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02 Apr 16:00

The Mystery of the Missing Black Holes

by Nadia Drake

In the census of black holes, there are basically two populations: The big, supermassive bruisers that churn away in the hearts of large galaxies, and the smaller, comparatively runty black holes that form when massive stars collapse and die.

But what about the medium-size black holes – the middleweights, the golden retrievers, the four-door sedans – that are neither galactic drain nor single stellar corpse?

According to some astronomers, these intermediate black holes, with masses equivalent to anywhere between 100 and 100,000 suns, should be everywhere. After all, those million-solar-mass galactic drains aren’t just born that way.

Trouble is, the middleweights are mostly missing. Decades of searching have only yielded a handful of strong candidates. Even this week’s episode of Cosmos: A Spacetime Odyssey, which dealt at length with black holes, didn’t mention the missing middleweights. But whether astronomers are having a hard time finding these intermediate mass black holes because they’re tricky to find, or just really, really hard to make is an open question.

“Black holes in general are hard to find because by definition, they don’t radiate any electromagnetic radiation,” says Sydney-based astrophysicist Sean Farrell.

Artist's conception of a lonely black hole, floating near a star cluster on the outskirts of the Milky Way. (David A. Aguilar, CfA)

Artist’s conception of a lonely black hole, floating near a star cluster on the outskirts of the Milky Way. (David A. Aguilar, CfA)

In 2008, graduate student Joana Rodrigues spotted what’s still the leading intermediate mass black hole candidate. Rodrigues, then at the Universite de Toulouse, was working with Farrell and his colleagues; she was looking for lonely neutron stars and other objects that shone brightly in x-rays, using the European Space Agency’s XMM-Newton space telescope.

Rodrigues saw something unexpected: An object that glowed extremely brightly in x-rays – what astronomers call an ultra-luminous x-ray source, or ULX.  Hovering 290 million light-years away in the halo of a galaxy known as ESO 243-49, the object was perplexing for several reasons.

First, this wasn’t just any old super-bright thing. It was ridiculously bright – more than 10 times brighter than any known ULX, and at least 100 million times brighter than the sun. That incredible brightness suggested something very energetic and active was taking place. And, the object, now called HLX-1 (for hyper-luminous x-ray source), wasn’t in the right place. Rather than being at the heart of its galaxy, it was off in the galactic periphery. Lastly, there seemed to be a disk of hot, turbulent gas swirling around it.

At first, Farrell says, he was pretty sure they’d gotten the object’s location wrong. All signs pointed to HLX-1 being a massive black hole in the process of yanking material from some nearby stars – the kind of thing that should be in the heart of a galaxy, rather than on the outside.

But follow-up observations suggested that HLX-1 really was on the fringe, and that the superhot gas likely came from a star being ripped apart by a black hole with several hundred solar masses.

In other words, the team seemed to have found an intermediate mass black hole.

Now, nearly six years later, HLX-1’s story has gotten even weirder. New measurements suggest it’s probably around 10,000 solar masses – still within the intermediate range. And in addition to that gassy disk, Hubble space telescope observations point to a dense population of young blue stars clustered around the black hole.

“The location of HLX-1 out in the halo of ESO 243-49 is a very unusual place to find young stars,” Farrell says. “Something would have had to trigger the formation of these stars in the recent past.”

That something might be the recent collision and merger of a dwarf galaxy with ESO 243-49 – a dwarf galaxy whose stars were absorbed by the larger galaxy and whose heart was punted into space. That heart is HLX-1. It simultaneously clings to some of its original stars and also supports a younger population formed during the galactic merger.

“Mergers of dwarf galaxies with large galaxies like the Milky Way are really common,” Farrell says. “So if dwarfs contain central black holes, then such black holes should be deposited in the halos of large galaxies.”

At a meeting in the Netherlands this week, astronomer Roberto Soria of Australia’s Curtin University ranked the existing IMBH candidates. At the top of his list? HLX-1.

But even though HLX-1 is the strongest IMBH candidate, it isn’t alone. Another candidate, M82 X-1, is nipping at its heels (M82 X-1 was second on Soria’s list). In 2006, a team led by astrophysicist Philip Kaaret of the University of Iowa spotted M82 X-1, about 11 million light-years away.

M82, a galaxy 11 million light-years away, hosts the second strongest intermediate mass black hole candidate. (NASA/ESA/Hubble Heritage Team)

M82, a galaxy 11 million light-years away, hosts another intermediate mass black hole candidate. (NASA/ESA/Hubble Heritage Team)

If you look toward the Big Dipper’s ladle, on a dark night with good binoculars you can see M82, the candidate’s host galaxy (this is the same galaxy in which a type 1a supernova exploded earlier this year). It appeared to Kaaret and his colleague Hua Feng as though the object they’d found – also a ULX – measured between 200 and 800 solar masses, and was snacking on a nearby red giant star.

More recently, teams have found intermediate mass black hole candidates in an irregular dwarf galaxy called I Zwicky 18 and on the fringes of the Circinus spiral galaxy (though that one – at 90 solar masses – is a little on the light side to be a bona fide candidate, says its discoverer, Dominic Walton of Caltech).

The dearth of candidates begs the question of whether these medium black holes are really as numerous as expected. Some astronomers, like Kaaret, suggest maybe not.

“I think they are so hard to find because they are so hard to form,” he says. “Most ‘stellar mass’ black holes form in the collapse of a single star.  It looks like one can get up to masses of about 50 or 80 – but less than 100 – solar masses this way. Intermediate mass black holes need a different mechanism.”

Others scientists, like Farrell, think these black holes are just hard to find.

Because black holes don’t emit any electromagnetic radiation, they’re more or less invisible when thrust upon the backdrop of dark, empty space. So, astronomers searching the sky for these cosmic objects have to get kind of lucky. They need to be looking in the right place, with the right instrument. Unless you spy something like a telltale jet, or accretion disk, or cluster of strange young stars, it’s hard to know that you might be looking at a black hole.

Perhaps galactic halos are the place to look for this missing class of black hole, Farrell says.

If intermediate mass black holes do form the hearts of dwarf galaxies, and if dwarf galaxies frequently merge with one another and with larger galaxies, then there could be many dark, punted hearts floating on the peripheries of large galaxies. Just like HLX-1.

“I think the likelihood that there are potentially hundreds of quiet intermediate mass black holes floating around in galaxy halos is probably pretty high,” Farrell says.

03 Apr 06:30

Is a Footprint the Right Metaphor for Ecological Impact? | Guest Blog, Scientific American Blog Network


Click thru for full article.

Is a Footprint the Right Metaphor for Ecological Impact? | Guest Blog, Scientific American Blog Network:

On the cover of Our Ecological Footprint, published in 1996, a giant foot stomps on the Western hemisphere, carrying the weight of cars, overpasses and skyscrapers. William Rees, a population ecologist at the University of British Columbia, first thought of the footprint metaphor while boasting to a graduate student about the “small footprint” of his new computer tower in 1992. Linguists trace the use of footprint to mean “space occupied” to 1965 when astronomers described the landing area for a spacecraft. It would be another fourteen years before a Senate committee first uttered “environmental footprint.” But is this the best metaphor for humanity’s impact on the natural world?

Today Our Ecological Footprint is a classic text among biologists, and “ecological footprint” and “carbon footprint” are terms as familiar as “Googling” and “selfie.” A number of NGOs offer ecological footprint calculators, including the Global Footprint Network, the WWF footprint calculator and the Earth Day Network Footprint Calculator. The calculators approximate the amount of biologically productive land required to generate the resources an individual or a population consumes and to absorb the waste that the individual or population leaves behind. The results of footprint calculators are often used to highlight global disparities. In 2007, for example, the U.S. footprint per capita was 9.0 global hectares while China’s was just 1.8. Global estimates of human impact on natural systems are bleak. Species are going extinct 1,000 to 10,000 times more rapidly than they historically have between major extinction events. There are as many introduced plant species on oceanic islands as native plants. Humans consume about one-third of all solar energy converted to plant matter through photosynthesis, and their actions directly impact 75 percent of terrestrial Earth – or, if we take climate change into account, the entire Earth. The magnitude of these changes has prompted some geologists and ecologists to favor the term “Anthropocene” when referring to the present geological age, even though the International Union of Geological Sciences still places us in the Holocene. Given the picture painted by such statistics, it is no surprise that the footprint metaphor has caught on. A footprint is a mark one never meant to leave: a revealing clue in a garden, a blemish on an otherwise sparkling floor. It evokes both the weight of whoever left it and that being’s ominous absence. Verbs popular among environmentalists include trample, trod, oppress and dominate. Heavy feet imply antagonism and the lack of intimacy between humans and the non-human world. Are we waiting for the other shoe to drop?

03 Apr 06:19

Listen/purchase: Foamy Lather by Ultralash An excellent and...


Featuring a member of Sleepytime Gorilla Museum on some tracks, as well.

Listen/purchase: Foamy Lather by Ultralash

An excellent and unusual little record.

03 Apr 00:29

Lots of awesome stuff here, plus melodious voices: Erika Moen,...


Dylan is incapable of being serious, it seems.

Lots of awesome stuff here, plus melodious voices:

Erika Moen, Amy Falcone, Lucy Bellwood, Dylan Meconis, and Steve Lieber discuss the ins and outs of freelancing in the creative world at ECCC 2014.

01 Apr 13:00

Oxytocin: Still Not a Moral Molecule

by Ed Yong

Oxytocin stokes the flames of in-group/out-group divisions. I once saw the spectacularly bad suggestion that cops should spray it on rioters.

Whenever the hormone oxytocin makes the news—and it does so regularly—the media can’t help but refer to it as the “love hormone”, “cuddle chemical” or “moral molecule”. Few substances enjoy such a positive public profile. Oxytocin, it is said, is at the core of all our virtues, from trust to empathy to cooperation.

This rose-tinted view is a sham.

As I’ve written before, oxytocin is more of a general social hormone—one that drives us to seek out social situations or that draws our attention to social cues. The results can be positive if we find ourselves in the right situation. Change the context, and oxytocin can reveal a dark side to its influence.

The latest example of this comes from Shaul Shalvi and Carsten de Dreu. They found that people who sniff oxytocin become more dishonest in a simple team game, but only if their lies benefit their group. If they play the game alone, oxytocin doesn’t change their behaviour for better or for worse. As de Dreu says, “This is the best evidence yet that oxytocin is not the ‘moral molecule,’. It doesn’t make people more moral or immoral. It shifts people’s focus from themselves to their group or tribe.”

I’ve written about the study in The Scientist, so head over there for the details. You might also enjoy my piece in Slate about the history of oxytocin hype and why it’s both dumb and dangerous.

29 Mar 16:00

I’ve Got Your Missing Links Right Here (29 March 2014)

by Ed Yong

Lots of stuff, some of it funny, some of it depressing as hell.

Sign up for The Ed’s Up, a weekly newsletter of my writing. Here’s a recent example.


Top picks

Excellent piece by Erika Check Hayden on the problems with poorly conducted mouse studies: wasted money, wasted lives, harmed patients.

Great Barrier Reef: an obituary. An immensely sad, interactive tribute to a fallen ecosystem.

The humble heroes of weight-loss surgery are stomach acids and gut microbes. Great piece by Virginia Hughes

The rise of ancient DNA is one of the most spectacular recent developments in biology. Ewen Callaway gives us a tour

EPIC! All 339 books referenced In “Gilmore Girls”. Also, god I miss those people.

How will science confirm this week’s big discovery about cosmic signals from the infant universe? Nadia Drake on the week’s big discovery.

““I had never seen a brain inside out before,” Gazzaley told me. “After that I couldn’t get back to work.” Carl Zimmer on new ways of visualising the brain.

My short feature on camouflage in the natural (and human) world, for New Scientist. Paywall.

Scientists synthesise an entire yeast chromosome from scratch (and with surprisingly heavy edits). By me.

How psychedelics are helping cancer patients fend off despair. Nice to see a piece (and research) on palliative care in cancer.

A gif of the skull of a two-faced calf, getting cleaned by flesh-eating beetles. And the video that inspired it. By Emily Graslie. Not for the faint-hearted.

Robots, robots everywhere: here’s Oliver Morton’s guide to his wonderful Economist special on robots.

Don’t write a story that is wrong. This is harder than it sounds.” Ian Sample’s excellent tips on good science journalism.

The New Yorker on the quest to apply artificial intelligence to the Chinese board game Go



As climate change progresses, Bangladesh will face the consequences earlier than most.

FDA says almost all manufacturers agree to agricultural-antibiotic controls. End of the battle, or just more of the same?

Hypnotic Art Shows How Patterns Emerge From Randomness in Nature

Pterosaurs are amazing, but surprisingly rare. Why?

Cuvier’s Beaked Whale sets new deep diving mammal record at 9,816 ft, 2,500 ft deeper than sperm whale

Lion versus croc, in a fight over hippo

Deep brain stimulation–a tool for treating Parkinson’s, but also a new way of eavesdropping on the brain.

Google Flu has been a spectacular failure. When it comes to Big Data, you can’t polish a turd.

So, why do snakes have two penises? (Post features all the snake penis photos you could possibly want.)

Conchs foil human collectors by evolving to be smaller.

Boom! Kakapo baby boom.

260-million-year-old spider tracks

An homage to Jane Goodall, who turns 80 next week.

Scientists convince people their hands are rocks

Nadia Drake asked a bunch of astronomers to name the Solar System’s biggest surprises

Mesmeric time-lapse scenes of swarming fireflies

A “fire tornado” whirls above a prairie

“Riding, poking, prodding or otherwise harassing a free-swimming large predatory animal for fun is a bad idea.”

18th century biologists made frogs wear tiny pants while having sex

New dwarf planet discovery hints at a hidden Super Earth in solar system

Neurosurgeons successfully implant 3D printed skull

Wagenmakers to priming psychologists: “nut up or shut up”.

Here’s Radiolab on what would happen if we annihilated all mosquitoes

Two halves of a fossil turtle bone are reunited after 163 years.

The de-extinction issue wastes considerable time “debating the consequences of a science that is yet to be realized.”

Squirrels Hibernate So Hard You Can Juggle Them

This post is a hilarious look at the sort of questions that people in medical charities get.

Heh. Classic children’s books that would be ruined by modern medicine

What happens when you put a fly in a particle accelerator? You get a really cool video

Nadia Drake has given the Milky Way 4 billion years to live, unless you concede to her demands.

Jimmy Wales has told a bunch of alternative medicine people moaning about Wikipedia where to stick it

Slo-mo vid of a goshawk flying through variously-shaped small holes

Gonorrhea bacteria hitchhike among people using ‘grappling hooks’ that grab onto semen proteins.

The cost of anti-vaccine fears in a gif. More from NPR

“What is it about meditation that opens the brain up to these kinds of hallucinations?”

When lab scientists used to pipette with their mouths

Homeopathic products recalled because they might contain actual medicine.

This computer can tell when humans are faking pain. More effective torture droids on the way.

Stick insects started mimicking plants 126 million years ago

Interactive images of how animals see the world

The evidence that phthalates damage male fertility is surprisingly strong. By Deborah Blum.

“The revived moss [has] been in a state of suspended animation since the age of King Arthur.”

Rootworm evolves resistance to GM corn, highlighting importance of crop rotation.

Why are there so many frickin’ huge ants?

“It might sound strange, but a shriveling Mercury is not unexpected.”

Add carbon nanotubes to plants to supercharge photosynthesis. Okay but how would you ever apply this in practice?

Weed: a gateway drug through the generations?

Refuting MMR/autism link decreased intent to vaccinate among parents w/ unfavorable vaccine attitudes

The NYT on the new generation of programmed ‘detect and respond’ brain implants for epilepsy

Two twins, separated by space. No, really, By Space.

“As consumers, when we own a black box, we’re letting other people design our world.” The wonderful Aatish Bhatia hacks Kinect to make a dance video

When Nature Looks Unnatural“—Sean Carroll on the recent discovery about inflation and the early universe.

10 persistent cancer myths and why there’s no evidence to back them up

What was the biggest animal gathering ever? Featuring herring, starlings, and Rod Stewart



“Mellow.” “Clucky.” “Stentorian grunting.” The mating calls of male tortoises

Dad turns kid vids into amazing superhero feats

Life before the internet

Bravo, Tom Whipple. You win the lede awards.

Huh. Cool things happen when you chuck sand in the air and photograph it with a high-speed camera

Onion: How a Predator drone works

A recent study has shown that if US parents read one more think piece about parenting they will go f**king apes**t”

Dr Manhattan performs Let It Go from Frozen.

Explaining phylogeny using candy bars

Teacher spoils a Game of Thrones death every time his class gets too noisy

Close-up shots of flames mid-burst look eerily like brains

Check out the winners of the Wellcome Image Awards, from a beautiful nit to a gorgeous kidney stone

The 20 best TED talks ever. This is absolute gold. Mine is basically #17



A journalist tells his mental illness story

Should you give journalists metrics about their stories?

“References enable TED to fulfil its goal of hosting ‘ideas worth spreading’ rather than mere ‘stories worth telling’.”

Utterly horrifying piece on what happens to ghost flights.

Q&A from Megan Garber, explaining Oculus Rift—Facebook’s recent mega-purchase. I especially like: “Sorry, but this whole thing sounds really nerdy.”

The radiovota: a 1930s “Like” button for the radio… that took 7 hours to register

Retraction Watch is a bastion of solid, important science journalism. Help Ivan Oransky and Adam Marcus with a small donation

Solid advice on story structure in book writing, and drawing inspiration from screenwriting.

Reason #7394 to kick the Daily Mail in its pathetic bigoted crotch



02 Apr 04:00


by Christopher Hastings

At least the Doc knows he's fucking up?


27p33 is a post from: The Adventures of Dr. McNinja Ads by Project Wonderful! Your ad could be here, right now.

27p33 is a post from: The Adventures of Dr. McNinja

Ads by Project Wonderful! Your ad could be here, right now.
16 Mar 19:49

The Birds And the Bees and the Pollinator Syndrome [Science Ink Sunday]

by Carl Zimmer
Tattoo by Dave Kotinsley, Gainesville, FL

Tattoo by Dave Kotinsley, Gainesville, FL

Jacob Landis writes, “I’m a graduate student at the University of Florida studying flower evolutionary development with a focus on plant/pollinator interactions. My ink represents the concept that I have been working on for almost 6 years now. This piece shows three species in the Phlox family. The red and white flowers are both part of the genus Ipomopsis and the blue/purple flower is in the closely related Polemonium. The pollinator of each flower is shown interacting with the flower. These interactions represent the concept of pollinator syndromes: certain features of the flower will attract certain pollinators. The long red tubular flowers attract hummingbirds, the white tubular flowers attract hawk moths, and the more open blue/purple flowers often attract bees.”

You can see the rest of the Science Tattoo Emporium here or in my book, Science Ink: Tattoos of the Science Obsessed(The paperback edition comes out in May; you can pre-order here.)

02 Apr 04:52

How To Draw A Kitty


Feed is wonky, but click through for gud comic.

Ads by Project Wonderful! Your ad could be here, right now.

I am back from Seattle and completely wiped out! So here is a comic thing I did for my tumblr a while back. Regular strips resume tomorrow!

01 Apr 05:01

on Fairness

by Ian

on Fairness

31 Mar 08:00

Prisoners of the Horde-Orcs.



Comic #2626

Comic Rank
27 Mar 15:30

These Are Some of the Solar System’s Biggest Surprises

by Nadia Drake

So. many. links.

The universe is full of surprises, but two discoveries in the outer solar system are dominating astronomy news this week.

First, astronomers reported yesterday that they have found a distant, tiny world – a small, icy body that lives in the darkness far beyond the orbit of Neptune. Called 2012 VP113, the world’s existence challenges theories describing the infant solar system, and flames speculation that a large planet hides on the fringes of detection. 2012 VP113 and its sibling Sedna are now the two farthest-flung, roundish objects we’ve spied whose gravitational allegiance lies with the sun.

Next, we learned of an asteroid-like body with rings. Called Chariklo, the ringed world is a Centaur – an icy, rocky object that lives between the orbits of Jupiter and Neptune. Chariklo is the first not-planet in the solar system known to have a ring system. And it isn’t just any old ring system – there are two bright, glimmering icy rings encircling the enigmatic, 248-kilometer-wide world. For decades, scientists had thought a small body’s gravity would be too weak to cling to rings like Saturn’s. “When it appeared, it was a complete surprise,” said Felipe Braga-Ribas, a planetary scientist at the National Observatory in Brazil, who discovered Chariklo’s rings hiding in a few seconds of observational data. “We started trying to understand it.”

While discussing the discovery with various planetary scientists, it became apparent that such surprises are the norm in planetary science. It seems the solar system has no shortage of unexpected offerings. “It’s one of these discoveries that you just don’t expect to have happen. But that’s the story of planetary science,” said Joseph Burns, a planetary scientist at Cornell University, while talking about Chariklo. “We go out and see what nature says.”

In honor of this week’s outer solar system double feature, I thought it would be fun to ask some scientists which discoveries they consider the most surprising. Whether recent or decades-old, nearby or faraway, groundbreaking or just “wow,” the discoveries described below invoke a delightful tour through the solar system’s many eclectic treasures.

And please, whether scientist or not, feel free to comment on this post and share your most surprising solar system moment – what has our planetary neighborhood surprised you with?


Q: Which discovery (or discoveries) in the solar system has most surprised you, and why? (responses have been lightly edited for length and clarity)

Ryan Anderson, astrogeologist, U.S. Geological Survey

For me, the biggest recent surprise was the discovery of plumes at Europa. A lot of times the big “surprises” make perfect sense in retrospect. We think Europa has liquid water under the ice and that the ice is shot through with fractures, so it makes sense that it might have plumes much like Enceladus at Saturn. But still, making sense of the discovery in retrospect doesn’t change the fact that it’s surprising and exciting when you first hear about it.

Erik Asphaug, planetary scientist, Arizona State University

My biggest surprise was seeing a comet split up into a dozen pieces in 1993, with the discovery of Shoemaker-Levy 9 when I was graduating from Arizona. Wow! I remember thinking, “How many comets get made in this way?” Twenty years later we’ve all been blown away by the sequential space missions to Wild 2, Tempel 1, and Hartley 2. They are all so different. After all this time we still know basically nothing about comets as geologic bodies, which makes them the most fun and rewarding objects of investigation.

Fran Bagenal, planetary scientist, University of Colorado

Volcanoes on Io, which revealed the most geologically active object in the solar system, and moons around asteroids (how did they get there?).

Michele Bannister, postdoctoral fellow, University of Victoria

How active so many of the icy worlds (moons, dwarf planets) of the Solar System are. Not only active in the great, slow past of geological time, but active now: We can see their surfaces change in our lifetime. Geysers on Enceladus, possible plumes on Ceres and Europa, suggestive geyser-features on Triton, storms and rivers on Titan…we’re living in a Solar System that is changing and dynamic.

Bill Bottke, planetary scientist, Southwest Research Institute

The Nice model, where the giant planets possibly started in a very different configuration than they have today; the ~200 km diameter naked iron core represented by the asteroid Psyche; the discovery of the Kuiper belt and more recently, Sedna and its brethren; not quite a discovery, but the paucity or absence (depending on who you believe) of ancient rocks on Earth that are older than 4 billion years; ice within the permanently shadowed craters on the Moon and Mercury; the prediction that many icy moons have deep oceans; the equatorial ridge around Iapetus, and the absolute weirdness of Miranda; how much our view of the solar system has fundamentally changed since the advent of fast computers and efficient numerical integration codes.  (Exoplanets!)

Mike Brown, astronomer, Caltech

Since the story on the second Sedna body is coming out, I am reminded just how incredibly surprised we were when we discovered Sedna. So surprised that we didn’t believe it for about a month until we got multiple confirmations and ruled out every other possibility. It was the only thing ever found so far away and it lived in an area of space where nothing should have been. I always said, at the time, that this is the best part of doing science, because when you find something that is not supposed to be there, you have learned something new about how the solar system works.

Joseph Burns, astronomer, Cornell University

If you go back long enough, a big [surprise] is just the nature of natural satellites. When I was growing up as an academic, satellites were supposed to be just bombarded, barren, cratered objects. Uninteresting. Why would you want to look at them? And then we got in orbit around Mars and saw Phobos and Deimos, and they were pretty bizarre-looking. And then Voyager went out – and suddenly you see Io. And it’s got volcanoes and sulfur, it looks like a pizza and has some sort of bizarre surface. And it turns out, when you go to every system, every one of the satellites is unique – and now, three of the possible abodes for life in the solar system are on moons.

Athena Coustenis, planetary scientist, Observatoire de Paris-Meudon, CNRS

For me, the most surprising discovery were the jets at Enceladus, because it demonstrated that we could find liquid water under the surface of the icy moons at 10 astronomical units, and challenges all the conventional habitable zone models…

Luke Dones, planetary scientist, Southwest Research Institute

We went in a decade from, “only Saturn has rings” to ring systems around all four giant planets. The ring arcs of Neptune were particularly surprising. Also, the very complicated orbital structure of the Kuiper Belt/trans-Neptunian region/inner Oort Cloud/whatever you want to call it. Most of the populations beyond Neptune could have formed closer to the Sun and moved out to their current locations, but there’s a “cold classical” population that seems like it’s always been where it is now.

And, the first extrasolar planets were found around a pulsar, of all places.

Lindy Elkins-Tanton, director of the Department of Terrestrial Magnetism, Carnegie Institution for Science

I was really surprised when Mercury’s magnetic field was found to be offset to the north; we’re used to a magnetic field whose pole can wander relative to the spin pole of the planet, but what about one whose magnetic equator is north of the planet’s equator? This surprise gives me the exciting idea that we may not understand magnetic dynamos very well after all!

Jay Farihi, astronomers, University College London

Comets in the main asteroid belt – they’re like comet-spies in the inner system where they don’t belong. Some main belt asteroids sometimes exhibit characteristics of comets – tails, outflows, etc. They are still poorly understood; it’s not clear if ice and volatiles are evaporating or being released from collisions or rotational break up.

David Grinspoon, astrobiologist, U.S. Library of Congress

I have been repeatedly surprised by the level of activity in small worlds that we “knew” should be old and dead, before we started exploring the outer solar system. Volcanoes on Io, geysers on Enceladus and now evidence of surface water on Asteroid Vesta?  The apparent prevalence of liquid water environments far beyond the sunny inner solar system is a delightful, ongoing set of surprises.

Avi Loeb, astrophysicist, Harvard University

The discovery of ice on Jupiter’s moon Europa – with potentially liquid water under it – was most surprising to me because this environment might host life (in other words, there might be fish in that water). Another surprising discovery was of Sedna, which is a Pluto-size object on an eccentric orbit extending thirty times farther than Neptune’s distance from the Sun. 

Ralph Lorenz, planetary scientist, Johns Hopkins University Applied Physics Laboratory

I wrote a paper in 1995 anticipating that we would not find sand dunes on Titan, which may be one of the most outstandingly bad predictions in planetary science (for interesting reasons) since some 15 percent of Titan turned out to be covered in giant dunes. Bigger picture, Titan turned out to be much more diverse than anyone remotely expected.  Pre-Cassini, everyone thought in one-dimensional terms – Titan is the same everywhere. We thought it would be wet (no dunes), and yet it has vast deserts.  It turns out climate (latitude) controls a lot – it’s wet too, just around the north polar regions. And nobody, not even us, expected us to be able to see the bottom of Ligeia Mare, all the way down to 170 meters. Titan’s seas must be amazingly clear.

Franck Marchis, planetary astronomer, Carl Sagan Center, SETI Institute

Asteroids are mini geological worlds with complex surface activity, differentiated interiors, complex evolution histories, and moons. Also, the satellites of Saturn – their shape, structure and evolution (captured or formed from the ring?) – and the complex interactions between Saturn, its ring system and its satellites. Io (with its outburst eruptions) and Europa and Jupiter’s magnetic field. There is still a lot to learn about the interaction of satellites and the giant planet’s magnetosphere — maybe a future promising way to detect moons around exoplanets?

Sarah Milkovich, planetary geologist, NASA’s Jet Propulsion Laboratory

I’d say three things: The plume at Enceladus, because this tiny moon is spitting out enough water to form the E-ring around Saturn! The plumes at Europa, because we didn’t see them from the Jovian system with the Galileo spacecraft, but from Earth with Hubble. The recurring slope linea (RSL) at Mars, because the idea of any kind of liquid water-related activity on Mars today is rather mind-boggling.

Catherine Neish, planetary scientist, Florida Institute of Technology

I think my top three are: 1. Ice on Mercury’s poles. Although I was only 11 when this was discovered using ground-based radar, I still think this stands out as one of the neatest discoveries in planetary science. The fact that there is water ice on the closest planet to the Sun just seems so incongruous (even though in retrospect it makes perfect sense). 2. Plumes on Enceladus. Water jetting directly into space! How neat is that? 3. Titan: The desert planet. Prior to the Cassini mission, a lot of people thought that Titan would be covered by a sea of liquid hydrocarbons. The Cassini-Huygens mission revealed it to be much more of a desert planet, with vast sand dunes near the equator, and only smaller lakes and seas near the poles.

Alex Parker, planetary astronomer, University of California, Berkeley

In recent memory, the most exciting and surprising series of confirmed discoveries were the detection of Pluto’s packed system of four small moons outside its very large moon Charon. They were unexpected, are in a surprisingly delicate configuration, and their origin and survival remains challenging for theorists to explain. They’re also particularly exciting in light of the fact that we now get to explore them up close when New Horizons visits the Pluto system next year!

Carolyn Porco, planetary scientist and Cassini imaging lead, Space Science Institute

I was part of the Voyager mission to the outer solar system.  Every stop was packed with surprises. But the best surprise of all was the spectacular geysering activity we on Cassini have found at the south pole of Enceladus.  We suspected that moon might have geysers of some sort.  But never did we imagine they’d be the phenomenally dramatic and huge things they turned out to be. It all comes down to a failure of imagination and our inability to divine the variety and spectacle of the phenomena that Mother Nature can create.

Christopher Russell, Geophysicist, Dawn mission principal investigator, UCLA

I will give you three answers, all from the moons of the outer solar system: The magnetic field of Ganymede (which seems to be generated by a magnetic dynamo similar to that in the Earth – no other moon is like that today, although our moon once was), the plume of Enceladus and the lakes on Titan. These moons were like small planets.

Mark Showalter, planetary astronomer, SETI Institute

I’ll vote for Saturn’s F ring as first imaged by Voyager 1. It showed the so-called “braids” (which aren’t really braids, of course) and it was the first time we all realized that a ring didn’t have to be circular and uniform.

Let me pass along a quick anecdote. At the moment that first image came down, one of the Imaging team scientists was doing an on-camera interview, which I was watching. Somewhat befuddled, he blurted out, “This is high on the list of things we didn’t expect to see!” I always wondered what else was on that list.

Linda Spilker, Cassini project scientist, Jet Propulsion Laboratory

For me, the discovery of the icy jets spewing out of the south polar region of Saturn’s tiny moon Enceladus was a big surprise. Enceladus is only 500 km in diameter and should have frozen solid long ago yet today it lofts icy particles and gas into space, creating Saturn’s diffuse E ring. The discovery of liquid methane lakes and seas at the north pole of Saturn’s giant moon Titan was another big surprise. Titan has a thick nitrogen atmosphere and methane plays the role on Titan, with clouds and rain, that water plays on Earth, creating river channels and filling lakes and seas which contain more than 100 times as much hydrocarbons than all of the oil and gas on Earth.

Alan Stern, New Horizons principal investigator, Southwest Research Institute

River valleys on Mars, volcanoes on Io, and the discovery that dwarf planets dominate the population of planets in our solar system. More generally, we should not be surprised at being surprised at the richness of nature — that’s a hallmark of planetary science.

Anne Verbiscer, planetary scientist, University of Virginia

I know this sounds awfully self-serving, but the discovery that surprised me the most was that of Saturn’s Phoebe Ring!  Yes, we planned our Spitzer observations with the intent of finding a ring, but we were really surprised (and delighted) to find that it was there!

Orbit diagram for the outer solar system. The Sun and Terrestrial planets are at the center. Jupiter, Saturn, Uranus and Neptune are in purple solid circles. The Kuiper Belt (including Pluto) is the dotted light blue region just beyond the giant planets. Sedna's orbit is shown in orange, and 2012 VP113's orbit is shown in red. (Scott Sheppard, Carnegie Institution for Science)

New orbit diagram for the outer solar system. The Sun and Terrestrial planets are at the center. Jupiter, Saturn, Uranus and Neptune are in purple solid circles. The Kuiper Belt (including Pluto) is the dotted light blue region just beyond the giant planets. Sedna’s orbit is shown in orange, and 2012 VP113′s orbit is shown in red. (Scott Sheppard, Carnegie Institution for Science)

This post has been updated to include more responses

31 Mar 08:00

And Sometimes You Just Move On

by Christopher Wright

Poe's Law.

29 Mar 17:13

The Absolute Weirdness of Miranda

by Nadia Drake

Click thru for picture.

Miranda looks like it’s been Frankensteined together. The small, lumpy moon orbits Uranus and has a surface covered by patches of intersecting ridges, weirdly bumpy terrain and pockmarked plains, and dark, irregular canyons. It’s kind of like a badly crafted moon-quilt, except there’s nothing warm and fuzzy about a barren chunk of icy rock with grooves that make the Grand Canyon look like a paper cut.

Earlier this week, I asked a bunch of scientists to share what they’ve been the most surprised by in the solar system. “The absolute weirdness of Miranda,” was one of the responses from planetary scientist Bill Bottke of the Southwest Research Institute. There are a number of bizarre satellites in the solar system, so Bottke pointing to Miranda meant it was worth a closer look.

Miranda was spotted in 1948 by Gerard Kuiper, but it wasn’t until Voyager 2 swung by the solar system’s most unfortunately named planet in 1986 that we got a good look at its little moon. Miranda is only 500 kilometers across, or about one-seventh the size of our moon.

Basically, Miranda appears as though it’s made out of pieces that don’t quite fit together properly, sort of like poor, lurchy Frankenstein. How the moon came to be like this is still a mystery. One theory suggests that in its first incarnation, Miranda was a less-grotesque, more-normal version of itself — until a giant impact or five came along and blew the moon apart. The pieces eventually reassembled, but not in a way that made much sense. Another hypothesis suggests that meteorite impacts locally melted the moon, and slush rising to the surface formed the giant, ridged patches scientists call “coronae.” Other theories have thrown in a little icy volcanism and internal heating caused by gravitational interactions with Uranus and its other moons. Or, Miranda could have begun to differentiate, with its internal layers separating into something like a core, mantle, and crust — but froze before it finished the job.

30 Mar 18:51

Tiny convention painting: Monkey King!

Tiny convention painting: Monkey King!

30 Mar 18:28

The Gospel According to Genius


You know, I'm actually really liking using a MBP, but I still don't think I could bring myself to ever give Apple money.

Howdy! I've been given a chance to do a weekly Apple-centric comic over on We're calling it Multi-Touch Theater and this is the second installment. (Last week's is here.) If the traffic is good, I can hopefully keep doing these on a weekly basis. Doing comics like this for other sites really helps me keep Diesel Sweeties running and ad-free, so please go give them both a read if you have a moment.

New strips will continue to run on Fridays, Steve willing. I'll keep running them in my feed as long as I'm able.


what's a gmail

27 Mar 11:51

Thursday round-up

by Amy Howe

Kind of a big deal.

The Court heard oral arguments in one case yesterday and issued an opinion in another, but the big news out of the Court continues to be Tuesday’s oral argument in the challenges to the Affordable Care Act’s contraception mandate.  At Talking Points Memo, Sahil Kapur has additional coverage of the oral argument here and here.  Commentary on the case comes from Noah Feldman at Bloomberg View, who focuses on what he describes as “two important wrinkles in the oral argument that . . . might tell us a lot about both the court’s potential holding and the tenor of the possible dissent”; from Andrew Cohen at The Week, who concludes that “the decision will be more a reflection of the court’s current ideology than about the stability of first amendment precedent or the text of the Religious Freedom Restoration Act”; from Daniel Fisher of Forbes, who predicts that “courts will soon be a lot busier trying to figure out whether a company is trying to avoid a law or regulation out of sincere religious beliefs or to save a buck”; from Brandon Garrett at ACSblog, who argues that the Court on Tuesday “could have pushed harder on a constitutional question that comes first: whether the lawsuit even belongs in a federal court”; from Kent Greenfield at The Prospect, who contends that, if the Court were to rule for Hobby Lobby,  “[j]ust like before the Civil Rights Act, each individual business will be able to pick and choose whether to assert a religious right to discriminate or refuse to provide insurance or pay a minimum wage”;  and from Michael Dorf at Verdict, who observes that, in the past, “claims like the one made by the current plaintiffs were less ideologically charged. Indeed, to the extent that there was any discernible ideological pattern, it was the opposite.”

Yesterday the Court issued a decision in United States v. Castleman, holding that Castleman’s state conviction for misdemeanor domestic assault qualifies as a “misdemeanor crime of domestic violence” and thereby prohibits him from having a gun.  Coverage of the Court’s decision comes from Nina Totenberg of NPR, Jess Bravin of The Wall Street Journal’s Law Blog, and Kent Scheidegger of Crime and Consequences.

After the decision in Castleman, the Court heard oral arguments in Wood v. Moss, in which the Court is considering claims by protesters opposed to the policies of then-President George W. Bush against the Secret Service agents who moved their protests away from the president.  Lyle Denniston covered the oral argument for this blog; other coverage comes from Nina Totenberg of NPR, Jess Bravin of The Wall Street Journal, and Ruthann Robson at the Constitutional Law Prof Blog.


  • At, Damon Root discusses the cert. petition filed recently in Courtney v. Danner, a challenge to a Washington law that gives “de facto monopoly privileges to companies providing commercial ferry service.”
  • At Concurring Opinions, Ronald K.L. Collins (also of this blog) reports that Shaun McCutcheon, the plaintiff in the challenge to the federal limits on aggregate campaign contributions, plans to write a book, to be released shortly after the Court’s decision in his case.

In association with Bloomberg Law

28 Mar 12:56

Friday round-up

by Amy Howe

In case you want to read more about Hobby Lobby's sham case before the court.

Commentary on the challenges to the Affordable Care Act’s contraception mandate continues to dominate Court-related news.  At Big Think, Steven Mazie discusses what he describes as the alliance of “strange bedfellows” supporting Hobby Lobby and Conestoga, the challengers in the case, while at Balkinization David Gans urges the Court to “recognize that the rights of Hobby Lobby’s thousands of employees – who have deeply held beliefs and convictions of their own – are at stake here, too.”  At First Things, Travis Weber urges the Court to strike down the mandate, arguing that it “puts the jobs, livelihoods, and healthcare of millions of Americans at risk by forcing those who stand up for their consciences to choose between paying crippling fines that could shut down their businesses or dropping the healthcare of their employees.” David Cortman echoes these arguments in an op-ed for The Washington Times, in which he writes that, “[i]f the government’s mandate is allowed to stand, people might be out of a job, have no insurance coverage and have less or no money to pay for these items should they choose to buy them.”  At The Volokh Conspiracy, Michael McConnell weighs in on some of the legal questions raised at Tuesday’s oral argument; he concludes by predicting that, in “the cold light of legal principle, the challenge to the contraceptive mandate will carry the day.”  And at Forbes, Trevor Burrus cautions that supporters of the mandate “who are opposing Hobby Lobby’s suit as an attempt to undercut women’s rights or as an attempt to let your boss choose your health care, should be thinking instead about the next big government mandate that could affect a business’s right of conscience that they actually care about.”


  • At Fortune, Roger Parloff previews next week’s oral arguments in Alice Corporation v. CLS Bank International, in which the Court will consider whether the Patent Act authorizes patents on software – more specifically, on computer-implemented inventions.   (Ronald Mann previewed the case for this blog earlier this month.)

In association with Bloomberg Law

28 Mar 19:09

Patent law’s deep questions and the government’s answers

by Eric Citron

Many lawyers come to the law for its deep philosophical questions—questions of morality, jurisprudence, and the public good.  These people usually think that patent law is exclusively for dorks, and that they should avoid it like the plague (in its generic, metaphorical sense—they aren’t really interested in the microbiology).  This is ironic, because patent law has a tendency to pose some of the hardest and most interesting philosophical questions the law has to offer:  What does it mean to invent a composition of matter or a new thing?  Where do we draw the line between the laws of nature and the application of those laws in some product of human ingenuity?  Think a computer is obviously a new and patentable machine?  (That’s got to be right.)  Well how will you deal with the fact that every piece of new software arguably makes it new again, capable of doing something no other machine has done before?  That thing the computer is doing may be very close to a patent-ineligible abstract idea or law of nature.  Should the software nonetheless be patent-eligible?  Always, often, sometimes, never?  This year’s intellectual property blockbuster, Alice Corp. v. CLS Bank International, poses some of these questions.

But while these are deep and interesting questions that lawyers should love to puzzle over, like many such ideas in science, they might be dangerous.  Intellectual property is hugely important to a number of the Nation’s biggest companies, is a massive economic driver in today’s economy, and poses a critical public policy issue about the balance between encouraging innovation and allowing for competition.  There is an abiding concern that questions about patent-eligibility posed at a high degree of generality represent a threat of unforeseen consequences to the very practical world of patent practice and product innovation.

The government’s position—set forth in its brief in Alice—is a study in the balancing act that the patent office and the courts often confront.  The government seems to view its take on software patent eligibility as a fairly narrow, middle-ground approach that scales down the deeply philosophical questions inevitably raised in cases like this.  For the government, this case is not about software patents so much as it is about business-method patents—which the government loosely defines throughout its brief as patents on “methods of organizing transactions and other human activities” or relationships.  These, the government says, are not eligible for patents because they are abstract ideas, not concrete inventions.  And furthermore, when you have such an abstract idea, you cannot make it concrete just by telling someone to do it on a computer.  Some software should be patent eligible, but at least not that.

This sets up a critical distinction for the government between two kinds of software inventions:  those that are patent eligible because they “disclose technological, scientific, or industrial innovations” and otherwise “improve the way computers function” (yay!); versus those that “are directed to organizing abstract concepts and relationships using a computer” (boo!).  Put otherwise, the government thinks you can get a patent on an idea for making computers more awesome, but you cannot necessarily patent your idea for making the world more awesome just because it uses a computer.

The government’s position is that this distinction tracks existing skepticism about business-method patents while still preserving a realm of “technical” innovation in computing that might seem intuitively patent-eligible.  The government even proposes a two-step approach where one first asks whether the core invention is a patent-ineligible abstract idea, and only considers the software application issues if that is so.  Accordingly, even some abstract ideas may be patent eligible as implemented through computer software, and conversely, software never loses its patent eligibility unless it at least embodies an abstract idea.  The hope seems to be that this position will preserve the ability of the patent office to work out a distinction between software that meaningfully moves forward the field of computing and software that merely takes a business method and turns it into ones and zeroes.

But without criticizing the government’s position at all—and indeed, while avoiding any comment on the merits of the case before the Supreme Court or what the Justices might do with it—it is worth saying that the government’s approach may turn out to be something of a greased-up watermelon: a thing that looks like it has real heft, but is almost impossible to firmly grasp.  Do programs that allow you to ask your computer natural language questions and get accurate answers (you may have met him or her) represent what the government calls “improvements in a computer’s operation as a computer,” or are they just computer-implemented embodiments of the world’s most common human interaction?  How about a computer that plays chess—a machine we have pursued since the famous hoax of the Mechanical Turk?  This all seems to trade on some deep, ontological account of what it means for a computer to function “as a computer,” which is just the kind of philosophical imponderable that makes these cases so hard, but also so much fun.

The reason this isn’t a criticism is that, as many scholars and judges have pointed out, every proposal for pinning down the distinction between patent-ineligible abstract ideas and patent-eligible innovations seems to slip out of your hands when you try to pick it up and work with it; the distinction between “technical” software innovations and software that simply implements an abstract idea may be the same.  The government has a “non-exhaustive list” of at least six factors you might consider in solving such puzzlers, but they do not seem easy to apply in any kind of mechanical way, and may be frustrating to the kinds of lawyers who like to respond to legal questions with answers rather than a new set of considerations.

For similar reasons, the government’s view of software patent eligibility may be more innocuous in name than it is in practice from the standpoint of existing patents (or not, or vice versa).  A lot would come to turn on a distinction that seems difficult to rigorously define ex ante.  Plain-English categorizations of alleged software inventions do not obviously fit into one or another of the proposed boxes:  For example, does a program that gets a computer to do something it has never done before make it function better “as a computer?”  (And while you are thinking about that, consider that your own intuitions about what makes a computer “a computer” might be largely a product of the software through which you have experienced its computational power.)  It is thus hard to know the exact zigs and zags even the government’s proposed course would cut through the existing software patent portfolios of the many companies watching this case with interest.  Perhaps the best that can be predicted is that, whatever comes of Alice, the patent office and the courts will end up drawing lines in practice with a lot of reflective equilibrium, much as they do now.

In association with Bloomberg Law

29 Mar 12:02

U.S. bypasses Korematsu plea (UPDATED)

by Lyle Denniston

This sort of tickles my inner conspiracy theorist.

UPDATE:  Saturday 2:05 p.m.  The government’s new brief is now available and can be read here.


The Obama administration, urging the Supreme Court to turn aside a new challenge to presidential power to detain individuals suspected of terrorism links, chose not to support a years-long campaign to get the Court to repudiate one of its most heavily criticized opinions from the World War II era.

In a brief filed this week in Hedges v. Obama (docket 13-758), the U.S. Solicitor General’s office said nothing about the 1944 ruling in Korematsu v. United States – a decision that upheld the conviction of a Japanese American for refusing to go to a wartime detention camp.

In January, government lawyers had been urged to use their reply to the Hedges petition to try to persuade the Court either to overrule outright the Korematsu decision, or at least to tell the Court that the government did not regard that precedent as support for any current detention authority.

The brief, filed Wednesday, did neither, focusing its argument mainly on the point that the individuals who filed the challenge — journalists, authors and political activists — did not have a right to sue because they actually were not threatened with detention and thus could not claim legal injury.

The Hedges case, if granted review, would put before the Court a significant controversy over what Congress meant three years ago in spelling out anew the power of the president to order the capture and possible long-term confinement of potential terrorists.  The controversy centers on whether that added new authority, or simply reaffirmed the power Congress had given the president right after the terrorist attacks on the U.S. in 2001.

To compromise a dispute over whether a restatement of detention authority would extend it to U.S. citizens, Congress wrote into a military defense bill a statement that nothing in the bill “shall be construed to affect existing law or authorities relating to the detention of United States citizens, lawful residents of the United States, or any other persons who are captured or arrested in the United States.”

A federal judge in New York City temporarily barred enforcement of the law after finding that the challengers had a “realistic fear” that they might be detained.  The judge said the challengers were likely to win the case after a full trial, on the theory that it violated First Amendment free-speech rights.  The judge later issued a permanent order against enforcement “in any manner, as to any person.”

The government then appealed to the U.S. Court of Appeals for the Second Circuit, which overturned the judge’s order.  It did so, however, only on the premise that — as the government claimed — the challengers could not sue because they could not prove that they were genuinely at risk of being detained under the 2011 provision.

In the court of appeals, the children of Fred Korematsu and two other Japanese Americans who were convicted of violating the wartime curfew and imprisonment orders — Gordon Hirabayashi and Minoru Yasui — urged the three-judge panel to rule that no part of detention authority relied upon the Korematsu precedent.  (In 1984, four decades after that ruling, all three of those men had had their convictions overturned in a highly unusual federal court decision.)

The Second Circuit did not react to that plea, instead ruling that the challengers contesting the new detention power lacked “standing” to sue.

When the lawyers for the challengers filed their petition in the Supreme Court last December, they asked the Supreme Court to take the case.  They raised First Amendment issues and “standing” issues, as well as a plea for the Court to overrule the Korematsu decision, if it were found to be any part of the justification for detention.

On the basis of that overruling plea, private lawyers who had succeeded in getting the three men’s wartime convictions overturned wrote to Solicitor General Donald B. Verrilli, Jr., asking him to use the government’s response in the case to support overruling Korematsu.

Although a response to that plea was not a part of the brief filed Wednesday, Verrilli argued at length that the four individual challengers were not at any risk of being detained, that the 2011 provision did not add to presidential authority, and that the Justices should deny review on the basis of a lack of “standing” to make the challenge.

After the challengers’ lawyers have a chance to reply to the government’s brief, the Court will decide whether to grant or deny review.  That action may come sometime in April or May.

In association with Bloomberg Law

29 Mar 19:29

Tiny convention painting #2: Elsa from Frozen!


The color version.

Tiny convention painting #2: Elsa from Frozen!

28 Mar 21:58

Tiny convention painting #1



Tiny convention painting #1

28 Mar 07:19

angeliska: I had a conversation with my Dad tonight that...


I was a big fan of the color kittens back in the day.


I had a conversation with my Dad tonight that reminded me of one my most favorite bedtime stories: The Color Kittens!

Man, I had forgotten all about the color kittens until this moment.

20 Mar 18:00

We Can Distinguish Between At Least A Trillion Smells

by Ed Yong

Take-away from this: some people smell way better than others.

Guesses have a strange way of disguising themselves as facts, and taking root in popular knowledge. Consider the claim that the human nose can distinguish between 10,000 different smells. The statement crops up in all manner of websites, along with textbooks and scientific publications.

The figure came from a paper published in 1927, which suggested that people could tell the difference between odours according to four different qualities—fragrant, acidic, caprylic, and burnt—along a nine-point scale. That gives us 6,561 distinguishable smells, which was later rounded up to 10,000!

And that’s it.

There wasn’t any evidence for any of these assumptions, but that didn’t stop an uneducated guess from becoming enshrined as fact.

When Andreas Keller at Rockefeller University learned about this, he was dissatisfied. He wanted to come up with a better estimate—one rooted in actual experiments.

Similar estimates already exist for vision. We know that our eyes are sensitive to wavelengths of light between 390 and 700 nanometres—that is, from red to violet. By doing comparisons within that range, scientists have shown that we can tell the difference between 2.3 million and 7.5 million colours.

The same applies to sound. We can hear frequencies between 20 and 20,000 Hertz—from four octaves below middle C to many octaves above it. Within that range, we can discriminate between around 340,000 tones.

But colours and tones are easy to probe. Both vary along a single dimension: wavelengths of light and frequencies of sound, respectively. Smells don’t have an equivalent. They are complicated cocktails of molecules; a rose, for example, owes its scent to some 275 ingredients. There’s no single metric that we can measure these against; instead, we’re forced to describe them with subjective adjectives. And unlike light and sound, which we can perceive within certain boundaries, there is potentially no limit to the combinations of molecules that could make up an odour.

To estimate the bounds of our sense of smell, Keller had to get creative.

He gave volunteers three jars, two of which contained the same smell. Their job was to find the odd one out. The team made the smells from the same pool of 128 ingredients, which were mixed together in groups of 10, 20 or 30. They then paired these mixtures up so that some pairs had no ingredients in common, some were almost identical, and most were somewhere in between. Each volunteer sat through 260 of these discrimination tests.

After crunching the numbers, the team found that when the pairs of mixtures overlapped by less than 51 percent, most of the volunteers could tell the difference between them. And if they overlapped by less than 57 percent, most of them were distinguishable. This means that the average person can tell the difference between 1.7 trillion (that’s 1,700,000,000,000)different combinations of 30 ingredients.

“It’s one of those moments you live for as a scientist: reframing a problem and finding the solution out in left field,” says Avery Gilbert, a smell scientist who first tracked down the origins of the spurious 10,000 number.

The 1.7 trillion figure is an average. At least one person in the study had an exquisitely sensitive nose that could potentially discriminate between more than 10 million trillion trillion combinations of 30 ingredients. Another volunteer could only make out around 70 million of them.

There’s good reason for this variability. The genes that create smell receptors—the proteins that recognise the molecules we inhale—are the largest family of genes in our genome. They’re also more variable than other genes. “As a consequence, everybody smells the olfactory environment with a different set of receptors and therefore perceives it differently,” says Keller.

The 1.7 trillion figure is also a gross underestimate. “There are probably billions of odorous molecules and we only worked with 128 of them,” says Keller. “Furthermore, we only mixed 30 components. There are many more mixtures with 40 or 50 components.”

Still, a trillion smells is still many more than the number of colours or tones we can perceive. There’s good reason for that too. “Smell evolved to help us detect small differences between different smells: the smell of my baby compared to the smell of my neighbour’s baby, or the smell of fresh milk compared to the smell of spoiled milk,” says Keller. “There really is no need to discriminate trillions of smells, but there is a need to discriminate very similar smells. As a consequence, we can discriminate very many different smells.”

“The numbers are staggering yet not that surprising,” says Gilbert. “Smell is, above all, a combinatoric sense. There is a large but finite number of odorous molecules in the world and they occur in an endless array of mixtures and concentrations. Yet here we are, sniffing at them and making these incredibly fine discriminations on a daily basis. We handle the complexity pretty well.”

“If we couldn’t discriminate a trillion different mixtures where would we be?” he adds. “We’d know when to take the garbage out, but we wouldn’t be able to tell one vintage of Bordeaux from another. In fact, if we couldn’t discriminate millions of combinations we wouldn’t have bothered to create Bordeaux in the first place.”

Reference: Bushdid, Magnasco, Vosshall & Keller. 2014. Humans Can Discriminate More than 1 Trillion Olfactory Stimuli. Science

13 Mar 06:46

A Guide to Lonely Planets in the Galaxy

by Nadia Drake

Stuff like this always shows up how science fiction falls often short at guessing about the universe.

Rogue planets are homeless worlds. They have neither sunrises nor sunsets, because unlike the planets we’re more familiar with, these lonely worlds aren’t tethered to a star. Instead, they travel in solitary arcs around the Milky Way’s core.

Earlier this week, Cosmos: A Spacetime Odyssey, introduced many of its viewers to the concept of these lonely planets.

“The galaxy has billions of them, adrift in perpetual night. They’re orphans, cast away from their mother stars during the chaotic birth of their native solar systems,” Neil DeGrasse Tyson says, as a planet emerges from the darkness. “Rogue planets are molten at the core, but frozen at the surface. There may be oceans of liquid water in the zone between those extremes. Who knows what might be swimming there?”

In the days that followed the show’s premiere, social media sites lit up with questions from viewers wondering what, exactly, these rogue worlds are — and could there really be billions of them, as Tyson said?

(The answer is yes. Probably.)

For decades, astronomers hypothesized that free-floating planets existed. But scientists needed a way to find them. The two most well-known ways of finding exoplanets rely on telltale signals coming from the planets’ stars – either wobbles caused by the gentle tugs of an orbiting planet’s gravity, or the slight dimming produced when a planet passes between Earth and its star.

So how do you find planets that have no stars?

For now, the best methods include looking for a young rogue’s heat in the infrared, and a technique called gravitational microlensing that works well for older, cooler planets, says astronomer David Bennett of the University of Notre Dame. Microlensing takes advantage of gravity’s ability to bend and mess with light. If a massive object – say, a rogue planet – passes between a star and Earth, the planet can act as a lens, curving and tweaking the star’s light as seen from Earth. In general, the more massive the planet, the more affected the light.

So far, using either method, we can’t easily detect starless planets that are smaller than a Jupiter, or at least 300 times the mass of Earth.

ESO/P. Delorme

Free-floating planet CFBDSIR 2149-0403 is the blue spot marked by crosshairs in the center of the infrared image. Click to enlarge. ESO/P. Delorme

Anyway, early observational hints of these untethered worlds turned up in the late 1990s, when a team of Japanese astronomers found evidence for warm, planetary mass objects in the Chamaeleon cluster, about 500 light-years away. Other teams soon reported more rogue candidates, in a cluster near the star sigma-Orionis, in the Orion nebula, in the Taurus star-forming region. More recently, in 2012, astronomers described a hot (700 degrees Celsius) homeless planet, clunkily named CFBDSIR2149-0403, just 100 light-years away.

Evidence for the “billions” parts of Tyson’s statement arrived in 2011. A microlensing study published in Nature suggested the Milky Way contains at least 400 billion star-less worlds, that the lonely planets are more common than stars like our sun. Data from two microlensing consortiums, known by the acronyms OGLE and MOA, pointed toward 10 possible free-floating planets, spotted over a two-year-long survey aimed toward the Milky Way’s galactic bulge.

Based on comparisons between the surveys’ detection efficiency, the probability of microlensing events, and the expected amount of lensing caused by planets and stars, the team concluded that these planetary lenses were everywhere. “There are statistical uncertainties in the analysis,” says Bennett, a member of the MOA consortium. “Four hundred billion planets is probably a good lower limit.”

But not everyone is convinced. Despite careful work by the authors, it’s still possible the objects detected are just very far from their stars, that they’re brown dwarfs (a type of low-mass pseudo-star that failed to ignite nuclear burning in its core), or that the galactic population estimates are off.

Since 2011, though, MOA has been hard at work analyzing larger data sets and refining estimates for how many free-floating planets populate the Milky Way. So far, Bennett says, new estimates appear to support the original finding that these rogue planets are really common. And, there are hints that we may soon be able to find smaller, untethered planets about the mass of Neptune – much too small to be mistaken for a failed star.

Southwest Research Institute

Artist’s conception of the solar system’s lost giant planet. Southwest Research Institute

Now, about those chaotic early years. Astronomers suspect that many free-floating planets are wandering through interstellar space because they’ve been kicked out of their home stellar systems. This process tends to happen early in a system’s history, says astrophysicist Greg Laughlin of the University of California, Santa Cruz. As planets in young systems settle into their orbits, their gravitational jostling can end up sending a sibling or two into space.

It’s possible that something like this happened in our solar system. Theories describing the early solar system don’t really work unless a fifth giant planet – another Uranus or Neptune – were present at the start (one of the problems with these models is that Earth sometimes ends up running into Venus, which we know didn’t happen). Later, as the planets begin to migrate, that fifth giant is kicked out of the solar system and sent flying into space.

Where it is now is anyone’s guess. “The damn thing could be half-way across the galaxy, for all we know,” says Konstantin Batygin, a post-doc at the Harvard-Smithsonian Center for Astrophysics.

Ok. What about the second part of Tyson’s quote? Could these worlds really have molten cores and subsurface oceans?

Perhaps surprisingly, the answer is yes. This part of the narrative echoes a paper published in 1999 by Caltech planetary scientist David Stevenson, who considered how Earth-mass planets cast from their solar systems might fare in outer space. Stevenson suggests that if these planets retained a hydrogen atmosphere, they could stay warm enough to have liquid water on their surface. A subsurface ocean could be present even without an atmosphere. And, larger planets are generally warmer than smaller planets, says Stevenson, who calculated that a cast-off Jupiter would only cool by about 15 Kelvin at its surface.

Let’s hope there are critters — preferably plesiosaurs or laser sharks — swimming in those rogue, subsurface seas.

 ESO/L. Calçada/P. Delorme/R. Saito/VVV Consortium

Artist’s representation of rogue planet CFBDSIR2149-0403. ESO/L. Calçada/P. Delorme/R. Saito/VVV Consortium


25 Mar 21:29

Birth control, business, and religious beliefs: In Plain English

by Amy Howe


Almost two years ago to the day, the Supreme Court heard oral arguments in a challenge to the Affordable Care Act’s individual mandate, which requires virtually everyone in the United States to buy health insurance or pay a penalty.  This morning, it heard a new and different challenge arising out of the Affordable Care Act:  can a business be required to provide its female employees with health insurance that includes access to free birth control, even if doing so would violate the strong religious beliefs of the family that owns the business?  After the oral argument today, it looked like the Court’s answer may well be no, although the decision may not prove as sweeping as some of the challengers might prefer.  And as is so often the case, it looks like Justice Anthony Kennedy may hold the key vote in the case.  Let’s talk about the proceedings at the Court today in Plain English.

Justices Sotomayor, Ginsburg and Kagan (Art Lien)

Justices Sotomayor, Ginsburg and Kagan (Art Lien)

As Lyle explained in his preview of today’s oral arguments, the two cases at the Court today (which were treated as one ninety-minute argument) were filed by two deeply religious families and their family businesses:  the Green family owns the craft chain Hobby Lobby and the Christian bookstore chain Mardel; the Hahn family owns the cabinet company Conestoga Wood Specialties.  Regulations issued under the Affordable Care Act require the companies to provide their female employees with health insurance that includes no-cost access to twenty forms of birth control.  The families, however, object on religious grounds to providing four of those forms – two brands of the emergency “morning after” pill and two kinds of interuterine devices (IUDs) – that prevent embryos from implanting in a woman’s uterus.  Because they believe that human life begins at conception, the families therefore believe that if the corporations were to cover those four forms of birth control, they would in essence be “complicit in abortion.”

The families and the companies went to court, arguing that the “birth control” mandate violated the Religious Freedom Restoration Act (RFRA), a 1993 law that Congress enacted as a response to a 1990 Supreme Court decision holding that an individual’s religious beliefs do not excuse him from having to follow a law that applies to everyone – in that case, a state law prohibiting the use of the hallucinogenic drug peyote.  (The Court also agreed to review whether the mandate violated the Hahn family and Conestoga’s religious rights under the First Amendment, but there was very little discussion of that question today.)  Under RFRA, the government cannot impose a “substantial burden” on the exercise of religion unless that burden uses the narrowest possible way to promote a very important interest of the government.

Former Solicitor General Paul Clement argued first today, on behalf of the challengers to the mandate (collectively referred to as “Hobby Lobby”), and the initial battle lines were quickly drawn.  Three of the Court’s more liberal Justices focused on the potential scope of the rule that Clement and his clients were advocating.  If Hobby Lobby prevailed, Justice Sonia Sotomayor asked, could employers refuse to cover other medical procedures, like blood transfusions?  Or, Justice Elena Kagan added, what about vaccinations?  Clement responded that any procedure to which an employer objected on religious grounds could be reviewed under the RFRA “substantial burden” test.  Hobby Lobby’s case, he argued, was an easy one, he argued:  the fact that the government has excused other employers – such as churches, small businesses, and religious non-profit groups – from having to comply with the mandate demonstrates that the government’s interest in having Hobby Lobby comply with the mandate is not very significant.  By contrast, he noted, an employer who objected to providing coverage for vaccinations, he noted, might have a tougher time meeting the RFRA test because of the very strong government interest in having as many people as possible vaccinated to prevent the spread of disease.  That answer did not seem to satisfy Kagan, who lamented that, if every medical treatment to which someone objects must be evaluated on a case-by-case basis,” everything would be piecemeal, nothing would be uniform.”

(Art Lien)

(Art Lien)

Kagan then turned to the prospect that a decision in Hobby Lobby’s favor would have sweeping effects on RFRA even more broadly, raising a point to which both Justice Ruth Bader Ginsburg and she would return to several times.  RFRA, Kagan suggested, was an uncontroversial law when Congress – by an almost unanimous vote – enacted it. That overwhelming support for the law strongly implies, she contended, that Congress certainly did not expect the law to apply to for-profit corporations, allowing them to seek religious exemptions from, for example, laws governing the minimum wage, child labor, or family leave.  And even if, as Clement assured the Court, courts have not previously seen such claims by for-profit corporations, Kagan predicted that a ruling in Hobby Lobby’s favor would cause religious objectors to “come out of the woodwork.”

After spending a few minutes on questions from Sotomayor about how the mechanics by which a corporation exercises religion, the Justices then plunged into the nitty-gritty of Hobby Lobby’s options under the ACA and the mandate, focusing in particular on whether the company faced a “substantial burden” for exercising its religious beliefs.  Kagan and Sotomayor suggested that the company could choose not to provide insurance for its employees at all, which would subject it to a penalty of $2,000 per employee – which, Kagan speculated, is probably less than it would have to pay to provide insurance for an employee.   And if that’s the case, Kagan continued, where is the substantial burden?   This theory seemed to pique the interest of Justice Anthony Kennedy, who is often regarded as a key vote in high-profile cases.  Assuming hypothetically that the costs to the company are the same whether it provides its employees with health insurance or instead pays the penalty and compensates the employees so that they can buy their own insurance, Kennedy asked Clement, what would your case be?  Clement countered that Hobby Lobby would still face a burden because, if it didn’t provide its employees with insurance, it wouldn’t be able to attract workers.

(Art Lien)

(Art Lien)

If Paul Clement faced tough and persistent questions from Justices Kagan, Sotomayor, and Ginsburg, Solicitor General Don Verrilli found Chief Justice John Roberts and Justices Alito and Scalia to be difficult sells during his forty-five minutes at the lectern.  Verrilli emphasized several points.  The first was that, in determining whether an exemption is available under RFRA, courts must consider the effect that the exemption will have on others – here, Hobby Lobby’s female employees, for whom contraceptive coverage will not be available.  Significantly, that argument seemed to carry at least some weight with Justice Anthony Kennedy, who earlier in the argument had expressed concern that an employer’s religious beliefs could trump the rights of female employees.  But other Justices were skeptical, asking Verrilli to identify language in RFRA that would even allow courts to consider the interests of the female employees.

Verrilli also urged the Court to focus, in deciding whether Hobby Lobby is even entitled to bring a lawsuit under RFRA, on whether the company is a “person” that can “exercise religion.”  And it would be, he argued, a “vast expansion” of the law for the Court to hold that for-profit corporations can make claims for religious exemptions from generally applicable laws.  But the Chief Justice suggested that the Court’s holding might not necessarily be that broad:  the Court could limit its decision in this case to whether corporations like Hobby Lobby, Mardel, and Conestoga, which are owned entirely by one family, have to comply with the mandate, without deciding whether a larger, publicly owned company can object to a law or regulation on religious grounds.

Several Justices also expressed doubt about whether, even if a corporation can exercise religion for purposes of RFRA, the government has a compelling interest in requiring corporations like Hobby Lobby to provide insurance that includes access to free birth control or the mandate is the narrowest possible way to do so.  On the first point, the Justices emphasized that the government has, for a variety of reasons, declined to require other employers – including churches and religious non-profits but also for-profit companies whose health insurance plans are grandfathered in – to comply with the mandate, thereby undermining the government’s argument regarding the mandate’s importance.  And on the second, Justice Antonin Scalia suggested that it wouldn’t be “terribly expensive” for the government, rather than the employers, to pay for the four forms of birth control at issue in this case.

Justice Stephen Breyer, who is often regarded as the fourth member of the Court’s more liberal wing, asked relatively few questions today, and the questions that he did ask for the most part did not tip his hand.  But, although the government will almost certainly need Breyer’s vote to prevail, that won’t be enough; it will need a fifth Justice, presumably Justice Kennedy.  Although Kennedy’s other comments and questions had suggested that his vote might be in play, any optimism that the government may have harbored probably faded when, toward the end of Verrilli’s argument, Kennedy told Verrilli that, under the government’s view of the case, a for-profit corporation like Hobby Lobby could also be required to pay for insurance that would cover abortions.

Will Justice Kennedy – as it appeared today – provide the key vote, or will we get a June surprise the way we did two years ago, in the Court’s ruling on the individual mandate?  We likely won’t know anything more until June, but whenever we do, we will be back to cover the ruling in Plain English.

In association with Bloomberg Law

21 Mar 16:00

How Will Science Confirm Those Cosmic Signals From the Infant Universe?

by Nadia Drake

Two things: One, I personally hope the BICEP2 results aren't confirmed, and two, it's incredible to me that shit we've got at the South Pole.

Announced on Monday, the detection of primordial gravitational waves – ripples in the fabric of the universe that tell us about the first trillionth of a trillionth of a trillionth of a second after the Big Bang – is already one of the biggest science discoveries of the year. In fact, it’s hard to think of something that can realistically top that.

That statement might sound a little hyperbolic, but it isn’t. Many cosmological ideas depend on the events in those very first, violent instants. Until now, we haven’t had much direct observational evidence pointing toward one theory or another.

“Most signs of what happened back then get obliterated,” says MIT physicist Frank Wilczek. “But gravitational waves interact so weakly with everything else that they propagate, they give us a record. What the team is seeing, or claims to be seeing, is the imprint of gravitational waves on the microwave background.”

A team using the BICEP2 detector at the South Pole found the waves’ imprints in the thermal radiation that’s left over from the Big Bang. Called the cosmic microwave background, this radiation forms the fabric that primordial gravitational waves press their fingerprints into, leaving swirly signatures that scientists call B-mode polarizations.


Gravitational waves from inflation generate a faint but distinctive twisting pattern in the polarization of the CMB, known as a “curl” or B-mode pattern. (Harvard University)

These signatures are predicted by a theory known as cosmological inflation, proposed in 1980.

Inflation suggests that the universe we observe today – flat, smooth, relatively uniform – is the result of an unbelievably rapid and accelerating expansion that lasted for a fraction of a second after the Big Bang. Just how fast was it? Wilczek calculates that the acceleration of the expansion was somewhere in the neighborhood of 1048 centimeters/second2 – a number so big it’s basically impossible to comprehend. (Appropriately, inflation theory is connected to one of everyone’s favorite mind-boggling outcomes: The multiverse.)

The gravitational wave discovery has been described in news stories this week as “The Big One,” “a window back to almost the beginning of time,” “as big as it gets,” “worthy of a Nobel prize,” and “a grand slam.”

But along with those descriptions are qualifiers like “if the discovery is confirmed” and “if it is real” – statements that suggest caution is still needed.

That’s not because the data are shaky, necessarily, though there are some sticky spots that need clearing up. Among other things, three data points are sitting in a weird place and contamination by other sources of polarization cannot yet be definitively ruled out.

“The quality of the observing team is widely known to be excellent,” says Matt Strassler, a physicist at Harvard University. “But there are enough little funny things in the data, so I’d feel a lot better when a second independent team sees the same [signal] that BICEP2 sees where they are supposed to see it, and not the same funny things in the data which shouldn’t be there if the interpretation as gravitational waves is right.”

One of the principles of empirical science is that an experiment or an observation must be repeatable. You must be able to replicate a result. Too often, though, nobody bothers to independently verify another team’s science (there are some notable exceptions, like this one); in this case, I think we’ll see a number of teams looking to replicate the BICEP2 observations, and quickly. Here, scientists will be working to rule out other sources of B-mode polarizations, verify the signal in other patches of sky, and see if it’s observable on more than one microwave frequency.

“The result can be checked within the next year or two, in a number of ways,” says Neil Turok, director of the Perimeter Institute for Theoretical Physics, noting one significant caveat to the discovery. “It is very important to check that the B-mode signal is not contaminated by — or entirely due to — radiation from dust or particles in our galaxy.”


Artist’s concept of the Planck satellite. (ESA/NASA/JPL-Caltech)

Turok and others suggest that the Planck space observatory, launched in 2009 and tasked with mapping the cosmic microwave background, could help clear this up. Gravitational waves aren’t the only astrophysical phenomena that can produce B-mode polarizations in the observed background; others include atmospheric distortions, synchrotron radiation, and galactic dust.

Unlike BICEP2, Planck is in space, which means it has less to contend with in terms of Earth’s atmosphere mucking up observations of the microwave background. Planck also studies a larger patch of sky, and has collected a pile of data about polarization caused by dust and galactic foreground radiation. Those observations will be crucial for ruling out these other sources of B-mode signals. Now, the Planck team is analyzing its polarization data and preparing a release for later this year. “Planck should be able to confirm or refute this result,” says physicist Paul Steinhardt of Princeton University.

Mark Kamionkowski, a theoretical physicist at Johns Hopkins University, notes that while Planck could be helpful, it wasn’t designed specifically to look for B-mode polarization in the cosmic microwave background. As a result, he says, there are some tricky instrumental effects that will need to be accounted for.

Instead, Kamionkowski points to a handful of experiments that are designed specifically to look for gravitational wave signatures. Among these are SPIDER and EBEX, which both rely on balloon-borne detectors, launched into the south polar atmospheric vortex from McMurdo Station in Antarctica. For several weeks near the height of southern summer, the Antarctic sky hosts a cadre of enormous science balloons; these two will be looking specifically for the curled imprints of gravitational waves (others study such things as cosmic rays).

But SPIDER, EBEX, and BICEP are not alone at the South Pole. There’s also the South Pole Telescope, right next door to BICEP at Amundsen-Scott South Pole Station. Last summer, the team running an experiment there called SPTPol announced the detection of a different kind of cosmic gravitational signature, known as lensing. Now, the telescope is searching for primordial B-modes, although in a slightly different way than BICEP.

“I am not entirely sure, but there is a good chance that the B-mode signal could be detected in SPTPol in cross-correlation with BICEP2,” Kamionkowski said. “I hope that the SPTPol and BICEP2 people can get together to look into this ASAP.”

The BICEP2 telescope's focal plane consisting of an array of 512 superconducting bolometers, designed to operate at 0.25 K (0.25 degrees Celsius above absolute zero) in order to reduce thermal noise in the detectors. (Anthony Turner, JPL)

The BICEP2 telescope’s focal plane consisting of an array of 512 superconducting bolometers, designed to operate at 0.25 K (0.25 degrees Celsius above absolute zero) in order to reduce thermal noise in the detectors. (Anthony Turner, JPL)

Also at the South Pole is BICEP2’s successor, called the Keck Array. The array is more sensitive than BICEP2 – it has 2,560 detectors in it, compared to BICEP2’s 512 detectors. It also studies the sky at a different frequency (100GHz) than BICEP2 (150GHz), and will be looking to confirm the presence of gravitational wave signatures at the second frequency.

At slightly less southerly latitudes, in the Chilean Atacama, a cluster of other experiments are ready to peer closely at the cosmic microwave background. Here, ACTPol, CLASS, ABS, and POLARBEAR take advantage of the bone-dry sky to stare at radiation from the beginning of time.

Just last week, POLARBEAR released the first direct detection of B-modes due to gravitational lensing, a different kind of distortion in the background radiation that’s caused by structure (things like galaxies and clumps of dark matter) in the universe.

“We were focused on the lensing because we knew that signal was there. We wanted to see it and prove our instrument was working well,” says observational cosmologist Adrian Lee of the University of California, Berkeley. Now, the team is gearing up to study gravitational wave B-modes.

“POLARBEAR is going to be looking for this signal,” Lee says. “We’re really motivated to try and confirm the results they’re seeing.”

How long will it be until we know whether BICEP2’s data can be confirmed? It’s hard to say. Estimates range from a few weeks to a few years. Until those data come down, physicists will remain what Strassler describes as cautiously optimistic.

“We will look for confirmation from all of these experiments,” Kamionkowski says.

The Dark Sector Lab (DSL), located 3/4 of a mile from the Geographic South Pole, houses the BICEP2 telescope (left) and the South Pole Telescope (right). (Steffen Richter, Harvard University)

The Dark Sector Lab (DSL), located 3/4 of a mile from the Geographic South Pole, houses the BICEP2 telescope (left) and the South Pole Telescope (right). (Steffen Richter, Harvard University)

17 Mar 19:00

How to Turn Gut Bacteria Into Journalists

by Ed Yong


The gut is a dark and hidden world. We usually only know what’s happening within it when something goes badly wrong. But there are trillions of microbes in our guts; with their first-hand experience, they’re perfectly positioned to tell us about what’s going on inside ourselves. Pamela Silver from Harvard Medical School is now training them to do that. Her team is transforming gut bacteria into journalists—microscopic reporters who cover the bowel beat.

So far, they have loaded E.coli—a common gut microbe—with a genetic circuit that allows it to detect and remember the presence of an antibiotic. These engineered bacteria can colonise the guts of mice to no ill effect. If the mice get the antibiotic in their diet, the bacteria all flip to a different state, which the team could assess by analysing the rodents’ poo.

It’s a simple proof-of-principle, and detecting an antibiotic isn’t massively useful. But the study lays the groundwork for more exciting applications, which the team are already starting to pursue. Imagine microbial reporters that can spot the chemical signatures of inflammation, disease-causing bacteria, or environmental toxins.

The project is part of the growing field of synthetic biology. Its practitioners bring the ethos of engineering into the world of living things, by combining different genetic “parts” or “modules” to create organisms with new abilities. Many of the initial successes were cute demos, like photographic bacteria, but the field is now moving towards more serious applications, like yeast that can brew antimalarial drugs, cells that self-destruct if they turn cancerous, or bacteria that make plant roots grow longer. “We’re tired of making toy systems that don’t necessarily have an application,” says Silver.

To create her reporter bacteria, Silver teamed up with two partners—Jeffrey Way at Harvard’s Wyss Institute, and a virus called lambda. Lambda is a bacteriophage—a virus that infects bacteria. Its life cycle has two stages—one where it actively reproduces and kills its host, and another where it wheedles its way into its host’s genome and sits there, dormant and harmless.

It flips between these two states using a genetic switch involving two genes—cI and cro—which mutually block each other. If cI wins this battle and Cro is inactive, the phage opts for the dormant, hidden lifestyle. If Cro wins and cI is inactive, the phage goes for the more lethal route. Environmental influences, like hunger or radiation, can change the balance between the two genes, flipping the phage from one lifestyle to another.

The lambda switch was perfect for Silver and Way’s needs—it provided a way of changing between two states, depending on an outside signal. It also came with two huge advantages.

First, in the 1970s and 80s, scientists like Mark Ptashne unpicked exactly how switch works at the most intimate level; Silver once worked in Ptashne’s lab, and Way was in a lab next door. “We understood it in a level of detail that you can’t get from a textbook,” he says.

Second, the lambda switch never fails. A cell is a chaotic environment, and genes get switched on by accident all the time. But that would be disastrous for lambda—if it flips from dormancy to active killing at the wrong moment, it risks going down with its host. So natural selection has fashioned a switch that goes all-or-nothing in two possible directions, and is extraordinarily stable. It just doesn’t flip by accident. “I’d challenge you to find a human-designed circuit that works that well,” says Silver.

The team took the switch out of the lambda genome and implanted it into E.coli. They tweaked it so that it starts in the cI state, and stably flips to the Cro state in response to an antibiotic called tetracycline. In the Cro state, the bacteria switch on another gene that turns them blue if they’re grown in the right conditions. The upshot: if you grow these bacteria in the lab, their colour will tell you if they’ve seen tetracycline. They detect, they remember, and they report.

At first, team members Jonathan Kotula and Jordan Kerns tested this modified switch in laboratory strain of E.coli. But eventually, they showed that it also works in a wild one that actually lives in mouse guts. When they fed this strain to the mice, it established itself nicely and behaved exactly as the team wanted. Both phases are important—the team need to be able to test future genetic circuits in lab-reared microbes that won’t cause problems for natural ones, but that will eventually work in natural strains once they have been perfected.

Chris Voigt from MIT is impressed, especially because the circuit “worked so robustly in the messy gut of a mouse”. Many synthetic biologists have tried to programme cells with specific genetic circuits, and while these often work in the lab, they fail in real environments. “This is one of the few examples—if not the only one—of a circuit working out of a test tube or fermenter,” says Voigt.

Silver and Way are now hard at work on their next applications, all of which use the lambda switch at their core. Their ultimate vision is to engineer bacteria that will not only detect changes in the gut but also respond to them. Imagine a strain that detects the early signs of inflammation and makes an anti-inflammatory drug, or that sense a harmful species of microbe and makes an antibiotic. They would be journalists and doctors.

“We know it’ll work,” says Silver. “We already have some preliminary data. Once we know the fundamentals of this device, we can keep on tweaking it, putting in downstream things like therapeutics or upstream thing like sensors.”

These applications may take many years to realise; for now, the team’s work is already a testament to the value of basic science. Back in the 1970s and 1980s, none of the scientists who were studying phages would ever have guessed that their work could be used in this way.

Even Way wasn’t convinced. “There were a huge amount of picky details that seemed like they could never possibly be relevant, or weren’t necessary for demystifying life,” he says. “But those picky details have been really useful in doing this engineering. The textbook level isn’t good enough, which is why a lot of attempts at synthetic biology fail, or create non-robust systems.” Nature makes things look simple, but to emulate it, we need to understand its details.

Reference: Kotula, Kerns, Shaket, Siraj, Collins, Way & Silver. 2014. Programmable bacteria detect and record an environmental signal in the mammalian gut. PNAS

More on synthetic biology: Can We Save the World by Remixing Life?

26 Mar 18:01

The Humble Heroes of Weight-Loss Surgery: Stomach Acids and Gut Microbes

by Virginia Hughes

This is a really weird effect. There's such an enormous volume of stuff we don't know about how the body works.

Update, 3/31: Today Schauer’s group released an updated study of the STAMPEDE bariatric surgery clinical trial results three years out. Participants who underwent surgery not only had near-normal levels of blood glucose after three years, but also reported higher quality-of-life scores compared with people who did not get surgery. 


If you heard of a treatment that effectively cured 40 percent of people with a devastating common disease — cancer, say, or Alzheimer’s — that would be front-page news, right? People would be gathering around water coolers across the world to gush about the progress of medical science.

We actually do have one such success story, though most people don’t think of it in such glowing terms: weight-loss surgery. A clinical trial published in 2012 studied obese people with diabetes after receiving either intensive medical therapy (which included lifestyle coaching, home glucose monitoring, diabetes medications, and a push to join Weight Watchers) or intensive medical therapy and weight-loss surgery. About 40 percent of those who got the surgery no longer had diabetes a year later, compared with 12 percent who had medical therapy alone. The vast majority of people who had surgery stopped taking their diabetes medications altogether. And the surgery group lost around 25 percent of their weight, whereas the medical therapy group lost just 5 percent.

When the study came out, “it did shake up the conventional thinking about diabetes, because it showed you can’t achieve these outcomes with drugs,” says Philip Schauer, director of the Bariatric and Metabolic Institute at the Cleveland Clinic, who led that trial.

And yet, despite the dramatic, scientifically supported advantages of bariatric surgery, relatively few obese patients have an operation. Around 200,000 bariatric surgeries are performed each year in the U.S., which Schauer (who’s a surgeon) points out is only about 1 percent of the 20 million Americans with severe obesity. “Surgery is definitely underutilized,” he says.

There are many reasons for this. Like all surgeries, this one comes with medical risks (about 1 in 300 patients die, and others get blood clots, gastrointestinal leaks, or bowel blockages). It’s no more risky than gallbladder or appendix surgery, but many patients and doctors perceive it to be worse, according to Schauer. Another hurdle is financial: The surgery costs up to $25,000, and about half of all insurance policies don’t cover it. Of the policies that do, many require patients to jump through hoops — such as first going on a nine-month, medically supervised diet — in order to qualify.

Even if there were no risks and no insurance barriers, bariatric surgery is probably not a practical solution for the escalating public-health problem of diabetes. Take one city: Cincinnati, Ohio. “According to our projections, by 2025 one-quarter of the population of Cincinnati will have type-2 diabetes,” says Randy Seeley, a neuroscientist at the University of Cincinnati and the director of the Cincinnati Diabetes and Obesity Center. Even if every diabetic who qualified for weight-loss surgery wanted to get it, “we don’t have enough surgeons and surgery tables.”

In today’s issue of Nature, Seeley and his colleagues have published a mouse study suggesting that, one day, doctors might be able to mimic the beneficial effects of surgery without actually doing the surgery.

That premise will seem crazy to most surgeons, and that’s because the conventional explanation for bariatric surgery’s effectiveness is mechanical. In the two most common procedures (known as Roux-en-Y gastric bypass, and vertical sleeve gastrectomy, or VSG), surgeons make the stomach drastically smaller:

“The common-wisdom explanation is that this is the intestinal equivalent of wiring your jaw shut,” Seeley says. That is: With a much smaller stomach, patients simply can’t absorb as many calories, so they lose weight and the weight-loss cures their diabetes. But Seeley doesn’t think this explanation makes sense. “It’s bologna,” he says.

He points out that, anecdotally, patients don’t feel as hungry after surgery as they used to. What’s more, within days of surgery — long before any substantial weight loss has occurred — many patients show such improvement in blood glucose levels that they can stop taking diabetes medications. All of this suggests that surgery changes not just the structure of the stomach, but its biochemistry.

Older studies have shown, in both humans and mouse models, that these surgeries increase the level of circulating bile acids — fluids made by the liver that help break down fats. Nobody knows why bile acids go up after surgery, but Seeley’s study suggests that they play a key role in its beneficial effects.

In addition to breaking down fats, bile acids are hormones, or signaling molecules that bind to receptors in cells all over the gut, including one called the farsenoid-X receptor, or FXR.

To see whether bariatric surgery influenced FXR activity, Seeley’s group overfed two types of mice: normal animals, and those genetically engineered to lack the FXR gene. After ballooning in size, both types of obese mice underwent VSG surgery.

One week after surgery, both types of mice dropped a ton of weight compared with controls that had had a sham surgery. The normal mice sustained most of that weight loss for the duration of the experiment, about 14 weeks. In contrast, the animals lacking the FXR gene gained the weight back by the fifth week.

In other words, the mice lacking FXR went through the same mechanical changes as the others — their stomachs shrunk in exactly the same way — and yet didn’t benefit from weight-loss surgery.

“It’s really superb science,” Schauer says, though it’s far too early to know whether the same thing is happening in people. Nevertheless, it’s an important study because it suggests that drug therapies might one day be designed to mimic these changes in FXR and possibly replace surgery altogether, he says. “Even as a surgeon, I would say, yeah, that would be a big advance.”

It probably won’t be as simple as turning up the FXR dial, though. FXR is a complicated gene whose activity changes depending on tissue type and environmental circumstances. For example, mice lacking FXR are actually resistant to getting obese in the first place. FXR codes for a transcription factor, a protein that itself regulates dozens of other genes. “It’s doing lots of different things in different tissues,” Seeley says. “One of the things we don’t know is, which population of FXR matters?”

To add yet another level of complexity, the gene also has a big influence on gut bacteria. Seeley’s study found several bacterial strains that change in response to surgery in the normal animals but not in those lacking FXR. A strain called Roseburia, for example, went up 12-fold in normal mice after surgery but did not change in the mutants. This is provocative because two studies have shown that people with type-2 diabetes carry abnormally low levels of this bug in their guts. And this is just one of many other recent reports linking gut microbes to obesity and diabetes. A study published a year ago showed that in mice, gastric bypass surgery changes the microbial make-up of the gut, and that this shift might explain the animals’ subsequent weight loss. “We’re starting to see a picture emerge,” Seeley says.

Seeley is a lab rat; he’s not a surgeon and not a doctor. So I was surprised to hear him passionately riff on the overwhelming benefits of weight-loss surgery, and bemoan our stubborn cultural stigma against obese people. “People tend to think of surgery as a tool to help people’s compliance, and that’s a problem,” he says. In his view, surgery is not about physically preventing obese people from eating more. It’s about fundamentally changing their metabolism so that they no longer need to eat more.

And why, I asked him, is the average Joe so resistant to this idea?

“Lean people want to take credit for being lean. They want to say it’s because I control my environment, I don’t go to McDonald’s, I work out,” he says. “But you can’t say that and not blame the obese individual for being obese.”

This is, in my opinion, a tragedy. As I’ve written about before, an overwhelming amount of evidence now suggests that obesity has little to do with willpower. More than a decade ago, researchers at 16 clinics in the United States enrolled thousands of overweight and obese people with diabetes on a strict weight-loss regimen that focused on diet and exercise. As published last year, this intensive, long-term intervention did very little in terms of weight loss, and had no effect on death rates from heart disease.

Sometimes, Seeley says, he wishes he were a cancer researcher. When cancer researchers tell their seat neighbor on an airplane what they study, “they don’t have to hear that person’s personal hypothesis of the cell cycle,” he says. But with obesity, everybody’s got a story. “We all have a highly embedded idea of this in our own heads,” he says. “So it’s tricky to have a discussion about it as a biomedical issue.”

25 Mar 15:33

Can We Beat Drug-Resistant Malaria At Its Birthplace?

by Ed Yong

Long, but really quite good piece on the on-going war against malaria in Southeast Asia.

In the war against malaria, one small corner of the globe has repeatedly turned the tide, rendering our best weapons moot and medicine on the brink of defeat. I travelled to Thailand and Burma to meet the scientists who are trying to eliminate resistant malaria before it defeats our best remaining drug. This story originally appeared in Mosaic and is republished under a CC-BY 4.0 licence.  

The meandering Moei river marks the natural boundary between Thailand and Myanmar. Its muddy waters are at their fullest, but François Nosten still crosses them in just a minute, aboard a narrow, wooden boat. In the dry season, he could wade across. As he steps onto the western riverbank, in Myanmar, he passes no checkpoint and presents no passport.

The air is cool. After months of rain, the surrounding jungle pops with vivid lime and emerald hues. Nosten climbs a set of wooden slats that wind away from the bank, up a muddy slope. His pace, as ever, seems relaxed and out of kilter with his almost permanently grave expression and urgent purpose. Nosten, a rangy Frenchman with tousled brown hair and glasses, is one of the world’s leading experts on malaria. He is here to avert a looming disaster. At the top of the slope, he reaches a small village of simple wooden buildings with tin and thatch roofs. This is Hka Naw Tah, home to around 400 people and a testing ground for Nosten’s bold plan to completely stamp out malaria from this critical corner of the world.

Malaria is the work of the single-celled Plasmodium parasites, and Plasmodium falciparum chief among them. They spread between people through the bites of mosquitoes, invading first the liver, then the red blood cells. The first symptoms are generic and flu-like: fever, headache, sweats and chills, vomiting. At that point, the immune system usually curtails the infection. But if the parasites spread to the kidneys, lungs and brain, things go downhill quickly. Organs start failing. Infected red blood cells clog the brain’s blood vessels, depriving it of oxygen and leading to seizures, unconsciousness and death.

When Nosten first arrived in South-east Asia almost 30 years ago, malaria was the biggest killer in the region. Artemisinin changed everything. Spectacularly fast and effective, the drug arrived on the scene in 1994, when options for treating malaria were running out. Since then, “cases have just gone down, down, down,” says Nosten. “I’ve never seen so few in the rainy season – a few hundred this year compared to tens of thousands before.”

But he has no time for celebration. Artemisinin used to clear P. falciparum in a day; now, it can take several. The parasite has started to become resistant. The wonder drug is failing. It is the latest reprise of a decades-long theme: we attack malaria with a new drug, it mounts an evolutionary riposte.

Back in his office, Nosten pulls up a map showing the current whereabouts of the resistant parasites. Three coloured bands highlight the borders between Cambodia and Vietnam, Cambodia and Thailand, and Thailand and Myanmar (Burma). Borders. Bold lines on maps, but invisible in reality. A river that can be crossed in a rickety boat is no barrier to a parasite that rides in the salivary glands of mosquitoes or the red blood cells of humans.

History tells us what happens next. Over the last century, almost every frontline antimalarial drug – chloroquine, sulfadoxine, pyrimethamine – has become obsolete because of defiant parasites that emerged from western Cambodia. From this cradle of resistance, the parasites gradually spread west to Africa, causing the deaths of millions. Malaria already kills around 660,000 people every year, and most of them are African kids. If artemisinin resistance reached that continent, it would be catastrophic, especially since there are no good replacement drugs on the immediate horizon.

Nosten thinks that without radical measures, resistance will spread to India and Bangladesh. Once that happens, it will be too late. Those countries are too big, too populous, too uneven in their health services to even dream about containing the resistant parasites. Once there, they will inevitably spread further. He thinks it will happen in three years, maybe four. “Look at the speed of change on this border. It’s exponential. It’s not going to take 10 or 15 years to reach Bangladesh. It’ll take just a few. We have to do something before it’s too late.”

Hundreds of scientists are developing innovative new ways of dealing with malaria, from potential vaccines to new drugs, genetically modified mosquitoes to lethal fungi. As Nosten sees it, none of these will be ready in time. The only way of stopping artemisinin resistance, he says, is to completely remove malaria from its cradle of resistance. “If you want to eliminate artemisinin resistance, you have to eliminate malaria,” says Nosten. Not control it, not contain it. Eliminate it.

That makes the Moei river more than a border between nations. It’s Stalingrad. It’s Thermopylae. It’s the last chance for halting the creeping obsolescence of our best remaining drug. What happens here will decide the fate of millions.

The world tried to eliminate malaria 60 years ago. Malaria was a global affliction back then, infecting hundreds of thousands of troops during World War II. This helped motivate a swell of postwar research. To fight the disease, in 1946 the USA created what is now the Centers for Disease Control and Prevention (CDC), the country’s premier public health institute. After a decisive national eradication programme, the nation became malaria-free in 1951. Brazil had also controlled a burgeoning malaria epidemic with insecticides.

Meanwhile, new weapons had emerged. The long-lasting insecticide DDT was already being widely used and killed mosquitoes easily. A new drug called chloroquine did the same to Plasmodium. Armed with these tools and buoyed by earlier successes, the World Health Organization formally launched the Global Malaria Eradication Programme in 1955. DDT was sprayed in countless homes. Chloroquine was even added to table salt in some countries. It was as ambitious a public health initiative as has ever been attempted.

It worked to a point. Malaria fell dramatically in Taiwan, Sri Lanka, India, the Caribbean, the Balkans, and parts of the south Pacific. But ultimately the problem was too big, the plan too ambitious. It barely made a dent in sub-Saharan Africa, where public health infrastructure was poor and malaria was most prevalent. And its twin pillars soon crumbled as P. falciparum evolved resistance to chloroquine and mosquitoes evolved resistance to DDT. The disease bounced back across much of Asia and the western Pacific.

In 1969, the eradication programme was finally abandoned. Despite several successes, its overall failure had a chilling impact on malaria research. Investments from richer (and now unaffected) countries dwindled, save for a spike of interest during the Vietnam War. The best minds in the field left for fresher challenges. Malaria, now a tropical disease of poor people, became unfashionable.



François Nosten always wanted to travel. His father, a sailor on merchant ships, returned home with stories of far-flung adventures and instilled a deep wanderlust. Nosten’s original plan was to work on overseas development projects, but one of his teachers pushed him down a different path. “He said the best thing you can do if you want to travel anywhere is to be a doctor. That’s why I started medical school.” As soon as he graduated, he joined Médecins Sans Frontières and started living the dream. He flew off to Africa and South-east Asia, before arriving in Thailand in 1983. There, he started treating refugees from Myanmar in camps along the Thai border.

In 1985, an English visitor arrived at the camps and Nosten took him for a random tourist until he started asking insightful questions about malaria. That man was Nick White. A British clinician, he was drawn to Bangkok in 1980 by the allure of the tropics and a perverse desire to study something unfashionable. The University of Oxford had just set up a new tropical medicine research unit in collaboration with Bangkok’s Mahidol University, and White was the third to join.

“The rosbif and the frog”, as Nosten puts it, bonded over an interest in malaria, a desire to knuckle down and get things done, and a similar grouchy conviviality. They formed a close friendship and started working together.

In 1986, they set up a field station for White’s Bangkok research unit: little more than a centrifuge and microscope within Nosten’s rickety house. Three years later, Nosten moved to Shoklo, the largest refugee camp along the Thai–Myanmar border and home to around 9,000 people. Most were Karen – the third largest of Myanmar’s 130 or so ethnic groups – who were fleeing persecution from the majority Bamar government. Nosten worked out of a bamboo hospital – the first Shoklo Malaria Research Unit.

Malaria was rife. Floods were regular. Military leaders from both Thailand and Myanmar occasionally ordered Nosten to leave. Without any electricity, he often had to use a mirror to angle sunlight into his microscope. He loved it. “I’m not a city person,” he says. “I couldn’t survive in Bangkok very well. I wasn’t alone in Shoklo but it was sufficiently remote.” The immediacy of the job and the lack of bureaucracy also appealed. He could try out new treatments and see their impact right away. He trained local people to detect Plasmodium under a microscope and help with research. He even met his future wife – a Karen teacher named Colley Paw, who is now one of his right-hand researchers (White was the best man at their wedding). These were the best years of his life.

The Shoklo years ended in 1995 after a splinter faction of Karen started regularly attacking the camps, in a bid to force the refugees back into Myanmar. “They came in and started shooting,” says Nosten. “We once had to hide in a hole for the night, with bullets flying around.” The Thai military, unable to defend the scattered camps, consolidated them into a single site called Mae La – a dense lattice of thatch-roofed houses built on stilts, which now contains almost 50,000 people. Nosten went with them.

He has since expanded the Shoklo Unit into a huge hand that stretches across the region. Its palm is a central laboratory in the town of Mae Sot, where Nosten lives, and the fingers are clinics situated in border settlements, each with trained personnel and sophisticated facilities. The one in Mae La has a $250,000 neonatal care machine, and can cope with everything short of major surgery. Nosten has also set up small ‘malaria posts’ along the border. These are typically just volunteer farmers with a box of diagnostic tests and medicine in their house.

“I don’t know anybody else who could have done what François has done,” says White. “He’ll underplay the difficulties but between the physical dangers, politics, logistical nightmares, and the fraught conditions of the refugees, it’s not been easy. He’s not a shrinking violet.”

Thanks to Nosten’s network, locals know where to go if they feel unwell, and they are never far from treatments. That is vital. If infected people are treated within 48 hours of their first symptoms, their parasites die before they get a chance to enter another mosquito and the cycle of malaria breaks. “You deploy early identification and treatment, and malaria goes away,” says Nosten. “Everywhere we’ve done this, it’s worked.”


Victories in malaria are often short-lived. When Nosten and White teamed up in the 1980s, their first success was showing that a new drug called mefloquine was excellent at curing malaria, and at preventing it in pregnant women. Most drugs had fallen to resistant parasites and the last effective one – quinine – involved a week of nasty side-effects. Mefloquine was a godsend.

But within five years, P. falciparum had started to resist it too. “We tried different things like increasing the dose, but we were clearly losing the drug,” says Nosten. “We saw more and more treatment failures, patients coming back weeks later with the same malaria. We were really worried that we wouldn’t have any more options.”

Salvation came from China. In 1967, Chairman Mao Zedong launched a covert military initiative to discover new antimalarial drugs, partly to help his North Vietnamese allies, who were losing troops to the disease. It was called Project 523. A team of some 600 scientists scoured 200 herbs used in traditional Chinese medicine for possible antimalarial chemicals. They found a clear winner in 1971 – a common herb called qing hao (Artemisia annua or sweet wormwood). Using hints from a 2,000-year-old recipe for treating haemorrhoids, they isolated the herb’s active ingredient, characterised it, tested it in humans and animals, and created synthetic versions. “This was in the aftermath of the Cultural Revolution,” says White. “Society had been ripped apart, there was still a lot of oppression, and facilities were poor. But they did some extremely good chemistry.”

The results were miraculous. The new drug annihilated even severe forms of chloroquine-resistant malaria, and did so with unparalleled speed and no side-effects. The team named it Qinghaosu. The West would know it as artemisinin. Or, at least, they would when they found out about it.

Project 523 was shrouded in secrecy, and few results were published. Qinghaosu was already being widely used in China and Vietnam when the first English description appeared in the Chinese Medical Journal in 1979. Western scientists, suspicious about Chinese journals and traditional medicine, greeted it with scepticism and wasted time trying to develop their own less effective versions. The Chinese, meanwhile, were reluctant to share their new drug with Cold War enemies.

During this political stalemate, White saw a tattered copy of the 1979 paper. He travelled to China in 1981, and returned with a vial of the drug, which he still keeps in a drawer in his office. He and Nosten began studying it, working out the right doses, and testing the various derivatives.

They realised that artemisinin’s only shortcoming was a lack of stamina. People clear it so quickly from their bodies that they need seven daily doses to completely cure themselves. Few complete the full course. White’s ingenious solution was to pair the new drug with mefloquine – a slower-acting but longer-lasting partner. Artemisinin would land a brutal shock-and-awe strike that destroyed the majority of parasites, mefloquine would mop up the survivors. If any parasites resisted the artemisinin assault, mefloquine would finish them off. Plasmodium would need to resist both drugs to survive the double whammy, and White deemed that unlikely. Just three days of this artemisinin combination therapy (ACT) was enough to treat virtually every case of malaria. In theory, ACTs should have been resistance-proof.

Nosten started using them along the Thai–Myanmar border in 1994 and immediately saw results. Quinine took days to clear the parasites and left people bed-ridden for a week with dizzy spells. ACTs had them returning to work after 24 hours.

But victories in malaria are often short-lived. In the early 2000s, the team started hearing rumours from western Cambodia that ACTs were becoming less effective. White tried to stay calm. He had heard plenty of false alarms about incurable Cambodian patients, but it always turned out that they were taking counterfeit drugs. “I was just hoping it was another of those,” he says.

It was not. In 2006, Harald Noedl from the Medical University of Vienna started checking out the rumours for himself. In the Cambodian village of Ta Sanh, he treated 60 malaria patients with artesunate (an artemisinin derivative) and found that two of them carried exceptionally stubborn parasites. These infections cleared in four to six days, rather than the usual two. And even though the patients stayed in a clinic outside any malaria hotspots, their parasites returned a few weeks later.

“I first presented those data in November 2007 and as expected, people were very sceptical,” says Noedl. After all, a pair of patients is an epidemiological blip. Still, this was worrying enough to prompt White’s team to run their own study in another nearby village. They got even worse news. The 40 people they treated with artesunate took an average of 3.5 days to clear their parasites, and six of them suffered from rebounding infections within a month. “Rapid parasite clearance is the hallmark of artemisinins,” says Arjen Dondorp, one of White’s colleagues based in Bangkok. “That property suddenly disappeared.”

Despite the hopes that ACTs would forestall artemisinin’s expiry, resistance had arrived, just as it had done for other antimalarials. And, as if to rub salt in the wound, it had come from the same damn place.


Why has a small corner of western Cambodia, no bigger than Wales or New Jersey, repeatedly given rise to drug-beating parasites?

White thinks that the most likely explanation is the region’s unregulated use of antimalarial drugs. China supplied artemisinin to the tyrannical Khmer Rouge in the late 1970s, giving Cambodians access to it almost two decades before White conceived of ACTs. Few used it correctly. Some got ineffective doses from counterfeit pills. Others took a couple of tablets and stopped once their fever disappeared. P. falciparum was regularly exposed to artemisinin without being completely wiped out, and the most resistant parasites survived to spread to new hosts. There is a saying among malariologists: “The last man standing is the most resistant.”

Genetic studies hint at other explanations. Early last year, Dominic Kwiatkowski from the University of Oxford showed that some P. falciparum strains from west Cambodia have mutations in genes that repair faults in their DNA, much like some cancer cells or antibiotic-resistant bacteria. In other words, they have mutations that make them prone to mutating. This might also explain why, in lab experiments, they develop drug resistance more quickly than strains from other parts of the world. Evolution is malaria’s greatest weapon, and these ‘hypermutators’ evolve in fifth gear.

Kwiatkowski’s team also found that P. falciparum is spookily diverse in west Cambodia. It is home to three artemisinin-resistant populations that are genetically distinct, despite living in the same small area. That is bizarre. Without obvious barriers between them, the strains ought to regularly mate and share their genes. Instead, they seem to shun each other’s company. They are so inbred that they consist almost entirely of clones.

Kwiatkowski suspects that these parasites descended from some lucky genetic lottery winners that accumulated the right sets of mutations for evading artemisinin. When they mate with other strains, their winning tickets break up and their offspring are wiped out by the drug. Only their inbred progeny, which keep the right combinations, survive and spread.

It undoubtedly helps that South-east Asia does not have much malaria. In West Africa, where transmission is high, a child might be infected with three to five P. falciparum strains at any time, giving them many opportunities to mate and shuffle their genes. A Cambodian child, however, usually sees one strain at a time, and is a poor hook-up spot for P. falciparum. The region’s infrastructure may also have helped to enforce the parasites’ isolation: local roads are poor, and people’s movements were long constrained by the Khmer Rouge.

West Cambodia, then, could be rife with P. falciparum strains that are especially prone to evolving resistance, that get many opportunities to do so because antimalarial drugs are abused, and that easily hold on to their drug-beating mutations once they get them.

These are plausible ideas, but hard to verify since we still know very little about how exactly the parasites resist a drug. Earlier cases of resistance were largely due to mutations in single genes – trump cards that immediately made for invincible parasites. A small tweak in the crt gene, and P. falciparum can suddenly pump chloroquine out of its cells. A few tweaks to dhps and dhfr, the genes targeted by sulfadoxine and pyrimethamine, and the drug can no longer stick to its targets.

Artemisinin seems to be a trickier enemy. Curiously, P. falciparum takes a long time to evolve resistance to artemisinin in lab experiments, much longer than in the wild. Those strains that do tend to be weak and unstable. “I suspect you need a complicated series of genetic changes to make a parasite that’s not lethally unfit in the presence of these drugs,” says White. “It would be unusual if this was a single mutation.”

Practices such as unregulated drug use and misuse may help encourage and accelerate the rate of such changes out in the field. Kwiatkowski’s study suggests that the parasites may have evolved artemisinin resistance several times over, perhaps through a different route each time. Several groups are racing to find the responsible mutations, with news of the first few breaking in December 2013. That’s the key to quickly identifying resistant parasites and treating patients more efficiently. (Currently, you can only tell if someone has artemisinin-resistant malaria by treating them and seeing how long they take to get better.) “We want to be able to track resistance using blood spots on filter paper,” says Chris Plowe at the University of Maryland School of Medicine, whose group is one of those in the race.

But time is running out. From its origins in Cambodia, resistance has reached the Thai–Myanmar border. Nosten has shown that the proportion of patients who are still infected after three days of ACT has increased from zero in 2000 to 28 per cent in 2011. Most are still being cured, but as artemisinin becomes less effective, its partner drug will have to mop up more surviving parasites. Plasmodium will evolve resistance to the partner more quickly, driving both drugs towards uselessness.

This is already happening in western Cambodia, where ACTs are failing up to a quarter of the time and many people are still infected a month later. Long-lasting infections will provide parasites with more chances to jump into mosquitoes, and then into healthy humans. Malaria cases will rise. Deaths will follow. “This is the silence before the storm,” says Arjen Dondorp. “The threat is still slightly abstract and there’s still not that much malaria, which doesn’t help with a sense of urgency. If we suddenly see malaria exploding, then it’ll be a clear emergency, but it’ll also be too late.”


In his office at Mahidol University, Nick White is surrounded by yellowing monographs of old malaria research and overlooked by a wall-mounted mosaic of drug packets made by his daughter. He is now the chairman of the Mahidol–Oxford Tropical Medicine Research Unit and a mentor to the dozens of researchers within. He is gently ranting.

“Everything to do with change in malaria meets with huge resistance,” he says. He means political resistance, not the drug kind. He means the decade it took for the international community to endorse ACTs despite the evidence that they worked. He means the “treacle of bureaucracy” that he and Nosten swim through in their push to eliminate malaria.

“The global response to artemisinin resistance has been a bit pathetic. Everyone will tell you how important it is and there have been any number of bloody meetings. But there is little appetite for radical change.” He misses the old days when “you could drive a Land Rover across borders in your khaki shorts and spray things and do stuff”.

From the outside, things look rosier. Malaria is fashionable again, and international funding has gone up by 15 times in the last decade. Big organisations seem to be rallying behind the banner of elimination. In April 2013, the World Health Organization published a strategy called The Emergency Response to Artemisinin Resistance

“It’s a marvellous plan,” he says drily. “It says all the right things, but we haven’t done anything.” It follows two other strategies that were published in 2011 and 2012, neither of which slowed the spread of artemisinin resistance. Elimination became a dirty word after the noisy failures of the 1950s and 60s, and the new strategies look like the same old tactics for controlling malaria, presented under the guise of eradicating it. “They’re prescriptions for inertia,” says White.

Worse, they are channelling funds into ineffective measures. Take insecticide-treated bednets, a mainstay of malaria control. “We’ve had meetings with WHO consultants who said, ‘We don’t want to hear a word against bednets. They always work.’ But how cost-effective are they, and what’s the evidence they work in this region? The mosquitoes here bite early in the evening. And who’s getting malaria? Young men. Are they all tucked up in their bednets by 6 o’clock? No. They’re in the fields and forests. Come on! It’s obvious.”

He says that resources could be better devoted to getting rid of fake drugs and monotherapies where artemisinin is not paired with a partner. That would preserve ACTs for as long as possible. The world also needs better surveillance for resistant parasites. White is helping with that by chairing the World-Wide Anti-Malarial Resistance Network – a global community of scientists who are rapidly collecting data on how quickly patients respond to drugs, the presence of resistance genes, the numbers of fake drugs, and more.

White also wants to know if artemisinin-resistant parasites from South-east Asia can spread in African mosquitoes. Hundreds of mosquito species can transmit malaria, but P. falciparum is picky about its hosts. If resistant strains need time to adapt to new carriers, they might be slow to spread westwards. If they can immediately jump into far-off species, they are a plane ride away from Africa. “That changes your containment strategy,” says White, “but stupidly, it’s cut out of every research application we’ve ever made.”

He is pessimistic. “I’m pretty confident we won’t win but I think we should try a lot harder than we have been. If we didn’t pull out all the stops and kids start dying of artemisinin-resistant malaria, and we can trace the genetic origins of those parasites to South-east Asia, we shouldn’t sleep easy in our beds.”


The Mosquito breederWhen Nosten’s team first arrived at Hka Naw Tah in February, they slept and worked from the village’s unassuming temple. Using development funds from their grant, they put up a water tower and supplied electricity for the local school. In return, the villagers built them a clinic – a spacious, open-sided hut with a sloping tin roof, benches sitting on a dirt floor, a couple of tables holding boxes of drugs and diagnostic kits, treatment rooms, and a computer station. It took just two days to erect.

The Karen respect strong leadership but there is an easy-going camaraderie in the clinic. When we arrive, one of the research assistants is napping across a bench. Nosten walks over and sits on him. “You see, and I think this is a good sign, that it’s hard to tell who’s the boss and who’s the patient,” he says.

Most of the villagers don’t seem sick, but many of them have malaria nonetheless. Until recently, Nosten’s team had always searched for the parasites by examining a drop of blood under a microscope. If someone is sick, you can see and count the Plasmodium in their red blood cells. But in 2010, they started collecting millilitres of blood – a thousand times more than the usual drops – and searching for Plasmodium’s DNA. Suddenly, the proportion of infected people shot up from 10–20 per cent to 60–80 per cent. There are three, four, maybe six times as many infected people as he thought.

“We didn’t believe it at first,” says Nosten, “but we confirmed it and re-confirmed it.” Perhaps the tests were giving false positives, or picking up floating DNA from dead parasites? No such luck – when the team treated people with ACTs, the hidden parasites disappeared. They were real.

These ‘sub-microscopic infections’ completely change the game for elimination. Treating the sick is no longer good enough because the disease could bounce back from the hordes of symptomless carriers. The strike will have to be swift and decisive. If it’s half-hearted, the most resistant parasites will survive and start afresh. In malarial zones, you need to treat almost everyone, clearing the parasites they didn’t even know they had. This is Nosten’s goal in the border villages like Hka Naw Tah. He has support from the Bill and Melinda Gates Foundation, one of the few large funders to have truly grasped the urgency of the situation and who are “very much in the mood for elimination”.

Killing the parasites is easy: it just involves three days of ACTs. Getting healthy people to turn up to a clinic and take their medicine is much harder. The team have spent months on engagement and education. The clinic is dotted with posters explaining the symptoms of malaria and the biology of mosquitoes. Earlier this morning, Honey Moon, a Karen woman who is one of Nosten’s oldest colleagues, knocked on the doors of all the absentees from the last round to persuade them to come for tests. As a result, 16 newcomers turned up for treatments, bringing the team closer to the full 393. Nosten is pleased. “In this village, I’m quite optimistic that most people will be free of the parasite,” he says.

Another village down the river is proving more difficult. They are more socially conservative and have a poorer understanding of healthcare. There are two factions of Karen there, one of which is refusing to take part to spite their rivals. “It’s a good lesson for us,” says Nosten. “These situations will be elsewhere.” Eliminating malaria is not just about having the right drug, the deadliest insecticide, or the most sensitive diagnostic test. It is about knowing people, from funders to villagers. “The most important component is getting people to agree and participate,” says Nosten. It matters that he has been working in the region for 30 years, that the Shoklo unit is a familiar and trusted name in these parts, that virtually all his team are Karen. These are the reasons that give Nosten hope, despite the lack of political will.

If the strategy looks like it is working after a year, they will start scaling up. Eventually, they hope to cover the entire sinuous border. I ask Nosten if he would ever consider leaving. He pauses. “Even if I wanted to go somewhere else, I’m more or less a prisoner of my own making,” he says. He would need to find a replacement first – a leader who would command respect among both the Karen and malaria researchers, and would be willing to relocate to a place as remote as Mae Sot. It is hard to imagine a second person who would tick all those boxes. Surrounded by airborne parasites, spreading resistance, and border-hopping refugees, François Nosten is stuck. He would not have it any other way.