Islands of the imagination

There's a long list of what have been nicknamed "phantom islands" -- islands that have been recorded on maps, sometimes for centuries, but then when people follow the map and go out where the island supposedly is, there's nothing there.

Well, there's something there, namely a shit tonne of salt water.  In one way, it's unsurprising that misidentifications like this can happen; icebergs, pumice rafts from volcanic eruptions, and even low cloud banks in the distance can look like land, and when you couple that with the desperation to reach terra firma a lot of mariners felt after weeks at sea, it's understandable that this sometimes occurred.  What's more curious is how persistent some of these phantom islands were -- there are ones that were only conclusively proven not to exist in the last two decades.

A big part of the problem is that in the days before satellites and GPS, when you were out at sea, it was awfully hard to be certain of exactly where you were.  Latitude, as it turns out, is fairly easy; in the Northern Hemisphere, the altitude of Polaris above the horizon (which you can measure with a sextant) is equal to the latitude.  (It's a little trickier in the Southern Hemisphere -- there is no "South Star" -- but with a little adjustment, the same principle can still be used.)

Longitude, on the other hand, is a whole other can of worms.

You can figure out your longitude using the rising times of various stars, but the hitch is that requires you have an accurate timepiece that isn't thrown off by the incessant jostling and jolting on board ship.  It wasn't until the eighteenth century that such a clock was invented, and it only went into widespread use in the nineteenth -- how this happened is the topic of Dava Sobel's wonderful book Longitude -- but even with more accurate timekeeping, figuring out exactly where in the trackless oceans you were was no easy task.  This is probably what happened with the nonexistent Saxemberg Island, first sighted in 1670, which appeared on maps for almost two hundred years (and was "viewed extensively from a distance" in 1804 and again in 1816).  It's now surmised that they were actually seeing the remote Tristan da Cunha Island, and had simply miscalculated where they were.

One that is likely to have been a combination of inaccurate longitude calculation and seeing something that looked like an island but wasn't is "New South Greenland," which was "discovered" by the curious figure of Captain Benjamin Morrell, originally of New York.  To say that Morrell had a checkered career is a bit of an understatement.  He ran away to become a sailor at age seventeen, served during the War of 1812 (and was captured twice by the British), but eventually rose through the ranks to captain the Wasp, which he took down into Antarctic waters in 1823.  He had a penchant for exaggeration and occasional outright lying, but in this particular case he seems to have simply been mistaken.  He reported an extensive land which he initially thought was part of the Antarctic Peninsula, and sailed along it for five hundred kilometers -- but subsequently he found his position to be ten degrees of longitude (at that latitude, about two hundred kilometers) east of where he thought he was, in a part of the ocean that has no land masses whatsoever and by later sounding was found to be 1,500 meters deep.  So what he saw clearly wasn't part of Antarctica.  What it actually was remains a mystery -- the best guess is a long connected chunk of icebergs.

For what it's worth, Morrell's career didn't improve much thereafter.  He was involved in piracy in China and Madagascar and was lucky to escape with his life, launched a fruitless search for gold in New Guinea, and supposedly died "of a fever" in Mozambique in 1838 -- although a letter with his signature showed up in New York in 1843, leading some people to believe he faked his own death to get away from all the people he'd defrauded or otherwise pissed off.

Sometimes imaginary islands get wrapped up in mythology, and that makes it even harder to tease out what's real and what isn't.  Penglai, "thirty thousand leagues off the east coast of Shandong, China," described as one of the homes of the "Great Immortals," is pretty certainly a tall tale -- although interestingly, there's a legend both in Vietnam and Japan pinpointing an island in more or less the same place (where it's called Bồng Lai and Hōrai, respectively).  Saint Brendan's Isle, supposedly first seen in 512 C.E. by the Irish monk/explorer Saint Brendan of Clonfert, is another one around which wild tales have arisen, but it was reported so persistently that its existence was considered a fact for hundreds of years.  (Its reputation for being the home of devils and demons led a priest in the Canary Islands to perform an exorcism directed toward the entire island in 1723.)  The last alleged sighting of Saint Brendan's Isle was in 1772, but it still appeared on maps -- somewhere off the west coast of Africa -- well into the nineteenth century.

Bedarra Island, off the coast of Australia, which is actually real [Image licensed under the Creative Commons Banfield1 at English Wikipedia, Bedarra Island aerial, CC BY-SA 3.0]

Sometimes islands do exist -- temporarily.  This seems to be the case with Bermeja, discovered by Spanish explorers off the coast of the Yucatán Peninsula in 1539, and extensively described (along with its precise location) by other mariners in the sixteenth century.  Expeditions to find it later proved unsuccessful, although close to the reported location there is a significant seamount.  It's likely that Bermeja was the victim of a combination of erosion and tectonic shifting, and what was once dry land now isn't.

A lot of them, though, have eluded explanation except as mirages.  This is almost certainly the case with the aptly-if-unfortunately-named Fata Morgana Island (a fata morgana is a common type of mirage experienced at sea, especially in polar regions).  The explorers Johan Peter Koch and Aage Bertelsen reported it -- once again, along with an exact location, off the northeast coast of Greenland -- in 1907, and its existence was confirmed from the air by Koch's son Lauge in 1933.  Unfortunately for all three of them, there's no land there, just lots of extremely cold salt water.  The sightings were undoubtedly a combination of mirages and wishful thinking.

In any case, our precision GPS systems, satellite photography, and (I hope) less tendency to fall for fanciful tall tales has improved our ability to discern between what's real and what's not.  Although I have to say I'm kind of disappointed that Antillia isn't real.  A favorite claim amongst the Spanish and the Portuguese until the sixteenth century, at which point their own explorers came back and reported that there wasn't anything where it allegedly was but a big blob of the Atlantic Ocean, Antillia supposedly had seven cities run like some utopian paradise, where everyone lived in harmony and there was no crime or violence, and its leaders were wise, kind, and benevolent.  I don't know about you, but if that one is ever rediscovered, I'm buying a plane ticket.

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The wheel of light

I absolutely love the fact that there are real phenomena that science hasn't yet explained.

It's not just from the standpoint of "scientists will always have a job," although that's part of it.  I'm also captivated by that sense of wonder I had as a child, contemplating something I'd noticed or heard about, and thinking, "Wow... I wonder how that works?"

A good example is something I first ran into a long time ago, from the delightful collection Strangely Enough! by C. B. Colby.  This book is a compendium of two-to-three page descriptions of what can probably best be described as Forteana -- odd or anomalous phenomena of various types.  Some are humorous; some are stories of hauntings, cryptids, and UFOs; a few are clearly in the realm of the tall tale.  (One that straddles the line between all of them is the scary story called "Whistle," about a elderly woman living with her dog in a small house in the hill country who hears a distant whistling noise, which gradually gets closer and closer.  It's terrifying in its subtlety and suggestiveness.  It was made into a seven-minute short film in 2008 by Eric Walter and Jon Parke which is well worth watching, preferably not when you're alone at night.)

One of the stories in Strangely Enough! that caught my eye when I first read it as a teenager was about a peculiar marine phenomenon that turns out to be absolutely real -- and still unexplained (although there is one possible explanation I'll get to).  It's nicknamed "Poseidon's wheel," and is most commonly seen at night in the Indian Ocean and tropical south Pacific, although it's been observed elsewhere multiple times.  Sailors report a giant, glowing wheel, with radial spokes like a wagon wheel, slowly rotating underwater.  

Here's the account in Colby's book, about an instance of the phenomenon observed from the Danish ship Bintang, in June of 1909 in the Straits of Malacca:

As the Bintang was steaming through the night in the Straits of Malacca, between Sumatra and the Malay Peninsula, the captain was astonished to see what appeared to be a long beam of light under the water.  Like the beam of a searchlight, it seemed to be sweeping across the floor of the sea.  The beam passed across the sea before him and was followed by another and then another, like the revolving spokes of a wheel, or searchlight beams following one another across the sky.

Soon, some distance from the ship, there appeared a brighter spot or hub, from which the long beams of underwater light seemed to stem.  The beam revolved slowly as the rotating "wheel" slowly approached the Bintang.  In the words of the captain, "Long arms issued from a center around which the whole system appeared to rotate."

The great revolving wheel was so huge that only half of it could be seen above the horizon.  As it revolved toward the Bintang, the crew stared in dumbfounded amazement.  Looking around, they realized that the long arms of light could not possibly be a reflection of their own lights, and there was no other ship in sight.

As the great silent revolving wheel of underwater light came nearer, it seemed to sink lower into the water and grow dimmer and dimmer.  Finally it vanished deep beneath the waves and the Straits of Malacca were once more black and empty.

It'd be tempting to dismiss this as falling into the "tall tale" category, but the Bintang is hardly the only ship whose crew reports seeing Poseidon's wheel.  Here's one of the best-documented accounts, from U. S. Naval Commander J. R. Bodler in 1952 (edited for length; you can read the entire account at the link provided):

My vessel had passed through the Strait of Hormuz, bound for India.  Little Quoin Island Light was still in sight on the starboard quarter, bearing 305° T, distance 20 miles.  The night was bright and clear, with very good visibility, no Moon.  The Third Mate called me to the bridge, saying that he had observed something he thought I should see.

About four points on the port bow, toward the coast of Iran, there was a luminous band which seemed to pulsate.  Its appearance suggested the aurora borealis, but much lower; in fact on or below the horizon.  Examination with binoculars showed that the luminous area was definitely below the horizon, in the water, and drawing nearer to the vessel.  With the approach of this phenomenon it became apparent that the pulsations seemed to start in the center of the band and flow outward towards its extremities.

At a distance of about a mile from the ship, it was apparent that the disturbance was roughly circular in shape, about 1000 to 1500 feet in diameter.  The pulsations could now be seen to be caused by a revolving motion of the entire pattern about a rather ill-defined center; with streaks of light like the beams of search-lights, radiating outward from the center and revolving (in a counterclockwise direction) like the spokes of a gigantic wheel.

For several minutes the vessel occupied the approximate center of the phenomenon.  Slightly curved bands of light crossed the bow, passed rapidly down the port side from bow to stern, and up the starboard side from aft, forward.  The luminosity was sufficient to make portions of the vessels upper work’s quite visible.  The bands of luminance seemed to pass a given point at about half-second intervals.  As may well be imagined, the effect was weird and impressive in the extreme; with the vessel seeming to occupy the center of a huge pinwheel whose “spokes” consisted of phosphorescent luminance revolving rapidly about the vessel as a hub...

The central “hub” of the phenomenon drew gradually to starboard, and passed aft; becoming more and more distant on the starboard quarter.  While it was still in sight, several miles astern, and appearing, by this time, as a pulsating band of light, a repetition of the same manifestation appeared fine on the starboard bow.  This was slightly smaller in area than the first, and a trifle less brilliant.  Its center passed slowly aft on the starboard side, with the pattern of revolving, luminous “spokes” clearly defined...

It is the present writer’s conviction that he has been privileged to witness one of the rare instances of a most curious and impressive natural phenomenon.  If other seafarers have had a similar experience, or anyone of scientific bent can offer an explanation of the foregoing, he would be most interested to learn more on the subject.

This phenomenon has been seen dozens of times, and described and sketched by crew members -- but to my knowledge, never successfully photographed.  Of course, paranormal "explanations" abound, including underwater alien craft (USOs?  Unidentified Swimming Objects?  I dunno).  But the most reasonable explanation I've heard has to do with a microscopic life form called a dinoflagellate.

Dinoflagellates are single-celled plankton, mostly marine.  They are nearly all harmless, although a few, like the species Karenia brevis, produce toxins -- Karenia is the one responsible for "red tide."  A couple, like the rather horrifying parasite Pfiesteria, are pathogenic.  

One group of dinoflagellates does something remarkable, though.  They're bioluminescent -- capable of using chemical reactions to produce light.  The evolutionary purpose is uncertain; it's hard to imagine what they gain by it.  But when there are enough of them present, the result is rather spectacular.

[Image licensed under the Creative Commons © Hans Hillewaert, Noctiluca scintillans, CC BY-SA 4.0]

What's relevant here -- besides the obvious bit that we have something underwater producing light -- is that bioluminescent dinoflagellates like Noctiluca produce light when the water is agitated.  When there's a bloom of Noctiluca, every wave crashing on the beach appears to sparkle -- a truly breathtaking sight.

Recall that the two sightings mentioned above, and as far as I know, all of the other accounts of the phenomenon, occurred from the decks of engine-propelled ships.  Ship engines produce a lot of noise, and some of it is subsonic -- large-wavelength, low-frequency compression waves radiating out from the belly of the ship.

As those compressional waves move through the water, perhaps that agitation is triggering light from the local population of bioluminescent dinoflagellates.  The "spoke" pattern could be explained by this; it might be that there's a standing wave being created, and the regularly spaced nodes and antinodes of the underwater sound waves correspond to (respectively) the dark and light bands.

One thing this doesn't explain, however -- at least not as far as I can see -- is that in most of the eyewitness accounts, the hub of the wheel appeared to be stationary, and the ship approached and then passed it.  If the source of the disturbance creating the light was the ship itself, you'd think the pattern would be centered on the ship, and then would travel with it (at least as long as it was in water containing the microorganisms).

So Poseidon's wheel remains a mystery, and the scientific explanation very much only a working hypothesis.

It's an intriguing phenomenon.  It's been documented far too many times to be an outright hoax or misrepresentation; and many of the people describing it fall into category of "credible witness with no particular reason to lie."  So at this point, we still don't know what's going on. 

But like I said, that's part of the fun of science.  We don't understand everything, not by a longshot.  There's still plenty to look at and wonder about.  And if you're ever sailing through the tropics, keep an eye out.  You might see a vast, glowing underwater wheel, rotating slowly -- and witness one of the weirdest unexplained phenomena I've ever heard about.

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Sailing the milky seas

Sometimes, the first thing you have to do in order to explain a mysterious phenomenon is to show that the mysterious phenomenon actually exists.

The human brain, as astronomer Neil deGrasse Tyson put it, is "rife with ways of getting it wrong."  He's not only talking about the unfortunate penchant some people have for perpetrating hoaxes; it's just that our preconceived notions, the selective filters on what we see and hear, and (let's face it) our ignorance about natural phenomena make it all too easy to misinterpret what we're seeing and hearing.  Dr. Tyson relates a particularly amusing example, a policeman out at night who gave chase on a mountain road to a UFO -- a bright light, he said, that was ahead of him near the horizon, and kept bobbing around, easily staying in the lead as he swerved back and forth around the curves.

Turns out what he was chasing was the planet Venus, and the bobbing motion was his brain's inability to sort out the fact that it was in a moving car traveling on a winding road.

Not all examples of oddball eyewitness testimony are that easily explained, however.  Take, for example, the reports that have come in for (literally) centuries from sailors out in the open ocean, of times that the seas suddenly take on an opaque, opalescent glow -- the so-called "milky seas" phenomenon.

It's not the same as ordinary bioluminescence, a sparkling and flashing of living organisms that are capable of producing light.  A well-known example is the dinoflagellate Noctiluca scintillans, which produces the blue glow sometimes seen in shallow tropical waters.  Bioluminescence, however -- at least the kind we know about -- is transitory, lasting for minutes, and even when it's due to microorganisms only affects a small area.

The "milky seas" phenomenon, however, lasts for hours, and there are accounts of ships traveling for a hundred miles through water that looks like "a plain covered with snow."  And unlike typical bioluminescence, whatever causes milky seas is suppressed by agitation -- the eyewitness accounts report that the bow wave of the ship is darker than the surrounding water.

The phenomenon has proven elusive, though.  First of all, whatever it is, it's rare; there are only a couple of reports a year.  This makes it hard to study, and also makes it tempting to attribute it to overactive imagination, or simple misreporting of something completely ordinary like the reflection of moonlight (a bit like our unfortunate Venus-chasing policeman).

But now, a paper this week in Proceedings of the National Academy of Sciences has shown conclusive evidence that it exists -- not only photographs and reports from a ship sailing near Java, but satellite images of the event taken on the same night.

On the left, the satellite image of the milky seas event; the brightly-lit strip in the top half of the photo is the island of Java.  On the right, a photograph taken by the crew of the Ganesha.

Explaining what's causing the phenomenon, however, is still not simple.  One theory is that it's being caused by a bloom of a so-far-unidentified species of bioluminescent bacteria, based on a single water sample from a milky seas event in the Arabian Sea in 1985.

But at least now we have hard evidence that it's something real.  "The biggest missing link in our study from last year was the lack of ground truth," said study lead author Steven Miller, of Colorado State University, who has been chasing this phenomenon for years.  "But this current study provides it.  It was a great relief to get this contact from the Ganesha crew."

It's fascinating how little we know about the oceans -- I've heard it said that we know more about the surface of the Moon than we do about the open ocean and seafloor, and I believe it.  But it looks like one of the ocean's mysteries has at least shown itself for sure.  We still don't have a certain explanation for it, but at least now we know the phenomenon is real.

So figuring out what's going on when the seas at night turn to milk is only a matter of time.

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The water world

Coming hard on the heels of an encouraging paper about the possibilities of near-light-speed travel, at which we might potentially have probe data from the nearest star to the Sun in ten years or so, we have an even more encouraging study of a place right here in the Solar System that might be worth looking at as a home of extraterrestrial life.

The place is Enceladus, the sixth largest moon of the planet Saturn.  It's a pretty decent-sized object, about one-seventh the diameter of the Earth.  Flyby data from the spacecraft Cassini in 2014 showed that it's a curious place, with a liquid water ocean capped by a shell of solid ice.  There are geysers coming up through cracks in the surface, and Cassini was able to sample the spray and confirm that it is, indeed, water.

Enceladus [Image is in the Public Domain courtesy of NASA/JPL and the Cassini probe]

But it's kind of a topsy-turvy world even so.  Here on the Earth, oceans are warmest at the top and coolest at the bottom; the deep parts of the ocean are the most stable ecosystems on Earth, always completely dark, under crushing pressure, and about four degrees Celsius (the temperature at which water is densest).  On Enceladus, it's the other way around; coldest on top, where it's in contact with the undersurface of the ice cap, and warmest at the bottom, where it's in contact with the core of the moon.  There's no land surface; the oceans on Enceladus are estimated at thirty kilometers deep (contrast that to an average three kilometers for Earth's oceans).

The upside-down temperature structure on Enceladus is what makes it an excellent place to look for extraterrestrial life, but to see why, we'll need to take a brief digression for a physics lesson.

One of the main drivers of ocean currents -- the movement of water not only horizontally, but vertically -- is convection, which is fluid flow because of differences in density.  One of the best-studied examples, which I described more fully in a post a few weeks ago, is the Atlantic Conveyor (known to scientists as the Atlantic Meridional Overturning Circulation), in which evaporation from the warm Gulf Stream as it flows north cools the water and makes it more saline, both of which have the effect of increasing its density.  Eventually, the blob of water becomes cool and saline enough that it exceeds the density of the water surrounding it, and it sinks.  This usually occurs in the North Atlantic southwest of Iceland, and that draw-down is what pulls more warm water north, keeping the whole system moving.

This has multiple effects, two of which concern us here.  The first is that it acts as a heat transfer mechanism, warming the air (and the land near it) and giving the American Northeast, the Maritimes of Canada, Iceland, and northwestern Europe the temperate climate they have, which otherwise would be a lot more like Siberia.  Second, the water carries with it nutrients of various sorts, and redistribution of those nutrients forms the basis of phytoplankton growth and the food chain.  (The most obvious example of this latter effect is the El Niño Southern Oscillation, in which upwelling of nutrient-laden water off the coast of Peru supports a huge population of fish -- until an El Niño year, when warm water flowing east blocks the upwelling, and the entire food chain collapses.  The four-year lots-of-fish to no-fish cycle was observed as far back at the seventeenth century, when the Spanish rulers of Peru noted that the collapse often started in midwinter, and gave it the name El Niño, which refers to the baby Jesus.)

So as long as you have alterations in density, a fluid will move.  It's what drives all weather, in fact; ground heating raises the temperature of air, lowering its density and making it rise, generating a low-pressure system that draws in more air to replace what's moving aloft.  This causes wind, and if the air has moisture, it'll condense out as it rises and cools, causing rain and/or snow.

Of course, the water drawn down by the sinking of the Gulf Stream near Iceland (or the air moving upward because of warming) is only half the picture.  It's got to come back somehow, and both the atmosphere and ocean are filled with convection cells, swirling, more-or-less circular currents following the motion both vertically and horizontally.  And once again -- to return to why the topic comes up -- these redistribute not only heat, but (in the case of water), nutrients.

On Enceladus, the pattern is upside down as compared to Earth's oceans.  Water in contact with the underside of the ice shell cools and eventually sinks, drawing warmer water up from near the center of the moon.  This mixing stirs the pot, and any potential nutrient chemicals don't just settle out on the bottom.  Thus, Enceladus is a prime candidate for extraterrestrial life of some sort.

To be sure, it'd be different from what we have here on Earth.  A lot different.  Despite the cracks and geysers, the ice shell on Enceladus is thick and pretty much solid, so any living things under there would never come into contract with direct rays of the Sun (as dim as they'd be out there).  The only energy source would be the warmth of the core, so there'd be no photosynthesis, only chemosynthesis, perhaps similar to the weird organisms near Earth's hydrothermal vents in the deep oceans.  

Even so, it's a prime spot to look for signs of life.  And unlike Proxima Centauri, the nearest star, which in a best-case scenario would require ten years for an outward-bound near-light-speed probe and returned signal back on Earth, the same round-trip to Enceladus would take on the order of three hours.  

Once again highlighting that the universe is freakin' huge.

If we can develop near-light-speed travel, maybe the first thing to do is to send some probes to explore our own Solar System more thoroughly.  Not only Enceladus, but a similar water-world moon of Jupiter, Europa, which is even closer.  I'd say the likelihood of finding intelligent life on either one is slim to none, so I wouldn't be looking for anything like the super-tech civilization on a planet orbiting Vega in the movie Contact, but I think there's an excellent chance that there's something living down there, even if it turns out to be only as complex as bacteria.

But even so.  How cool would that be?  A life form completely unrelated to anything we have down here.  And if we did find life on Europa or Enceladus, it would really bolster the hunch I've had for years, which is that life is common in the universe.

And I, for one, would settle for that in a heartbeat.

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The sad truth of our history is that science and scientific research has until very recently been considered the exclusive province of men.  The exclusion of women committed the double injury of preventing curious, talented, brilliant women from pursuing their deepest interests, and robbing society of half of the gains of knowledge we might otherwise have seen.

To be sure, a small number of women made it past the obstacles men set in their way, and braved the scorn generated by their infiltration into what was then a masculine world.  A rare few -- Marie Curie, Barbara McClintock, Mary Anning, and Jocelyn Bell Burnell come to mind -- actually succeeded so well that they became widely known even outside of their fields.  But hundreds of others remained in obscurity, or were so discouraged by the difficulties that they gave up entirely.

It's both heartening and profoundly infuriating to read about the women scientists who worked against the bigoted, white-male-only mentality; heartening because it's always cheering to see someone achieve well-deserved success, and infuriating because the reason their accomplishments stand out is because of impediments put in their way by pure chauvinistic bigotry.  So if you want to experience both of these, and read a story of a group of women who in the early twentieth century revolutionized the field of astronomy despite having to fight for every opportunity they got, read Dava Sobel's amazing book The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars.

In it, we get to know such brilliant scientists as Willamina Fleming -- a Scottish woman originally hired as a maid, but who after watching the male astronomers at work commented that she could do what they did better and faster, and so... she did.  Cecilia Payne, the first ever female professor of astronomy at Harvard University.  Annie Jump Cannon, who not only had her gender as an unfair obstacle to her dreams, but had to overcome the difficulties of being profoundly deaf.

Their success story is a tribute to their perseverance, brainpower, and -- most importantly -- their loving support of each other in fighting a monolithic male edifice that back then was even more firmly entrenched than it is now.  Their names should be more widely known, as should their stories.  In Sobel's able hands, their characters leap off the page -- and tell you a tale you'll never forget.

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

Death in the seas

It's amazing what scientists sometimes miss.

This is not meant to be any kind of indictment of scientists, or science in general.  It's just part of the game, honestly; sometimes it takes a while for the evidence to be uncovered, while sometimes previous theories act as blinders -- such as the long-held idea of the Earth's geology being driven by geosynclines, huge downward folds in the Earth's crust, that were supposed to explain both sedimentary rock strata and orogeny (mountain-forming).  Never mind that no one could quite explain why geosynclines occurred; most of it seemed to be hand-waving talk about masses of eroded sediments causing blocks of crust to fault and tilt like a teeter-totter.  Despite there being no plausible mechanism, this idea was so entrenched in the scientific minds of the nineteenth and early twentieth century that even as the evidence for plate tectonics accrued, most geologists dismissed it as fancy -- until the discovery of the magnetic stripes on either side of the Mid-Atlantic Rift Zone proved plate tectonics beyond any question.

But like I said, sometimes the problem is that the evidence takes a while to come together.  For example, consider the paper in Nature Ecology & Evolution that appeared a while back, called, "The Pliocene Marine Megafauna Extinction and Its Impact on Functional Diversity," by a team led by Catalina Pimiento of the University of Zürich.  In it, the researchers describe an enormous mass extinction that happened between two and three million years ago -- pretty close to recent, in geological terms -- and which scientists had previously been almost entirely unaware.

Mass extinctions leave a huge footprint in the geological record.  Not only does biodiversity drop dramatically from one stratum to the one immediately above it, but the drastic differences in the sorts of species you find on either side -- who were the winners and losers -- is usually an obvious marker that something enormous has happened.

Paleontologists have identified what they call the Big Five:

• The Ordovician-Silurian Extinction (440 million years ago)
• The Devonian Extinction (365 million years ago)
• The Permian-Triassic Extinction (250 million years ago)
• The Triassic-Jurassic Extinction (210 million years ago)
• The Cretaceous-Tertiary Extinction (66 million years ago)

All of these have been well-established for over a century, although convincing explanations for the cause of each is still a subject of heated discussion.  But the much more recent extinction that was the subject of the Pimiento et al. paper, which occurred at the boundary between the Pliocene and Pleistocene Epoch, was overlooked despite its magnitude.

The authors write:

The end of the Pliocene marked the beginning of a period of great climatic variability and sea-level oscillations.  Here, based on a new analysis of the fossil record, we identify a previously unrecognized extinction event among marine megafauna (mammals, seabirds, turtles and sharks) during this time, with extinction rates three times higher than in the rest of the Cenozoic, and with 36% of Pliocene genera failing to survive into the Pleistocene.  To gauge the potential consequences of this event for ecosystem functioning, we evaluate its impacts on functional diversity, focusing on the 86% of the megafauna genera that are associated with coastal habitats.  Seven (14%) coastal functional entities (unique trait combinations) disappeared, along with 17% of functional richness (volume of the functional space). 

A loss of 36% of the marine genera is huge.  Especially when you consider that some of the vanished species weren't exactly tiny obscure sea bugs.  One of the victims was Carcharodon megalodon, the largest shark species known, which reached a length of fifteen meters from tip to tail and weighed upward of fifty metric tons.  What seems to have hidden this event from view is that it mainly impacted marine organisms, whose remains may well have been fossilized, but most of which are still underwater (there hasn't been that much large-scale geological shift in two million years, so most Pliocene-age rocks are pretty much still sitting where they formed).

[Image is in the Public Domain]

But this research also uncovered an interesting pattern in the extinction.  Warm-blooded animals were hit way harder than cold-blooded ones; consider that the event wiped out 55% of marine mammals and 35% of marine birds, but only 9% of sharks.  (For some reason, sea turtles also took a huge hit; 43% of the known species of Pliocene sea turtles were wiped out.)

The surmise by the scientists is that the Pliocene-Pleistocene Extinction was caused by large-scale sea level fluctuations altering oceanic current patterns and eradicating coastal habitat.  Climate change today seems to be aiming toward a similar target.  "This study shows that marine megafauna were far more vulnerable to global environmental changes in the recent geological past than had previously been assumed," said study lead author Catalina Pimiento.  "This also points to a present-day parallel: Nowadays, large marine species such as whales or seals are also highly vulnerable to human influences."

So here we have another cautionary tale, if we needed one.  Once again, marine mammals are at risk, but this time it's human activity that's driving the change.  Polar bears -- sometimes referred to as the "poster child for climate change" -- are likely to be extinct by 2100 if we stay on the trajectory we're on.

You have to wonder what future paleontologists will make of our age.  Will the sedimentary rocks forming today tell the story of a sudden, drastic decrease in biodiversity?  Will there be any way to tell what caused it?  Who will be the winners -- and who the losers?

And most frightening of all, will we still be around to consider the question?

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

Being in the middle of a pandemic, we're constantly being urged to wash our hands and/or use hand sanitizer.  It's not a bad idea, of course; multiple studies have shown that communicable diseases spread far less readily if people take the simple precaution of a thirty-second hand-washing with soap.

But as a culture, we're pretty obsessed with cleanliness.  Consider how many commercial products -- soaps, shampoos, body washes, and so on -- are dedicated solely to cleaning our skin.  Then there are all the products intended to return back to our skin and hair what the first set of products removed; the whole range of conditioners, softeners, lotions, and oils.

How much of this is necessary, or even beneficial?  That's the topic of the new book Clean: The New Science of Skin by doctor and journalist James Hamblin, who considers all of this and more -- the role of hyper-cleanliness in allergies, asthma, and eczema, and fascinating and recently-discovered information about our skin microbiome, the bacteria that colonize our skin and which are actually beneficial to our overall health.  Along the way, he questions things a lot of us take for granted... such as whether we should be showering daily.

It's a fascinating read, and looks at the question from a data-based, scientific standpoint.  Hamblin has put together the most recent evidence on how we should treat the surfaces of our own bodies -- and asks questions that are sure to generate a wealth of discussion.

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

Healing the ocean with syphilis

I think the homeopaths have reached some kind of Derp-vana this week with the announcement by British practitioner Grace DaSilva-Hill that we need to administer homeopathic preparations...

... to the ocean.

[image courtesy of the Wikimedia Commons]

I'm not making this up.  In a story broken by Andy Lewis on Quackometer, we find out that DaSilva-Hill is lamenting the state of the world's oceans, a sentiment with which I have to agree.  But what she proposes to do about it is to treat it with homeopathic "remedies:"

Thanks in advance to all of you who have already agreed to participate in this initiative of sending a homeopathic remedy to heal the oceans. 

The remedy that has been selected is Leuticum (Syph) in the CM potency. 

Just mix one or two drops in some water and offer it to the ocean wherever you happen to be, on 21 November, with pure love and intention...  If you live close to a river that can be done, too, or even just send the remedy down the toilet wherever you happen to be.

Well, I can't argue with the value of flushing homeopathic "remedies" down the toilet.  In my opinion, that should be done right at the factory where they're manufactured.

And what is "Leuticum," you may be wondering?  According to a homeopathy website, Leuticum is a "nosode" -- a "remedy" made from diluted bodily discharges.  And if you're not sufficiently disgusted yet, the bodily discharge involved in Leuticum is infected material from someone with syphilis.

Oh, but wait!  Leuticum is good stuff!  According to the site, it's useful for treating people who:

• are afraid of the dark
• are in chronic pain
• suffer from hair loss
• smell bad

In addition, we find out that you can use it to treat "persons with pale, fine textured skin, who are slender, having graceful movements," and also people with oral cancer.

What this has to do with the ocean is beyond me.

Of course, since the whole idea of homeopathy is that the more dilute the stuff gets, the more powerful it is, dumping it in the ocean is sort of the right approach, isn't it?  You might want to know what we're starting with, though.  What is a "CM potency" -- the strength of the original remedy?  Well, I looked it up on the Wikipedia page on homeopathic dilutions, and therein I found that a CM dilution represents a dilution of 1 part of the original substance in 10 to the 200,000th power parts of water.  If that's a little hard for you to visualize, it amounts to taking a milliliter of the original substance, and diluting it in a sphere of water about 100 light years in diameter, then taking a drop of that and diluting it again by the same amount, and repeating the process 4,000 times.

So what she's saying is to take a drop of that, and throw it in the ocean.

Or in a river.  Or down the toilet.  Or, she says, if you can't even manage that, just take some regular old water and think happy thoughts at it:

Even if you do not have the remedy in a physical form, you can still speak the name of the remedy to a glass of water, and the water will memorise the energy of the remedy (Dr. Masaru Emoto's work).

Dr. Emoto, you may remember, is the Japanese nutjob who thought that if you swear at water and then freeze it, it will form ugly crystals.

But like I said, maybe this is a good thing.  Keeping the homeopaths busy chucking their "remedies" in the ocean is better than what they have been doing lately, like going over to West Africa to try to treat Ebola with water and sugar pills.  I guess if it keeps them busy and out of harm's way, it's all good.

Especially since they can't be accused of putting something that has any side effects into the ocean.  Or, actually, something with any effects at all.