Weathering the storm

Something that really grinds my gears is how quick people can be to trumpet their own ignorance, seemingly with pride.

I recall being in a school board budget meeting some years ago, and the science department line items were being discussed.  One of the proposed equipment purchases that came up was an electronic weather station for the Earth Science classroom.  And a local attending the meeting said, loud enough for all to hear, "Why the hell do they need a weather station?  If I want to know what the weather is, I stick my head out the window!  Hurr hurr hurr hurr durr!"

Several of his friends joined in the laughter, while I -- and the rest of the science faculty in attendance -- sat there quietly attempting to bring our blood pressures back down to non-lethal levels.

What astonishes me about this idiotic comment is two things: (1) my aforementioned bafflement about why he was so quick to demonstrate to everyone at the meeting that he was ignorant; and (2) what it said about his own level of curiosity.  When I don't know something, my first thought is not to ridicule but to ask questions.  If I thought an electronic weather station might be an odd or a frivolous purchase, I would have asked what exactly the thing did, and how it was better than "sticking my head out the window."  The Earth Science teacher -- who was in attendance that evening -- could then have explained it to me.

And afterward, miracle of miracles, I might have learned something.

All sciences are to some extent prone to this "I'm ignorant and I'm proud of it" attitude by laypeople, but meteorology may be the worst.  How many times have you heard people say things like, "A fifty percent chance of rain?  How many jobs can you think of where you could get as good results by flipping a coin, and still get paid?"  It took me a fifteen-second Google search to find the weather.gov page explaining that the "probability of precipitation" percentages mean something a great deal more specific than the forecasters throwing their hands in the air and saying, "Might happen, might not."  A fifty-percent chance of rain means that in the forecast area, any given point has a fifty percent chance of receiving at least 0.01" of rain; from this it's obvious that if there's a fifty percent chance over a large geographical area, the likelihood of someone receiving rain in the region is much greater than fifty percent.  (These middling percentages are far more common in the northern hemisphere's summer, when much of the rain falls in the form of sporadic local thunderstorms that are extremely hard to predict precisely.  If you live in the US Midwest or anywhere in the eastern half of North America, you can probably remember times when you got rain and your friends five miles away didn't, or vice versa.)

[Image licensed under the Creative Commons Walter Baxter, The Milestone weather forecasting stone - geograph.org.uk - 1708774, CC BY-SA 2.0]

The problem is, meteorology is complex.  Computer models of the atmosphere rely on estimates of conditions (barometric pressure, temperature, humidity, air speed both vertically and horizontally, and particulate content, to name a few) along with mathematical equations describing how those quantities vary over time and influence each other.  The results are never completely accurate, and extending forward in time -- long-range forecasting -- is still nearly impossible except in the broadest-brush sense.  Add to that the fact there are weather phenomena that are still largely unexplained; one of the weirdest is the Catatumbo lightning, which occurs near where the Catatumbo River flows into Lake Maracaibo in Venezuela.  That one small region gets significant lightning 140 to 160 days a year, nine hours per day, and with lightning flashes from sixteen to forty times per minute.  The area sees the highest density of lightning in the world, at 250 strikes per square kilometer -- and no one knows why.

[Image licensed under the Creative Commons Fernando Flores, Catatumbo Lightning (141677107), CC BY-SA 3.0]

Despite the inaccuracies and the gaps in our understanding, we are far ahead of the idiotic "they're just flipping a coin" that the non-science types would have you believe.  The deadliest North American hurricane on record, the 1900 Galveston storm that took an estimated eight thousand lives, was as devastating as it was precisely because back then, forecasting was so rudimentary that almost no one knew it was coming.  Today we usually have days, sometimes weeks, of warning before major weather events -- and yet, if the prediction is off by a few hours or landfall is inaccurate by ten miles, people still complain that "the meteorologists are just making guesses."

What's grimly ironic is that we might get our chance to find out what it's like to go back to a United States where we actually don't have accurate weather forecasting, because Trump and his cronies have cut the National Weather Service and the National Oceanic and Atmospheric Administration to the bone.  The motivation was, I suspect, largely because of the Right's pro-fossil-fuels, anti-climate-change bias, but the result will be to hobble our ability to make precise forecasts and get people out of harm's way.  You think the central Texas floods in the first week of July were bad?

Keep in mind that Atlantic hurricane season has just started, as well as the western wildfire season.  The already understaffed NWS and NOAA offices are now running on skeleton crews, just at the point when skilled forecasters are needed the most.  My intuition is you ain't seen nothin' yet.

Oh, and don't ask FEMA to help you after the disaster hits.  That's been cut, too.  Following the Texas floods, thousands of calls from survivors to FEMA were never returned, because Homeland Security Secretary Kristi Noem was too busy cosplaying at Alligator Auschwitz to bother doing anything about the situation.  (She responded to criticism by stating that FEMA "responded to every caller swiftly and efficiently," following the Trump approach that all you have to do is lie egregiously and it automatically becomes true.)

Ignorance is nothing to be embarrassed about, but it's also nothing to be proud of.  And when people's ignorance impels them to elect ignorant ideologues as leaders, the whole thing becomes downright dangerous.  Learn some science yourself, sure; the whole fifteen-year run of Skeptophilia could probably be summed up in that sentence.

But more than that -- demand that our leaders base their decisions on facts, logic, science, and evidence, not ideology, bias, and who happens to have dumped the most money into the election campaign.  We're standing on a precipice right now, and we can't afford to be silent.

Otherwise I'm very much afraid we'll find out all too quickly which way the wind is blowing.

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Cats in boxes

Any cat owners amongst my readers will undoubtedly know about the strange propensity of cats to climb into boxes.  Apparently it works for cats of all sizes:

With apologies to Robert Burns, a cat's a cat for a' that.

In fact, it doesn't even have to be a real box:

I've never heard a particularly convincing explanation of why cats do this.  Some people suggest it's because being in close quarters gives them a sense of security, perhaps a remnant of when they lived in the wild and slept in burrows or caves.  Me, I suspect it's just because cats are a little weird.  I've been of this opinion ever since owning a very strange cat named Puck, who used to sleep on the arm of the couch with one front and one back leg hanging limp on one side of the arm and the other two dangling over the other side, a pose that earned her the nickname "Monorail Cat."  She also had eyes that didn't quite line up, and a broken fang that caused her tongue to stick out of one side of her mouth.  She was quite a sweet-natured cat, really, but even people who love cats thought Puck looked like she had a screw loose.

The topic comes up because of a delightful piece of research in the journal Applied Animal Behaviour Science.  The paper was titled "If I Fits, I Sits: A Citizen Science Investigation into Illusory Contour Susceptibility in Domestic Cats," by Gabriella Smith and Sarah-Elizabeth Byosiere (of Hunter College) and Philippe Chouinard (of LaTrobe University), and looked at data collected from cat owners to find out if cats are fooled by the Kanizsa Rectangle Illusion.

The Kanizsa Rectangle Illusion is an image that tricks the brains into seeing contours that aren't there.  Here's one representation of it:

To most people, this looks like an opaque white rectangle laid over four black hexagons, and not what it really is -- four black hexagons with triangular wedges cut out.  Apparently the brain goes with an Ockham's Razor-ish approach to interpreting what it sees, deducing that a white rectangle on top of black hexagons is much more likely than having the cut-out bits just happening to line up perfectly.  It's amazing, though, how quickly this decision is made; we don't go through a back-and-forth "is it this, or is it that?"; the illusion is instantaneous, and so convincing that many of us can almost see the entire boundary of the rectangle even though there's nothing there.

Well, apparently, so can cats.  And, as one would expect, they sit in the middle of the nonexistent rectangle just as if it was a real box.  The authors write:

A well-known phenomenon to cat owners is the tendency of their cats to sit in enclosed spaces such as boxes, laundry baskets, and even shape outlines taped on the floor.  This investigative study asks whether domestic cats (Felis silvestris catus) are also susceptible to sitting in enclosures that are illusory in nature, utilizing cats’ attraction to box-like spaces to assess their perception of the Kanizsa square visual illusion...  [T]his study randomly assigned citizen science participants booklets of six randomized, counterbalanced daily stimuli to print out, prepare, and place on the floor in pairs.  Owners observed and videorecorded their cats’ behavior with the stimuli and reported findings from home over the course of the six daily trials...  This study revealed that cats selected the Kanizsa illusion just as often as the square and more often than the control, indicating that domestic cats may treat the subjective Kanizsa contours as they do real contours.

It's a fascinating result, and indicative that other animal species see the world much as we do.  It still doesn't explain why cats like to sit in boxes, though.  I think my conclusion ("cats are weird") covers it about as well as anything.  But at least in one way, our perceptual/interpretive centers are just as weird as the cats' are.  I'm not inclined to go sit in a box, but it does make me wonder what our pets would think if we showed them other optical illusions.

I doubt my dogs would be interested.  If what they're looking at has nothing to do with food, petting, napping, or playing, they pretty much ignore it.  Must be nice to see the world in such simple terms.

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Footprints

The southern tip of mainland Italy is called Calabria.  It's a strikingly beautiful place, containing three national parks (Pollino National Park, Sila National Park and Aspromonte National Park), and a stretch of coastline -- near Reggio, facing across the Straits of Messina to Sicily -- that poet Gabriele D'Annunzio called "the most beautiful kilometer in Italy."  It's a region blessed with more than its share of dramatic scenery.

[Image licensed under the Creative Commons Cliff at Tropea, Italy, Sep 2005 , CC BY-SA 2.5]

Calabria forms the "toe of Italy's boot."  I remember noticing the country's odd shape when I was a kid and first became fascinated with maps (a fascination that remains with me today), and wondering why it looked like that; back then, when plate tectonics was still a new science, I doubt they really understood it on a level any deeper than "it's near a plate margin, and that moves stuff around."  Today, we have a much more detailed understanding of the geology of the area, and it is complex.

Tectonic map of southern Italy and Sicily [Image licensed under the Creative Commons Jpvandijk, J.P. van Dijk, Janpieter van Dijk, Johannes Petrus van Dijk, CentralMediterranean-GeotectonicMap, CC BY-SA 4.0]

On its simplest level, the entire southern half of Italy is being pushed to the southeast, and it's riding up and over the northern edge of the African Plate.  This process is responsible not only for the volcanism of the region -- Mount Etna being the most obvious example -- but the massive earthquakes that have shaped it, in part creating the gorgeous topography.  (It also has made it a dangerous place to live.  The Messina Earthquake of 1908, with an epicenter right across the straits from Calabria, had a magnitude of 7.1 and killed an estimated eighty thousand people, most of them in the first three minutes after the quake struck and the majority of the buildings collapsed.)

As interesting as the geology of the region is, that's not what spurred me to write about the topic today.  What I'd like to tell you about is Calabria's tremendous linguistic diversity, an embarrassment of riches packed into a small geographical area.  The main language, of course, is standard Italian, but a great many people there (especially in the southern parts) speak Calabrian, a Greek-influenced-Latin derivative that is mostly mutually intelligible with Italian but has some distinct vocabulary and pronunciations. 

Then there's Grecanico, which is derived from an archaic dialect of Byzantine Greek, and is spoken by a group of people descended from folks who settled in the region more than a thousand years ago and have somehow maintained their ethnic identity the whole time.  It's written with the Latin, not Greek, alphabet -- but other than that has more in common with Thessalian Greek than with Italian.

Another language that has little to do with Italian is Arbëresh, a dialect of Albanian brought in with migrants during the Late Middle Ages.  From some of its idiosyncrasies, it appears to be related to Tosk Albanian, a group of dialects spoken in the southern parts of Albania, near the border of Greece.  It's astonishing that we can still identify the part of the world the ancestors of the Arbëreshë people came from centuries ago -- by the peculiarities of the language they have spoken during the more than six hundred years they've lived in isolated communities in Calabria.

Finally, there's Gardiol, which is related to Occitan (also known as Provençal or Languedoc), the Romance language widely spoken in the southern half of France.  Like with Calabrian (and also Catalan in Spain), most Occitan speakers in France speak the majority language as well, but use Occitan when speaking with family, friends, and locals.  The ancestors of the speakers of Gardiol came in with the persecution of the Waldensian "heretics" in France in the thirteenth century, who found a refuge in a thinly-populated part of northern Calabria.  Once again -- amazingly -- they've retained their ethnic identity and language through all the vagaries of time since their arrival.

All of that -- and standard Italian as well -- in an area of around fifteen thousand square kilometers, a little more than the size of the state of Connecticut.

UNESCO describes all four of these languages -- Calabrian, Grecanico, Arbëresh, and Gardiol -- as "in serious danger of disappearing."  It's sad to think of these footprints of history vanishing, and taking along with them pieces of human culture that somehow had persisted for centuries.  I understand why this happens; in modern life, speaking and writing the dominant language is not only useful, it's often essential for getting a job and making a living.  These little pockets of other languages survived better when people had little mobility and even less connectedness to others living far away.  In today's world, they seem doomed.

Change is the fate of all things, but it inevitably comes with a sense of loss.  The linguistic diversity of the beautiful region of Calabria will, very likely, soon be gone.  Like biodiversity loss, this diminishes the richness of our world.  I hope that linguists are working to catalog and study these unique languages -- before the last native speakers are gone forever.

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Hello, dolly

You may have heard that a 54-year-old paranormal investigator named Dan Rivera died a few days ago while on tour with a supposedly possessed Raggedy Ann doll named "Annabelle."  I know I have, because about two dozen loyal readers of Skeptophilia have sent me links about the story.

Positively DO NOT.  Whatever you were thinking about doing, just DON'T.

According to the most recent news releases, police found no signs of foul play or anything suspicious about Rivera's death, although more information may come out once an autopsy is performed.

Annabelle has a long history.  Her reputation for supernatural hijinks goes back to the 1970s, when her owner reported odd and scary behavior (moving on her own, leaving scrawled and threatening notes, knocking stuff over in the middle of the night) to none other than Ed and Lorraine Warren.  Ed Warren was a "self-taught demonologist," which is pretty much the only kind there is at the moment, given that Cotton Mather, Tomás de Torquemada, and Girolamo Savonarola are no longer in charge of designing university curricula.  Lorraine was a "light-trance medium" who assisted her husband on his demon-hunting expeditions.  If you've heard of them, it's probably because of their involvement in the famous Amityville Horror case, which was the subject of much hype and a movie featuring one (1) puking nun.  (Interesting fact: my wife, who grew up on Long Island, worked in a record store in Amityville during the height of the craze.  She and her coworkers were constantly being asked "Where's the Horror House?"  Their stock answer was "Take the first left, go about a mile to the third stoplight, then turn right.  Three blocks down, on the right."  In point of fact, none of them knew nor cared where the Horror House was, because they rightly believed that the entire story was bullshit.)

In any case, Annabelle was given to the Warrens, who locked her up in a cabinet in the museum of the occult they ran, but they said they still periodically found her running loose when they got there in the morning, and more than once they heard eerie laughter when no one was there.  This drew the attention of various people, all of whom regretted getting involved.  These allegedly included a skeptic who was given "psychic slashes" that drew blood; a priest who insulted Annabelle and forthwith ran his car into a tree; and a homicide detective who was stabbed by the doll, "receiving injuries that forced him into an early retirement."

The museum closed after Lorraine's death at age 92 in 2019, and the New England Society for Psychic Research took charge of Annabelle, sending her out earlier this year on a "Devils On the Run" tour that showcased items from the Warrens' collection.

You have to wonder why they did this.  I would think the members of the New England Society for Psychic Research would, by and large, believe that all this possessed-doll stuff is completely reasonable.  So wouldn't they go, "Hell no, we gotta keep Annabelle locked up, she's too dangerous, someone could get hurt"?  Nope, they sent her right out on tour, suggesting that either they (1) believe Annabelle's powers are real but don't give a damn if she does injure someone, (2) believe in some psychic stuff but figure Annabelle is nonsense, or (3) don't believe any of it but saw a good opportunity to cash in on the fact that lots of other people do.

You also have to wonder what they think now that one of her handlers has died.

Of course, the great likelihood is that Rivera died of natural causes.  I get that 54 is a pretty young age to drop dead; it'd be surprising, given that I am a 64-year-old person, if that thought didn't cross my mind.  But I'm going to follow my Prime Directive of eliminating all the normal and natural explanations before jumping to a paranormal or supernatural one, and I think once we learn what the autopsy finds, it'll turn out Rivera had a heart attack or stroke.

So it's sad -- from the tributes written by his friends, he sounds like he was a good guy -- but unlikely to be due to the evil machinations of "Annabelle."

One of the people who sent me a link added the message, "Be careful what you write about her, though!  She'll get even with you if you make fun!"  My response to that is:

Ha ha ha ha ha, Annabelle, you are ugly and your mom dresses you funny.  You've got a blank expression, a goofy smile, and what is that triangle-thing in the middle of your face supposed to be?  You call that a nose?  Oh, and you don't like my saying all that?  What're you gonna do about it?  Go ahead, girl, gimme your best shot.  I dare you.

Okay, that should do it.  I'm not sure what the priest said who ended up wrecking his car, but maybe this will be enough for some psychic retribution.

I'll report here if I have any sudden attacks of gout or bursitis or brain aneurysms or whatnot.  Myself, I think I'll probably be okay, but we'll see.  Gordon vs. Annabelle 2025 -- who are you rooting for?

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Who benefits?

One of the most curious features of evolutionary biology is the cui bono principle.

Cui bono? is Latin for "who benefits?" and is an idea that found its first expression in courts of law.  If a crime is committed, look for who benefitted from it.  In evolutionary biology, it's adjuring the researcher to look for an evolutionary explanation for seemingly odd, even self-harming behavior.  Somebody, the principle claims, must benefit from it.

A while back, I did a post on one of the strangest and most complex examples of cui bono; the pathogen Toxoplasma gondii, a protist that primarily infects humans, cats, rats, and mice.  In each, it triggers changes in behavior, but different ones.  It turns rats and mice fearless, and in fact, makes them attracted to the smell of cat urine.  Infected cats are more gregarious and needing of physical contact (either with other cats or with humans).  Humans are more likely to be neurotic and anxious, impelling them to seek comfort from others... including, of course, their pets.  Each of these behaviors increases the likelihood of the pathogen jumping to another host.

That this behavioral engineering is successful can be gauged by the fact that by some estimates three billion people are Toxoplasma-positive.  Yes, that's "billion" with a "b."  As in, one third of the human population.  I can pretty much guarantee that if you've ever owned a cat, you are Toxoplasma-positive.

What effects that has had on the collective behavior of humanity, I'll leave you to ponder.

I just ran into another cool example of cui bono a couple of days ago -- well, cool if you're not a tomato grower.  This is another one for which the answer to "who benefits?" turns out to be a pathogen, this time a virus called tomato yellow leaf curl virus, which has the obvious effect on infected plants.

Uninfected (top) and infected (bottom) tomato plants [Image credit: Zhe Yan et al., MDPI]

The researchers, led by Peng Liang of the Chinese Academy of Agricultural Sciences, noticed a strange pattern; there's a pest of tomato plants (and many other crops) called the silverwing whitefly (Bemisia tabaci) that shows a distinct preference for tomato plants depending on who is infected with what.  If the whitefly is uninfected with the virus, it's preferentially attracted to infected tomato plants; if the whitefly is already infected, it shows a preference for uninfected plants.

So cui bono?  The virus, of course.  Infected whiteflies pass the virus along to uninfected plants, and uninfected whiteflies pick the virus up from infected plants.  Clever.  Insidious, but damn clever.

Liang et al. found that the virus accomplishes this by meddling with a chemical signal from tomato plants called β-myrcene.  The virus actually up-regulates the β-myrcene gene -- essentially, turning the volume up to eleven on β-myrcene's production -- which attracts uninfected whiteflies.  Once the virus gets into the whiteflies, it dials down the sensitivity of the whiteflies' β-myrcene receptors, making them less attracted to it.  

No need to be lured in by the infected plants if you're already infected yourself.

So like with Toxoplasma, we have here a microscopic pathogen that is manipulating the behavior of more than one host species.  It's fascinating but creepy.  You have to wonder what other features of our behavior are being steered by pathogens we might not even be aware of.  Recent studies have found that between five and eight percent of our DNA is composed of endogenous retroviruses -- scraps of DNA left behind by viruses in the genomes of our forebears, and which are suspected to have a role in multiple sclerosis and some forms of schizophrenia.

Who knows what else they might be doing?

If you find this whole topic a little shudder-inducing, you're not alone.  Science is like that sometimes.  If there's one thing I've learned, it's that the universe is under no compulsion to make me feel comfortable.  If you agree, sorry I put you through reading this.  Go cuddle with your kitty.

I'm sure that'll make you feel better.

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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, 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, though, 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 a new look at one of the biggest 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 the news appeared to be good; from a range of between 50 and 500 kilometers per second per megaparsec, 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 like red shift, Cepheid variables (stars whose period of brightness oscillation varies predictably with their intrinsic brightness, making them a good "standard candle" to determine the distance to other galaxies), and type 1a supernovae to figure out how fast the galaxies we see are receding from each other.  The other 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 fast it's expanding.

So this is a little like checking my bathroom scale by weighing myself on it, then comparing my weight as measured by the scale at the gym and seeing if I get the same answer.

And the problem is, the measurement of the Hubble constant by these two methods is increasingly looking like it's resulting in two irreconcilably different values.  

The genesis of the problem is that as our measurement ability has become more and more precise, the error bars associated with data collection have shrunk considerably.  And if the two measurements were not only precise, but also accurate, you would expect that our increasing precision would result in the two values getting closer and closer together.

Exactly the opposite has happened.

"Five years ago, no one in cosmology was really worried about the question of how fast the universe was expanding," said astrophysicist Daniel Mortlock of Imperial College London.  "We took it for granted.  Now we are having to do a great deal of head scratching – and a lot of research...  Everyone’s best bet was that the difference between the two estimates was just down to chance, and that the two values would converge as more and more measurements were taken. In fact, the opposite has occurred.  The discrepancy has become stronger.  The estimate of the Hubble constant that had the lower value has got a bit lower over the years and the one that was a bit higher has got even greater."

This discrepancy -- called the Hubble tension -- is one of the most vexing problems in astrophysics today.  Especially given that repeated analysis of both the methods used to determine the expansion rate have resulted in no apparent problem with either one.

The two possible solutions to this boil down to (1) our data are off, or (2) there's new physics we don't know about.  A new solution that falls into the first category was proposed last week at the annual meeting of the Royal Astronomical Society by Indranil Banik of the University of Portsmouth, who has been deeply involved in researching this puzzle.  It's possible, he said, that the problem is with one of our fundamental assumptions -- that the universe is both homogeneous and isotropic.

These two are like the ultimate extension of the Copernican principle, that the Earth (and the Solar System and the Milky Way) do not occupy a privileged position in space.  Homogeneity means that any randomly-chosen blob of space is equally likely to have stuff in it as any other; in other words, matter and energy are locally clumpy but universally spread out.  Isotropy means there's no difference dependent on direction; the universe looks pretty much the same no matter which direction you look.

What, Banik asks, if our mistake is in putting together the homogeneity principle with measurements of what the best-studied region of space is like -- the parts near us?

What if we live in a cosmic void -- a region of space with far less matter and energy than average?

We've known those regions exist for a while; in fact, regular readers might recall that a couple of years ago, I wrote a post about one of the biggest, the Boötes Void, which is so large and empty that if we lived right at the center of it, we wouldn't even have been able to see the nearest stars to us until the development of powerful telescopes in the 1960s.  Banik suggests that the void we're in isn't as dramatic as that, but that a twenty percent lower-than-average mass density in our vicinity could account for the discrepancy in the Hubble constant.

"A potential solution to [the Hubble tension] is that our galaxy is close to the center of a large, local void," Banik said.  "It would cause matter to be pulled by gravity towards the higher density exterior of the void, leading to the void becoming emptier with time.  As the void is emptying out, the velocity of objects away from us would be larger than if the void were not there.  This therefore gives the appearance of a faster local expansion rate...  The Hubble tension is largely a local phenomenon, with little evidence that the expansion rate disagrees with expectations in the standard cosmology further back in time.  So a local solution like a local void is a promising way to go about solving the problem."

It would also, he said, line up with data on baryon acoustic oscillations, the fossilized remnants of shock waves from the Big Bang, which account for some of the fine structure of the universe.

"These sound waves travelled for only a short while before becoming frozen in place once the universe cooled enough for neutral atoms to form," Banik said.  "They act as a standard ruler, whose angular size we can use to chart the cosmic expansion history.  A local void slightly distorts the relation between the BAO angular scale and the redshift, because the velocities induced by a local void and its gravitational effect slightly increase the redshift on top of that due to cosmic expansion.  By considering all available BAO measurements over the last twenty years, we showed that a void model is about one hundred million times more likely than a void-free model with parameters designed to fit the CMB observations taken by the Planck satellite, the so-called homogeneous Planck cosmology."

Which sounds pretty good.  I'm only a layperson, but this is the most optimistic I've heard an astrophysicist get on the topic.  Now, it falls back on the data -- showing that the mass/energy density in our local region of space really is significantly lower than average.  In other words, that the universe isn't homogeneous, at least not on those scales.

I'm sure the astrophysics world will be abuzz with this new proposal, so keep your eyes open for developments.  Me, I think it sounds reasonable.  Given recent events here on Earth, it's unsurprising the rest of the universe is rushing away from us.  I bet the aliens lock the doors on their spaceships as they fly by.

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Ringing the changes

I find human behavior absolutely baffling a lot of the time.

I've spent a significant fraction of my life thinking, "Why did (s)he do/say that?"  One positive result of this is that it's turned me into a dedicated observer of the other members of my species.  Even so, I have to say that my efforts have, on the whole, been a failure.  After 64 years on this planet I'm no closer to figuring out why people act the way they do than I was on day one.

Mind you, I'm not saying all the behavior is bad.  It's just that a lot of it is weird.  Take, for example, the English practice of change ringing, one subset of a larger topic called campanology -- the study of bells.

[Image licensed under the Creative Commons Keichwa at German Wikipedia., Poppenreuth-glocke-1695, CC BY-SA 3.0]

"Ringing the changes" involves taking a sequence of tuned bells and using them to ring a series of patterned mathematical permutations.  So with six bells -- numbered from 1 (the highest-pitched) to 6 (the lowest) -- it might start with a straight cadence down the scale, 1-2-3-4-5-6.  But from there?

One possibility is called a "Plain Bob Minor" (being England, all of the patterns have extremely creative and quirky names), in which each bell takes a turn working its way down the sequence and then back up, and the rules are (1) no sequence can happen twice, and (2) each bell can only switch on each subsequent sequence by a single position.  Here's a part of the Plain Bob Minor pattern, following the positions of the #1 and #2 bells with blue and red lines, respectively:

As you can see, the pattern is mathematical; in fact, whole books have been written analyzing the math of change ringing.  And let me tell you, it's complex.

I first ran into change ringing in the wonderful mystery novel The Nine Tailors by the brilliant British author Dorothy Sayers.  The whole story revolves around it; even the chapters are named after change-ringing patterns, often involving clever puns (Sayers is at her sparkling, intellectual best in this book).  Despite being fairly good at math, how the patterns work (on the larger scale) escapes me; but -- amazingly -- practicing change-ringers have entire sequences memorized.

This is even more astonishing when you consider that a "Full Peal of Seven" -- seven tuned bells -- has 7! (seven factorial, or 5,040) different permutations, each of which has to be rung in its proper place. 

Ringing a Full Peal of Seven takes over three hours.

Here's a group of people doing a sequence called "Jump Changes," which requires twelve bells.  Fear not, this is only a small part of the sequence.  A Full Peal of Twelve would (literally) take years to ring.

What strikes me about change ringing is that although it's mathematically and historically interesting, it's not very interesting to listen to.  At least not for me.  Because a Full Peal goes through all possible permutations, it includes some that sound pretty random.  And long sequences just kind of go on and on.  And on.

In the case of Full Peals of Twelve, AND ON AND ON AND ON.

So it seems like kind of an odd hobby.  Don't get me wrong; I'm glad people are keeping it up.  For one thing, if you watched that video, you probably noticed that change ringing would be really good for building upper-body strength.  For another, it's a piece of English culture that goes back centuries, and it would be sad if it died out.  But more than that, I love that people are so devoted to something so purely weird.

I might not get why this pastime appeals to you, but more power to you if it does.  Hell, if I can spend my time making ceramic Doctor Who figurines, you can be deeply invested in memorizing mathematical patterns of bell ringing.

Maybe I don't understand all the strange side alleys of human behavior, but I definitely encourage them.  The world would be a far happier place if more people devoted their energy into odd and pointless, but entirely harmless, hobbies, rather than using it to figure out how to make groups of people they don't like as miserable as possible.

So hooray for weirdness.  Be proud of what you love, even if other people don't approve.  I was told over and over when I was a child, "No one wants to hear about that," whenever I talked about stuff I was interested in.  The experience left me with a lifelong reluctance to talk to people about what I love most.

And how sad is that?

So let your freak flag fly.  You collect bottle caps?  Cool!  You're a geocacher?  Awesome!  You carve little statues out of bars of soap?  Amazing!  We need more of that kind of thing, and less of... *gestures around vaguely at everything*

Time to ring the changes on your own individuality.  Proudly.

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