Looking for Martians

When I first read C. S. Lewis's book Out of the Silent Planet, when I was in high school, one of the things that struck me was his vision of life on Malacandra -- what we here on Earth call Mars.

Malacandra, Lewis tells us, is evolved sentient life much earlier than the Earth did, and is therefore approaching the end of its habitability -- the planet is cooling (the majority of its surface is too cold, and the air far too thin, to support life), and its three species of intelligent life have retreated to the deepest parts of the canyons, where the hot springs keep things comfortable.  Given that this is Lewis, there are supernatural overtones to the story, and it's a rollicking good adventure, but what stuck with me most is his vision of a planet that is dying.  Just about every other science fiction novel or movie or television show at the time seemed to picture things as static -- whatever the civilization was, it was just kind of there.  You got the impression things could go on that way forever.

Lewis, on the other hand, recognized not only that organic life forms evolve, but that the planets they live on change as well, and not just in relatively minor ways such as the arrangement of the continents and the depth of the oceans and the presence or absence of ice caps.  The entire planet can shift in such a way as to become uninhabitable -- and, as Lewis points out, that will be the ultimate fate of the Earth as well.

Mars just happened to be closer to the end than we are.

[Image licensed under the Creative Commons ESA - European Space Agency & Max-Planck Institute for Solar System Research for OSIRIS Team ESA/MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA, OSIRIS Mars true color, CC BY-SA 3.0 IGO]

The truth of Lewis's vision has been realized lately in our discovery that long ago, Mars was warm enough to have liquid water and a significant atmosphere.  And this week, a paper came out in Nature Communications that analyzes date from the HiRISE camera on board NASA’s Mars Reconnaissance Orbiter showing that Mars's rivers and oceans left behind layers of sedimentary rock -- a site where future exploration might look for fossils of Martian life.

"Unfortunately we don’t have the ability to climb, to look at the finer-scale details, but the striking similarities to sedimentary rocks on Earth leaves very little to the imagination," said lead author Francesco Salese, from Utrecht University in the Netherlands, in a press release.   "To form these 200-metre-thick deposits we needed conditions that would have required an environment capable of maintaining significant volumes of liquid water."

What this means is that not only was it warmer, the atmosphere was thicker.  The current thin atmosphere on Mars's surface means the pressure is low enough that water would evaporate away post-haste.  A billion years ago, Mars's climate was a great deal more like Earth's is today, but why the change happened isn't known.

I doubt it was the evil eldil from Thulcandra smiting the planet with his mighty fist, but otherwise, Lewis's picture of Mars's evolution toward the dead world it currently is was remarkably prescient.

"We’ve never seen an outcrop with this amount of detail on it that we can definitely say is so old,” said study co-author Joel Davis, postdoctoral researcher at the Natural History Museum in London.  "This is one more piece of the puzzle in the search for ancient life on Mars, providing novel insight into just how much water occupied these ancient landscapes...  The rivers that formed these rocks weren’t just a one-off event — they were probably active for tens to hundreds of thousands of years."

I hope this will spur us to launch more projects with landers that can excavate and analyze these rocks, looking for (amongst other things) fossils.  What we can do remotely, albeit amazing, is still pretty rudimentary -- we can't launch an electron microscope into space yet -- but even a preliminary analysis of the sedimentary layers could produce some fascinating results.

Unfortunately, even if further exploration will discover traces ancient Martian life, I doubt they'll resemble Lewis's hrossa, séroni, and pfifltriggi.  A pity.  Those things were pretty cool.

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This week's Skeptophilia book recommendation is about a phenomenal achievement; the breathtaking mission New Horizons that gave us our first close-up views of the distant, frozen world of Pluto.

In Alan Stern and David Grinspoon's Chasing New Horizons: Inside the Epic First Mission to Pluto, you follow the lives of the men and women who made this achievement possible, flying nearly five billion kilometers to something that can only be called pinpoint accuracy, then zinging by its target at fifty thousand kilometers per hour while sending back 6.25 gigabytes of data and images to NASA.

The spacecraft still isn't done -- it's currently soaring outward into the Oort Cloud, the vast, diffuse cloud of comets and asteroids that surrounds our Solar System.  What it will see out there and send back to us here on Earth can only be imagined.

The story of how this was accomplished makes for fascinating reading.   If you are interested in astronomy, it's a must-read.

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

In your wildest dreams

So, last night, this weird thing happened.  I was skinnydipping in the Caribbean, swimming along trying to get to the other side, when I noticed some people on a boat following me.  They started yelling at me, not (surprisingly) to ask why I was out in the middle of the ocean, but to let me know that there was a hurricane coming and I'd better swim faster because otherwise I wouldn't reach Senegal (which is apparently on the "other side of the Caribbean") in time to avoid drowning in the storm.  They then motored off to get to safety themselves.  It never crossed my mind to wonder why, if the situation was so dire, they hadn't hauled me aboard.  Maybe it was because they were embarrassed by the fact I was naked and they didn't have an extra pair of swim trunks, although I don't remember being much bothered by the fact myself.  Or maybe it was because I'd apparently gotten out there myself, I could damn well get myself out of it, and they'd done their duty by at least letting me know that I was about to be in the middle of a cyclone.

I don't remember what happened after that.  I think it got a little weird.

Somewhere along the way, I woke up, and in the words that every bad fantasy writer has written at some point, "He realized it was only a dream."  Lying there in the dark, I started wondering why my errant brain had come up with something that odd, and came to the conclusion that it was an amalgam of various things over the last few days, like the NOAA bulletin I read saying we were likely to have an above-average year for dangerous hurricanes, and looking at some photos someone posted on Twitter from West Africa.  The skinnydipping part at least makes a modicum of sense because I love to swim but kind of hate swearing swim trunks.  Fortunately I have a pond that's in the privacy of my fenced back yard and only visible from the road if you look exactly in the right direction at exactly the right time, and my opinion is if someone's that determined to see my bare ass, they can have at it.  (Of course, given the way the weather's currently going in the Northeast, it'll probably be August before I'd be willing to swim without a fully-insulated dry-suit, much less naked.)

And for the record, this dream still wasn't as completely fucked up as my wife's dream a couple of nights ago about being tackled by an enormous kangaroo, or the one last night where she had rented an apartment in Washington D.C. but was dismayed to find that it had no door, and the only way you could get in was by climbing through the mail slot.

Apparently even King Solomon had some weird dreams, because I don't know what the hell this is about.  Luca Giordano, The Dream of Solomon (1694) [Image is in the Public Domain]

All of this comes up because of a paper this week in Cell Reports about a study of two epileptic patients who had implants to monitor their brain activity.  These electrodes were supposed to act as neuromuscular interfaces, allowing the individuals to overcome motor paralysis and move their arms simply by thinking about it, but along the way the devices made sensitive readings of neural firing patterns.  And what the researchers found was that when the patients went into the REM (rapid eye-movement) phase of sleep, during which we dream, the brain was apparently replaying firing patterns for motor control that had been learned the previous day.

So the researchers had the patients play a mental game of "Simon" -- remember the popular electronic toy where you had to press buttons to repeat a pattern of sounds and colors?  Of course, given these individuals' disabilities, they couldn't play the actual game, so the scientists instructed the patients to think through and recall the pattern they'd just seen, picturing themselves pushing the buttons in the correct order.

Then the patients took a nap.  And during REM, the same pattern emerged as they'd seen during the mental game.

Apparently, they were playing Simon in their dreams.

My wife had an experience like this back when she was in graduate school, and engaged in the occupation that all serious grad students take part in, namely: playing video games instead of studying.  In her case, it was Tetris, and she finally realized she was spending way too much time playing it when she started having Tetris dreams.

But evidently this is something we all do, and gives us a lens into why we dream in the first place.  It's long been thought that dreaming has to do with memory consolidation -- reinforcing pathways that the brain has decided are important, moving critical memories into long-term storage, and pruning away information that is less essential.  Your brain makes the understandable (if sometimes erroneous) judgment that if you repeat an activity a bunch of times, it must have some survival value, and you replay it while you sleep so you can do it more fluidly when you're awake.

Even if all you're practicing is your ability to stack up bunches of colored blocks while vaguely Russian-sounding music plays in the background.

"This study is fascinating," said Dr. Richard Isaacson, director of the Alzheimer's Prevention Clinic at Weill Cornell Medicine and New York-Presbyterian Hospital, who was not involved in the study, in an interview with CNN.  "Despite decades of research, it remains somewhat unclear how 'short-term' memories get filed away to become 'long-term' memories that can be recalled later.   Using a brain-computer interface is an exciting way to study memory since it can record brain cell activity patterns and then look for those exact patterns later...  This supports the notion that in order to optimize memory function and learning, people need to prioritize restful activities -- most importantly adequate sleep -- to keep our 'engines' running at peak performance."

Which is fascinating, but hardly news to chronic insomniacs like myself.  I know that after a night's poor sleep, everything -- memory, motor responses, mood, sensory awareness -- is affected negatively.  The restorative power of sleep is well-documented, and absolutely essential to health, both physical and mental.

What this study does, though, is to pinpoint one of the ways sleep helps us -- by reinforcing our memory of critical events from the previous days.  We already knew why dreams are so bizarre; during REM, the prefrontal cortex -- which among many other things, acts as a sort of "reality filter," allowing you to sift fact from fantasy -- is essentially offline.  Apparently the memory consolidation function works best when you can get the hypercritical "Okay, that is clearly not real" part of your brain out of the way.

But I still don't think it can explain why I was swimming toward Senegal, naked, during a hurricane.

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

This week's Skeptophilia book recommendation is about a phenomenal achievement; the breathtaking mission New Horizons that gave us our first close-up views of the distant, frozen world of Pluto.

In Alan Stern and David Grinspoon's Chasing New Horizons: Inside the Epic First Mission to Pluto, you follow the lives of the men and women who made this achievement possible, flying nearly five billion kilometers to something that can only be called pinpoint accuracy, then zinging by its target at fifty thousand kilometers per hour while sending back 6.25 gigabytes of data and images to NASA.

The spacecraft still isn't done -- it's currently soaring outward into the Oort Cloud, the vast, diffuse cloud of comets and asteroids that surrounds our Solar System.  What it will see out there and send back to us here on Earth can only be imagined.

The story of how this was accomplished makes for fascinating reading.   If you are interested in astronomy, it's a must-read.

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

Strange attractor

I've always found the concept of the Strong Anthropic Principle wryly amusing.

The idea here is that something (usually a benevolent deity) fine-tuned the universe in just such a way to be hospitable for us -- for having forces perfectly balanced to hold matter together without causing a runaway collapse, for having gravitational pull strong enough to form stars and planets, for having electromagnetic forces of the right magnitude to generate the chemical reactions that ultimately led to organic molecules and life, and so on.

To me, this argument ignores two awkward facts.  First, of course our universe has exactly the right characteristics to generate and support life; if it didn't, we wouldn't be here to consider the question.  (This is called the "Weak Anthropic Principle," for obvious reasons.)  Second, though -- the Strong Anthropic Principle conveniently avoids the fact that a large percentage of the Earth, and damn near 100% of the universe as a whole, is completely and unequivocally hostile to us, and probably to just about any living thing out there.

It's one of those hostile bits that got me thinking about the whole issue today, because astronomers just last week observed a phenomenon called a fast radio burst in our own galaxy -- a mere thirty thousand light years away -- and the thing that produces it is not only bizarre in the extreme, but is something that we're very, very lucky not to be any closer to.

The beast that produces this is called a magnetar, and appears to be a rapidly-spinning neutron star, with a mass of two to three times that of the Sun but compressed into a sphere only about twenty kilometers in diameter.  This means that the surface gravitational attraction is astronomical (*rimshot*).  Any irregularities in the topography would be crushed, giving it a smooth surface with a relief less than that of a brand-new billiard ball.

The most bizarre thing about magnetars, however, is the immense magnetic field that gives them their name.  Your typical magnetar has an average magnetic field flux density of ten billion Teslas -- on the order of a quadrillion times the field strength of the Earth.  This is why they are, to put it mildly, really fucking dangerous.  The article in Astronomy about last week's discovery explained it graphically (if perhaps using slightly more genteel language):

The magnetic field of a magnetar is about a hundred million times stronger than any human-made magnet.  That’s strong enough that a magnetar would horrifically kill you if you got within about 620 miles (1,000 km) of it.  There, its insanely strong magnetic field would pluck electrons from your body’s atoms, essentially dissolving you.

This brought up a question in my mind, though; magnetic fields of any kind are made by moving electrical charges -- so how can a neutron star (made, as one would guess, entirely of neutrons) have any magnetic field at all, much less an insanely strong one?  Turns out I'm not the only one to ask this question, as I found out when I did some digging and stumbled on the Q-and-A page belonging to Cole Miller, Professor of Astronomy at the University of Maryland.  Miller says the reason is that not all of the particles in a neutron star are neutrons.  While the structure as a whole is electrically neutral, about ten percent of the total mass is made up of electrons and protons that are free to move.  Take those charged particles and whirl them around hundreds of times per second, and you have a magnetic field that is not only insanely strong, but really fucking dangerous.

This all comes up because of last week's observation of a thirty-millisecond-long fast radio burst coming from within our galaxy.  All the others that have been detected were in other galaxies, and the distances involved (not to mention how sporadic they are, and how quickly they're over) make them difficult to explain.  But this comparatively nearby one gave us a load of new information -- especially when a second burst came from the same magnetar a few days later.

[Image licensed under the Creative Commons ESO/L. Calçada, Artist’s impression of the magnetar in the extraordinary star cluster Westerlund 1, CC BY 4.0]

As this observation was only made last week, astronomers and astrophysicists are still trying to explain it, including odd features such as its relative faintness.  As compared to bursts from other galaxies this one was a thousand times less luminous.  Why is still a matter of conjecture.  Is it because bursts this weak occur in other galaxies, but from this distance would be undetectable?  Is it because the distant galaxies are much younger (remember, looking out in space is equivalent to looking back in time), so stronger bursts only happen early in a galaxy's evolution?  At this point, we don't know.  As Yvette Cendes, author of the Astronomy article, put it:

It is far too early to draw a firm conclusion about whether this relatively faint FRB-like signal is the first example of a galactic fast radio burst — making it the smoking gun to unlocking the entire FRB mystery.  And there are also still many preliminary questions left to answer.  For example, how often do these fainter bursts happen?  Are they beamed so not all radiation is equally bright in all directions?  Do they fall on a spectrum of FRBs with varying intensities, or are they something entirely new?  And how are the X-ray data connected?

As usual with science, the more we know, the more questions we have.

In any case, here we have a phenomenon that's cool to observe, but that you wouldn't want to be at all close to.  Not only do we have the magnetic field to worry about, but the burst itself is so energetic that anything nearby would get flash-fried.

So "the universe is fine-tuned to be congenial to us" only works if you add, "... except for the 99.9% of it that is actively trying to kill us."  Not that this makes it any less magnificent, but it does make you feel a little... tiny, doesn't it?  Probably a good thing.  Humans do stupid stuff when they start thinking they're the be-all-end-all.

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

This week's Skeptophilia book recommendation is about a phenomenal achievement; the breathtaking mission New Horizons that gave us our first close-up views of the distant, frozen world of Pluto.

In Alan Stern and David Grinspoon's Chasing New Horizons: Inside the Epic First Mission to Pluto, you follow the lives of the men and women who made this achievement possible, flying nearly five billion kilometers to something that can only be called pinpoint accuracy, then zinging by its target at fifty thousand kilometers per hour while sending back 6.25 gigabytes of data and images to NASA.

The spacecraft still isn't done -- it's currently soaring outward into the Oort Cloud, the vast, diffuse cloud of comets and asteroids that surrounds our Solar System.  What it will see out there and send back to us here on Earth can only be imagined.

The story of how this was accomplished makes for fascinating reading.   If you are interested in astronomy, it's a must-read.

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

There's a word for that

I've always had a fascination for words, ever since I was little.  My becoming a writer was hardly in question from the start.  And when I found out that because of the rather byzantine rules governing teacher certification at the time, I could earn my permanent certification in biology with a master's degree in linguistics, I jumped into it with wild abandon.  (Okay, I know that's kind of strange; and for those of you who are therefore worried about my qualifications to teach science classes, allow me to point out that I also have enough graduate credit hours to equal a master's degree in biology, although I never went through the degree program itself.  My progress through higher education, if viewed from above, would have looked like a pinball game.)

In any case, I've been a logophile for as long as I can remember, and as a result, my kids grew up in a household where incessant wordplay was the order of the day.  Witness the version of "Itsy Bitsy Spider" I used to sing to my boys when they were little:

The minuscule arachnid, a spigot he traversed
Precipitation fell, the arachnid was immersed
Solar radiation
Caused evaporation
So the minuscule arachnid recommenced perambulation.

Okay, not only do I love words, I might be a little odd.  My kids developed a good vocabulary probably as much as a defense mechanism as for any other reason.

[Image is in the Public Domain]

All of this is just by way of saying that I am always interested in research regarding how words are used.  Recently, a friend sent me a link about a set of data collected by some Dutch linguists regarding word recognition in several languages (including English) -- and when they looked at gender differences, an interesting pattern emerged.

What they did was to give a test to see if the correct definitions were known for various unfamiliar words, and then sorted them by gender.  It's a huge sample size -- there were over 500,000 respondents to the online quiz.  And they found that which words the respondents got wrong was more interesting than the ones they got right.

From the data, they looked at the words that showed the greatest recognition disparity between the genders.  The top twelve words that men got wrong more frequently than women were:

• taffeta
• tresses
• bottlebrush (the plant, not the kitchen implement, which is kind of self-explanatory)
• flouncy
• mascarpone
• decoupage
• progesterone
• wisteria
• taupe
• flouncing
• peony
• bodice

Then, there were the ones women got wrong more frequently than men:

• codec
• solenoid
• golem
• mach
• humvee
• claymore
• scimitar
• kevlar
• paladin
• bolshevism
• biped
• dreadnought

There are a lot of things that are fascinating about these lists.  The female-skewed words are largely about clothes, flowers, and cooking; the male-skewed words about machines and weapons.  (Although I have to say that I have a hard time imagining that anyone, male or female, wouldn't recognize the definition of "tresses" and "scimitar.")

It's easy to read too much into this, of course.  Even the two words with the biggest gender-based differences (taffeta and codec) were still correctly identified by 43 and 48% of the male and female respondents, respectively.  (Although I will admit that one of the "male" words -- codec -- is the only one on either list that I wouldn't have been able to make a decent guess at.  It means "a device that compresses data to allow faster transmission," and I honestly don't think I've ever heard it used.  However, that probably has more to do with my complete technological ineptitude than it does my gender.)

It does point out, however, that however much progress we have made as a society in creating equal opportunities for the sexes, we still have a significant skew in how we teach and use language, and in the emphasis we place on different sorts of knowledge.

I was also interested in another bit of this study, which is the words that almost no one knew.  Their surveys found that the least-known nouns in the study were the following twenty words.  See how many of these you know:

• genipap
• futhorc
• witenagemot
• gossypol
• chaulmoogra
• brummagem
• alsike
• chersonese
• cacomistle
• yogh
• smaragd
• duvetyn
• pyknic
• fylfot
• yataghan
• dasyure
• simoom
• stibnite
• kalian
• didapper

As you might expect, I didn't do so well with these.   There are three I knew because they are biology-related (chaulmoogra, cacomistle, and dasyure); one I got because of my obsession with the weather (simoom); one I got because my dad was a rockhound (stibnite); and one I got because of my degree in linguistics (futhorc -- see, the MA did come in handy!).   The rest I didn't even have a guess about.   (I did look up "genipap" because it sounds like some kind of STD, and it turns out to be "a tropical American tree with edible orange fruit and useful timber.")

I'm not entirely sure what all this tells us, other than what we started with, which is that words are interesting.  At least I think so, and I'm pleased to say that my kids still do, too. My younger, who is now 29, was chatting with me on the phone recently, and I asked him how he was settling into the new apartment he moved into a few weeks ago.

"Fine," he said.  "Although a lot of my stuff is still in boxen."

Only someone in my family would think "ox-oxen, box-boxen."

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

This week's Skeptophilia book recommendation is about a phenomenal achievement; the breathtaking mission New Horizons that gave us our first close-up views of the distant, frozen world of Pluto.

In Alan Stern and David Grinspoon's Chasing New Horizons: Inside the Epic First Mission to Pluto, you follow the lives of the men and women who made this achievement possible, flying nearly five billion kilometers to something that can only be called pinpoint accuracy, then zinging by its target at fifty thousand kilometers per hour while sending back 6.25 gigabytes of data and images to NASA.

The spacecraft still isn't done -- it's currently soaring outward into the Oort Cloud, the vast, diffuse cloud of comets and asteroids that surrounds our Solar System.  What it will see out there and send back to us here on Earth can only be imagined.

The story of how this was accomplished makes for fascinating reading.   If you are interested in astronomy, it's a must-read.

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

The return of the senses

The news has been pretty uniformly dismal lately.

I don't even have to list all the ways.  We've all been inundated by the headlines, not to mention how these developments have changed our lives, and it's becoming increasingly clear those changes aren't going away soon.  It's easy to get discouraged, to decide that everything is bleak and hopeless.

So today, I want to look at a new development that should make you feel at least a little better about what humanity can accomplish -- in this case, for people who have been through the devastating experience of losing a limb.

A high school friend of mine was involved in a terrible accident on his family farm and ended up losing both of his arms from the elbow down.  He was fitted with prosthetic arms, and after recovering managed amazingly well -- his courage and fortitude through this ordeal was something that inspired our entire school, and still inspires me to this day.  But his prostheses were no real replacements for lower arms and hands, and there was (and is) a lot he could not do.

Those limitations might soon be a thing of the past.

A collaboration between Chalmers University of Technology, Sahlgrenska University Hospital, the University of Gothenburg, and Integrum AB (a Swedish medical technology firm), the Medical University of Vienna, and the Massachusetts Institute of Technology has produced prosthetic arms for three amputees in Sweden that interface directly with the user's nerves, muscles, and skeletons.  Not only does this mean that the patient has much improved fine motor control over the prosthetic hand, but the nerve connection runs both ways, not only delivering output to control what the hand does, but relaying input received by the hand back to the brain.

Put simply: this prosthesis has a sense of touch.

"Our study shows that a prosthetic hand, attached to the bone and controlled by electrodes implanted in nerves and muscles, can operate much more precisely than conventional prosthetic hands," said Max Ortiz Catalan, who headed the research and was lead author on the paper describing it that appeared last week in the New England Journal of Medicine, in an interview with Science Daily.  "We further improved the use of the prosthesis by integrating tactile sensory feedback that the patients use to mediate how hard to grab or squeeze an object.  Over time, the ability of the patients to discern smaller changes in the intensity of sensations has improved."

The new prostheses, as amazing as they are, are just the first step.  "Currently, the sensors are not the obstacle for restoring sensation," said Ortiz Catalan.  "The challenge is creating neural interfaces that can seamlessly transmit large amounts of artificially collected information to the nervous system, in a way that the user can experience sensations naturally and effortlessly."

It's kind of amazing how fluid the human brain can be.  Neuroscientist David Eagleman, in his brilliant talk "Can We Create New Senses for Humans?", describes our sensory organs as being like the peripherals in a computer system -- and explains how quickly the brain can learn to obtain the same information from a different peripheral.  Some of his examples:

• blind people using echolocation -- clicks -- to create a "soundscape" and navigate their surroundings
• in a separate experiment, the blind using a head-mounted camera connected by an electrical lead to a flat, horseshoe-shaped piece of metal resting on the tongue -- the camera translates what it "sees" into a pattern of tiny voltage changes in the piece of metal, which the brain converts to rudimentary visual images
• the hearing impaired using a vibrating vest hooked up to a microphone to learn to "hear" through the vibrations on their skin

For me, the most stunning thing about these examples is that the brain learns to reinterpret the signals coming from the "peripheral" -- in the first example, sounds activate the visual cortex; in the second, touch stimuli activate the visual cortex; in the third, touch stimuli activate the auditory cortex.  All neural signals are the same; the brain simply decides how to interpret them.  You literally are seeing with your ears, seeing with your tongue, or hearing with your skin.

Here, though, the peripheral really is a peripheral, i.e., a machine.  You're not co-opting one of your pre-existing senses for a different purpose; you're hooking in an external apparatus to your brain, receiving input from an array of computerized sensors.  You may have been reminded, as I was, of Luke Skywalker:

It's a phenomenal improvement over previous prostheses, that were moved by muscle contractions in the arm it was attached to; here, the prosthesis is not only mind-controlled, it sends information back to the brain about what it's touching, giving the wearer back at least the beginnings of a sense of touch.

"Right now, patients in Sweden are participating in the clinical validation of this new prosthetic technology for arm amputation," said Ortiz Catalan.  "We expect this system to become available outside Sweden within a couple of years, and we are also making considerable progress with a similar technology for leg prostheses, which we plan to implant in a first patient later this year."

So the news these days isn't all bad, even if you have to dig a bit to find the heartening parts.  Regardless of what's happening now, I remain an optimist about human compassion and human potential.  I'm reminded of the final lines of the beautiful poem "Desiderata" by Max Ehrmann: "With all its sham, drudgery and broken dreams, it is still a beautiful world.  Be cheerful.  Strive to be happy."

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

This week's Skeptophilia book recommendation is about a phenomenal achievement; the breathtaking mission New Horizons that gave us our first close-up views of the distant, frozen world of Pluto.

In Alan Stern and David Grinspoon's Chasing New Horizons: Inside the Epic First Mission to Pluto, you follow the lives of the men and women who made this achievement possible, flying nearly five billion kilometers to something that can only be called pinpoint accuracy, then zinging by its target at fifty thousand kilometers per hour while sending back 6.25 gigabytes of data and images to NASA.

The spacecraft still isn't done -- it's currently soaring outward into the Oort Cloud, the vast, diffuse cloud of comets and asteroids that surrounds our Solar System.  What it will see out there and send back to us here on Earth can only be imagined.

The story of how this was accomplished makes for fascinating reading.   If you are interested in astronomy, it's a must-read.

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

The stories the bones tell

The field of forensic anthropology has made amazing strides in the past decades.  Fifty years ago, about all we could count on was identification of gender and suspected ethnic origin, and an estimate of age at death.  Now we are able to use data from bones to reconstruct much of the person's life history.

And sometimes, that history is pretty unpleasant.

One of the first cases in which the entire arsenal of sophisticated analytical techniques was used was "Ötzi," the "Ice Man" of the Alps whose body had been hidden underneath the edge of a glacier in the Italian/Austrian Alps for over five thousand years.  What we now know about Ötzi and his origins is kind of mind-blowing.  From pollen grains found in his clothing, we know he died in early summer, but his last meal contains "einkorn" wheat and sloes, both of which are harvested in the fall -- leading to the conclusion that his people knew how to preserve food over the winter.  He had no less than 61 tattoos, all geometrical and presumably symbolic, perhaps representing magical rituals.  (Or maybe, like me, he had ink just because he thought it was cool.)  He had a copper knife and particles of copper residue in his hair, suggesting he or someone he lived very near was involved in copper smelting.  From an isotopic analysis of his tooth enamel, we even know a bit of his life history -- he appears to have spent his childhood near the present town of Feldthurns, Italy, but at some point in his youth went to a valley fifty kilometers farther north.

Things took a grim turn, however, when the forensic anthropologists started looking into how he died.  Initially it was suspected he'd died in a fall down the hillside, as he had cracked ribs and surface bruises -- possibly resulting in his being knocked unconscious and dying of exposure.  But the truth seems a good bit harsher.  Ötzi has an arrowhead lodged in his upper chest, near the upper lobe of his left lung.  This wasn't an old injury; his shirt had a tear at the same place as the entry wound.  The conclusion from the placement and apparent trajectory of the arrow is that it would have severed arteries in his left pectoral muscle, leading to his death from blood loss.

We humans have been doing bad things to each other for a very, very long time.

If you needed further proof of this, consider the paper in Current Biology that came out two days ago, sent to me by a friend and loyal reader of Skeptophilia, and the reason I've gone into this rather morbid subject today.  In "Origin and Health Status of First-Generation Africans from Early Colonial Mexico," by a team led by Rodrigo Barquera of the Department of Archaeogenetics of the Max Planck Institute for the Science of Human History, we hear about three sixteenth-century skeletons recently found in Mexico that tell a horrific tale of abduction, slavery, and abuse.

The three individuals are clearly of African origin, based not only on skeletal morphology but on tooth-filing patterns that are characteristic of the Fang people of Equatorial Guinea, Cameroon, and Gabon.  Not only that, but one of them had a characteristically African strain of hepatitis B, and another had remnants of the bacteria species (Treponema pallidum ssp. pertinue) that causes the horrific tropical disease yaws (if you choose to investigate further into this disease, do not look at the photographs unless you have a strong stomach -- you have been warned), which is most common in west and central Africa.  In fact, the current presence of yaws in Latin America is almost certainly the result of its having been brought in by the African slave trade.

It only gets worse when you read about the evidence of abuse these skeletons show.  The authors write:

Osteological analyses of the three individuals reveal evidence suggesting a life experience of conflict and hardship.  Individual ML8 SL 150 (SJN001) was found with five buck shots and two healing needles (used in traditional medicine) in the thoracic cavity, as well as gunshot wounds.  Both SJN001 and SJN003 (ML8 SLU9B 296) presented porotic hyperostosis and cribra orbitalia, two pathological changes associated with a skeletal response to nutritionally inadequate diets, anemia, parasitic infectious diseases, and blood loss.  Individual ML8 San José 214 (SJN002) displayed several skeletal changes associated with intense labor and heavy manual activity, including enthesopathies on the clavicle and scapulae as well as osteophytic lipping on the joint surfaces with some additional joint contour deformation at the sternoclavicular joint of the clavicle.  Additionally, he suffered from a poorly aligned complete fracture in the right fibula and tibia, resulting in associated joint changes of the knee, including osteochondritis dissecans of the distal femoral surface with joint contour deformation and associated osteophytic lipping of the articular surface margin.  Furthermore, this individual displayed osteoarthrosis of the lumbar vertebrae in addition to signs of deficient oral health and cut marks on the frontal bone.

"All of us involved in the study were highly touched by the whole story about these three persons, everything that they went through," study lead author Barquera said.  "Knowing that they were first-generation enslaved Africans brings a new perspective on the whole subject because you know they were abducted.  You're seeing all these maltreatment signatures on the bones that came with this abduction, what they suffered for the rest of their lives."

And "the rest of their lives" turned out to be short.  All three of the individuals died in their early or mid-twenties.  Whether they died of disease, malnutrition, murder, or the cumulative abuse they'd suffered isn't known, because they show signs consistent with all possible combinations of the above.

All of it brings home once again the accuracy of Thomas Hobbes's words in his book Leviathan, wherein he characterizes the lives of our ancestors as having been "solitary, poor, nasty, brutish, and short."  It's true that a lot of the poorness and nastiness was circumstantial, and due to bad diet and the prevalence of (then-untreatable) diseases.

But a frightening piece of the "nasty, brutish, and short" part was due to the horrible mistreatment of humans by other humans, often for no better reason than territory, power, rivalries, and tribalism.  I wish I could tell you we've grown beyond all that.  I mean, there's been progress; I wouldn't trade my life here in the 21st century for what Ötzi or the owners of the Mexican skeletons endured.  But that insularity, suspicion, and tribalism is deep within our cultural genes, needing little more than a moment's adversity to bring it to the surface.

Bringing to mind another quote, this one from the Latin playwright Plautus -- Homo lupus homini est (man is a wolf to men).

Which, in my opinion, is slanderous toward the wolves.  They may be fierce, but I've yet to see a wolf enslave another wolf.  On the whole, their society seems a great deal more peaceable than ours is.

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

This week's Skeptophilia book recommendation is an important read for any of you who, like me, (1) like running, cycling, and weight lifting, and (2) have had repeated injuries.

Christie Aschwanden's new book Good to Go: What the Athlete in All of Us Can Learn from the Strange Science of Recovery goes through all the recommendations -- good and bad, sensible and bizarre -- that world-class athletes have made to help us less-elite types recover from the injuries we incur.  As you might expect, some of them work, and some of them are worse than useless -- and Aschwanden will help you to sort the wheat from the chaff.

The fun part of this is that Aschwanden not only looked at the serious scientific research, she tried some of these "cures" on herself.  You'll find out the results, described in detail brought to life by her lucid writing, and maybe it'll help you find some good ways of handling your own aches and pains -- and avoid the ones that are worthless.

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

Looking for a biosignature

From Gordon's Obsession #1 (paleontology) yesterday, today we're moving on to Gordon's Obsession #2: outer space and extraterrestrial life.

No, unfortunately, I'm not about to announce we've located the Andorian home world.  Maybe next time.

We're returning to this favorite topic of mine because of a paper this week in Astrophysical Journal Letters by a team led by Lisa Kaltenegger, of the Carl Sagan Institute of Cornell University, right in my part of the world in upstate New York.  Kaltenegger et al. describe models they've developed to refine how we look for Earth-like exoplanets -- by trying to figure out what our own world would have looked like from the depths of space during its entire geological history.

In "High-Resolution Transmission Spectra of Earth Through Geological Time," Kaltenegger's team recognizes the phenomenon we've discussed here before -- that seeing farther out into space means seeing further back into time.  An intelligent, technological alien species as little as 150 light years away wouldn't have any way of knowing that the Earth hosted a complex civilization with its own sophisticated scientific and technological capabilities, because they'd be seeing us as we were 150 years ago -- before the invention of long-distance radio-wave communication.  To them, the Earth would be a small rocky planet that was entirely silent, and apparently, devoid of life.

So are we making the same mistake with the exoplanets we're seeing?  And is there a way to get beyond that, and find "biosignatures" -- detectable traces of life on a far-distant world?

The key, says Kaltenegger, is in the world's atmosphere.  As the light from its host star passes through the thin envelope of gases surrounding the planet, the light is altered; each kind of gas has a specific set of frequencies it can absorb, and those are selectively removed from the stellar light, creating a dark-line or absorption spectrum.  This gives a fingerprint of what gases are there -- and, potentially, tells us what's going on down on the planet's surface, including whether or not there's anything alive.

The data they're using comes primarily from two sources -- the orbiting James Webb Space Telescope, and the Extremely Large Telescope out in the Atacama Desert of Chile.

I don't know about you, but the name of the latter always makes me laugh.  I'm picturing the scientists coming up with a name for the observatory after it was complete:

Scientist #1:  So, what are we gonna name our telescope?
Scientist #2:  How about naming it after Edwin Hubble?
Scientist #1:  No, that one's already taken.
Scientist #2:  Well, what's this thing's most outstanding feature?
Scientist #1:  It's extremely large.
*pause*
Scientist #1 and #2, together:  Heyyyyyy......!

But I digress.

Kaltenegger's team is looking for the presence of highly-reactive gases -- oxygen being the most obvious example -- that wouldn't be in an atmosphere unless something was continually pumping it out.  While there could be a non-biological way to inject large quantities of oxygen into an atmosphere, the better likelihood is some analogue to photosynthesis.

In other words, life.

The nice thing about this approach is that the presence of oxygen would have been detectable here on Earth over a billion years ago -- thus, potentially detectable by technological aliens from up to a billion light years away.  That's quite a window.  "Even though extrapolations from our findings suggest that one out of five stars hosts a planet which could be like Earth, it would be extremely surprising if all of them were at our Earth’s evolutionary stage," Kaltenegger said.  "So taking Earth’s history into account to me is critical to characterize other Earth-like planets."

What the team did is predict what the absorption spectra of the Sun's light would look like after passing through the Earth's atmosphere during the various periods of our prehistory -- the anoxic period (prior to the evolution of photosynthesis), the time during which aerobic life was present but uncommon, the transition to the land & evolution of plants, and so on, up through the Industrial Revolution, when (as James Burke put it in After the Warming) "instead of the atmosphere doing things to us, we started doing things to it."

The technique is not without its difficulties, however, most notably that the absorption spectrum of one of the biologically-produced reactive gases they studied -- methane -- is awfully close to that of water.  So teasing apart what's the signature of a ubiquitous compound, and what's the actual fingerprint of life, may not be simple.

What's certain is that we've only scratched the surface of what's out there.  At present there are a few more than 4,000 exoplanets identified, a lot of which are gas-rich Jovian planets that are likely not to have a solid surface.  (The reason for this is that the two main techniques for locating exoplanets, stellar occlusion and detection of a "wobble" in the star's position, work much better if the planet in question is large, biasing us against detecting small rocky worlds like our own.)  But if Kaltenegger is right that twenty percent of stars have Earth-sized planets, that's a lot of potential homes for alien life.

I don't know about you, but to me, that's tremendously exciting.  Even if we can't detect Vulcans and Klingons and Andorians yet, we might just be able to see if there's life at all out there.

And I'd be satisfied with that.  Just knowing we're not all alone in the cosmos would be reassuring, even if we don't know what that alien life is like, or whether they might be looking back at us through their own telescopes.

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

This week's Skeptophilia book recommendation is an important read for any of you who, like me, (1) like running, cycling, and weight lifting, and (2) have had repeated injuries.

Christie Aschwanden's new book Good to Go: What the Athlete in All of Us Can Learn from the Strange Science of Recovery goes through all the recommendations -- good and bad, sensible and bizarre -- that world-class athletes have made to help us less-elite types recover from the injuries we incur.  As you might expect, some of them work, and some of them are worse than useless -- and Aschwanden will help you to sort the wheat from the chaff.

The fun part of this is that Aschwanden not only looked at the serious scientific research, she tried some of these "cures" on herself.  You'll find out the results, described in detail brought to life by her lucid writing, and maybe it'll help you find some good ways of handling your own aches and pains -- and avoid the ones that are worthless.

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