Anomaly analysis

I try to be tolerant of people's foibles, but one thing that annoys the absolute hell out of me is when someone is obviously ignorant of the basic facts of a subject, and yet expects everyone to treat their opinion about it as if it had merit.

It's why "the Big Bang means nothing exploded and made everything" (cosmology) and "why are there still monkeys?" (evolutionary biology) both make me see red almost instantaneously.  Fer cryin' in the sink, if you're going to talk about something, at least take the five minutes it requires to read the fucking Wikipedia page on the topic first.  Yes, I suppose you're "entitled to your opinion" regardless, but I'm in no way required to treat such idiocy as if it were Stephen Hawking levels of brilliance.

I mean, I have a lot of faults, but one thing I try to avoid is pontificating on subjects about which I am ignorant.  I have a pretty good idea of the limits of my own knowledge, and I am unhesitating in saying, "Sorry, I don't know enough to comment about that."

It's really not that hard to say.  Try it, you'll see.

What brings this whole infuriating subject up is all the people who weighed in on something that is honestly a very cool piece of research, which came out in the journal Geophysical Research Letters last week.  A team led by geophysicist Charlotte Gaugné-Gouranton, of Paris City University, used satellite data to analyze a peculiar shift in the Earth's gravitational field that affected a huge region of the eastern Atlantic Ocean.

The team is uncertain what caused the anomaly, which lasted for about two years and then subsided back into its original state.  "By analyzing time series of GRACE [Gravity Recovery and Climate Experiment]-derived gravity gradients, we have identified an anomalous large-scale gravity gradient signal in the eastern Atlantic Ocean, maximum at the beginning of 2007, which cannot be fully explained by surface water sources nor core fluid flows," the researchers wrote.  "This leads us to suggest that at least part of this signal could reflect rapid mass redistributions deep in the mantle."

The team suspects it might have been caused by a sudden phase transition in a common mantle mineral called bridgmanite (Mg,Fe(SiO3)), which could cause mass redistribution because of changes in density, similar to what happens when water freezes into ice.  But further research is needed to confirm this explanation.

Well, in a classic case of people adding 1 + 1 and getting 73.8, we immediately had dozens of self-styled experts adding "anomaly" to "gravity" and multiplying by "cannot be fully explained" and getting... well, take a look for yourself:

• "Advanced technology of alien manufacture is capable of 'shielding' from gravity and is the means of FTL propulsion that's been observed over and over.  This 'blink' means it's finally been captured by scientific equipment.  Countdown until the government denials start."
• "Disruptions like this are to be expected during the End Times.  Hell is on the move."
• "The scientists know more than they're letting on.  I wouldn't live along the East Coast of the United States if you paid me.  Connections to La Palma?"  [Nota bene: La Palma is one of the Canary Islands, home to a volcano that has been erupting intermittently since 2021, and was the subject of a rather hysterical BBC documentary in 2000 about how the island could split in half and cause a megatsunami -- something geologists have determined is extremely unlikely]
• "When those windows open and close again, it is a sign of the Celestial Ascension.  We should expect more of the same very soon."
• "I'm surprised they let this study get published.  Something that can change the Universal Law of Gravity, and they're shrugging it off as an 'anomaly'?  But now that the secret is out, why hasn't this been headline news worldwide?"
• "The LHC [Large Hadron Collider] went online in 2008.  Not a coincidence.  It's only a theory, but they said that the LHC could create mini black holes, and this may be proof."
• "Movement within the Hollow Earth.  But movement of what?  Stay tuned, folks, this is big."

*brief pause to stop banging my head against my desk while whimpering softly*

Okay, let's all just hang on a moment.  First of all, this anomaly was vast in size, but tiny in magnitude.  The fluctuation was small enough that it was undetectable on the Earth's surface (the scientists' own words) and was only caught by highly sensitive sensors on satellites that had been specifically designed to detect minute shifts in the Earth's gravitational field.  Second, it wasn't a "blink" -- it lasted for over two years.  Third, it peaked back in 2007, so whatever it was ended seventeen years ago, and in that time we have seen no Atlantic megatsunamis, aliens, Celestial Ascensions, or hellmouths opening.  Fourth, a shift in the gravitational field just means "something with mass moved," not a "change in the Universal Law of Gravitation."  Fifth, if the LHC had created a dangerous mini black hole, you'd think the physicists right there in Switzerland would have been the first to know, not some geologists working out in the Atlantic.  Sixth, you can't give an idea legitimacy simply by adding the phrase "it's only a theory;" if a claim was stupid before, it's still stupid after you say that.  In fact, it might be even stupider.

Seventh, and most importantly: for fuck's sake, people.

Captain Picard has absolutely had it with this kind of nonsense.

It's not that we laypeople -- and I very much include myself in that term -- can't get carried away by the hype sometimes.  In fact, when I first read about the La Palma thing a few years ago, I was honestly kind of freaked out by it; devastating landslide-induced megatsunamis have happened before (in fact, long-term followers of Skeptophilia might recall that I've written about two of them here -- the Storegga Slide and the Agadir Canyon Avalanche).  But then I did what everyone should do when they're confronted with a claim outside of their area of expertise; I did a little digging to find out what the scientists themselves had to say on the topic, and I found out that just about all geologists agree that while La Palma is clearly seismically active, it's unlikely to fracture and create an ocean-wide megatsunami.

At that point, I just kind of went, "whew," and resumed business as usual.  I did not then go on to claim that the scientists were wrong, the island was too going to fracture, and aliens from the Hollow Earth were going to use their anti-gravity faster-than-light propulsion to come out and usher in either the End Times or the Celestial Ascension, depending on which version you went for earlier.

Look, it's not that there's anything specifically dangerous about thinking there's an alien base under the eastern Atlantic.  It's more that such fuzzy irrationality very quickly becomes a habit.  Once you're accustomed to demanding respect for a claim that upon examination turns out to be "this crazy, fact-free idea I just now pulled out of my ass," you begin to apply the same demand for your uninformed opinions on medicine, the economy, and politics.

Which in one sentence explains why the United States is currently a slow-motion train wreck.

It all goes back to what Isaac Asimov said in 1980, doesn't it?  Seems like a good place to end:

There is a cult of ignorance in the United States, and there has always been.  The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means "my ignorance is just as good as your knowledge."

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A celestial do-si-do

A common -- although, as it turns out, completely understandable -- error is to say that the Earth and other planets orbit the Sun.

No, I'm not recommending a return to the geocentric model, where the Earth is at the center of the universe and everything orbits around it in perfect circles, as decreed by the Almighty at the moment of creation (which, of course, was six thousand years ago).  The inaccuracy I'm referring to is much smaller than that -- but is still significant.

Instead of saying "the planets orbit the Sun," the more precise way to state it is that the planets and the Sun all orbit their common center of gravity.  Newton's Third Law describes how every force exerted creates an equal and opposite force -- so just as the Sun is pulling on the Earth, the Earth is pulling on the Sun.  The result is that both are in a dance around the system's center of gravity.  Given the Sun's vastly larger mass, their mutual center of gravity is well inside the Sun, so to say "the Earth orbits the Sun" is a sufficiently close approximation to account for what we observe on a daily basis.

The effect is big enough, though, that this is one of the ways that exoplanets have been discovered -- mostly in nearby systems, where it's easier to see.  A star with an unseen companion gets pulled around as they orbit their common center of gravity, so from our perspective it looks like the star has a slight wobble.  As the wobble is bigger if the planet has a larger mass, this technique has been used mostly to find exoplanets that are gas giants, like Jupiter and Saturn, which are big enough to sling their host star around more effectively.

Sometimes, though, looking for a stellar wobble results in discovering something else -- an invisible object much too massive to be a planet, in a celestial do-si-do with a star.

That was the subject of a paper published this week in The Open Journal of Astrophysics, describing research led by Kareem El-Badry of Caltech.  The team found 21 stars with heavy but invisible companions, which from their size appear to be neutron stars, the collapsed, ultra-dense cores left behind by giant stars after they exhaust their fuel.

The curious thing is that prior to the formation of a neutron star, the giant star went supernova -- so why didn't that colossal explosion completely blow away the Sun-like star it's paired with?  The simple answer is we don't know.  "We still do not have a complete model for how these binaries form," El-Badry said.  "In principle, the progenitor to the neutron star should have become huge and interacted with the solar-type star during its late-stage evolution.  The huge star would have knocked the little star around, likely temporarily engulfing it.  Later, the neutron star progenitor would have exploded in a supernova, which, according to models, should have unbound the binary systems, sending the neutron stars and Sun-like stars careening in opposite directions...  The discovery of these new systems shows that at least some binaries survive these cataclysmic processes even though models cannot yet fully explain how."

If El-Badry et al.'s research bears up, it will be the first time neutron stars have been detected purely by their gravitational effects.

So that's today's cool news from science.  A stellar dance between a Sun-like star and a collapsed, super-dense neutron star.  And I love that El-Badry ends with the words, "... models cannot yet fully explain how."  Focus on the word "yet."  These are the sorts of things that push science forward -- some unexplained observation that makes scientists scratch their heads.  As Isaac Asimov put it, "The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!', but '... that's funny.'"

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The cotton-candy planet

There's a general pattern you see in astrophysics, which arises from the fact that gravity is both (1) always attractive, never repulsive, and (2) extremely weak.

It's hard to overstate the "extremely weak" bit.  The next strongest of the four fundamental forces, electromagnetism, is 36 orders of magnitude stronger; that is, the electromagnetic force is 1,000,000,000,000,000,000,000,000,000,000,000,000 times more powerful than gravity.  This may seem odd and counterintuitive, since the gravitational pull on your body seems pretty damn strong (especially when you're tired).  But think about it this way; if you use a refrigerator magnet to pick up a paper clip, that little magnet is able to overcome the force of the entire Earth pulling on the clip in the opposite direction.

The practical result of these two features of gravity is that at small scales and low masses, the effects of gravity are essentially zero.  If I'm picking up a book, I don't have to adjust for the negligible gravitational attraction between myself and the book, only the attraction between the book and the enormous mass of the Earth.  On the largest scales, too, the effects of gravity more or less even out; this is called the flatness problem, and is something I dealt with in more detail in a recent post.  (Plus, on these cosmic scales, the force of expansion of spacetime itself -- something that's been nicknamed dark energy -- takes over.)

It's at mid-range scales that gravity becomes seriously important -- objects the size of planets, stars, and galaxies.  And there, the other feature of gravity kicks in; that it always attracts and never repels.  (Whatever Lost in Space may have had to say about anti-gravity, there's never been evidence of any such thing.)  So for objects between the size of planets and galaxies, gravity always wins unless there is some other force opposing it.

This, in fact, is how stars work; the pull of gravity from their mass causes the matter to collapse inward, heating them up until the fusion of hydrogen starts in the core.  This generates heat and radiation pressure, a balancing force keeping the star in equilibrium.  Once the fuel runs out, though, and that outward force diminishes, gravitational collapse resumes -- and the result is a white dwarf, a neutron star, or a black hole, depending on how big the star is.

All of this is just a long-winded way of saying that if you've got a mass big enough to form something on the order of a planet or star, it tends to fall inward and compress until some other force stops it.  That's why the insides of planets and stars are denser than the outsides.

Well, that's how we thought it worked.

The latest wrench in the mechanism came from the discovery of a planet called WASP-193b orbiting a Sun-like star about 1,200 light years away.  On first glance, WASP-193b looks like a gas giant; its diameter is fifty percent larger than Jupiter's.  So far, nothing that odd; exoplanet studies have found lots of gas giants out there.

But... the mass of WASP-193b is only one-seventh that of Jupiter, giving it the overall density of cotton candy.

So I guess in a sense it is a gas giant, but not as we know it, Jim.  At an average density of 0.059 grams per cubic centimeter, WASP-193b would float on water if you could find an ocean big enough.  Plus, there's the problem of what is keeping it from collapsing.  A mass one-seventh that of Jupiter is still an impressive amount of matter; its gravitational pull should cause it to pull together, decreasing the volume and raising the density into something like that of the planets in our own Solar System.  So there must be something, some force that's pushing all this gas outward, keeping it... fluffy.  For want of a better word.  

But what that force might be is still unknown.

"The planet is so light that it's difficult to think of an analogous, solid-state material," said Julien de Wit of MIT, who co-authored the study, in an interview with ScienceDaily.

[Image licensed under the Creative Commons NOIRLab/NSF/AURA/J. da Silva/Spaceengine/M. Zamani, Artist impression of ultra fluffy gas giant planet orbiting a red dwarf star, CC BY 4.0]

"WASP-193b is the second least dense planet discovered to date, after Kepler-51d, which is much smaller," said Khalid Barkaoui, of the Université de Liège's EXOTIC Laboratory and first author of the paper, which was published in Nature Astronomy last week.  "Its extremely low density makes it a real anomaly among the more than five thousand exoplanets discovered to date.  This extremely-low-density cannot be reproduced by standard models of irradiated gas giants, even under the unrealistic assumption of a coreless structure."

In short, the astrophysicists still don't know what's going on.  Twelve hundred light years from here is what amounts to a planet-sized blob of cotton candy orbiting a Sun-like star.  I'm sure that like the disappearing star from my post two days ago, the theorists will be all over this trying to explain how it could possibly happen, but thus far all we have is a puzzle -- a massive cloud of matter that is somehow managing to defy gravity.

As Shakespeare famously observed, there apparently are more things in heaven and earth than are dreamt of in our philosophy.

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A twist in the fabric

All of us learned about gravity in elementary school, often starting with the anecdote about Isaac Newton seeing a falling apple and wondering why it was pulled toward the Earth.  What's weirdest about the phenomenon, though, is that while we can characterize gravitational force mathematically to just about any precision you want, explaining why it works is not nearly so easy.  Einstein, in his General Theory of Relativity, visualized it as a warping of space -- that anything with mass literally pulls on the spacetime fabric, in much the way that a heavy weight depresses the surface of a trampoline.  Picture rolling a small ball toward the weight on the trampoline; the ball will speed up, but it's not because the weight is somehow magically pulling on the ball.  It's because the ball is following the contours of a warped space.

Move that two-dimensional model up by one dimension, and you have an idea of how gravity operates.

Even Einstein, though, couldn't figure out how to make his gravitational model work in the realm of the very small.  Trying to unite the theory of gravity with the theories of quantum mechanics has, so far, proven impossible.  That combo -- called a "Grand Unified Theory" -- has defied the best minds in the field.  In fact, just last month an experiment in Italy failed to find predicted violations of Pauli's Exclusion Principle which would have supported some of the leading contenders for a unified model, most notably string theory.

So it's back to the drawing board.  And despite astrophysicist Neil deGrasse Tyson's statement that "scientists are always at the drawing board," this has got to be frustrating -- and raises question of whether a unified theory of gravity and quantum physics is even possible.

Meanwhile, a bit like the apocryphal bumblebee who by the principles of aerodynamics can't fly but doesn't know this so goes ahead and flies anyhow, gravity continues to warp space all around us even though we can't really explain it.  Just as well, because otherwise we'd obey Newton's First Law of Motion and go flying off the Earth at our current rate of speed in a direction tangent to its surface, until we encountered a fixed object, which in my case would be the wall of my house.

And out in space, gravity keeps twisting the fabric of spacetime, resulting in some pretty amazing structures.  In fact, this is why the topic comes up; just last week, there were two studies looking at the effects of extreme gravity on astronomical objects, both of which will make you glad we live here on a paltry little planet with a relatively small ability to warp space.

The first, out of the University of Washington, looked at the anomalous -- if beautiful -- shape of the Butterfly Nebula, the remnants of a star that exhausted its fuel and jettisoned the entire out of surface into a pair of mirror-image cones.

[Image is licensed under the Creative Commons Hubble ESA, NGC 6302 (50033189356), CC BY 2.0]

What apparently happened is that the star which blew up had a companion star, and the gravitational pull of that companion funneled the debris into the beautiful, gossamer "wings" the nebula shows today.  But even that hypothesis hasn't been enough to account for the nebula's odd shape.

"The Butterfly Nebula is extreme for the mass, speed and complexity of its ejections from its central star, whose temperature is more than two hundred times hotter than the Sun yet is just slightly larger than the Earth," said Bruce Balick, who led the team studying the nebula.  "I've been comparing Hubble images for years and I've never seen anything quite like it...  At this point, [all we have are] hypotheses.  What this shows us is that we don't fully understand the full range of shaping processes at work when planetary nebulae form.  The next step is to image the nebular center using the James Webb Space Telescope, since infrared light from the star can penetrate through the dust."

The second study, from NASA and the Goddard Space Flight Center, looked at a different way that a star can end its life.  It used data from the Hubble Space Telescope to look at a star in the galaxy ESO-583-G004, three hundred million light years away, and found evidence of a black hole that was in the process of swallowing a nearby star -- pulling it into a torus, or donut, shape.  It's unknown if the ill-fated star was already a companion to the black hole, or if it got gravitationally captured, but either way the outcome was the same.

I.e., not good.

The star was "tidally disrupted" -- for that, read "ripped to shreds" -- and the stellar material swung into an "accretion disk" as big as the Solar System.  "We saw this early enough that we could observe it at these very intense black hole accretion stages," said Peter Maksym, of the Harvard Center for Astrophysics, who co-authored the study.   "We saw the accretion rate drop as it turned to a trickle over time...  We're looking somewhere on the edge of that donut.  We're seeing a stellar wind from the black hole sweeping over the surface that's being projected towards us at speeds of twenty million miles per hour (three percent the speed of light).  We really are still getting our heads around the event.  You shred the star and then it's got this material that's making its way into the black hole.  And so you've got models where you think you know what is going on, and then you've got what you actually see.  This is an exciting place for scientists to be: right at the interface of the known and the unknown."

Right, in fact, at Tyson's "drawing board."

It's a thrilling time for scientists; so much is explained, but every question that's answered raises ten more questions.  The hydra-headed nature of science is just how it goes, though.  And even if some of the big questions do eventually get answered -- whether, for example, there's a quantum theory of gravity -- I don't think we'll be reaching the edges of what's knowable for a very long time.

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Newton modified

Back in the 1970s and 1980s, astrophysicist Vera Rubin discovered something odd about the rates at which stars were revolving around their home galaxies; the stars in the outer reaches of the galaxy were orbiting as quickly as the ones nearer to the center.

Called the "flat rotation curve problem," this observation flies in the face of an astronomical principle that's been known since the seventeenth century, which is Kepler's Third Law.  Kepler's Third Law states that for bodies orbiting the same center of gravity, the square of the orbital period (time taken for the object to make a single orbit) is proportional to the cube of the average distance between the object and the center of gravity.  Put more simply, the farther out an orbiting object is, the slower it should be moving.  This law holds beautifully for the planets, asteroids, and comets in the Solar System.

Unfortunately, when Rubin looked at galactic rotation rates, she found that Kepler's Third Law appeared not to hold.  What it looked like was that there was a great deal more mass in the galaxy than could be seen, and that mass was spread out in some kind of invisible halo surrounding it.  That additional mass would account for the flatness of the rotation curves.

It was forthwith nicknamed dark matter.

The calculations of Rubin and others showed that the amount of dark matter was not insignificant.  Current estimates place it at around 27% of the total mass of the universe.  Only 5% is baryonic (ordinary) matter, so the matter we can't see outweighs ordinary matter by over a factor of five.  (The other 68% is the even weirder and more elusive dark energy, about which we know next to nothing.)

The problem is, every experiment designed to directly detect dark matter has resulted in zero success.  Whatever it is, it seems not to interact with ordinary matter at all other than via its gravitational pull.  These repeated failures drew rueful comparisons between dark matter and the luminiferous aether, the mysterious substance through which light waves were alleged to propagate.  The aether was proposed back in the nineteenth century because it was hard to imagine how light waves moved through a vacuum unless it had a medium -- what, exactly, was waving?  The existence of aether was conclusively disproven by the elegant Michelson-Morley experiment, which showed that unlike any other kind of wave, the speed of light waves seemed to be invariant regardless of the direction of motion of the observer.  It remained for Albert Einstein to explain how that could possibly be -- and to figure out all the strange and counterintuitive outcomes of this phenomenon, with his Special and General Theories of Relativity.

More than one modern physicist has surmised that dark matter might similarly be the result of a fundamental misunderstanding of how gravity works -- and that we are just waiting for this century's Einstein to turn physics on its head by pointing out what we've missed.

Enter Israeli physicist Mordehai Milgrom.

Milgrom is the inventor of MoND (Modified Newtonian Dynamics), a model which -- like the Theories of Relativity -- proposes that the explanation for the anomalous observations is not that there's some unseen and undetectable substance causing the effect, but that our understanding of how physics works is incomplete.  In particular, Milgrom says, there needs to be a modification to the equations of motion at very small accelerations, such as the ones experienced by stars orbiting in the outer reaches of galaxies.

With those modifications, the orbital rates make perfect sense.  No dark matter needed.

The Whirlpool Galaxy [Image licensed under the Creative Commons NASA/ESA/JPL/Hubble Heritage Team & C. Violette, M51 (2), CC BY-SA 4.0]

As with relativity -- and any other time someone has claimed to overturn a long-established paradigm -- MoND hasn't achieved anywhere near universal acclaim.  The Wikipedia article on it (linked above) states, gloomily, "no satisfactory cosmological model has been constructed from the hypothesis."  And it does lack the blindingly bright insight of Einstein's models, where taking the "problem of the seeming invariance of the speed of light" and turning it into the "axiom of the actual invariance of the speed of light" triggered a shift in our understanding that has since passed every empirical test ever designed.  Compared to Einstein's model, MoND almost seems like "Newton + an add-on," with no particularly good explanation as to why high accelerations obey Newton's laws but low ones don't.  (Of course, there's a parallel here to Einstein, as well -- at low speeds, Newton's laws are accurate, while at near-light speeds, Einsteinian effects take over.  So maybe Milgrom is on to something after all.)

After all, it's not like the other option -- dark matter -- has much going for it experimentally.

And MoND just got a significant leg up with an observation of the behavior of star clusters that was the subject of a paper in Monthly Notices of the Royal Astronomical Society last week.  In open star clusters, as new stars ignite it produces an outward push that can blow away material (including other stars), creating two "tidal tails" that precede and trail the cluster as it moves through space.  According to Newtonian dynamics (with or without dark matter), the two tails should have about the same mass.

"According to Newton's laws of gravity, it's a matter of chance in which of the tails a lost star ends up," explains Dr. Jan Pflamm-Altenburg of the Helmholtz Institute of Radiation and Nuclear Physics at the University of Bonn.  "So both tails should contain about the same number of stars.  However, in our work we were able to prove for the first time that this is not true: In the clusters we studied, the front tail always contains significantly more stars nearby to the cluster than the rear tail."

This peculiar observation fits the predictions of MoND much better than it does the predictions of the Newtonian model.

"The results [of simulations using MoND] correspond surprisingly well with the observations," said Ingo Thies, co-author of last week's paper.  "However, we had to resort to relatively simple computational methods to do this.  We currently lack the mathematical tools for more detailed analyses of modified Newtonian dynamics."

So the matter is very far from settled.  What's certain is that, similar to the physicists' situation in the late nineteenth century with regards to the behavior of light, there's something significant we're missing.  Whether that's some odd form of matter that doesn't interact with anything except via gravity, or because we've got the equations for the laws of motion wrong, remains to be seen.

And of course, after that, we still have dark energy to explain.  I think the physicists are going to be busy over the next few decades, don't you?

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Even spookier action

Once again, I've had my mind blown by a set of experiments about the behavior of subatomic particles that teeters on the edge of what my layman's brain can understand.  So I'm gonna tell you about it as best I can, and I would ask that any physics types in the studio audience let me know about any errors I make so I can correct 'em.

You're undoubtedly aware of the quote by Einstein having to do with "spooky action at a distance," which is how he viewed the bizarre and counterintuitive features of the physics of the very small such as quantum superposition and entanglement.  Both of these phenomena, though, have been explained by the model that particles aren't the little pinpoint masses we picture them as, but spread-out fields of probabilities that can interact even when they're not near each other.

But that still leaves intact the conventional view, certainly the common-sense one, that one object can't affect another unless the field generated by one of them intersects the field generated by the other, whether that field be gravity, electromagnetism, or either of the two less-familiar nuclear forces (strong and weak).  Not as obvious is that this influence is generally transmitted by some sort of carrier particle being exchanged between the two -- although the carrier particle that transmits the gravitational force has yet to be discovered experimentally.

This is one of the main reasons that unscientific superstitions like astrology can't be true; it's positing that your personality and life's path are affected by the position of the Sun or one of the planets relative to a bunch of stars that only appear to be near each other when viewed from our perspective.  Most of those stars are tens to hundreds of light years away, so any influence they might have on you via the four fundamental forces is about as close to zero as you could possibly get, because all four of them dramatically decrease in intensity the farther away you get.  (As Carl Sagan quipped, at the moment of your birth, the obstetrician who delivered you was exerting a greater gravitational pull on you than Jupiter was.)

So the bottom line appears to be: no interaction between the fields generated by two objects, no way can they influence each other in any fashion.

But.

In 1959, two physicists, Yakir Aharonov and David Bohm, published a paper on what has come to be known as the Aharonov-Bohm effect.  This paper concluded that under certain conditions, an electrically-charged particle can be affected by an electromagnetic field -- even when the particle itself is shielded in such a way that both the electric field and magnetic field it experiences is exactly equal to zero, and the particle's wave function is blocked from the region that is experiencing the field.

So that leaves us with one of two equally distasteful conclusions.  Either the measured electric and magnetic fields in a region don't tell us all we need to know to understand the electromagnetic potential a particle is experiencing, or we have to throw away the principle of locality -- that an object can only be influenced by the conditions in its local environment.

(Nota bene: in physics, "local" has a rigorous definition; two phenomena are local relative to each other if the amount of time a cause from one can precede an effect on the other is equal to or greater than the amount of time it would take light to travel from the position of the cause to the position of the effect.  This is the basis of the reluctance of physicists to believe in any kind of superluminal information transfer.)

What's more troubling still is that this isn't just some theoretical meandering; the Aharonov-Bohm effect has been demonstrated experimentally.  So as bafflingly weird as it sounds, it apparently is a built-in feature of quantum physics, as if we needed anything else to make it even crazier.

But maybe this is just some weirdness of electromagnetism, right?  Well, that might have been believable...

... until now.

In a paper three days ago in Science, five physicists at Stanford University -- Chris Overstreet, Peter Asenbaum, Joseph Curti, Minjeong Kim, and Mark Kasevich -- have demonstrated that the same thing works for gravitational interactions.

This is bizarre for a variety of reasons.  First, the Aharonov-Bohm effect is just bizarre, in and of itself.  Second, as I mentioned earlier, we don't even have experimental proof that gravity has a carrier particle, or if perhaps it is just a description of the curvature of space -- i.e., if gravity is a completely different animal from the other three fundamental forces.  Third, and weirdest, the equations governing gravity don't mesh with the equations governing the other three forces, and every effort to coalesce them and create a "Grand Unified Theory" has met with failure.  Combining the gravitational field equations with the ones in the quantum realm generates infinities -- and you know what that does.  

"Every time I look at this experiment, I’m like, 'It’s amazing that nature is that way,'" said study co-author Mark Kasevich, in an interview with Science News.

"Amazing" isn't how I would have put it.  In Kasevich's situation, I think what I'd have said would have been more like, "Holy shit, what the hell is going on here?"  But I'm kind of unsubtle that way.

So what it seems to indicate to me is that we're missing something pretty fundamental about how forces work, and that this is an indication that there's a serious gap in the theoretical underpinning of physics.

(Nota bene #2: I still think astrology is bullshit, though.)

It's tempting for us laypeople to just throw our hands up in despair and say, "Okay, this stuff is so weird it can't be true."  The problem is, if you buy into the methods of science -- which I hope all of us do -- that's the one response you can't have.  The experimental evidence is what it is, whether you like (or understand) it or not, and if it contradicts your favorite model of how things work, you have to chuck the model, not the evidence.  Or, as Neil deGrasse Tyson more eloquently and succinctly put it, "The wonderful thing about science is that it works whether or not you believe in it."

So it looks like we're stuck with this even-spookier-action-at-a-distance, as counterintuitive as it sounds.  Objects can interact with each other gravitationally even when the gravitational field produced by object #1 is exactly zero where object #2 is currently sitting.  And this is about the limit of what I can explain, so if you ask me to clarify further, I'm afraid my response will be a puzzled head-tilt much like what my dog gives me when I tell him something he just can't comprehend, like why I don't want to go outside and play ball with him when it's subzero temperatures and snowing.

But I'll end on a more academic note, with a quote by the famous biologist J. B. S. Haldane, that I've used before in posts about quantum physics: "The universe is not only queerer than we imagine, it is queerer than we can imagine."

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Since reading the classic book by Desmond Morris, The Naked Ape, when I was a freshman in college, I've been fascinated by the idea of looking at human behavior as if we were just another animal -- anthropology, as it were, through the eyes of an alien species.  When you do that, a lot of our sense of specialness and separateness simply evaporates.

The latest in this effort to analyze our behavior from an outside perspective is Pascal Boyer's Human Cultures Through the Scientific Lens: Essays in Evolutionary Cognitive Anthropology.  Why do we engage in rituals?  Why is religion nearly universal to all human cultures -- as is sports?  Where did the concept of a taboo come from, and why is it so often attached to something that -- if you think about it -- is just plain weird?

Boyer's essays challenge us to consider ourselves dispassionately, and really think about what we do.  It's a provocative, fascinating, controversial, and challenging book, and if you're curious about the phenomenon of culture, you should put it on your reading list.

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

The cosmic whirligig

It seems like whenever I look at the realm of the very large or the very small, I quickly get overwhelmed by scale.

I remember, for example, when a teacher in high school was trying to impress upon us kids how small atoms were, and asked us the following question: if you counted up the number of atoms in a typical raindrop, then someone gave you that many grains of sand, how much sand would you have?

A bucket?  A swimming pool full?  A whole beach full?  All of those, it would seem, constitute a crapload of sand grains.  Surely there can't be more atoms in a raindrop than there are sand grains on a typical beach.

But there are.  By several orders of magnitude.  Her answer was that you'd have enough sand to fill a trench a meter deep and a kilometer across, stretching from New York to San Francisco.  (I've never checked her math, but from other similar analogies, it seems pretty spot-on.)

The same happens when I'm considering things that are very large; as much as I've studied astronomy, I never fail to be blown away simply by how enormous the universe is.  In fact, this is why the topic comes up -- a paper in Nature Astronomy last week by astrophysicists Peng Wang and Noam Liebeskind (of the University of Potsdam), Elmo Tempel (of the University of Tartu, Estonia), Xi Kang (of Zhejiang University, and Quan Guo (of Shanghai Astronomical Observatory) has demonstrated that there are filaments spanning entire galactic superclusters, and possibly longer than that.

[Image licensed under the Creative Commons The cosmic web, CC BY-SA 4.0]

The presence of these filaments, which seem to be composed largely of dark matter, comes from their effects on the galaxies they pass near.  As if they were the axle of an enormous whirligig, the filaments cause the galaxies to circle around them, drawn in by the gravitational pull.  The existence of the filaments was demonstrated by the fact that the galaxies on one side exhibit a lower than expected red shift and the ones on the other side a higher than expected red shift, meaning one side is moving away from us and the other side toward us -- just as you'd expect if the galaxies were circling some invisible center of gravity.

As with any groundbreaking discovery, it's opened up as many questions as it's answered.  "It's a major finding,” said study co-author Noam Libeskind, in an interview with Vice.  "It's a pretty big deal that we've discovered angular momentum, or vorticity, on such a huge scale.  I think it will help people understand cosmic flows and how galaxies are moving throughout the cosmic web and through the universe... [and] to understand the important scales for galaxy formation and ultimately, why everything in the universe is spinning and how spin is generated.  That is a really, really hard question to solve.  It's an unsolved question in cosmology."

That was my first reaction; what on earth (or off it, in this case) could generate that kind of angular momentum?  Think of the mass of a typical galaxy, and imaging that you tie that amount of mass at the end of a long rope and try to swing it in circles.

That's the quantity of energy we're talking about, here.  Multiplied by the number of galaxies in the universe.

But the upshot is that the universe on the largest scales seems to have an intrinsic spin, and no one knows why.  All I know is that it makes me feel very, very small.

Of course, I'm way larger than the atoms in a raindrop.  So there's that.  Now that my mind is sufficiently blown, I think I need to go huddle under my blanket for a while, because the universe is sometimes a really overwhelming place to live.

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One of the most devastating psychological diagnoses is schizophrenia.  United by the common characteristic of "loss of touch with reality," this phrase belies how horrible the various kinds of schizophrenia are, both for the sufferers and their families.  Immersed in a pseudo-reality where the voices, hallucinations, and perceptions created by their minds seem as vivid as the actual reality around them, schizophrenics live in a terrifying world where they literally can't tell their own imaginings from what they're really seeing and hearing.

The origins of schizophrenia are still poorly understood, and largely because of a lack of knowledge of its causes, treatment and prognosis are iffy at best.  But much of what we know about this horrible disorder comes from families where it seems to be common -- where, apparently, there is a genetic predisposition for the psychosis that is schizophrenia's most frightening characteristic.

One of the first studies of this kind was of the Galvin family of Colorado, who had ten children born between 1945 and 1965 of whom six eventually were diagnosed as schizophrenic.  This tragic situation is the subject of the riveting book Hidden Valley Road: Inside the Mind of an American Family, by Robert Kolker.  Kolker looks at the study done by the National Institute of Health of the Galvin family, which provided the first insight into the genetic basis of schizophrenia, but along the way gives us a touching and compassionate view of a family devastated by this mysterious disease.  It's brilliant reading, and leaves you with a greater understanding of the impact of psychiatric illness -- and hope for a future where this diagnosis has better options for treatment.

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

 

Order of operations

I try not to write in Skeptophilia about topics I don't fully understand -- well, at least understand as fully as my brainpower and the available information allow.  But today I'm going to tell you about a recent paper in theoretical physics that blew my mind so completely that I had to write a post about it, even though saying "I don't completely comprehend this" is a serious understatement.

So here goes.  Just don't ask me to clarify further, because the most you'll get is the Canine Head-Tilt of Puzzlement.

The paper, which appeared last week in Nature Communications, is entitled "Bell's Theorem for Temporal Order," and was written by Magdalena Zych and Fabio Costa (of the University of Queensland), Igor Pikovski (of Harvard University), and Časlav Brukner (of the University of Vienna).  The issue the four physicists were looking at was the seeming paradox of the different way that time (specifically, temporal order) fits into general relativity and quantum theory.  In relativity, the flow of time depends on your relative speed and the distribution of mass near you; in general, the faster you're going, or the nearer you are to a massive object, the slower your clock runs.  Because reference frame is relative (thus the name of the entire theory), you don't notice this effect yourself -- to you, your clock runs just fine.  But to someone observing you at a distance, the flow of time in your frame of reference has become more sluggish.

Weird enough, but that's only the beginning.  To take the most familiar example, consider two astronauts in spacecraft zooming away from each other at a substantial fraction of the speed of light.  To astronaut A, his clock is running fine, and astronaut B's clock is slow (because he's moving away from A at a high speed).  But from B's perspective, it's A that's moving; so B thinks his own clock is accurate, and A's is the one that's running slow.

And it's not that one's right and the other is somehow being fooled.  Both of them are right -- because time is relative to your speed.

As an outcome of this (and germane to the paper I referenced), what this also means is that A and B can differ in what they perceive as the time order of two events.  Occurrences that appear simultaneous to one of the astronauts might appear sequential to the other.

With me so far?  Well, the problem that Zych et al. were investigating was that in quantum theory, there's no allowance for relativistic ordering of events.  Time's arrow is one-directional, and if event X followed Y in one reference frame, it would do so on all reference frames.

Well, that's what the physicists thought -- until this paper showed a theoretical framework that suggests otherwise.

Zych et al. proposed a thought experiment involving two spaceships, one of which is near a massive object (which, as I mentioned, warps spacetime in such a way as to slow down the passage of time).  They're engaged in a war game that requires them to fire their phasers simultaneously and immediately afterward start their engine so as to dodge the blast.  The problem is, the ship near the massive object will have a slower clock, and will not be able to fire quickly enough to escape being blasted by the other ship.

So far, weird but not that hard to understand.  What Zych et al. did was to ask a single question: what if the two ships were in a state of quantum superposition before they fired?

Superposition is one of the weirdest outcomes of quantum physics, but it's been demonstrated experimentally so many times that we have no choice but to accept that this is how the universe works.  The idea is that if a physical system could exist in two or more possible states, its actual state is an array of possibilities all existing at the same time until some measurement destroys the superposition and drops the system into one of the possible outcomes ("collapsing the wave function").  The most famous iteration of this is Schrödinger's Cat, who is both alive and dead until the box is opened.

In the case of the ships, the superposition results in quantum entanglement, where the entire system acts as a single entity (in a causal sense).  Here's how the result is described in a press release from the University of Vienna:

If a powerful agent could place a sufficiently massive object, say a planet, closer to one ship it would slow down its counting of time.  As a result, the ship farther away from the mass will fire too early for the first one to escape. 

The laws of quantum physics and gravity predict that by manipulating a quantum superposition state of the planet, the ships can end up in a superposition of either of them being destroyed...  The new work shows that the temporal order among events can exhibit superposition and entanglement – genuinely quantum features of particular importance for testing quantum theory against alternatives.

So each of the ships is in a state of both being destroyed and not being destroyed, from the standpoint of an outside observer -- until a measurement is made, which forces the system into one or the other outcome.

Note what this isn't saying; it's not implying that one of the ships was destroyed, and we simply don't know which yet.  It's implying that both ships are in an entangled state of being blasted to smithereens and not.

At the same time.

The authors write:

This entanglement enables accomplishing a task, violation of a Bell inequality, that is impossible under local classical temporal order; it means that temporal order cannot be described by any pre-defined local variables.  A classical notion of a causal structure is therefore untenable in any framework compatible with the basic principles of quantum mechanics and classical general relativity.

All of which leaves me sympathizing a great deal with Winnie-the Pooh.

So there you have it.  It turns out that the universe is a weird, weird place, where our common-sensical notions of how things work are often simply wrong.  Even though I'm far from an expert -- I run into the wall pretty fast when I try to read actual papers in physics, or (for that matter) in most scientific fields -- I find it fascinating to get a glimpse of the actual workings of the cosmos.

Even if it blows my tiny little mind.

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This week's Skeptophilia book recommendation is a must-read for anyone interested in astronomy -- Finding Our Place in the Universe by French astrophysicist Hélène Courtois.  Courtois gives us a thrilling tour of the universe on the largest scales, particularly Laniakea, the galactic supercluster to which the Milky Way belongs, and the vast and completely empty void between Laniakea and the next supercluster.  (These voids are so empty that if the Earth were at the middle of one, there would be no astronomical objects near enough or bright enough to see without a powerful telescope, and the night sky would be completely dark.)

Courtois's book is eye-opening and engaging, and (as it was just published this year) brings the reader up to date with the latest information from astronomy.  And it will give you new appreciation when you look up at night -- and realize how little of the universe you're actually seeing.

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

Waterworks

Thanks to a loyal reader of Skeptophilia, I now know that apparently there is a growing number of people who believe that water is not H2O.

Unsurprisingly, if you created a Venn diagram between these people and the people who believe the Earth is flat, there'd be a large overlap.  So not only have the scientists been lying to us about the shape of the Earth, they've been lying to us about the nature of water.  Who knows what else they've been telling us that's wrong?  Maybe DNA is actually made of tiny bendy-straws.  Maybe the stars are  fireflies that landed on the hemispherical glass sky-dome that covers the (flat) Earth.  Maybe our brains actually aren't neural tissue, but a couple of pounds of banana pudding with crushed vanilla wafers mixed in.

I know that's what my brain feels like at the moment.

Note for the record that I am not here addressing a philosophical argument that was in vogue a few years ago about the "nature of water," that contended (with some justification) that because an individual H2O molecule did not have the properties we associate with water -- clarity, wetness, ability to dissolve stuff, and so on -- that H2O was, in fact, not water.  And that some things we call water (e.g. ocean water) are not pure H2O.

That was a discussion about how we use words, which is an important enough topic, although sometimes it gets pushed far enough that it seems to me to be no different than arguing about how many angels could dance on the head of a pin.  Which, I suppose, explains why I went into science and not philosophy.

Nor am I talking about hair-splitters who say that even pure water isn't pure H2O -- that in a glass of pure water, some of the molecules are dissociated into H+ (more correctly, H3O+) and OH- ions.  I call them "hair-splitters" because under ordinary conditions, out of every 10,000,000 molecules of water, 9,999,999 of them are in the form of H2O and 1 is in the form of H+/OH-.  (Which, for science-minded types, directly leads to why the pH of pure water is 7, something I could explain further if anyone's interested.)

But no, what I'm referring to here is the people who think that water molecules are not H2O.  In one example the loyal reader sent me -- and one is about all I can stand to look at in detail -- the person argues that water can't be H2O, it actually is O2.

Yes, diatomic oxygen, like the stuff that makes up 20% of the air we're breathing.  So if he was right, we could breathe underwater, which would be pretty fucking cool, but which I clearly refuted fifteen years ago when I nearly drowned in a scuba accident.  I can say from personal experience that what I was attempting to breathe was not oxygen.

Here's a small sample of the argument the person gives, if I can dignify it by that name.  Grammar and spelling has been left as-is, because you can only write [sic] so many times.

[W]ater, as oxygen molecule, is only formed by two oxygen atoms. We think the difference between water and oxygen molecules must be found at the different phase of variation of the intersected gravitational fields that creates their different electrical configurations and spatial symmetries. 

For us each material mass has its own gravitational field that vary – expands and contracts – with a specific frequency. When two gravitational fields – from two oxygen masses, by example – intersect, they create in their mutual intersection some new fields with different motions and pressures that are currently known as “chemical bonds”. 

I used above the term “mass” and non “atom” because here we are thinking about a different model of “atom”. For us material masses do not have electrical charges inside of them. Electrical charges for us are consequences of intersections of at least two gravitational fields that vary with the same or opposite phase. So, we think about electrical charges like fields that moves and create different pressures inside them... 

In our perspective water molecules do not have Hydrogen atoms. They only have 2 Oxygens. So we think that for transforming water molecules into Oxygen molecules and oxygen molecules into water molecules it is only necessary to change the phase of variation of one of their intersected gravitational fields to make equal or opposite.

Right!  Sure!  What?

To go through the scientific inaccuracies here would take me all day, but let me start out with the most egregious: nothing about the interaction between two molecules, or the atoms within a molecule, has the least thing to do with gravity.  Gravity is (by far) the weakest of the four fundamental forces.  If you compare gravity to electromagnetism -- which is the force that holds molecules together -- electromagnetism is 10 ^36 times stronger.

That's 1 followed by 36 zeroes, folks.

The only reason gravity seems so strong to us is that we're comparing things to the gravitational pull of the Earth, and the Earth is freakin' huge.  On the scale of molecules, gravitational interaction is so small that it is, for all practical purposes, zero.

The other thing that bears mention is that you can demonstrate that water is proportionally composed of two atoms of hydrogen and one atom of oxygen by the simple experiment performed back in 1976 by me and my lab partner John in high school chemistry, namely running an electric current through water to break it up and collecting the gases in two separate test tubes.  You can show they're not the same by inserting a lighted wooden splint into the two tubes -- the one with the hydrogen will give a musical little "pop" as the hydrogen around the mouth of the tube ignites with the oxygen in the air; the one with the oxygen will begin to burn merrily.

Or, you can do what John did, which was to bubble the hydrogen gas into the oxygen tube, and then insert the lighted splint.  The result was:

BANG

... as the two gases, in exactly the right proportions, combusted back into water.  This left John holding the remains of a broken test tube, wearing a terrified expression, with his eyebrows singed off and his hair blown back in the fashion of a Looney Tunes character who has just had a gun fired directly into his face.

It also bears mention that this is the same reaction that did this:

[Image is in the Public Domain]

So the weight of the evidence is very much in favor of water being dihydrogen monoxide.  Just as well; rewriting all those textbooks would be a serious pain in the ass.

It's unsurprising, as I mentioned, that many of the Water-Is-Actually-Oxygen people are also The-Earth-Is-Flat people.  Once you've decided that (1) evidence and logic are inadmissible for determining the truth, and (2) all the experts are lying to you for their own nefarious purposes, the jig is up.

Now, I need to go have another cup of coffee, and see if I can reconfigure the banana pudding in my head back into neural tissue.  The vanilla wafer crumbs are making the inside of my skull itch.

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I picked this week's Skeptophilia book recommendation because of the devastating, and record-breaking, fires currently sweeping across the American west.  Tim Flannery's The Weather Makers is one of the most cogent arguments I've ever seen for the reality of climate change and what it might ultimately mean for the long-term habitability of planet Earth.  Flannery analyzes all the evidence available, building what would be an airtight case -- if it weren't for the fact that the economic implications have mobilized the corporate world to mount a disinformation campaign that, so far, seems to be working.  It's an eye-opening -- and essential -- read.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]