Crying wolf

While I understand being deeply fascinated with a specific subject, there's a point at which an interest becomes an idée fixe.  The result, especially for a scientist, is such a single-minded focus that it can cloud judgment with regards to the strength of the evidence.  We've seen that here at Skeptophilia before -- two examples that immediately come to mind are the Sasquatch-hunting geneticist Melba Ketchum and the British proponent of extraterrestrial panspermia, Chandra Wickramasinghe.  And the problem is -- for them, at least -- their obsessions have had the effect of completely destroying their credibility in the scientific community.

I can already hear the objections -- that (1) said scientific community is a hidebound, reactionary bunch of sticks-in-the-mud who resist like mad any new ideas, and (2) there are times the mavericks have been vindicated (sometimes after a long and arduous battle to get someone, anyone, to take them seriously).  The former can sometimes be true, but almost all scientists are well aware that groundbreaking ideas -- as long as they are supported by adequate evidence -- are how careers are made.  Look at the list of Nobel Prizes in the sciences in the past fifty years if you want examples.  Virtually all of them were awarded for research that expanded our scientific models dramatically (in some cases, overturned them entirely).  

As far as the second -- that sometimes the fringe-dwelling researchers who say "our entire prior understanding of the science is wrong" turn out to be correct -- okay, yeah, it happens, but if you consider the history of scientific paradigm shifts, what will jump out at you is how seldom that actually occurs.  The Copernican/Galilean/Keplerian heliocentric theory, Newton's Theory of Gravity, Maxwell's and Faraday's studies of electromagnetism, the Germ Theory of Disease, Einstein's Theories of Relativity, quantum/atomic theory, thermodynamics, Darwin's evolutionary model, Hubble and the Big Bang, the gene as the carrier of inheritance, and the plate tectonic model of Vine and Matthews. 

And that's about it, in the last five hundred years.

The point is, we're in a position now where the amount of evidence amassed to support the edifice we call science is so colossal that the "it could all be proven wrong tomorrow" objection I used to hear from my students (especially the lazy ones) is about as close to absurd as you want to get.  Sure, there will be some modifications made to science in the future.  A few -- probably very few -- will be major revisions.  But there's no reason to think that science as it stands is in any way unstable.

And people who come at it with earthshattering claims based on extremely slim evidence are almost certainly wrong.

Which brings us to Avi Loeb.

Loeb is an astrophysicist at Harvard University who has garnered significant notice (and notoriety) in the past few years from his fixation on the extrasolar source of some astronomical objects.  (By extrasolar I mean "originating from outside the Solar System.")  In 2017 he made headlines by claiming that the oddball astronomical object 'Oumuamua was not only extrasolar -- something fairly certain given its trajectory -- but that it was the remnant of a spacecraft from an intelligent extraterrestrial civilization.  Since then, his obsession with extraterrestrials visiting the Solar System has become so intense that it has drawn unfortunate comparisons with this guy:

The latest salvo from Loeb et al. is a sample of metallic beads scavenged from the floor of the Pacific Ocean near Papua New Guinea, that Loeb says are the remnants of a meteor that exploded in 2014.  So far, nothing to raise an eyebrow; meteoritic debris is cool but hardly uncommon.

But (as always) he goes one rather enormous step further, and claims that the meteor it came from was extrasolar, and the concentrations of metals in the beads indicate the object that exploded may have been an alien spacecraft.

Look, I'm as eager as the next Doctor Who aficionado to have a meet-cute with intelligent aliens.  (As long as they don't turn out to be Daleks, Sontarans, or Stenza.  I do have my boundaries.)  Hell, the way things are going down here on Earth, I might even ask to be taken on as a crew member when they leave.  But if you're asking me to believe you have bits of an alien spaceship, I'm gonna need more than a few oddball microscopic metal beads.

Extraordinary claims require extraordinary evidence, as Carl Sagan used to put it.  And this ain't it.  

At the moment, Avi Loeb is increasingly reminding me of a famous character from fiction -- The Boy Who Cried Wolf.  I have no problem with Loeb and his friends continuing to search; maybe (to quote a luminary of the field) The Truth Is Out There, and Loeb's dogged determination will eventually pay off.  But the problem is, there's a significant chance that (like The Boy in the fable) if he ever actually does find the hard evidence he's looking for, by that time he'll have exhausted people's patience to the point that everyone will have stopped paying attention.

So sorry to rain on the UFOs-and-aliens parade, but me, I don't think we've got anything here but some pieces of a curious metallic meteorite.  Worthy of study, no doubt, but as far as what it tells us about extraterrestrial intelligence, the answer seems to be: nothing whatsoever.

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Splitting the Moon

Gervase of Canterbury was a twelfth-century English monk who lived from about 1141 to 1210.  He is best known as a historical chronicler, and wrote accounts of both the secular and ecclesiastical history of Britain, as well as producing quantities of maps showing the landholdings and bishoprics at the time.  Both of these have been of considerable value to scholars, and his writings are lucid, fact-based, and clear-eyed.

Which makes the other event he wrote about even more curious.

In June of the year 1178, Gervase says, some of the monks of the abbey were out on the lawn at twilight, enjoying a bit of leisure time in the pleasant warmth of early evening.  That was when they saw something astonishing:

[On the evening of June 18, 1178] after sunset when the Moon had first become visible, a marvelous phenomenon was witnessed by some five or more men...  Now there was a bright new Moon... its horns were tilted toward the east; and suddenly the upper horn split in two.  From the midpoint of the division a flaming torch sprang up, spewing out, over a considerable distance, fire, hot coals, and sparks.  Meanwhile the body of the Moon which was below writhed, as it were, in anxiety and to put it in the words of those who reported it to me and saw it with their own eyes, the Moon throbbed like a wounded snake.  Afterwards it resumed its proper state.  This phenomenon was repeated a dozen times or more, the flame assuming various twisting shapes at random and then returning to normal.  Then after these transformations the Moon from horn to horn, that is along its whole length, took on a blackish appearance.  The present writer was given this report by men who saw it with their own eyes, and are prepared to stake their honor on an oath that they have made no addition or falsification in the above narrative.

I first heard about this peculiar account almost exactly eight hundred years after it happened, on the episode of Carl Sagan's Cosmos called "Heaven and Hell."  Sagan's take on the story is that what Gervase wrote is substantially true; that despite the superstition of the time, he transcribed an unembellished record of what the other monks had seen.  Further, Sagan said, the survey work done on the Moon since that time found what may account for the odd event -- a 22-kilometer-wide recent crater just barely over the edge of the near-Earth side on the northeastern quadrant, named Giordano Bruno after the martyred sixteenth century astronomer.  What the monks witnessed was the meteorite impact that produced the crater, first creating a plume of molten rock and then scattering dark ash across the Moon's surface.  Interestingly, Giordano Bruno has rays of debris surrounding it, suggesting its recent origins:

[Image is in the Public Domain courtesy of NASA/JPL]

Further evidence supporting this conjecture is that laser rangefinding data shows that the Moon is oscillating slightly -- in Sagan's words, "ringing like a bell" -- at a frequency consistent with a meteor impact eight hundred years earlier.

Not everyone agrees with this interpretation, however.  Paul Withers, of the University of Arizona's Lunar and Planetary Laboratory, points out that such an impact would have accelerated much of the debris to escape velocity, and a significant quantity of it would have been pulled in by the Earth's more powerful gravitational field, triggering "blizzard-like meteor storms" with as many as fifty thousand meteors per hour for several days, perhaps up to a week.  No one recorded any such event.  Surely the meticulous Chinese and Korean astronomers of the time would have seen and written about such an unprecedented phenomenon.  In fact, nobody else on Earth we know of who was keeping records at the time even recorded witnessing the initial impact -- if impact it was.

Withers suggests a much more local, and prosaic, solution; what the monks of Canterbury saw was a bolide, a meteor that explodes in midair.  The most famous bolide is the Chelyabinsk meteor of February 2013, when an estimated eighteen meter long, nine thousand metric tonne chunk of rock exploded over the Russian town of Chelyabinsk, creating a tremendous fireball and shattering windows throughout the region.  The Canterbury event, Withers said, was a bolide over southeastern England that just happened to create its fireworks in front of the crescent Moon, which would explain why it wasn't seen elsewhere.

I'm not entirely happy with this explanation, either.  As Chelyabinsk illustrates, bolides are loud.  There is nothing in Gervase's account indicating that the Canterbury event made any sound at all.  Plus -- if you'll look at videos of the Chelyabinsk meteor (you can see a short clip at the page linked above) -- they move fast, leaving behind a bright streak.  Surely the monks of Canterbury had seen "shooting stars" many times before, and would have reported this not as a phenomenon on the Moon, but simply a humongous shooting star that exploded.

And finally, if it was a bolide, how could this account for the monks' statement that the paroxysms on the Moon were "repeated a dozen times or more"?

I'm still leaning toward the lunar impact explanation, myself, but I'm aware that it leaves plenty of unanswered questions.  It's a curious account, however you look at it.  We may never know for certain what happened, but even so, we're lucky that someone as clear-headed as Gervase of Canterbury was around during those dark and superstitious times to record an event that surely must have scared the absolute hell out of everyone who witnessed it.

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Rock of ages

One of the simplest, but one of the most mind-blowing, concepts in science is that matter is recycled indefinitely.

It came up in a variety of ways in my biology classes, most frequently because of the water cycle, nitrogen cycle, and carbon cycle.  I always told my classes, "Every drop of water in your body has been in many forms.  It's been in clouds, it's been in rain, polar ice, the oceans and lakes.  It's been tree sap, bird blood, and dinosaur piss.  It never is created or destroyed, it just keeps getting reused."

This recycling, however, does make certain things hard to study, because the process of the recycling often erases where those molecules had been before and what they'd been doing.  This is most obvious in geological cycles.  When a geologist says, "This rock is recent, it was formed only a few hundred years ago," or "this is an ancient rock dating back to around eight hundred million years ago," (s)he is not talking about the materials; the materials, for the most part, all ended up on Earth at around the same time.  (Exceptions are meteorites, which will come up again shortly.)  The materials that make up yesterday's cooled lava rock and the rock of the Precambrian-Age Laurentian Shield of Canada are the same age; what's different is when the last event occurred that modified them enough to erase their previous history.

Because those history-erasing processes are happening all the time, this makes it difficult to find rocks that are over a billion years old, because the likelihood of a rock surviving unmelted all that time is virtually nil.  This makes our knowledge of the geological history of the Earth sketchier and sketchier the further back in time we go, and honestly, any models we have about the position of the continents and their relationships to the current configuration pretty quickly devolve into pure speculation much earlier than the Cambrian Period -- meaning that 7/8 of the entire history of the Earth is pretty much uncharted territory, geologically-speaking.

All of this is why it was quite a shock when I found out, from a paper in Proceedings of the National Academy of Sciences this week, that a rock has been found containing grains that date from between five and seven billion years ago, and some may be older than that.

Electron micrographs of presolar grains from the Murchison meteorite [Image by Philipp R. Heck, et al., of the University of Chicago]

If you're saying, "Wait, isn't that older than the Earth?", the answer is "yes."  The Earth's surface cooled and became solid on the order of 4.6 billion years ago.  So how can this possibly be correct?

The grains, it turns out, are part of a space rock called the Murchison meteorite that landed in Australia in 1969, so while everything on Earth was getting melted down, smashed, and mixed around, the rock of the Murchison meteorite was safely out in space, preserving the interior as a sort of time capsule of the very early Solar System.  These "presolar grains" of silicon carbide were dated using known conversion rates of the component atoms to other elements from interacting with cosmic rays, in some cases giving ages that are about as old as the Sun itself.

As far as how this can be, it bears keeping in mind that the Sun itself is thought to be a "third-generation star," so therefore nowhere near as old as the Universe as a whole.  The earliest stars were composed solely of hydrogen (and helium, as the hydrogen fuel was consumed), and heavier elements formed in the death throes of those stars.  The heaviest elements all were formed in supernovas, so any star enriched in these elements -- as our Sun is -- must contain materials from at least one, probably more, previous generations of stars.

So these silicon carbide grains were formed from atoms generated in stellar furnaces that predated the Sun (thus their name, "presolar grains"), and were floating around in interstellar space for all that time until a chunk of them happened to discover that Australia was in the way.  Fortunately for us; it gives us a chance to see materials about as old as you could find anywhere -- dating back to a time when the Solar System was still a ring of coalescing debris around a very young star.

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This week's Skeptophilia book of the week is scarily appropriate reading material in today's political climate: Robert Bartholomew and Peter Hassall's wonderful A Colorful History of Popular Delusions.  In this brilliant and engaging book, the authors take a look at the phenomenon of crowd behavior, and how it has led to some of the most irrational behaviors humans are prone to -- fads, mobs, cults, crazes, manias, urban legends, and riots.

Sometimes amusing, sometimes shocking, this book looks at how our evolutionary background as a tribal animal has made us prone all too often to getting caught up in groupthink, where we leave behind logic and reason for the scary territory of making decisions based purely on emotion.  It's unsettling reading, but if you want to understand why humans all too often behave in ways that make the rational ones amongst us want to do repeated headdesks, this book should be on your list.

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

Tut tut

Yesterday we heard about how some oddly-shaped markings on Pluto are evidence of an extraterrestrial base, or possibly the home of intelligent fungus-creatures, as hath been prophesied in the writings of H. P. Lovecraft.  Today, we find out that...

... King Tutankhamun was half-alien.

The whole thing comes up because of a cool archaeological discovery, that a dagger found in the hoard buried with King Tut had a blade forged from a meteorite.  The paper describing the research, written by Daniela Cornelli et al. and published last week in Meteoritics and Planetary Science, had the following to say:

Scholars have long discussed the introduction and spread of iron metallurgy in different civilizations.  The sporadic use of iron has been reported in the Eastern Mediterranean area from the late Neolithic period to the Bronze Age.  Despite the rare existence of smelted iron, it is generally assumed that early iron objects were produced from meteoritic iron.  Nevertheless, the methods of working the metal, its use, and diffusion are contentious issues compromised by lack of detailed analysis.  Since its discovery in 1925, the meteoritic origin of the iron dagger blade from the sarcophagus of the ancient Egyptian King Tutankhamun (14th C. BCE) has been the subject of debate and previous analyses yielded controversial results.  We show that the composition of the blade (Fe plus 10.8 wt% Ni and 0.58 wt% Co), accurately determined through portable x-ray fluorescence spectrometry, strongly supports its meteoritic origin.  In agreement with recent results of metallographic analysis of ancient iron artifacts from Gerzeh, our study confirms that ancient Egyptians attributed great value to meteoritic iron for the production of precious objects.  Moreover, the high manufacturing quality of Tutankhamun's dagger blade, in comparison with other simple-shaped meteoritic iron artifacts, suggests a significant mastery of ironworking in Tutankhamun's time.

Which is pretty darn cool.  The dagger is gorgeous, too:

But of course, "cool archaeological discovery" isn't enough for some people.  The fact that King Tutankhamun had a dagger made from a meteorite (or at least was buried with one) has to mean that the Boy King himself had ancestry from outer space.

Tut's father was the oddball King Akhenaten, who attempted to abolish the national polytheistic religion and replace it with a more-or-less monotheistic worship of the Sun ("Aten"), with predictable results.  The road to popularity does not come from a political figure saying, "You all need to change what you believe right now."  (In fact, the only time I've ever heard of a state religion being decided by decree, peacefully, was the Christianization of Iceland in the year 1,000 C.E., in which the people let the leaders decide if they were going to follow the Christian god or the old Norse gods.  The leaders decided on Christianity, and the entire nation submitted to baptism without a drop of blood shed.)

Be that as it may, Akhenaten was an odd dude.  In depictions of him -- those that survived the wholesale re-conversion of Egypt to the old polytheistic religion at his death -- he is even a strange-looking fellow, with a long, thin face, skinny arms, and a pot belly.  So it's not to be wondered at that the aliens-and-spaceships cadre decided that he couldn't possibly be human.

Pharaoh Akhenaten [image courtesy of the Wikimedia Commons]

So we have the following appearing over at the wonderful site Ancient UFO:

One of the most interesting characteristics of Akhenaten, is that he is always depicted with a long, elongated skull.  Most Egyptian scholars have attributed this to artistic style peculiar to his reign.  Surely though, it is more likely that he actually had an enlarged cranium?  Artistic depictions of Akhenaten, usually show him with an elongated head, wide hips and a round belly.  It has been suggested by researchers that these features are attributed to a disorder called Froehlich’s Syndrome.  This disorder is typified by an elongated face and an androgynous figure...  [But] could this be because Akhenaten was perhaps actually extraterrestrial?

And now, they say, we have the clincher; a dagger whose blade came from outer space.

The problem is, the dagger was made from a meteorite.  I.e., a piece of space rock that struck the Earth.  The ancient Egyptians didn't have to go out into space to mine it, or anything.  The fact that they used meteoritic iron just means they were clever about using stuff they found, not that they were aliens.  King Tut's having a dagger with a blade made from a meteorite doesn't mean that he was half-alien any more than my possession of a t-shirt made in China makes me Chinese.

Of course, the problem is the usual one; the woo-woos in question had already decided that Akhenaten was an alien, so the dagger was just one more bit of confirmation bias in their favor.  So my saying all of this certainly won't stop the speculation.  Look for a highly scientific documentary on Tutankhamun's alien ancestry to show up on the This Really Isn't History Channel soon.