A cataclysmic pirouette

Hamlet famously states to his friend, "There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy," and every time we look into the night sky, we're reminded how true that is.

In the last hundred years astronomers have discovered deadly gamma-ray bursters and black holes, neutron stars for which a teaspoon of their material would weigh as much as a mountain, planets made of stormy swirls of ammonia, methane, and hydrogen, ones made of super-hot molten metal, water-worlds completely covered with deep oceans.  We've seen newborn stars and stars in their violent death throes, looked out in space and back in time to the very beginning, when the universe itself was in its infancy.

Even with all these wonders, new and bizarre phenomena are still being discovered every time our technology improves.  Take, for example, the "cataclysmic variable" that was the subject of a paper in Nature this week, a pair of stars locked in such a tight dance that they whirl around their common center of gravity in only fifty-one minutes.

Given the euphonious name ZTF J1813+4251, this pair of stars is comprised of a white dwarf -- the burnt-out core of a low-mass star like the Sun -- and an even more lightweight star not much bigger than the planet Jupiter.  The white dwarf has been swallowing (the astronomical term is "accreting") the hydrogen fuel from its partner, and they're drawing closer together, meaning that the process will speed up.  Eventually all that will be left of the partner star will be its core, and astronomers predict that at that point, they will have an orbital period of eighteen minutes.  But once the accretion process ends, drag in the pair's movement will rob energy from the system, the wild stellar pirouette will slow down, and they will gradually start to move apart again.

It's fortunate that the partner star is as light as it is; if it had more mass, it would be headed toward one of the most violent fates a star can have -- a type 1a supernova.  White dwarfs are the remnants of stars that have exhausted all their fuel, and they shrink until the inward pull of gravity is counterbalanced by the mutual repulsion of the negatively-charged electrons that surround the atoms they're made of.  There's a limit, though, to how much this repulsive force can withstand; it's called the Chandrasekhar limit, after its discoverer Subrahmanyan Chandrasekhar, and is equal to 1.44 solar masses.  For a lone white dwarf -- as our Sun will one day be -- this is not a problem, as there won't be anything substantial adding to its mass after it reaches that point.

The situation is different when a low-mass star is in a binary system with a giant star.  When the low-mass star burns out and becomes a white dwarf, it begins to rob its partner of matter -- just as ZTF J1813+4251 is doing.  But in this case, there is a lot more mass there to rob.  Eventually, the white dwarf steals enough matter from its companion to go past the Chandrasekhar limit, and at that point, the mutual repulsion of the electrons in the stars atoms lose their contest with the inward pull of gravity.  The white dwarf's core collapses completely, making the temperature skyrocket so high that its helium ash can fuse into carbon and other heavier elements, suddenly releasing catastrophic amounts of energy.  The result is...

... boom.

In the process, the matter from the exploded dwarf star is scattered around the cosmos, and becomes the parent material for forming planets.  It is, in fact, how most of the carbon, oxygen, and nitrogen in our bodies were formed.

As Carl Sagan famously said, "We are made of starstuff."

A type 1a supernova remnant [Image is in the Public Domain courtesy of NASA/JPL]

But ZTF J1813+4251 isn't headed for such a dramatic exit -- eventually the white dwarf will pull away the outer layers of the partner star's atmosphere, and after that the two will just spiral around each other wildly for a few million years, gradually cooling and slowing from their current frenetic pace.  So maybe "cataclysmic" isn't the right word for this pair; their crazy tarantella will simply wind down, leaving two cold clumps of stellar ash behind.

Honestly, if I were a star, I think I'd rather go out with a bang.

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The face of evil

I just finished a book that I'm going to be thinking about for a very long time; Alice Oseman's wonderful, devastating, beautiful, heartbreaking, and ultimately triumphant novel Radio Silence.

What has kept my mind coming back to the story over and over since closing the last page is not the pair of main characters, Frances Janvier and Aled Last, as well-drawn and engaging as they are; it's a minor character -- at least judging by the number of scenes in which she actually appears -- Aled's mother, Carol Last, whose influence pervades the entire story like some kind of awful miasma.

She's not what I would call "big evil."  Mrs. Last is no Sauron, no Darth Vader, no Jadis the White Witch.  She has no desire to rule the world and mow down thousands.  Her evil is so small as to be almost banal.  She "redecorates" Aled's room while he's away at school, destroying all of his posters and adornments, even painting over the mural of a galaxy he'd created on his ceiling, replacing it with a blank white surface.  She has his old dog put down without his knowledge, without even a chance to say goodbye.  She sends him a saccharine text every single time he makes a new episode of his beloved podcast, about spending his time in more productive pursuits instead of his "silly little show."  She takes her daughter's "inappropriate" clothing and burns it in the back yard, right in front of her.

And each and every time, she has an unshakable justification for why she does what she does.  There's always a reason, and any objections have about as much effect on her as an ocean wave striking a cliff face.  In the most chilling scene in the whole book, Mrs. Last proudly shows Frances what she's done to Aled's room while he's away, saying with a tight little smile, "It's just a few little rearrangements here and there.  I'm sure he'll appreciate a change...  Feels very fresh, don't you think?  A cleaner, emptier space makes a cleaner, sharper mind."

She doesn't even listen for Frances's response; of course the answer is yes.

For the Mrs. Lasts of the world, the answer is always yes.

It's a tribute to Alice Oseman's skill as a novelist that my response to Mrs. Last was as strong as it was.  But why we all feel revulsion at such a character is telling.  It's like an analysis I read a while back of why the most hated character in the Harry Potter universe isn't Lord Voldemort -- far and away, it's Dolores Umbridge.  

Very few of us, fortunately, ever meet a Lord Voldemort.

But all of us know a Dolores Umbridge.  A teacher, a boss, a family member, a significant other, an acquaintance who, given a little power, uses it to tear down the souls of the vulnerable or dependent, and remodel them to suit.  A person who couches it all with a sweet smile that never reaches the eyes and a declaration of, "You know it's all for your own good, dear."

This, for most of us who have read the Potter series, is the real face of evil, not the grotesque, distorted visage of Lord Voldemort.

I know a lot of the reason that both Dolores Umbridge and Mrs. Last made me as sick at heart as they did is that my own childhood was laced through with this sort of thing.  Nothing as overt as what Dolores did to Harry or what Mrs. Last did to her children, perhaps; but the message I got was nothing if not consistent.  "You can't possibly like that music/television show/book/movie, can you?"  "Why are you wasting your time with that?"  "Mrs. So-and-So's son has accomplished so much, she must be so proud of him.  Maybe you should try following his example."  "Why bother with that?  You'll just give up in three weeks when you find out how hard it is."  And, most pervasively, over and over again, "No one wants to hear about that," whenever I talked about what I cared most deeply about, what I was passionate about.

My response was much like Aled's in Radio Silence; hide.  Protect what I loved so it wouldn't be destroyed.  It came out in uglier ways, sometimes; I did my own share of mistreating those who were vulnerable, to my everlasting shame, living up to my grandma's wise if tragic words that "hurt people hurt people."  I became secretive, angry, and deeply despondent.

And it took me years to admit that this subversive attempt to demolish who I actually was and rebuild some new, improved version was nothing short of emotional abuse.

That the Mrs. Lasts in my own life didn't win was more due to luck than anything I did to stop them.  For the past twenty years especially I have been fortunate enough to have people in my life who are determined to nurture rather than destroy, and I can say truly that they saved my life, both figuratively and literally.  

I'll end this post with an exhortation to be that for the people around you; do not ever underestimate the power of simply appreciating and loving those you meet for who they are, embracing their weird, unique wonderful selves without feeling any need to change them.  Drop the desperate need to hem people in, to make them conform to some arbitrary standards of how they dress, what they eat, what music and books and shows they love.  Thank heavens we don't all feel passionate about the same stuff, right?  How boring would it be if every last person had exactly identical tastes, loves, opinions, and obsessions?

I'll end with a quote from someone I've quoted here many times before: journalist Kathryn Schulz, whose astonishing TED Talk "On Being Wrong" should be required listening for everyone.  Toward the end, she has an observation about why different perspectives don't imply that one person is right and the other is wrong -- and how sterile the world would be if that were true:

But to me, what's most baffling and most tragic about this is that it misses the whole point of being human.  It's like we want to imagine that our minds are these perfectly transparent windows and we just gaze out of them and describe the world as it unfolds.  And we want everybody else to gaze out of the same window and see the exact same thing.  That is not true, and if it were, life would be incredibly boring.  The miracle of your mind isn't that you can see the world as it is.  It's that you can see the world as it isn't.  We can remember the past, and we can think about the future, and we can imagine what it's like to be some other person in some other place.  And the most beautiful part is that we all do this a little differently.

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Putting Christ back in... Halloween?

Every year about this time, evangelicals start stepping up the pressure on Christians to discourage them and their children from participating in Halloween, an event that they see as celebrating Satan.  Some of the devout even believe that demonic curses can be transmitted via Halloween candy.  This has made the candy manufacturers sit back, in the fashion of Jabba the Hutt, and say, "Your fundamentalist mind-tricks will not work on us.  Bo shuda."  Then they give a nasty throaty chuckle and respond by bringing out the Halloween candy even earlier each year, until eventually they'll be putting out next year's candy on November 1 of this year.

Most of the rest of us just seem to find the whole thing unintentionally hilarious.

[Image licensed under the Creative Commons Paul Hermans, Halloween in Uikhoven 27-10-2020 19-07-07, CC BY-SA 4.0]

The evangelicals, who in this fight see themselves in the role of Luke Skywalker, are not going to give up and let themselves be eaten by the Sarlacc (i.e. Satan), so every year, they gird their loins and prepare for battle.  This year's sortie, which I swear am not making up, is called "JesusWeen."  At first I thought, especially given the cringe-y name, that this was some sort of parody site intended to ridicule the fear-mongering, but it seems to be entirely serious.  Meant to encourage Christians to do something more than hiding inside and locking the doors on Halloween, JesusWeen suggests some bold and proactive steps, to wit:

• handing out Bibles or scripture verses instead of candy;
• putting up signs in your town, encouraging people to give up participating in Halloween;
• having prayer circles with neighborhood children instead of joining in trick-or-treating;
• and going door-to-door on Halloween night, evangelizing and trying to get the demonic-candy purveyors to see the error of their ways.

All of which makes me wonder if these people have ever met any actual children.  I don't know about you, but when I was a kid, if my friends and I had gone trick-or-treating, and a family had handed out scripture verses instead of mini-Milky Way bars, they would still be trying to find their house underneath the mass of toilet paper.

You have to kind of admire the JesusWeen people for their Daniel-in-the-lions'-den approach to winning a battle against impossible odds.  And however medieval their beliefs seem to be, no one can accuse them of being in the Dark Ages with respect to electronic networking. They have a JesusWeen chat, are on Twitter (@JesusWeen), and have several videos on YouTube.  They seem quite optimistic -- their website says, "Jesus Ween (Oct 31st) is expected to become the most effective Christian outreach day ever and that's why we also call it 'World Evangelism JesusWeen Venue: In Every Country, Every City, Every Street, Every Home.'"

I dunno.  That seems kind of like wishful thinking to me.  I'm doubting that Bibles are ever going to be the draw for kids that candy is.  My guess is that no one who wasn't already a believer is going to have some kind of epiphany because of JesusWeen, and once you get a reputation for inviting trick-or-treating kids into your house for a prayer circle, you probably won't be getting many visitors on Halloween night, except maybe the police.

So that's the news from the evangelical movement.  Whatever else you can say about these people, they're consistent -- once they decide something, they follow through.  I almost hope that we have some show up at our door on Halloween night, just for the amusement value.  Maybe I'll hand out Richard Dawkins books.

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A singular scientist

Science has become the realm of specialists, and I am by nature a thoroughgoing generalist.  (Less kind words like "dilettante" and "dabbler" have also been applied to me.)  The result is that although I have a decent background in a good many areas of science, my knowledge of most of them is shallow at best by today's standards.  Even though I taught biology for over three decades, papers in peer-reviewed journals in most realms of biological science -- immunology and biochemistry come to mind -- lose me after the first couple of sentences.

One exception is the field of evolutionary biology and its sibling, evolutionary genetics.  These subjects have been something of a fascination of mine since I was in college, and looking back, I rather wish I had pursued them as a career.  My AP Biology students always reacted with tolerant amusement at my obvious excitement once we got to those topics, so at least my background was put to some good use.

This love for evolution and genetics is why I was absolutely thrilled when I heard that the winner of this year's Nobel Prize in Medicine and Physiology was the eminent Swedish researcher Svante Pääbo.  Pääbo is the founder of the field of paleogenetics -- the use of DNA from fossils to reconstruct the evolutionary history of a species.

[Image licensed under the Creative Commons The Royal Society, Professor Svante Paabo ForMemRS, CC BY-SA 4.0]

Pääbo is best known for his accomplishing something no one thought was possible: extracting DNA from fossilized bones.  His attitude when told something is impossible is, "Watch me."  Working at the Max Planck Institute for Evolutionary Genetics in Leipzig, Germany, he developed a pioneering technique to extract DNA from bones, first the mt (mitochondrial) DNA, which is passed only through the maternal line, and finally the nuclear DNA.

It was Pääbo's technique that allowed researchers to determine the placement of our near relatives the Neanderthals and Denisovans, the latter using only eight fossil fragments from sites in Russia, China, and northern Laos.  Without Pääbo's work, much of what we know about our own prehistory would still be a mystery.

Pääbo is also a remarkably humble, genial man.  When he received the call of his win, he was incredulous, and thought he was the victim of a prank by his friends.  A bit of questioning established that no, he had in fact clinched the highest honor in the scientific world.  Characteristically, in a press conference shortly afterward, he directed the attention outward from himself to the subject he loves.  "The thing that is amazing to me," he said, "is that we now have some ability to go back in time and actually follow genetic history and genetic changes over time."

Others were more effusive about the contributions of this soft-spoken gentleman.  "Nobody believed him [about extracting fossil DNA]," said Leslie Vosshall, neuroscientist at Rockefeller University.  "Everyone thought it was contamination or broken stuff  from living people.  Just the mere fact that he did it was so improbable.  That he was able to get the complete genome sequence of a Neanderthal was viewed, even up until he did it, as an absolutely impossible feat...  He's a singular scientist."

Indeed.  I remember reading papers by Pääbo and his colleague, the late Luigi Luca Cavalli-Sforza, when I was in graduate school, and being absolutely fascinated by the light they shone on the genetic underpinnings of evolutionary biology.  That one of my science heroes won the Nobel Prize makes me very, very happy.  

I congratulate him, and wish him many more years of blowing our minds with his groundbreaking research into our own deep past.

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I'm so blue

Since we haven't looked at loopy claims from the alternative health crowd in a while, today we're going to check out a site that tells you how to make "Blue Solar Water."

According to the site with the euphonious name "Ho'oponopono," making "Blue Solar Water" is simple.  Here's how a "Blue Solar Water" enthusiast, Mabel Katz, explains it:

1. Get a blue glass bottle.  Any color blue, from light blue to dark blue will work.
2. Fill with tap water and cover with a non-metallic lid -- cork, plastic, even cloth wrapped with a rubber band will work because the purpose of the lid is just to keep the dirt and bugs (that Love Blue Solar Water) out.
3. Place in the Sun for an hour or more.  Mabel comments that when left longer, it is sweeter.
4. When done, your Blue Solar Water can be stored in the refrigerator in any container -- glass, plastic, etc.
5. ENJOY!  How Much Blue Solar Water to drink?  Dr. Ihaleakala Hew Len once shared that, for the sole purpose of CLEANING memories, he drinks a gallon and a half of Blue Solar Water a day!

So, yeah.  "Cleaning memories."  Katz tells us that it's useful for erasing your memory, which I find a troubling idea.  I already have to re-enter a room three times to remember why I went there.  I'm not sure I need anything that's going to make me forget more than I already do.

[Image licensed under the Creative Commons Blue glass bottle, England, 1871-1920 Wellcome L0058775, CC BY 4.0]

But that's not its only use.  Check it out:

• Add some to your Coffee, Tea, Cocoa, Juice, etc.
• Add Blue Solar Water to everything you cook -- Pasta, Soup, Oatmeal, scrambled eggs, etc. Remember, just a drop of Blue Solar Water will solarize all of it.
• Add some Blue Solar Water to your washing machine when washing clothes.
• Spray some in your dryer.
• Add it to your radiator to make your car hummmm.
• Add it to your bath water.
• Spray yourself with Blue Solar Water after showering.
• Spray rooms with Blue Solar Water.
• Gargle with it.
• Wash Floors with it.
• Wash your car with Blue Solar Water.

These are just a few of the ways that we have used Blue Solar Water. Have FUN with it and be Creative in finding new ways to CLEAN with Blue Solar Water.

I'm reminded of the old Saturday Night Live sketch about New Shimmer -- "It's a floor wax and a dessert topping!"

I have to admit, that none of the listed applications are a problem, if any of that floats your boat (and I'm sure that "Blue Solar Water" will make your boat not only float, but "hummmmm.")  After all, it's just water.  Like, plain old water.  So if you get a happy feeling by spraying water all over your house, then don't let me stand in your way.

There's a problem, however.  I live in upstate New York, where the sun only comes out when it thinks no one is looking.  How can I "solarize" my water when the sun isn't shining?  Well, fortunately, Mabel Katz is way ahead of me:

[A] very small amount of Blue Solar water, even one drop, added to regular water will solarize it.  You can also solarize it under an incandescent clear light (blue bottle) for an hour, or an incandescent blue light (clear bottle) for an hour.

So that's convenient.  She even has an answer for what to do when you run out, or don't have time to "solarize" any more water:

You can also use it mentally.  Mentally repeat "Solar Water."  This will work when you REALLY cannot prepare it or have access to it.  God will do it for you ONLY when you cannot do it physically.

Which raises magical thinking to a whole new level.  "Here's how to make the magic water... but really, all you have to do is think about magic water and the magic will happen!"

So anyhow, many thanks to the loyal reader who sent me the link.  It's a little troubling that every time I think I have plumbed the depths of human gullibility, I find that there are many more circles of hell still below me.  Maybe I need to gargle with some "Blue Solar Water" and erase the memory, because if I do any more headdesks, I'm gonna end up with a concussion.

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Flotsam and jetsam

One of the topics I keep coming back to here at Skeptophilia is the possibility of extraterrestrial intelligence.  I have to admit, it's a bit of an obsession with me, and has been ever since I watched Lost in Space and the original Star Trek as a kid.

As with so many things, though, this fascination runs headlong into my staunch commitment to rationality, hard evidence, and the scientific method.  The SETI (Search for Extraterrestrial Intelligence) program has, to date, found no particularly good candidates for a signal from an alien race.  The Fermi paradox -- Enrico's famous question that if the likelihood of extraterrestrial life is so high, then "where is everyone?" -- brings us to the rather depressing answer of the three f's, about which I wrote in detail a couple of years ago.

UFO aficionados point toward all of the sightings of alleged alien spacecrafts, and the more skeptical of them rightly insist that even if it's only a small fraction of them that aren't dismissible because of the usual explanations (hoaxes, camera glitches, natural phenomena mistaken for UFOs, etc.), those few are still worth investigating.  Physicist Michio Kaku, who has gained a bit of a reputation for being out in the ionosphere on the topic, said, "You simply cannot dismiss the possibility that some of these UFO sightings are actually sightings from some object created by an advanced civilization… on the off chance that there is something there, that could literally change the course of human history."

But the fact remains that at present we have zero scientifically admissible evidence for the existence of ET. 

Not so fast, says physicist B. P. Embaid, of Central University in Venezuela, in a paper available at arXiv (but not yet peer reviewed).  Embaid has been studying minerals found in meteorites, and he found two -- heideite and brezinaite -- that he says are superconductors that can only be synthesized in a laboratory.

And therefore, the meteorites in which they were found are fragments of a wrecked spaceship.

In Embaid's favor is the fact that heideite and brezinaite are weird minerals, and have never been found in a single natural terrestrial sample.  Brezinaite was created in 1957 by carefully layering chromium and sulfur; heideite eleven years later, by chemically combining chromium, iron, sulfur, and titanium.  Since their first synthesis, both minerals have been found in meteorites, but they have never been seen otherwise, even in ore samples rich in the constituent elements.

So, Embaid says, these are technosignatures -- relics from a technological civilization.

Predictably, my response is:

But I reluctantly must add that I need a good bit more than this to land myself squarely in Embaid's camp.  There's an important word I left out of my statement regarding heideite and brezinaite never showing up in terrestrial samples -- yet.  Recall that the element helium was first discovered on the Sun, from its characteristic spectral lines, long before it was detected in Earth's atmosphere.  I'm also reminded of the discovery in a meteorite of nonperiodic quasicrystals, a form of matter not thought to be naturally occurring anywhere, by a team led by physicist Paul Steinhardt (and which was the subject of his fascinating book The Second Kind of Impossible, which I highly recommend).  It's always tempting to assume that what we know now represents the final, definitive answer, and forget that nature has a way of surprising us over and over.

So could the discovery of two odd superconducting minerals in meteorites mean that we're looking at the flotsam and jetsam of a wrecked extraterrestrial spacecraft?  Sure.  We shouldn't dismiss that possibility simply because the bent of a lot of scientists is to scoff at UFOlogy; that is in itself a bias.  But based on what we currently have, it is way premature to conclude that the anomalous meteorites are technosignatures.  

Now, if a meteorite contained some superconducting materials laid out in a pattern reminiscent of a circuit board, then you might have me convinced.  That, after all, is how the Tenth Doctor figured out what was going on in "The Fires of Pompeii:"

And hey, if a piece of evidence is good enough for the Doctor, it's good enough for me.

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Lost beneath the waves

Ever heard of the Kingdom of Cantre'r Gwaelod?

If not, I hadn't either. Those of you with a linguistic bent might surmise from the name that the kingdom had something to do with Wales, and you'd be right.  The sad tale of the lost Kingdom of Cantre'r Gwaelod is one of the dozens of inundation myths (although using that last word may be inappropriate, as you'll see in a moment), including the Breton city of Ys and the Arthurian legend of the Kingdom of Lyonesse.  Both were allegedly destroyed for their wickedness by drowning in the ocean.  If this puts you in mind of J. R. R. Tolkien's fictional land of Númenor, that's no coincidence; Ys and Lyonesse were part of the inspiration for Tolkien's doomed kingdom of the Second Age of Middle Earth.

The less-famous Kingdom of Cantre'r Gwaelod has some striking parallels.  Originally made up of a broad, fertile valley west of Wales, the land was swallowed up by the sea and now lies beneath Cardigan Bay.  Instead of the sinfulness that did in Ys, Lyonesse, and Númenor, Cantre'r Gwaelod was supposedly destroyed by negligence; in the Black Book of Carmarthen, a thirteenth-century document that is the earliest surviving manuscript written entirely in Welsh, the unfortunate kingdom met its doom because a maiden named Mererid who had been tasked with tending a well fell asleep, and the well overflowed and flooded the entire land.

What, exactly, Mererid was supposed to do about a well that was flowing so fast that it could inundate a whole country while someone was taking an afternoon nap is uncertain.  But in the legend, the poor girl got the blame, and so the matter has stood.

But what separates Cantre'r Gwaelod from other lost-lands myths, including the most famous one -- Atlantis -- is that the Welsh version may actually have some basis in fact.

The Gough Map [Image is in the Public Domain]

Two researchers, Simon Haslett, Professor of Physical Geography at Swansea University, and David Willis, Professor of Celtic History at the University of Oxford, found evidence on one of the earliest maps of Great Britain of two low-lying islands in what is now Cardigan Bay.  The document, called the Gough Map after its last owner prior to its donation to the Bodleian Library at Oxford, dates back to the fourteenth century, although many historians believe it to be a copy of an earlier map.  And it indicates that parts of Cardigan Bay were once dry land, and further, that the contours and terrain of these islands are reminiscent of the descriptions of Cantre'r Gwaelod from the Black Book of Carmarthen:

This study investigates historical sources, alongside geological and bathymetric evidence, and proposes a model of post-glacial coastal evolution that provides an explanation for the ‘lost’ islands and a hypothetical framework for future research: (1) during the Pleistocene, Irish Sea ice occupied the area from the north and west, and Welsh ice from the east, (2) a landscape of unconsolidated Pleistocene deposits developed seaward of a relict pre-Quaternary cliffline with a land surface up to ca. 30 m above present sea-level, (3) erosion proceeded along the lines of a template provided by a retreating shoreline affected by Holocene sea-level rise, shore-normal rivers, and surface run-off from the relict cliffline and interfluves, (4) dissection established islands occupying cores of the depositional landscape, and (5) continued down-wearing, marginal erosion and marine inundation(s) removed the two remaining islands by the 16th century.  Literary evidence and folklore traditions provide support in that Cardigan Bay is associated with the ‘lost’ lowland of Cantre’r Gwaelod.

So it looks like we may have here another example of a legend with some basis in fact.  A good many of the inundation myths -- including, very possibly, the Great Flood in the Bible -- might have come from the fact that at the end of the last Ice Age, the seas were rising, and previously dry land such as Beringia (between Russia and Alaska) and Doggerland (between England and continental Europe) were drowned.  Cantre'r Gwaelod, perhaps, was a victim of the same sea level rise -- but unlike the others, we appear to have a map showing exactly where it lay.

And maybe once and for all we can absolve poor Mererid of any responsibility for its demise.

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