Retreating into science

I try to keep myself informed about what's going on in the world, but lately, what's going on in the world has led me to the unfortunate conclusion that humans are, by and large, crazy.  It's not a comforting thought.  But between the shootings, terrorist attacks, civil unrest, and the Republican National Convention, I seem to have no other option.

Because the news I'm seeing out there is simply too depressing, for today's post I'm retreating to my happy place, better known as science.

Think of it as my answer to flowers, rainbows, and friendly bunnies.

So let's take a look at a few new developments in the scientific world, and take a refreshing break from the irrationality and insanity that is the main course in the media these days.

First, from field biologist Claire Spottiswoode of the University of Cambridge, we have a charming study of a partnership between humans and wild animals -- in this case, between human honey-hunters in Africa and a little brown bird called the Greater Honeyguide.

Honeyguides have been partners with humans for as far back as we have any information.  Honey-hunters in Mozambique call in the birds with a trilling sound, and the birds then lead their human pals to bees' nests.  When the nest is raided, the humans share some of the honeycomb with their guides, so it's a mutually beneficial relationship.

"Communication between domesticated species and people is well known, but the fascinating point in the case of the honeyguide is that it describes such a relationship between a wild animal and humans," said behavioral biologist Claudia Wascher of the University of Anglia Ruskin (UK), commenting on Spottiswoode's study.  "This has not been described scientifically before."

Greater Honeyguide [image courtesy of photographer Gisela Gerson Lohman-Braun and the Wikimedia Commons]

"The results show that there is communication between humans and free-living wild animals that the animals understand," Spottiswoode said.  "There is a rich cultural diversity of interaction between humans and honeyguides.  We'd love to try to understand it."

Next, we have a discovery from the world of astronomy.  Two rocky, Earthlike planets have been discovered that lie in the habitable zone -- around the same star.

The star, called TRAPPIST-1, is only 40 light years away.  While it is certain that the two planets, dubbed TRAPPIST-1-b and c, have atmospheres and are not gas giants like Jupiter and Saturn, it remains to be seen whether they actually are capable of harboring life.

"Now we can say that these planets are rocky. Now the question is, what kind of atmosphere do they have?" study author Julian de Wit of MIT said.  "The plausible scenarios include something like Venus, where the atmosphere is dominated by carbon dioxide, or an Earth-like atmosphere with heavy clouds, or even something like Mars with a depleted atmosphere.  The next step is to try to disentangle all these possible scenarios that exist for these terrestrial planets."

However, it must be said that "only 40 light years away" is still far too distant for any conventional spacecraft to reach.  Even communicating via radio waves wouldn't be very interesting, given the forty year transit time (one way) for messages:

Earth scientist: "Hi there, alien civilization!"
*80 year wait*
Alien scientist on TRAPPIST-1-b: "Hi, Earthling! How's it hangin'?"
Earth scientist: "I'm fine, how're the wife and kids?"
*another 80 year wait*
Alien scientist on TRAPPIST-1-b: "They're doing well, and yours?"

 So it doesn't really lend itself to scintillating repartee. But it's still a tremendously exciting discovery, further indicating that habitable planets are probably common in the universe -- and that we might not be alone after all.

From geologists Guilherme Gualda (of Vanderbilt University) and Stephen Sutton (of the University of Chicago) we have a paper that indicates that supervolcanoes might only give a year's warning before a colossal eruption.  They studied the Bishop Tuff, an outcropping in California that formed 760,000 years ago during the massive Long Valley Caldera eruption, and through analysis of quartz crystals deposited there concluded that the decompression gas bubbles that initiate the explosion form really quickly.

"The evolution of a giant, super-eruption-feeding magma body is characterized by events taking place at a variety of time scales," said Gualda.  "Tens of thousands of years are needed to prime the crust to generate sufficient eruptible magma.  Once established, these melt-rich, giant magma bodies are unstable features that last for only centuries to few millennia.  Now we have shown that the onset of the process of decompression, which releases the gas bubbles that power the eruption, starts less than a year before eruption."

When people think of supervolcanoes, they usually come up with Yellowstone, but it bears mention that there are other supervolcanoes in the world -- Campi Flegrei in Italy, Oruanui in New Zealand, and Toba/Tambora in Indonesia, to name three.  So it's a good thing that the geologists are monitoring the situation, although you have to wonder what they'd do if they found that an eruption was imminent.  "Evacuate Italy" doesn't seem like a viable plan.  But because I said that this post was going to be cheerful and uplifting, perhaps I'd better move on.


Researchers at Cardiff University in Wales have just made a discovery that could help the world move to a post-fossil-fuel economy: that using a cheap catalyst and sunlight, hydrogen gas can be made from grass clippings.

The technique is called photocatalysis, and the catalyst is nickel.  (The process also works well using palladium or gold as a catalyst, but that ups the cost significantly.)  Basically, the idea is that using the catalyst and sunlight as an energy source, cellulose in plant matter can be broken down and produce hydrogen, which can then be used to power hydrogen fuel cells.

"Hydrogen is seen as an important future energy carrier as the world moves from fossil fuels to renewable feedstocks, and our research has shown that even garden grass could be a good way of getting hold of it," said Michael Bowker, who headed the study at Cardiff.  "This is significant as it avoids the need to separate and purify cellulose from a sample, which can be both arduous and costly...  Our results show that significant amounts of hydrogen can be produced using this method with the help of a bit of sunlight and a cheap catalyst."

And when you consider the amount of cellulose-rich agricultural waste that is simply discarded -- think rice husks and cornstalks -- it'd be an amazing breakthrough to be able to use it for fuel production.

So that's our brief retreat into the cheering world of scientific discovery.  It's nice to know that there are still people who are working toward understanding the universe and bettering humanity, and that they're not all crazed, foaming-at-the-mouth lunatics.  It's a refreshing thought.  Maybe I should sustain the feeling by avoiding the news for a while.  I'll miss hearing the spin about Donald Trump's speech last night at the RNC, which would be an added benefit.

Stellar anomaly

Given that my interests are pretty well known to my friends and family, whenever anything interesting happens on the Bigfoot, ghosts, or aliens scene, I'm sure to be sent the relevant links more than once.

This time it's aliens, with the discovery of an anomalous light-dimming pattern in a star with the euphonious and easy-to-remember name of KIC 8462852.   You probably know that light-dimming is one of the main ways that astrophysicists locate exoplanets -- if a telescope on Earth detects a periodic dimming of the light from a star, it is likely to mean that a planet is in transit across it, temporarily blocking its light.  From the period and the extent of the dimming, inferences can be made about the size of the planet and its distance from its home sun.

But this time scientists have found something odd, because whatever is causing the dimming of KIC 8462852 is not acting in a regular or predictable fashion.  And whatever it is seems to be large.  Even a Jupiter-sized planet only blocks 1% of a star's light.  This star is undergoing an irregular diminution of its light... of up to 22%!

[graph of light intensity over time, after Boyajian et al.]

The most mysterious thing about the phenomenon is its lack of periodicity.  At the moment, scientists simply don't know what this means.  And idle speculation, without a good model for what's going on, is not usually fruitful in science, so the astronomers and astrophysicists are being circumspect.  Here's what astronomer Phil Plait had to say:

The authors of the paper went to some trouble to eliminate obvious causes.  It’s not something in the telescope or the processing; the dips are real.  It’s not due to starspots (like sunspots, but on another star).  My first thought was some sort of planetary collision, like the impact that created the Moon out of the Earth billions of years ago; that would create a lot of debris and dust clouds.  These chunks and clouds orbiting the star would then cause a series of transits that could reproduce what’s seen.

Plait admits the downside of this idea, which is that dust and debris should emit infrared light as it's warmed by the star it surrounds, and we're not seeing that.  Others have suggested clouds of comets...  or an alien megastructure.

Seriously.  Years ago Freeman Dyson proposed that a sufficiently advanced civilization could disassemble planets to build a huge sphere around its star, thus capturing (and utilizing) virtually all of the star's emitted energy.  (Dyson spheres show up all the time in science fiction, most famously in the Star Trek: The Next Generation episode "Relics," and in Larry Niven's book Ringworld.)  A partially-constructed Dyson sphere, or one that had been damaged, might be expected to have the irregular light-dimming profile we're seeing in KIC 8462852.

But even the people who work at SETI (Search for Extraterrestrial Intelligence) are being cautious.  There are other possible explanations that have to be ruled out before we can say with any kind of confidence that we're looking at something other than a purely natural phenomenon.  Recall that the discovery of pulsars back in 1967 by Jocelyn Bell Burnell was at first thought to be evidence of an alien signaling device -- in fact, the first pulsars to be detected were nicknamed LGMs (Little Green Men).  Fairly quickly, of course, it was found that there was a completely natural explanation for the observation.

As Jason Wright, astronomer at Pennsylvania State University, put it, "We have to keep in mind Cochran's Command to Planet Hunters: Thou shalt not embarrass thyself and thy colleagues by claiming false planets."

But SETI, quite rightly, is already requesting radio telescope time to study the phenomenon.  If this is evidence of an intelligent alien civilization, there should be a way to support this with additional evidence.  Until then, it's premature to state with confidence that this is anything other than an unexplained stellar anomaly.

It hardly needs to be added that I would be beside myself if it turns out we are looking at extraterrestrial intelligence.  Finding evidence that we are not alone has been one of my dearest desires since I was a child, probably explaining why I have various posters in my classroom featuring aliens, including Fox Mulder's famous UFO poster from The X Files with the legend, "I Want to Believe."  But I, like Plait and Wright and Tabetha Boyajian, the astronomer who discovered the anomaly, want to move forward cautiously here.  There is a long list of weird observations that have at first been touted as evidence of aliens and other fringe-y claims, and have not borne up under additional study.  The best I can say at the moment is that this one looks hopeful -- and certainly deserving of intense further investigation.

The source of the noise

A common theme in Skeptophilia is that people in general need to learn some scientific terminology.

Not only is science cool, and thus learning about it a worthy goal in and of itself; but knowing how science works, and some of the field's vocabulary, will keep you from being duped.  As we've seen over and over, the world is full of folks who either through ignorance or outright duplicity misrepresent what scientists are doing -- and without adequate mental firepower, you're gonna fall for their nonsense every time.

As an example, this weekend, a story started popping up all over that claimed that we'd finally received a good candidate for an alien signal from an extrasolar planet.  This immediately caught my eye -- it is one of my dearest wishes that we have incontrovertible evidence of alien intelligence before I die.  I'd be perfectly satisfied if it comes in the form of some kind of radio signal, but if an actual alien spacecraft landed in my back yard, that would also be acceptable, at least until they started vaporizing my dogs with laser pistols.

So my reaction was one of cautious enthusiasm.  Cautious, because I suspected that if this had actually happened, it would be all over the news, not just surfacing in the form of links on Twitter and Facebook.  But the stories all made the same claim.  Here's an excerpt from the version that appeared on UFO Blogger:

Astronomers have picked up a mystery "noise" which they believe could be coming from an Earth-like planet in the outer space [sic]. After analyzing the strange signals emitting from the object, scientiscientistssts [sic] are certain that a habitable planet exists some 22 light years away, a report said. 

In 2010, scientists had dismissed the mystery noise or signals as stellar bursts but after the latest research it was clear that an Earth-like planet, or Gliese 581d, has conditions which could support life, and is likely to be a rocky world, twice the size of Earth.

Okay, given the typos and grammar, it's not exactly the most credible of reports.  But all of the links I saw agreed; an extrasolar planet called Gliese 581d, 22 light years from Earth, had been reported as the source of a strange, unexplained noise.  The planet was bigger than Earth, but in the "Goldilocks Zone" -- the "just right" region around its star where water would be in liquid form, and therefore a place where life something like what we have here could evolve.

So immediately I started picturing Star Trek-style aliens, complete with fake rubber alien noses and bad accents.  Then I thought of the amazing final scene in Star Trek: First Contact, which is clearly the best movie the franchise ever produced, wherein Zefram Cochrane shakes hands with a Vulcan for the first time.  And before you know it, I had myself worked up into a lather about the possibilities.

Then I thought, "Calm down, dude.  Verify your sources."  So I typed "noise Gliese 581d" into a Google search to see if I could find out where this information had come from.  Clearly it was all similar enough that it had some kind of common origin, and it wasn't wacky enough to have come from The Weekly World News.  And after five minutes' search, I found the press release in Phys.org that had caused the stir -- the origin of the "noise."

And I put "noise" in quotation marks for a good reason, as you'll see.  The press release was a blurb summarizing a paper in Science by Anglada-Escudé and Tuomi called "Stellar activity masquerading as planets in the habitable zone of the M dwarf Gliese 581."  Here's the relevant passage:

A report published in Science has dismissed claims made last year that the first super-Earth planet discovered in the habitable zone of a distant star was 'stellar activity masquerading as planets.' The researchers are confident the planet named GJ 581d, identified in 2009 orbiting the star Gliese 581, does exist, and that last year's claim was triggered by inadequate analysis of the data.

The planet candidate was spotted using a spectrometer which measures the 'wobble', small changes in the wavelength of light emitted by a star, caused as a planet orbits it. In 2014 researchers revisiting the data said that the 'planet' was actually just noise in the data caused by starspots. The possible existence of the planet was widely dismissed without further questioning. 

But now researchers from Queen Mary University of London (QMUL) and University of Hertfordshire have questioned the methods used to challenge the planet's existence. The statistical technique used in the 2014 research to account for stellar activity is simply inadequate for identifying small planets like GJ 581d.

Note the use of the word "noise" twice.  This, apparently, is the source of the story of an alien noise coming from Gliese 581d.

Scientists use the word "noise" differently from the rest of us.  To a scientist, "noise" is scatter in the data, background junk, that might obscure something real and measurable (the "signal").  If you have enough noise, the signal becomes impossible to detect, so reducing the noise in a data set is critical.  A high "signal-to-noise ratio" is what you're after; lots of signal, little noise.  So when the astrophysicists re-analyzed the data from 2009 that had been rejected last year as supporting an Earth-like extrasolar planet around Gliese 581, they found a way of reducing the noise in the data, and were able to confirm that the planet did, actually, exist.

What they did not find was some kind of unexplained noise coming from Gliese 581d.  The noise was the scatter in the data, not some Klingon sending an insulting message at the Earth such as "Hab SoSlI' Quch" ("Your mother has a smooth forehead").

Not that I'm happy to report this, mind you.  No one would be more thrilled than me if we had received an alien communiqué, even if it contained an insult.  But unfortunately, the stories about mysterious and unexplained alien noises turn out to be unmysterious and completely explainable ignorance of bloggers regarding the use of scientific vocabulary.

So we keep waiting.  Given the number of extrasolar planets the astronomers are discovering, I'm still optimistic that one day, we'll find the aliens.  Or maybe they'll find us.  Either way, it'd be amazing, because, after all, Heghlu'meH QaQ jajvam ("Today is a good day to die").