

The work of John Snow led to a complete change in attitude toward sanitation, sewers, and safe drinking water, and in only a few years completely changed the face of the city of London.  Snow, and the epidemic he halted, are the subject of the fantastic book The Ghost Map: The Story of London's Most Terrifying Epidemic -- and How It Changed Cities, Science, and the Modern World, by science historian Steven Johnson.  The detective work Snow undertook, and his tireless efforts to save the London poor from a horrible disease, make for fascinating reading, and shine a vivid light on what cities were like back when life for all but the wealthy was "solitary, poor, nasty, brutish, and short" (to swipe Edmund Burke's trenchant turn of phrase).

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


Friday, September 17, 2021

Prolix proverbs

I thought I'd have a little fun with this week's Fiction Friday, and throw some word puzzles at you.  It may stretch the definition of Fiction Friday, but oh well.

It's my blog and I'll do what I like.

When I was in high school -- so, many years ago (how many is left as an exercise for the reader) -- my English teacher, Ms. Reinhardt, gave us a set of puzzles: familiar sayings, aphorisms, and clichés in unfamiliar guise.  Amazingly enough, I kept my copy all these years, and just ran across it this evening while searching for something else.

[Image licensed under the Creative Commons Wikimedia Foundation, Puzzly puzzled, CC BY-SA 3.0]

I don't know what their origin is -- I don't think she made them up -- but wherever they're from, they're cool brain-teasers.  (And if anyone does know the source, let me know so I can credit them properly.)  How many of them can you figure out?
1. A lithoid form, whose onward course
Is shaped by gravitational force
Can scarce enjoy the consolation
Of bryophytic aggregation.

2. To carry haulm of cereal growth
The tylopod is nothing loath;
But just one haulm too many means
That dorsal fracture supervenes.

3. When, nimbus-free, Sol marches by
Across the circumambient sky,
To graminiferous meads repair --
Your instant task awaits you there!

4. There is no use in exhortation
To practice equine flagellation,
If vital forces did depart
And still the breath, and cease the heart.

5. That unit of the avian tribe
Whose movements one can circumscribe
In manu, as a pair will rate
Subarborially situate.

6. For none who claims to represent
The Homo species sapient,
Will loiter Einstein's fourth dimension
Or sea's quotidian declension.

7. Faced with material esculent
As source of liquid nourishment
Avoid excess; 'twill but displease
Of culinary expertise.

8. Conducting to the watering place
A quadruped of equine race
Is simple; but he may not care
To practice imbibition there.

9. The coroner observed: "Perpend,
The death of this, our feline friend,
Reflects preoccupation shown
With business other than his own."

10. Of little value his compunctions
Who executes clavigerous functions,
When once from circumambient pen
Is snatched its equine denizen.
Have fun!  (And drop me an email if you want a hint or get stumped and are desperate for answers.)

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

London in the nineteenth century was a seriously disgusting place to live, especially for the lower classes.  Sewage was dumped into gutters along the street; it then ran down into the ground -- the same ground from which residents pumped their drinking water.  The smell can only be imagined, but the prevalence of infectious water-borne diseases is a matter of record.

In 1854 there was a horrible epidemic of cholera hit central London, ultimately killing over six hundred people.  Because the most obvious unsanitary thing about the place was the smell, the leading thinkers of the time thought that cholera came from bad air -- the "miasmal model" of contagion.  But a doctor named John Snow thought it was water-borne, and through his tireless work, he was able to trace the entire epidemic to one hand-pumped well.  Finally, after weeks and months of argument, the city planners agreed to remove the handle of the well, and the epidemic ended only a few days afterward.

The work of John Snow led to a complete change in attitude toward sanitation, sewers, and safe drinking water, and in only a few years completely changed the face of the city of London.  Snow, and the epidemic he halted, are the subject of the fantastic book The Ghost Map: The Story of London's Most Terrifying Epidemic -- and How It Changed Cities, Science, and the Modern World, by science historian Steven Johnson.  The detective work Snow undertook, and his tireless efforts to save the London poor from a horrible disease, make for fascinating reading, and shine a vivid light on what cities were like back when life for all but the wealthy was "solitary, poor, nasty, brutish, and short" (to swipe Edmund Burke's trenchant turn of phrase).

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


Thursday, September 16, 2021

Bias amplification

Last week I had a frustrating exchange with an acquaintance over the safety of the COVID-19 vaccine.

He'd posted on social media a meme with the gist that there'd been so much waffling and we're-not-sure-ing by the medical establishment that you couldn't trust anything they said.  I guess he'd seen me post something just a few minutes earlier and knew I was online, because shortly afterward he DMd me.

"I've been waiting for you to jump in with your two cents' worth," he said.

I guess I was in a pissy mood -- and to be honest, anti-vaxx stuff does that to me anyhow.  I know about a dozen people who've contracted COVID, two of whom died of it (both members of my graduating class in high school), and in my opinion any potential side-effects from the vaccine are insignificant compared to ending your life on a ventilator.

"Why bother?" I snapped at him.  "Nothing I say to you is going to make the slightest bit of difference.  It's a waste of time arguing."

He started in on how "he'd done his research" and "just wasn't convinced it was safe" and "the medical establishment gets rich off keeping people sick."  I snarled, "Thanks for making my point" and exited the conversation.


It's kind of maddening to be told "I've done my research" by someone who not only has never set foot in a scientific laboratory, but hasn't even bothered to read peer-reviewed papers on the topic.  Sorry, scrolling through Google, YouTube, and Reddit -- and watching Fox News -- is not research.

Unlike a lot of anti-science stances, this one is costing lives.  Every single day I see news stories about people who have become grievously ill with COVID, and whose relatives tell tearful stories after they died about how much they regretted not getting the vaccine.  Today's installment -- from a man in Tennessee who has been in the hospital for three weeks and is still on oxygen -- "They told us not to worry, that it was just a bad cold.  They lied."

The problem is -- like my acquaintance's stubbornly self-confident "I've done my research" comment -- fighting this is a Sisyphean task.  If you think I'm exaggerating, check out the paper that came out this week in Journal of the European Economic Association, about some (actual, peer-reviewed) research showing that not only do we tend to gloss over evidence contradicting our preferred beliefs, when we then share those beliefs with others, our certainty we're right increases whether or not the people we're talking to agree with us.

The phenomenon, which has been called bias amplification, is like confirmation bias on steroids.  "This experiment supports a lot of popular suspicions about why biased beliefs might be getting worse in the age of the internet," said Ryan Oprea, who co-authored the study.  "We now get a lot of information from social media and we don't know much about the quality of the information we're getting.  As a result, we're often forced to decide for ourselves how accurate various opinions and sources of information are and how much stock to put in them.  Our results suggest that people resolve this quandary by assigning credibility to sources that are telling us what we'd like to hear and this can make biases due to motivated reasoning a lot worse over time."

I don't even begin to know how to combat this.  The problem is, most laypeople (and I very much include myself in this) lack the expertise to comprehend a lot of peer-reviewed research on immunology, which is usually filled with technical jargon and abstruse details of biochemistry.  And every step you take away from the actual research -- from university or research-lab press releases, to summaries in popular science magazines, to blurbs in ordinary media, to Some Guy's blog -- introduces more opinions, oversimplifications, and outright misinformation.

And I'm completely aware that Skeptophilia is also Some Guy's blog.  I will say in my own defense, however, that I do try to base what I write on the actual research, not on Tucker Carlson quoting Nicki Minaj's tweets about how her boyfriend got the COVID vaccine and afterward his balls swelled up.  (No, I am not making this up.)

So that's today's rather discouraging scientific study.  It's sad that so many of us have to become gravely ill, or watch someone we love die in agony, before we'll admit that we might have been wrong.  I'll just end with what the research -- from the scientists themselves -- has to say: the COVID vaccines are safe and effective, and the vast majority of people who have had severe COVID are unvaccinated.  The "breakthrough cases" of vaccinated people testing positive almost never result in hospitalization, and when they do, it's because of comorbidities.

But don't take my word for it.  If you honestly want to know what the research says, and you're willing to keep an open mind on the topic and shape your opinion based upon the evidence, start here.  And after that, go out and get the fucking vaccine.

Seriously.

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

London in the nineteenth century was a seriously disgusting place to live, especially for the lower classes.  Sewage was dumped into gutters along the street; it then ran down into the ground -- the same ground from which residents pumped their drinking water.  The smell can only be imagined, but the prevalence of infectious water-borne diseases is a matter of record.

In 1854 there was a horrible epidemic of cholera hit central London, ultimately killing over six hundred people.  Because the most obvious unsanitary thing about the place was the smell, the leading thinkers of the time thought that cholera came from bad air -- the "miasmal model" of contagion.  But a doctor named John Snow thought it was water-borne, and through his tireless work, he was able to trace the entire epidemic to one hand-pumped well.  Finally, after weeks and months of argument, the city planners agreed to remove the handle of the well, and the epidemic ended only a few days afterward.

The work of John Snow led to a complete change in attitude toward sanitation, sewers, and safe drinking water, and in only a few years completely changed the face of the city of London.  Snow, and the epidemic he halted, are the subject of the fantastic book The Ghost Map: The Story of London's Most Terrifying Epidemic -- and How It Changed Cities, Science, and the Modern World, by science historian Steven Johnson.  The detective work Snow undertook, and his tireless efforts to save the London poor from a horrible disease, make for fascinating reading, and shine a vivid light on what cities were like back when life for all but the wealthy was "solitary, poor, nasty, brutish, and short" (to swipe Edmund Burke's trenchant turn of phrase).

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


Wednesday, September 15, 2021

Acoustic illusions

Some years ago I was in a musical trio called Alizé that specialized in traditional French folk music.  One weekend we played a gig at a local music festival, and we were approached by a very nice fellow named Will Russell who told us how much he'd enjoyed our playing -- and said he thought we should record an album.

Will is no amateur music enthusiast.  He runs Electric Wilburland, a recording studio in Newfield, New York, not far from where I live.  Will is a Grammy-winning sound engineer, and as we soon found out, is truly gifted at making musicians sound their absolute best.  He also has some nifty tricks up his sleeve, which we discovered when we were working on the audiofile for a four-tune medley we'd just recorded.

"What's your concept for this one?" Will asked.

We explained to him that the first tune is solemn, almost religious-sounding, and it gradually ramps up until reaching a peak in the last tune, a lightning-fast dance tune called "Gavotte des Montagnes."

"So we start out in church," our guitarist explained, "then there's the recessional... then there's the party."

Will frowned thoughtfully.  "Okay, for the first bit, in church.  Do you know what church you want it to be in?"

I thought he was joking.

"No, really," he explained.  "I have acoustic sampling from a bunch of different cathedrals.  Do you want to sound like you're in St. Paul's?  Or York Minster?  Or Chartres Cathedral?  Or...?"

"No way," I said.

He proceeded to play our track to us, applying the acoustics of various different cathedrals.  We ended up picking Chartres, not only because it sounded awesome, but because it seemed appropriate for a French song.

[Image licensed under the Creative Commons Marianne Casamance, Chartres - Cathédrale 16, CC BY-SA 3.0]

With all due modesty -- and with many thanks both to Will and to my bandmates -- the album (titled Le Canard Perdu) came out sounding pretty cool, and if you're so inclined, it's available on iTunes.

The topic comes up because of a paper this week in Science Advances by a team led by Theodor Becker of ETH Zürich, which has looked at the question of how we know what kind of space we're in acoustically, and then seeing if there's a way to mimic that by altering the qualities of the sound -- characteristics like reverb, interference patterns between whatever's producing the sound and the various echoes from surfaces, and so on.  The ultimate goal is to achieve whatever kind of acoustic illusion you want, from being in a particular cathedral to being underwater to having the echoes (or even the original sounds) cloaked entirely.

I don't pretend to understand the technical bits; but the results are mind-boggling.  The authors write:

[W]e demonstrate in 2D acoustic experiments that a physical scattering object can be replaced with a virtual homogeneous background medium in real time, thereby hiding the object from broadband acoustic waves (cloaking).  In a second set of experiments, we replace part of a physical homogeneous medium by a virtual scattering object, thereby creating an acoustic illusion of an object that is not physically present (holography).  Because of the broadband nature of the control loop and in contrast to other cloaking approaches, this requires neither a priori knowledge of the primary energy source nor of the scattered wavefields, and the approach holds even for primary sources, whose locations change over time.

The military applications of this technology are apparent; cloaking the sound of a surveillance device (or other piece of equipment), or creating the illusion that it's something (or somewhere) else, are of obvious utility in military settings.  As a musician, I'm more interested in the creative aspects.  The ability to create what amount to acoustic illusions is a significant step up from Will's already-impressive magic trick of teleporting us to Chartres Cathedral.

The purists in the studio audience are probably bouncing up and down in their chairs with indignation at the idea of further mechanizing the process of making (and recording) music.  I've heard plenty of musicians decrying the use of features like auto-tune -- the usual objection being that it allows second-rate singers to tune up electronically and sound way better than they actually are.

No doubt it's sometimes used that way, but I'll throw out there that like any technology for enhancing the creative process, it can be used as a cheat or it can be used to further expand the artistry and impact of the performance.  One example that immediately comes to mind is the wild, twisty use of auto-tune in Imagine Dragons' brilliantly surreal song "Thunder:"


But for innovative use of technology in music, there's no one better than the amazing British singer Imogen Heap.  Check out her use of looping for this mind-boggling --and live -- performance of her song "Just for Now:"


I've been a musician for forty years and have been up on stage more times than I can even begin to estimate, and I can't imagine having the kind of coordination to pull off something like that in front of a live audience.

So I find the Becker et al. paper exciting from a number of standpoints.  When you think about it, musicians have been experimenting with new technology all along, and not just with electronic tinkering.  Every time a new musical instrument is invented -- regardless if it's a viola da gamba or a theremin -- it expands what kind of auditory experience the listener can have.  When electronic music first gained momentum in the 1960s with pioneers like Wendy Carlos and Isao Tomita, it elicited a lot of tut-tutting from the classical music purists of the day -- but now just about everyone recognizes them for their innovative genius.  Masterpieces like Carlos's Switched-On Bach and The Well-Tempered Synthesizer and Tomita's Firebird and The Snowflakes are Dancing have rightly taken their place amongst the truly great recordings of non-standard performances of classical music.

I'll be interested to see where all this leads.  I'll end with a quote from Nobel-Prize-winning biochemist Albert Szent-Györgyi.  He was speaking about science, but it could apply equally well to any creative endeavor.  "Discovery consists of seeing what everyone has seen, and thinking what nobody else has thought."

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

London in the nineteenth century was a seriously disgusting place to live, especially for the lower classes.  Sewage was dumped into gutters along the street; it then ran down into the ground -- the same ground from which residents pumped their drinking water.  The smell can only be imagined, but the prevalence of infectious water-borne diseases is a matter of record.

In 1854 there was a horrible epidemic of cholera hit central London, ultimately killing over six hundred people.  Because the most obvious unsanitary thing about the place was the smell, the leading thinkers of the time thought that cholera came from bad air -- the "miasmal model" of contagion.  But a doctor named John Snow thought it was water-borne, and through his tireless work, he was able to trace the entire epidemic to one hand-pumped well.  Finally, after weeks and months of argument, the city planners agreed to remove the handle of the well, and the epidemic ended only a few days afterward.

The work of John Snow led to a complete change in attitude toward sanitation, sewers, and safe drinking water, and in only a few years completely changed the face of the city of London.  Snow, and the epidemic he halted, are the subject of the fantastic book The Ghost Map: The Story of London's Most Terrifying Epidemic -- and How It Changed Cities, Science, and the Modern World, by science historian Steven Johnson.  The detective work Snow undertook, and his tireless efforts to save the London poor from a horrible disease, make for fascinating reading, and shine a vivid light on what cities were like back when life for all but the wealthy was "solitary, poor, nasty, brutish, and short" (to swipe Edmund Burke's trenchant turn of phrase).

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


Tuesday, September 14, 2021

Unknown unknowns

One of my college physics professors made a statement to his class that was mind-boggling in its inaccuracy.  We'd been learning about the subatomic particles, and he was telling us about the smallest pieces of matter known: quarks.  Physicists had given the different types of quarks fanciful names -- up, down, top, bottom, charmed, strange.  His commentary was something of a sneer: "When scientists spend their times giving ridiculous names to physical phenomena, you know there must not be much in the way of new things waiting to be studied."

Even at the time -- I was about twenty -- it seemed humorless and mean-spirited to claim that just because scientists are having a little fun with naming stuff, they're wasting their time playing around rather than engaging in actual science.  Much later, I ran into Lord Kelvin's statement along the same line, that "There is nothing new to be discovered in physics now.  All that remains is more and more precise measurement."  

The problem was that Kelvin said this in 1900 -- immediately before Einstein and Schrödinger turned all of physics on its head with the theories of relativity and quantum mechanics, respectively.

So saying "there's nothing left to study" is not only arrogant, it's entirely inaccurate.  The preposterous implication is that right now we have a good idea of how much is left that we don't know.  It reminds me of Donald Rumsfeld's much-ridiculed statement about "known knowns, known unknowns, and unknown unknowns."  Yeah, he could have phrased it a little better, but honestly, he had a point.  There isn't any way to estimate the extent of what we're not even aware that we don't know.  The only thing we can go by is the history of science -- which pretty clearly shows that every time we think we have everything explained, the universe steps in a with a well-aimed dope slap.

I started thinking about all this because of a press release in Science Alert about a mysterious radio source near the center of the Milky Way that has astrophysicists scratching their heads.  To quell the immediate reaction a lot of folks are having, no one at this point is saying anything about aliens, or at least no one with any credibility.  But the behavior of the source is odd enough even without bringing in the Daleks or the Andorians or the Stenza or whoever your favorite extraterrestrial bad guys are.

The radio source is euphoniously named ASKAP J173608.2-321635.  (I wonder if my long-ago physics professor would have approved of that name as sufficiently serious.)  The radio emissions from ASKAP-etc. are odd in a variety of respects.  The source emits radio waves for weeks, then will suddenly "turn off" for a while before just as suddenly beginning to shine again.  The electromagnetic radiation from it is highly polarized -- the waves line up, all vibrating in the same direction, like a bunch of people creating waves in long springs, and everyone oscillating the springs up-and-down rather than each spring moving in some randomly-chosen plane of vibration.

The source was discovered through a collaboration between the Australian Square Kilometre Array Pathfinder (that's where "ASKAP" comes from) and the  MeerKAT radio telescope, near Cape Town, South Africa (speaking of whimsical names; the "KAT" part of the name stands for "Karoo Array Telescope;" "meer" is Afrikaans for "more."  It also, of course, riffs on the name of the comical little African mammal of the same name).  This isn't the first time this combo has found something strange.  Earlier this year, they found another yet-to-be-explained interstellar object, the aptly-named "Odd Radio Circles" that have bright edges and dimmer interiors, like giant gossamer soap bubbles.

A MeerKAT image of the center of the Milky Way, as viewed in radio wavelengths

Astrophysicists have considered a number of explanations for these strange objects, and so far, none of them have panned out.  "Possible identifications [include] a low-mass star/substellar object with extremely low infrared luminosity, a pulsar with scatter-broadened pulses, a transient magnetar, or a Galactic Center Radio Transient," the research team writes, "[but] none of these fully explains the observations, which suggests that ASKAP J173608.2-321635 may represent part of a new class of objects being discovered through radio imaging surveys."

So once again, we're confronted with how little we know.  We've come a long way, there's no doubt about that; our scientific achievements as a species are pretty damn impressive, especially considering that serious research has only been going on for a couple of centuries of the tens of thousands of years humans have been at least somewhat technological.  But there will always be more mysteries to solve, more puzzles to put together, more questions to ask.

I'll end with a quote from astrophysicist John Bahcall, whose research into the behavior and properties of neutrinos in the 1960s gave us a new window into why stars shine:

I do not personally want to believe that we already know the equations that determine the evolution and fate of the universe; it would make life too dull for me as a scientist…  I hope, and believe, that the Space Telescope might make the Big Bang cosmology appear incorrect to future generations, perhaps somewhat analogous to the way that Galileo’s telescope showed that the earth-centered, Ptolemaic system was inadequate...  Every time we get slapped down, we should thank Mother Nature -- because we're about to learn something important.

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London in the nineteenth century was a seriously disgusting place to live, especially for the lower classes.  Sewage was dumped into gutters along the street; it then ran down into the ground -- the same ground from which residents pumped their drinking water.  The smell can only be imagined, but the prevalence of infectious water-borne diseases is a matter of record.

In 1854 there was a horrible epidemic of cholera hit central London, ultimately killing over six hundred people.  Because the most obvious unsanitary thing about the place was the smell, the leading thinkers of the time thought that cholera came from bad air -- the "miasmal model" of contagion.  But a doctor named John Snow thought it was water-borne, and through his tireless work, he was able to trace the entire epidemic to one hand-pumped well.  Finally, after weeks and months of argument, the city planners agreed to remove the handle of the well, and the epidemic ended only a few days afterward.

The work of John Snow led to a complete change in attitude toward sanitation, sewers, and safe drinking water, and in only a few years completely changed the face of the city of London.  Snow, and the epidemic he halted, are the subject of the fantastic book The Ghost Map: The Story of London's Most Terrifying Epidemic -- and How It Changed Cities, Science, and the Modern World, by science historian Steven Johnson.  The detective work Snow undertook, and his tireless efforts to save the London poor from a horrible disease, make for fascinating reading, and shine a vivid light on what cities were like back when life for all but the wealthy was "solitary, poor, nasty, brutish, and short" (to swipe Edmund Burke's trenchant turn of phrase).

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


Monday, September 13, 2021

A genetic mixed bag

One of the subtlest features of the evolutionary model, and one often misunderstood even by people who understand and accept natural selection, is what we mean by "selective advantage."

On the surface, it's simple enough; any inheritable feature that confers longer, healthier life or more (and more vigorous) offspring.  The problem is, there are two twists on phenotype that make this a bit more complicated than it seems at first.

The first is that physical expression of genes is seldom unequivocally either good or bad for the organism.  The "unequivocally bad" ones are often discussed in introductory biology classes because they are simple; Tay-Sachs disease, for example, caused by inheriting a particular recessive allele from both parents, kills the brain cells and usually causes death by age four.  But most traits have good features and bad, so the question becomes, "Is this good for the organism on balance?"  One instance is our upright posture and bipedal gait.  It confers some advantages -- two of the more commonly-cited ones are leaving our hands free to manipulate tools, and giving us greater sight-distance for spotting predators.  (Nota bene: no one's sure which of those advantages led to our ancestors walking upright, or if it was something else entirely; saying "these are some of the advantages" is not the same as saying "these were the advantages that drove selection for this trait.")  The downside of upright posture, though -- given that we still have the basic spine shape as our knuckle-walking forebears -- is that humans have some of the worst lower back problems to be found in the animal world, with the only ones having it worse being Bassett hounds and dachsunds.

And the low-slung backs of Bassetts and wiener dogs are hardly the fault of natural selection.

Another complicating factor is pleiotropy -- which is that many genes have multiple effects, often only loosely related to each other.  The classic example of pleiotropy is the connection between coat and eye color, and inner ear development, in cats.  White, blue-eyed cats are frequently deaf -- the same gene that blocks pigment formation (and causes the white coat and blue eyes) hinders development of the cochlea, resulting in deafness.

What makes it even more complex is that sometimes a gene can have a drastically different set of effects depending on whether you have one copy (are heterozygous) or two (are homozygous).  It was long a puzzle of evolutionary science why some deleterious recessive genes are so common.  If having two copies of a gene kills you, effectively removing two copies of the allele from the gene pool, you'd expect the frequency of the allele to decrease over time.  So why do some really nasty genes stick around?

[Image is in the Public Domain]

Two examples where we've actually figured out the answer are the genes that cause cystic fibrosis (a horrible lung disease which is one of the more common serious genetic disorders in Caucasians) and sickle-cell anemia (an equally-dreadful blood disorder common in sub-Saharan Africans and African Americans).  While having two copies of either of those genes is certainly awful, having only one is beneficial, giving the individual an advantage over both the ones who have two bad copies and the ones who have two good copies of the allele.  In the case of cystic fibrosis, being heterozygous gives infants a significantly lower chance of contracting infantile diarrheal disease, which in cultures with limited access to medical care is a major killer of babies.  In sickle-cell anemia, having one copy of the allele gives you resistance to malaria -- so in malaria-ridden areas, homozygous recessive people die of sickle-cell anemia, and homozygous dominant people die of malaria.  Heterozygous individuals escape both.

Even seemingly unimportant genes can sometimes have unexpected effects.  It was long thought that the blood-type alleles -- nicknamed A, B, and O -- had no effect on anything other than blood transfusion compatibility.  It was recently discovered that the O blood type allele, which is the most common, confers resistance to smallpox.  So in areas that had smallpox epidemics, the individuals who were type A (the most susceptible allele) were much more likely to die, leaving the type Os at a significant selective advantage.  A map of the incidence of smallpox in Europe and a map of the frequency of the O blood type allele line up almost perfectly.

The reason all this comes up is because of a paper last week in the journal Development that looked at a rather horrifying genetic disorder called holoprosencephaly, where something interferes with prenatal forebrain development.  Affected children end up with malformed brains and multiple facial disfigurements -- cleft palate, cleft lip, and eyes that are extremely close together (in fact, sometimes they're fused).  These babies almost always die in utero.

Geneticists at the Max Delbrück Center for Molecular Medicine found two mutations that influenced the development of holoprosencephaly, which are called ULK4 and PTTG1.  Both of these genes regulate expression of the ultra-important sonic hedgehog gene, which is responsible for organ formation, nervous system development, and such fundamental features as symmetrical limb placement.  The researchers found that these two genes prevent holoprosencephaly, which you'd think would be enough of an advantage that it would eventually lead them to becoming fixed (everyone in the population being homozygous) except for rare cases of mutations.

Where it gets more interesting is that the researchers found that ULK4 and PTTG1 have other effects besides stopping holoprosencephaly in its tracks.  ULK4 is associated with schizophrenia and bipolar disorder -- and PTTG1 is linked to cancer.

So like cystic fibrosis and sickle-cell anemia, it's not as simple as saying "this allele is the good one, and this is the bad one."  And because both of the negative effects of ULK4 and PTTG1 affect individuals later in life, very likely after they have made the decision whether to have kids, the positive effect (surviving gestation) far outweighs the negative ones, at least from an evolutionary standpoint.

As I used to tell my AP Biology classes, "evolution doesn't really give a damn what happens to you after you've successfully procreated."  Harsh, but true in its essence.

So genetics and evolution are, like most things, a mixed bag.  They're a lot more complicated than they may seem at first, enough that it's kind of impressive researchers have been able to figure out how they work.  Considering what could potentially go wrong with development, I'm kind of blown away by how often things go right.  When my first wife found out she was pregnant, I spent the next eight or so months worrying, because I knew enough genetics to realize how bad things could be.  When my older son was born -- completely normal, except that he looks exactly like me, which is unfortunate but not fatal -- it was an incredible relief.

It may not be true that "a little knowledge is a dangerous thing," but sometimes it can be a bit stress-inducing.

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London in the nineteenth century was a seriously disgusting place to live, especially for the lower classes.  Sewage was dumped into gutters along the street; it then ran down into the ground -- the same ground from which residents pumped their drinking water.  The smell can only be imagined, but the prevalence of infectious water-borne diseases is a matter of record.

In 1854 there was a horrible epidemic of cholera hit central London, ultimately killing over six hundred people.  Because the most obvious unsanitary thing about the place was the smell, the leading thinkers of the time thought that cholera came from bad air -- the "miasmal model" of contagion.  But a doctor named John Snow thought it was water-borne, and through his tireless work, he was able to trace the entire epidemic to one hand-pumped well.  Finally, after weeks and months of argument, the city planners agreed to remove the handle of the well, and the epidemic ended only a few days afterward.

The work of John Snow led to a complete change in attitude toward sanitation, sewers, and safe drinking water, and in only a few years completely changed the face of the city of London.  Snow, and the epidemic he halted, are the subject of the fantastic book The Ghost Map: The Story of London's Most Terrifying Epidemic -- and How It Changed Cities, Science, and the Modern World, by science historian Steven Johnson.  The detective work Snow undertook, and his tireless efforts to save the London poor from a horrible disease, make for fascinating reading, and shine a vivid light on what cities were like back when life for all but the wealthy was "solitary, poor, nasty, brutish, and short" (to swipe Edmund Burke's trenchant turn of phrase).

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