Thy fearful symmetry

For some of the most fundamental aspects of life, it's uncertain whether or not evolution was constrained.

The question has great significance with regards to the possibilities for extraterrestrial life.  I grew up watching Lost in Space and The Invaders and the original Star Trek, and later The X Files and Star Trek: The Next Generation and Doctor Who.  But while those classic shows piqued my budding interest in exobiology, my training in actual biology taught me that whatever the aliens look like, they will almost certainly not be humans with odd facial protuberances and strange accents.  How evolution plays out on other planets is impossible to say, but it's likely to be vastly different from the pathways taken by life on Earth.  I still remember reading Stephen Jay Gould's essay "Replaying the Tape" from his excellent book on the Cambrian-age Burgess Shale fauna, Wonderful Life, and being blown away by the following passage:

You press the rewind button and, making sure you thoroughly erase everything that actually happened, go back to any time and place in the past -– say, to the seas of the Burgess Shale.  Then let the tape run again and see if the repetition looks at all like the original.  If each replay strongly resembles life’s actual pathway, then we must conclude that what really happened pretty much had to occur.  But suppose that the experimental versions all yield sensible results strikingly different from the actual history of life?  What could we then say about the predictability of self-conscious intelligence? or of mammals?

His point was that a great deal of evolution appears to be contingent -- dependent on events and occurrences that would be unlikely to repeat in exactly the same way.  And while there's no way to re-run the tape on the Earth, considering the issue of constraint vs. contingency has profound implications regarding what we're likely to find elsewhere in the universe.  If we did find extraterrestrial life, would we even recognize it if we saw it? 

One good example is the fact that terrestrial life is based on carbon -- but is that necessarily true everywhere?  Sure, carbon's pretty cool stuff, with its four snazzy valence electrons and all, but maybe there are other ways to build functional organic molecules.  The original Star Trek gave a shot at addressing this, with the silicon-based Horta in the episode "The Devil in the Dark."  Silicon, like carbon, has four valence electrons, and thus is capable of bonding into complex rings and chains, and could possibly be the basis of an alternative biochemistry, although its affinity for stabilizing as silica (silicon dioxide), its low solubility in water, and the rigidity of its bonding structure all argue against it being anywhere near as good as carbon.

What about oxygen use?  Even here on Earth, we have living things that get by just fine without it; they're the anaerobes, and include such familiar fermenters as yeast and Lactobacillus acidophilus (the bacteria responsible for yogurt), and such bad guys as the causative agents of tetanus, botulism, and gangrene.  Being aerobic certainly seems like a great innovation -- it increases the efficiency of a cell's energy utilization by a factor of eighteen -- but it certainly isn't a requirement.  In fact, probably the most common life form on Earth, individual for individual, are methanogens -- deep sea-floor bacteria that metabolize anaerobically and produce methane as a waste product.  By some estimates, methanogens may outnumber all other living things on Earth put together.

So maybe anaerobic respiration isn't as efficient as aerobic respiration, but apparently it works well enough.

There are other features that deserve consideration, too.  How many of the things we take for granted about animal life are ubiquitous not because they were the result of strong natural selection, but simply because one of our ancestors had those features and happened to be the one that survived?  I'm guessing that having the sensory organs, central processing unit (brain), and the mouth clustered together at the anterior end of the animal will turn out to be common; it makes sense to have your perceptive equipment and your feeding apparatus pointing basically in the direction you're most likely to move.  And speaking of movement, how that's accomplished is probably going to turn out to be fairly uniform everywhere, because there aren't that many ways to fashion an appendage for walking, flying, or swimming.

But what about symmetry?  The vast majority of animals are bilaterally symmetric, meaning that there's only one axis of symmetry that divides the animal into mirror-image halves.  (A few have radial symmetry, where any line through the center works -- jellyfish being the most obvious example.)  Even animals like starfish, that seem to have some weird five-way symmetry, are actually bilateral; it's obvious if you look at starfish larva, and in fact is given away by the position of the sieve plate (the opening through which they draw in water), which is off-center.

True multiple-line symmetry doesn't seem to exist in the animal world, and even in science fiction most aliens are depicted as being nicely bilateral.  An exception are the Antarctic Elder Things, an invention of H. P. Lovecraft, which have pentaradial symmetry -- further illustrating that as unpleasant a person as Lovecraft evidently was, he had a hell of an imagination.

[Image licensed under the Creative Commons Tom Ardans - blog - Facebook, Old One by Tom Ardans, CC BY-SA 3.0]

So are most animals bilateral because it's got some kind of selective advantage, or simply because we descend from bilateral creatures who survived well for other reasons?  In other words, is it selected for, or an accidental neutral mutation?

One clue in all this is a discovery in South Australia that was described in a paper a while back in Proceedings of the National Academy of Sciences.  Paleontologists found a fossil half the size of a grain of rice that is over half a billion years old, and is the oldest truly bilateral animal ever found -- meaning what we're looking at may be a very close cousin to the ancestor of all the current bilateral animals on Earth.

In "Discovery of the Oldest Bilaterian from the Ediacaran of South Australia," by Scott D. Evans and Mary L. Droser (of the University of California-Riverside), Ian V. Hughes (of the University of California-San Diego), and James G. Gehling (of the South Australia Museum Department of Paleontology), we read about Ikaria wariootia, a teardrop-shaped critter whose unprepossessing appearance belies its significance.  This tiny little proto-worm might actually be our great-great-great (etc. etc. etc.) grandparent.

The impressions left by Ikaria wariootia [Image credit: Scott D. Evans, UCR]

Not only was it bilateral, it had a throughput digestive system (two openings, one-way flow of material), another innovation that has turned out to be pretty important.  "One major difference with a grain of rice is that Ikaria had a large and small end," said study lead author Scott Evans, in an interview with The Guardian.  "This may seem trivial but that means it had a distinct front and back end, which is the kind of organization that leads to the variety of things with heads and tails that are around today."

Of course, this doesn't solve the question of whether bilateral symmetry is constrained or not.  My guess is that if it turns out to be, it will be because mirror-symmetry is easier to produce genetically.  A lot of the homeotic genes (genes that guide the development of overall body plan) work by creating a gradient of some chemical or another, so the polarity of structures is established (head here, butt there, and so forth).  It might simply be easier to establish a one-way gradient, with a high on one end and a low on the other, than one with multiple highs and lows arranged symmetrically.

Although we do manage to do a five-point gradient in the development of our fingers and toes, so it's doable.  It just may not be common.

In any case, here we have a creature that may be the reason we're arranged bilaterally, whether or not it gives us any sort of advantage.  Kind of humbling that we might come from a millimeter-wide burrowing scavenger.  I guess that's okay, though, if it'll keep humanity from getting any cockier than it already is.

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Scary times

Dear Readers:

This is to let you know of some upcoming changes.

Some of you might know I also write over at Substack, and over there have focused mainly on writing, fiction, storytelling, and how stories and mythology have woven their way through history.  I've noticed that in the last year or two, this site (and Blogger in general) has been swamped with bots and AI scrapers, and I think it's time to switch platforms, and only write through Substack.

I welcome you all to subscribe to my site at the link above (for free!).  The plan is on Mondays and Thursdays, I'll focus on stories, storytelling, and language, and on Tuesdays and Fridays I'll write the science news and critical thinking posts you've found here at Skeptophilia.  Wednesdays and Saturdays will be anyone's guess!  Sometimes one, sometimes the other, sometimes wherever my chaotic brain takes me.

At some point I'll be offering in addition some paid-subscriber-only content, like audio chapters from one of my books, some quick video mini-lessons on a topic in critical thinking, or something else fun and extra.  But for now, everything's free for everyone.

If you've been accessing Skeptophilia through social media (Facebook or Bluesky), no worries -- I'll still be posting links there, so you don't have to do anything different.  The links will look a bit different, but that's the only change.

This week, I'll have Tuesday's and Friday's posts in both places, but Friday will be the last post here at Skeptophilia.  Starting next week, I'll only be posting to Substack.  However, my old Skeptophilia posts will still be available here to browse through!

I hope you'll join me over there, subscribe, and continue to comment and interact!

I've been at this for sixteen years -- thanks for the encouragement that keeps me going.

Best,

Gordon

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It's an interesting question to consider how long a human life expectancy would be if we had a time machine (or, as my friend Andrew Butters would correct me, a space-time machine).

There are all the possibilities during recorded history, some of which would be dramatically worse than others (depending, of course, on exactly where you decided to go).  Southeastern Europe in the mid-fifth century would be a poor choice, given the fact that Attila the Hun was kind of trampling the place, causing chaos amongst the Goths (who were already there) and the Romans (who wished the whole lot of them would just go away).  Just about anywhere and any time, of course, would have been worse if you were poor; the "nasty, poor, brutish, and short" quip about people's lives in the past is all too accurate, and worse still if you didn't have privilege (a condition that sadly hasn't changed much).

But if you could add in prehistoric times, there are choices that would be a great deal worse than any time in recorded history.  And that's even assuming you're eliminating periods prior to the Great Oxidation Event, when the Earth's atmosphere would have killed you rapidly if you didn't think to bring along an oxygen supply.  Likewise, let's put out of the running the Late Ordovician (Hirnantian) Glaciation Event, when damn near the entire Earth was covered in glacial ice, and events like the Chicxulub Meteorite Collision.  Hard to imagine how we could survive either one of those.

One time period that often comes up in these discussions is the Carboniferous.  This was the era of the enormous arthropods -- dragonflies like Meganeura with its 75-centimeter wingspan, and the two-meter-long millipede Arthropleura -- which are thought to have evolved because of the favorable conditions of warmth, moisture, and an oxygen concentration in the atmosphere that may have exceeded thirty percent.  But honestly, there's no certainty these things would have been all that dangerous to something the size of a human; so other than the "ooh, icky, creepy-crawlies with lots of legs" issue, the Carboniferous would probably not have been all that bad.

For my money, the odds-on winner is the mid- to late-Cretaceous.  Not, perhaps, for the reason you're thinking; that period of Earth's (pre)history always brings to mind the Tyrannosaurus rex and the Velociraptor, which were certainly scary beasts.  But they are far from the only thing you'd have to worry about, should your space-time machine drop you off there.

I wrote just last month about the Kem Kem Formation in Morocco, a shale and limestone deposit formed when that part of the world was a shallow ocean, and what is now the Sahara was a tropical rain forest.  This place was, to put not too fine a point on it, a fucking nightmare.  It was home to the schoolbus-sized theropod Carcharadontosaurus, which had twenty-centimeter teeth serrated like steak knives; twenty-meter long crocodilians like Aegisuchus; and the pterodactyloid Apatorhamphus, with a five-meter wingspan and dozens of needle-sharp teeth.

Carcharodontosaurus skull [Image licensed under the Creative Commons Matthew Deery, Ultimate Dinosaurs Carcharodontosaurus, CC BY 2.0]

Oh, so don't head to Morocco, then!  We'd be fine!  Right?

Not really.  The region bordering the  Western Interior Seaway, which bisected North America from north to south during the same time period (and is why Montana, the Dakotas, Nebraska, and Kansas are such great places to find fossils), was no better.  There was a horrific fish called Xiphactinus that was five meters long.  The Seaway was also home to mosasaurs, carnivorous reptiles that could get to be over twice that length.  The plesiosaurs, whose shape will be familiar to aficionados of the Loch Ness Monster, were longer still.

If you were to visit the Cretaceous, going for a nice skinnydip would not be recommended.

Xiphactinus skeleton [Image licensed under the Creative Commons Jonathan Chen, Xiphactinus AMNH, CC BY-SA 4.0]

The reason this stuff all comes up is a rather ghastly set of fossils from that time period that was the subject of a paper in Nature this week.  A group of paleontologists, let by Jongyoon Jung of the University of Texas - Austin, discovered sets of tracks at a Cretaceous-age site in South Korea.  One of the sets has been analyzed and found to come from an azhdarchid pterosaur that is new to science.  The team named it Jinjuichnus procerus, and from its tracks they've concluded that (1) it seems to have come down to the ground to hunt, (2) walked on its knuckles while it was doing so, and (3) had an eight-meter wingspan.  If that's not bad enough, there's a second set of tracks, from an unidentified small terrestrial vertebrate.  The two sets of tracks intersect, and there's a confused mess of marks at their intersection.

Guess what that means.

If our imaginations weren't bad enough, the scientists have kindly provided us with the following artist's rendition of the event:

[Image credit: artist Jun Seung Yi, Creative Commons CC BY 4.0 License]

Just in case you needed some more fuel for your dreams tonight.

So.  Yeah.  Dinosaur enthusiast though I am, I would not jump at the chance for a trip back to the Cretaceous.  In fact, considering what I know about most of Earth's geological time periods, I think I'll stay put right here where there are not many creatures with Big Nasty Pointy Teeth, and there are nice features like modern medicine, water purification systems, and indoor plumbing.

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Attack of the goblins

Don't worry, the techbros tell us.  AI is gonna be awesome.  Look at how much it can do, how fast it's improving.  At the same time, the scoffers tell us that okay, maybe it's pretty impressive, but keep in mind it's just completely deterministic software, and its failings happen mainly because it's been trained on questionable input.  You hear the phrase "garbage in, garbage out" pretty frequently, usually along with a shrug of the shoulders.

What both of these viewpoints fail to acknowledge is how freakin' weird some of the AI/LLMs have been acting.  We had a guy named Matt Schlicht creating an AI-only social media site called "Moltbook" -- in 72 hours, over a million AI accounts had joined, and within a week they'd created their own religion, called the "Church of Molt."  Just a few weeks ago, a company called Just Like Me launched an AI Jesus, trained on the King James Bible no less, whom you can have a chat with for $1.99 a minute.  AI Jesus is a vaguely Middle Eastern-looking guy with long tousled hair and a gentle smile, and although the company says in the fine print that this "is not Jesus Christ himself, and does not possess divine authority," I can only imagine the effect such a conversation might have on someone who is already a true believer.

But if you think this is as weird as it gets, I got news for you.

Open AI's ChatGPT -- one of the most widely used AI/LLMs in the world -- has suddenly developed a strange affinity for...

... I swear I'm not making this up...

... goblins.

The problem apparently started last November, when there was a strange uptick in ChatGPT's use of words like goblin, gremlin, and troll.  At first, it just seemed like a quirk, and that perhaps it was happening because people heard from friends that they'd been getting responses involving mythological humanoids, so they put in prompts themselves that generated such output.  But it quickly became obvious that this was more than a blip caused by the users' own prompts.  By the time ChatGPT 5.4 came out two months ago, the use of gremlin had risen by 52%, and goblin by 175%.  And it continued to accelerate.

"The problem evolved from a minor quirk into a persistent 'verbal tic' that was showing up in almost every user conversation," said a company spokesperson.

The origin of the problem, Open AI claims, is that one of the settings you can use when you set up your AI's profile is a persona called "Nerdy," which is described as follows:

You are an unapologetically nerdy, playful and wise AI mentor to a human.  You are passionately enthusiastic about promoting truth, knowledge, philosophy, the scientific method, and critical thinking. […]  You must undercut pretension through playful use of language.  The world is complex and strange, and its strangeness must be acknowledged, analyzed, and enjoyed.  Tackle weighty subjects without falling into the trap of self-seriousness.

Apparently during training, humans who were reviewing the "Nerdy" AI responses to prompts and questions unconsciously rewarded them for using language involving mythological references, such as calling a dangerous place "a troll's lair."  This created a feedback loop in which such "quirky" responses multiplied.  Then, because there's no hard barrier between the different styles of AI personalities -- they're often trained from the same datasets -- the goblins jumped into other personas, and soon, they were everywhere.

The coders started frantically trying to find a solution, and they found the only thing that worked was a top-down, brute force command: “Never talk about goblins, gremlins, raccoons, trolls, ogres, pigeons, or other animals or creatures unless it is absolutely and unambiguously relevant to the user’s query.”

I'm not sure how the raccoons and pigeons got involved, but may as well cover your bases, I guess.

Anyhow, this has more or less fixed the immediate problems, except for two things -- one funny and one not so funny.

The funny one is that of course the conspiracy theorists think that goblins are showing up in ChatGPT because there actually are goblins -- well, electronic ones -- within the internet, and they're trying to get out.  Or warn us of something.  Or steal our souls.  Or destroy the world.  You know the drill; something odd happens, and the modern Chickens Little start running around claiming the sky is falling.  Then, it turns out there's a completely prosaic explanation for what happened, and they calm down for exactly 5.8 milliseconds until they find the next odd thing that's trying to kill us all, and they move on to that, ad infinitum.

The less funny thing is that this kind of unexpected response is an indicator that we really don't have any good way of predicting what AI is going to do.  Okay, yeah, it's running on a purely deterministic machine, but that doesn't mean that its behavior is going to be predictable; hell, the human brain is (at least according to a lot of neuroscientists) a deterministic machine, and we humans can be mighty fucking unpredictable at times.  There's this thing called an emergent property -- something that comes out of the interactions of the parts of the whole, and could not even in principle be predicted from watching the behavior of the pieces in a purely reductionistic fashion -- and AI is looking like it's going to have some emergent properties that will take some monitoring.

We lucked out this time that the "goblins" thing turned out to be more of a quirky nuisance than a real problem, but there's no guarantee that'll be the case next time.  Consider, for example, that just a couple of days ago, an AI being used to handle a routine task for a software company called PocketOS deleted the company's entire database within seconds of being activated -- bypassing all of the security firewalls by using a programming token key no one at the company even knew existed.

And our government "leaders" are gung-ho about turning over our nation's fiscal management and defense to AI-based systems.  Hello?

What the fuck are you people thinking?

Anyhow, like I've said before, so often I'm getting tired of hearing it my own self, we need to put the brakes on AI.  Like, now.  Not that anyone's going to.  The "Oh, it won't happen to me" thing is just too strong.

I'm just hoping the next round of goblins that are released don't have their fingers on any literal triggers.

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Cracker crumbs

Three years ago, I wrote here at Skeptophilia about the scary Cascadia Subduction Zone, which is capable of enormous earthquakes and tsunamis -- and which, unfortunately, lies right off the coast of British Columbia, Washington, and Oregon.  A subduction zone is a region along which two plates are coming together, forcing one underneath the other.  Because rocks experience a high degree of friction, the two plates often get stuck, sometimes for centuries, and then can give suddenly.  This lurch is what causes big earthquakes.

The motive forces here are convection and drag.  Rising plumes of magma underneath ridges diverge, and the friction between the magma plume and the underside of the plates forces them apart.  Where the leading edge of the plate strikes another, something's got to give.  In this case, the oceanic Juan de Fuca Plate, made of (relatively) thin, brittle basaltic rock, hits the old, thicker and colder North American Plate.  The Juan de Fuca Plate jams up and eventually plunges underneath.  The downward drag produces a trench, and inland from the trench you often find volcanoes, created as the subducted plate melts and the molten rock pushes its way to the surface.  (This is how the Cascade Volcanoes, most famously Mount Rainier, Mount Shasta, Mount Hood, and Mount Saint Helens, formed.)

The red dots are undersea earthquakes; the green ones, on-land earthquakes.  [Image is in the Public Domain courtesy of the United States Geological Survey]

What hasn't been clear until now is how exactly subduction happens.  We know that the process usually isn't smooth (as I described, it often goes by fits and starts rather than releasing the compressional force gradually).  But what happens to the plate itself as it descends and is destroyed in the upper mantle?

Thanks to a new study out of Louisiana State University, we now have our first good picture of how this process occurs.

It turns out that the destruction of the last piece of a plate, such as Juan de Fuca -- which is one of the only remaining fragments of the Farallon Plate, that once underlay most of the northeastern Pacific Ocean -- is anything but orderly.  The (relatively) small slab of solid rock beneath the ocean off the coast of the Pacific Northwest is being bent as its eastern edge is pulled downward, creating multiple fractures and dozens of "microplates."  "Getting a subduction zone started is like trying to push a train uphill -- it takes a huge effort," said geologist Brandon Shuck, lead author of the study, which appeared in Science Advances. "But once it's moving, it's like the train is racing downhill, impossible to stop.  Ending it requires something dramatic -- basically, a train wreck...  This is the first time we have a clear picture of a subduction zone caught in the act of dying.  Rather than shutting down all at once, the plate is ripping apart piece by piece, creating smaller microplates and new boundaries.  So instead of a big train wreck, it's like watching a train slowly derail, one car at a time."

Which, if you think about it, makes sense.  Picture shoving together two saltine crackers.  One will likely push underneath the other, but the leading edges are going to crumble, and what you'll be left with will probably be a disordered pile of cracker crumbs.

This process doesn't really change the picture with regards to earthquake risk; just because the plate is shattering into smaller chunks doesn't mean the effects will be small when the breaks occur.  One example -- the Shuck et al. research found a major, 75-kilometer long fault where pieces of it have dropped by five kilometers.  The scary part is that despite the fault collapse, it's not done separating.  "This is a very large fault that's actively breaking the [subducting] plate," Shuck said.  "It's not one hundred percent torn off yet, but it's close."

Further reinforcing my assessment that while I dearly love the Pacific Northwest for some of the most beautiful scenery in the world and the absolute best gardening climate in the United States, I'd never live there again.

It bears mention, however, that it may be that the fault won't rupture for another two hundred years; on the other hand, it could happen tomorrow.  While our ability to analyze plate tectonics is light years beyond what it was even thirty years ago, when the situation in the Northwest first began to come clear, we still don't have any way to determine when the earthquake will happen with any kind of precision.  At the moment, all we know is that it will rupture, sooner or later.

And I don't want to be anywhere near it when it does.

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Tense situation

In my Critical Thinking classes, I did a unit on statistics and data, and how you tell if a measurement is worth paying attention to.  One of the first things to consider, I told them, is whether a particular piece of data is accurate or merely precise -- two words that in common parlance are used interchangeably.

In science, though, they don't mean the same thing.  A piece of equipment is said to be precise if it gives you close to the same value every time.  Accuracy is a higher standard; data are accurate if the values are not only close to each other when measured with the same equipment, but agree with data taken independently, using a different device or a different method.

A simple example is that if my bathroom scale tells me every day for a month that my mass is (to within one kilogram either way) 239 kilograms, it's highly precise, but very inaccurate.

This is why scientists always look for independent corroboration of their data.  It's not enough to keep getting the same numbers over and over; you've got to be certain those numbers actually reflect reality.

This all comes up because of an exciting new approach to one of the most vexing scientific questions known -- the rate of expansion of the entire universe.

[Image is in the Public Domain, courtesy of NASA]

A while back, I wrote about some experiments that were allowing physicists to home in on the Hubble constant, a quantity that is a measure of how fast everything in the universe is flying apart.  And initially, the news appeared to be good; from a range of between 50 and 500, physicists had been able to narrow down the value of the Hubble constant to between 65.3 and 75.6.

The problem is, nobody's been able to get closer than that -- and in fact, recent measurements have widened, not narrowed, the gap.

There are two main ways to measure the Hubble constant.  The first is to use information from Type 1A supernovae (whose brightening and eventual dimming curves are connected to their intrinsic brightness) and Cepheid variables (stars whose period of brightness oscillation varies predictably with their luminosity); these properties make them good "standard candles" to determine the distance to other galaxies.  Once you know a star's intrinsic luminosity, you can use that to determine how far away it is -- just as you can estimate your distance to an oncoming motorcycle at night because you know how bright a motorcycle's headlight actually is.  This, coupled with the galaxy's redshift, allows you to figure out how fast the galaxies we see are receding from each other, and thus, how fast space is expanding. 

The other method is to use the cosmic microwave background radiation -- the leftovers from the radiation produced by the Big Bang -- to determine the age of the universe, and therefore, how much bigger it's gotten since then.  The problem with this method is that it relies heavily on the correctness of our current models of the evolution of the universe, some of which have resulted in predictions not matched by the available observations.

Here's the issue: not only does each of the methods -- standard candles/cosmic ladder, and the CMBR method -- each have its difficulties, the measurement of the Hubble constant by these two methods has resulted in two irreconcilably different values.

So the astrophysicists have tried to narrow in from both ends.  Improve the data, and improve the models.  This backfired.  As our measurement ability has become more and more precise, the error bars associated with data collection have shrunk considerably; at the same time, the models have improved dramatically.  You'd think this would result in the two values getting closer and closer together.

Exactly the opposite has happened.

This result, called the Hubble tension, is considered to be one of the most frustrating problems in astrophysics.  And it's not just some fringe-y side quest; this is a fundamental issue with our understanding of the entire universe.

Here's where the new research, out of the Technical University of Münich, comes in.  You probably know about the phenomenon of gravitational lensing, where light traveling through the curved space near a massive object (like a galaxy or a supermassive black hole) gets bent, in much the same fashion as light going through a glass lens.  Sometimes this causes distant bright objects to look like they're stretched, or even multiplied.  For these objects, there is more than one pathway the light can take through space to get here to us, so the image we see is distorted.

Well, we've just detected one of the most remarkable examples of gravitational lensing ever observed; a supernova in a brilliant galaxy whose light split up into five separate paths in order to get here.

Put a different way, we saw the same supernova occur five different times.

Now, here's the kicker: because the paths that each of those beams of light took to get here differ in distance, comparing the timing of arrival of each image could give us the first-ever direct, no-assumptions-required method of measuring the Hubble constant, one with far fewer systematic uncertainties.

"We nicknamed this supernova SN Winny, inspired by its official designation SN 2025wny," said astrophysicist Sherry Suyu, who co-wrote the paper on the discovery.  "It is an extremely rare event that could play a key role in improving our understanding of the cosmos.  The chance of finding a superluminous supernova perfectly aligned with a suitable gravitational lens is lower than one in a million.  We spent six years searching for such an event by compiling a list of promising gravitational lenses, and in August 2025, SN Winny matched exactly with one of them."

In-depth analysis of the timing and positions of the five supernova appearances is currently underway.

Whether this will resolve the Hubble tension, of course, remains to be seen.  The worst-case scenario is that the SN Winny data doesn't agree with either the cosmic ladder value or the CMBR value, or has error bars large enough to overlap with both.  A happier outcome would be a decisive landing in one camp or the other -- although that'd still leave the astrophysicists puzzling over why the losing method doesn't work.

But it's an incredible discovery, and I know I'll be watching the science news to see what comes out of it.  Settling the Hubble tension question would be an amazing coup; having it resolved because of a one-in-a-million observation of a lensed supernova -- well, if you don't find that super cool, I don't even know what to say to you.

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Heap of trouble

In my AP Biology class, we did a lab that involved extracting chlorophyll from spinach leaves.  The first step was to grind the leaves into a paste with a bit of solvent, which we did the old-fashioned way using a mortar and pestle.

The instructions said to add a "small amount of fine sand" to the leaves (to act as an abrasive, facilitating the breakup of the tough cell walls), and one of my students -- a little on the tightly-wound side, as I recall -- asked how much to add.

"Doesn't matter," I said.  "Some.  A pinch.  You're going to filter it out at the end anyhow."

This didn't satisfy her.  Everything else was measured to high accuracy, so the sand should be, too.  How much sand was "some"?

I grabbed a pinch of sand between my thumb and index finger and tossed it into the mortar.

"There you go," I said.  "All fixed."

She gave me the suspicious side-eye, as if by my insouciance I had ruined her chance of getting good results.  As I recall, she did just fine on the lab, but I don't think she quite trusted my lab technique afterward.

A couple of amused students who overheard the conversation got into a discussion about the imprecision of measuring-words in English, and decided to fix matters by constructing a list:

2: a couple
3: a few
4: some
5: a bunch
6: a lot
7: quite a lot
8: a helluva lot
etc.

I recall that they got up to 20, which was "a shitload."

After showing the list to me, they did admit that these designations could shift depending on what you're talking about.

What I didn't realize until recently was that this discussion, as lighthearted (honestly, ridiculous) as it was, touched on a paradox that has been around for at least 2,400 years -- the Sorites Paradox.  The name comes from the Greek word σωρός, meaning "heap," and is attributed to the fourth century B.C.E. philosopher Eubulides of Miletus, who is said to have formulated it.  It goes something like this:

Let's say you have a million grains of sand in a pile, sitting on the left side of the table.  Nearly everyone would agree that this constitutes a "heap of sand."  On the right side of the table, you have a single grain of sand.  No one, I suspect, would say that one grain of sand is a heap.  Okay, so that means that if you remove one grain at a time from the left-hand side, at some point it changes from "a heap" to "not-a-heap."

When does that happen?

It's not just the word heap that has this problem.  Take away one teaspoonful of water at a time from the ocean, and at some point -- admittedly, it'd take a while -- what's left would no longer be an "ocean."  When does that change happen?

How about old?  Along the pathway of life, I think we can all agree that a fifteen-year-old is "young," and a ninety-year-old is "old."  So, when do things flip?

I'm currently sixty-five, and I will not admit to being old, so anyone inclined to answer should keep that in mind.

This also relates to another famous paradox, the Ship of Theseus.  If you take Theseus's ship and replace, one at a time, each of the components that make it up, at what point does it cease to be the original ship?

One solution to the Sorites Paradox is simply to declare these things a continuum, which therefore renders such questions essentially meaningless.  The problem is, the number of grains of sand in a heap isn't a continuum; it's necessarily an integer (you can't have a heap made of 1,827,793-and-a-half grains of sand).  Neither, for that matter, are the pieces of a ship.  So while this might be a reasonable response in cases of true continua (such as age, water volume, or the colors of light in a rainbow), it doesn't work in systems with discrete states.

So maybe it's just unanswerable, and relies simply on usage -- language is inherently vague, and there's nothing to be done.  This is the stance of British philosopher Timothy Williamson and others, who solve the Sorites Paradox by shrugging their shoulders; there is a point where a heap becomes not-a-heap, but where the point lies is unknowable.

While all this might seem like nothing more than philosophical noodling, it has its serious applications.  The question of when depictions of sex in movies cross the line into obscenity or pornography (therefore suggesting that they should be subject to censorship) made it all the way to the Supreme Court, which ruled that the movie in question -- Louis Malle's The Lovers -- wasn't pornography, even if the court couldn't come up with a good definition of where the line was.  "I could never succeed in intelligibly [defining pornography]," Justice Potter Stewart famously said, "but I know it when I see it."

The Sorites Paradox also has a strange connection to evolutionary biology, and one that knocks a neat hole into the creationists' assertion that every species represents a "kind" that is in some sort of hard-and-fast, unchangeable box.  The issue is with ring species, of which there have been several described (two well-studied ones are circumpolar populations of gulls of the genus Larus, and populations of the Greenish Warbler around the Himalayas).  In a ring species, adjacent, similar-but-distinct groups can interbreed, and thus by definition should belong to the same species.  The problem is, the ends of the ring have diverged enough that where they do overlap, they no longer can interbreed, and thus should be separate species.  But where do you draw the line?  No matter where you do, you end up separating individuals that (by the canonical definition of the word species) should belong together.

Or -- to take Williamson's approach -- maybe the problem is trying to force a fuzzy reality to conform to limited, inaccurate use of language, and the word species is simply kind of a mess.  This is my opinion on the matter; I tend to agree with my evolutionary biology professor, who memorably said, "The only reason we came up with the concept of species is that we have no near relatives."

A ring species of salamanders in California [Image licensed under the Creative Commons Thomas J. Devitt, Stuart J.E. Baird and Craig Moritz, Ensatina eschscholtzii ring species, CC BY 2.0]

Anyhow, that's today's consideration of a philosophical problem that has been around for over two thousand years, and thus is clearly above my pay grade to weigh in on.  Not that this ever stops me.  Now, y'all'll have to excuse me, because I need to go work in my garden spreading the heap of bark mulch we just had delivered, an amount that is clearly "a shitload."

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The Estes method

In somewhat the same vein as yesterday's post, which was about the capacity of subsonic standing waves to induce the sensations we often associate with a haunting, today we have: a way to pick paranormal messages out of ambient (and random) noise.

You've probably heard about the idea of electronic voice phenomena, which was popularized as a ghost-hunting method by Latvian paranormal researcher Konstantīns Raudive in the 1970s and has become a standard tool in the kit ever since.  The idea is that you place a recording device of some kind -- it started out with reel-to-reel, then cassette tape recorders, and finally moved on to digital voice recorders -- in an allegedly haunted location, leave it running, and later listen to the recording for any anomalous sounds.  Adepts claim that they hear human voices.

The method was used to great effect in the brilliant Doctor Who episode "Hide," although it turned out that what Clara and the Eleventh Doctor were talking to wasn't a ghost, it was a time-traveler trapped in an alternate universe.  As one does. 

Some of these EVP are more convincing than others, but all of them tend to be muffled and slurred, and to benefit greatly from the phenomenon of suggestion -- once someone tells you that the voice is a ghost saying "I died in 1859" you're much more likely to hear the message.  This is the same thing that occurred with the foolishness surrounding backmasking -- that supposedly, rock bands were including satanic messages in their music that could only be understood consciously if you played the song backwards, but could be somehow picked up subliminally even if you heard it played forwards.  (One of the most popular claims of backmasking involved Led Zeppelin's famous "Stairway to Heaven.")  The problem is, even played backwards, the messages are pretty damn garbled -- but miraculously clear up when you know ahead of time what it's supposed to be saying.

As James Randi put it, "You can't miss it if I tell you what's there."

Graphical plot of white noise waveform [Image licensed under the Creative Commons Omegatron, White-noise, CC BY-SA 3.0]

There's apparently a new way to approach all this that's becoming popular amongst the ghost hunting crowd, and I learned about it from British paranormalist Ashley Knibb's website just yesterday.  It's called the "Estes method," named after Estes Park, Colorado, home of the Stanley Hotel (made famous in The Shining).  The idea here is that a volunteer "receiver" is blindfolded and puts on headphones connected to a radio that's set on "scan" mode, so the only auditory input (s)he gets is blips and fragments of speech or music, interspersed with white noise.  Another volunteer, the "recorder," asks questions -- not of the receiver, but of any ghosts that happen to be present -- while the receiver (who, presumably, can't hear the receiver) reports any interesting phrases heard from the random radio input, which the recorder then writes down.

The claim is that this isolates the receiver; (s)he relies only on any ghosts present to jigger about with the radio and use its audio output to answer what the recorder is asking.

Well, okay.  There are a couple of problems with this, and to his credit, Knibb mentions both of them (although you get the feeling he is still inclined to think that something paranormal may be going on here).

The first is that how the random phrases picked up by the receiver are interpreted afterward is very much dependent upon the subjective opinions of the ones doing the interpretation.  You may recall the famous experiment done by Carl Sagan in a high school class, where he told the students that their birthdates and times had been used to draw up astrological charts and create a personality profile for each of them, and handed out cards with the results.  The students were then asked to rate how accurately it described them, from zero to ten.  Not a single card received a score lower than six; most were between eight and ten.

Wow, astrology vindicated, right?

Not exactly.  Sagan then had the students exchange cards with a neighbor -- and it turned out they'd all been given the same personality profiles.

The point is, when we are given some random piece of text, we're all too likely to interpret it as if it means something -- especially if we walked into the situation already primed to think it does.

The second problem, of course, is exactly the same as what I described in yesterday's post; apophenia, our built-in tendency to find order in random input.  The receiver in the Estes method is trying his/her hardest to listen for anything that sounds meaningful; after all, that's why (s)he's there.  It's not a far step to consider the possibility that the receiver might (even if unconsciously) create something meaningful out of what is, honestly, chaos.

Again, as with yesterday, I'm not accusing anyone of anything underhanded.  Hoaxes aren't even necessary, given how easily our own sensory-perceptive systems can play us false.

So I'm not thinking the Estes method is going to convince anyone who's not already convinced.  As far as the ghost hunters go, no harm if it amuses you, but it still doesn't meet the minimum criterion required for acceptable evidence in a scientific setting.

Me, I'm still in the camp of Andrew MacPhee, the hard-nosed skeptic in C. S. Lewis's novel That Hideous Strength:

"My uncle, Dr. Duncanson," said MacPhee, "whose name may be familiar to you — he was Moderator of the General Assembly over the water, in Scotland — used to say, 'Show it to me in the word of God.'  And then he’d slap the big Bible on the table.  It was a way he had of shutting up people that came to him blathering about religious experiences.  And granting his premises, he was quite right.  I don’t hold his views, Mrs. Studdock, you understand, but I work on the same principles.  If anything wants Andrew MacPhee to believe in its existence, I’ll be obliged if it will present itself in full daylight, with a sufficient number of witnesses present, and not get shy if you hold up a camera or a thermometer."

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