The Six Things That Make Stories Go Viral Will Amaze, and Maybe Infuriate, You

January 21, 2014

Posted by Maria Konnikova

When Jonah Berger was a graduate student at Stanford, in the early aughts, he would make a habit of reading page A2 of the Wall Street Journal, which included a list of the five most-read and the five most-shared articles of the day. “I’d go down to the library and surreptitiously cut out that page,” he recalls. “I noticed that what was read and what was shared was often different, and I wondered why that would be.” What was it about a piece of content—an article, a picture, a video—that took it from simply interesting to interesting and shareable? What pushes someone not only to read a story but to pass it on?

The question predates Berger’s interest in it by centuries. In 350 B.C., Aristotle was already wondering what could make content—in his case, a speech—persuasive and memorable, so that its ideas would pass from person to person. The answer, he argued, was three principles: ethos, pathos, and logos. Content should have an ethical appeal, an emotional appeal, or a logical appeal. A rhetorician strong on all three was likely to leave behind a persuaded audience. Replace rhetorician with online content creator, and Aristotle’s insights seem entirely modern. Ethics, emotion, logic—it’s credible and worthy, it appeals to me, it makes sense. If you look at the last few links you shared on your Facebook page or Twitter stream, or the last article you e-mailed or recommended to a friend, chances are good that they’ll fit into those categories.

Aristotle’s diagnosis was broad, and tweets, of course, differ from Greek oratory. So Berger, who is now a professor of marketing at the University of Pennsylvania’s Wharton School, worked with another Penn professor, Katherine Milkman, to put his interest in content-sharing to an empirical test.
Together, they analyzed just under seven thousand articles that had appeared in the Times in 2008, between August 30th and November 30th, to try to determine what distinguished pieces that made the most-emailed list. After controlling for online and print placement, timing, author popularity, author gender, length, and complexity, Berger and Milkman found that two features predictably determined an article’s success: how positive its message was and how much it excited its reader. Articles that evoked some emotion did better than those that evoked none—an article with the headline “BABY POLAR BEAR’S FEEDER DIES” did better than “TEAMS PREPARE FOR THE COURTSHIP OF LEBRON JAMES.” But happy emotions (“WIDE-EYED NEW ARRIVALS FALLING IN LOVE WITH THE CITY”) outperformed sad ones (“WEB RUMORS TIED TO KOREAN ACTRESS’S SUICIDE”).

Just how arousing each emotion was also made a difference. If an article made readers extremely angry or highly anxious—stories about a political scandal or new risk factor for cancer, for example—they became just as likely to share it as they would a feel-good story about a cuddly panda. (In this particular study, certain pieces were coded as eliciting arousing emotions; in a follow-up, arousal was further measured physiologically.)

Berger and Milkman went on to test their findings in a more controlled setting, presenting students with content and observing their propensity to pass it along. Here, too, they found the same patterns.
Amusing stories that had been chosen specifically because they were positive and arousing were shared more frequently than less amusing ones. Anger-inducing stories were shared more than moderate takes on the same events. When the researchers manipulated the framing of a story to be either negative (a person is injured) or positive (an injured person is “trying to be better again”), they found that the positive framing made a piece far more popular. The findings have since been replicated by several independent research teams, who have found that videos that shock or inspire are more likely to be shared on Facebook and more likely to gain viral traction.

Positivity and arousal go a long way toward explaining the success of Web sites like Upworthy, which started in 2012 and is known for using headlines designed to make you laugh, cry, or feel righteous anger (for example, on the site right now, “A Hilarious Stand-Up Routine About How Commercials for Black People Actually Sound” and “The Struggles of Being a Woman in a Male-Dominated Field Summed Up in a Short Comic”). Even the site’s tearjerker content has a positive message: “Watch a Teenager Bring His Class to Tears Just by Saying a Few Words,” reads one.
Despite launching less than two years ago, the site has steadily climbed the ranks of Internet popularity, ranking third in a December rating of Facebook shares, right behind BuzzFeed and the Huffington Post. Its posts are like the infamous cat videos on YouTube—funny, positive, and arousing—but taken to a new level. Still, as Berger points out, “There are lots of cat videos that don’t get shared”—and lots of would-be Upworthys that never quite make it. So what characterizes the ones that do?

Since his initial foray into the nature of sharing, Berger has gone on to research and test a variety of viral-promoting factors, which he details in his new book, “Contagious: Why Things Catch On.” Almost ten years in, he feels he’s discovered a formula of sorts: as sites like Upworthy or BuzzFeed would likely put it, The Six Things You Need to Know to Make Your Voice Heard. While emotion and arousal still top the list, a few additional factors seem to make a big difference. First, he told me, you need to create social currency—something that makes people feel that they’re not only smart but in the know. “Memes like LOLcats, I think, are a perfect example of social currency, an insider culture or handshake,” Berger told me. “Your ability to pass it on and riff on it shows that you understand. It’s the ultimate, subtle insider signal: I know without yelling that I know. When your mom sees an LOLcat, she has no idea what it is.” When Upworthy first started, not everyone knew what it was, and the videos seemed fresh. Now they are being derided as link bait and mocked. Other sites, including the Washington Post, are copying their formula.

The presence of a memory-inducing trigger is also important. We share what we’re thinking about—and we think about the things we can remember. This facet of sharing helps explain the appeal of list-type stories (which I wrote about in detail last month), as well as stories that stick in your mind because they are bizarre. Lists also get shared because of another feature that Berger often finds successful: the promise of practical value. “We see top-ten lists on Buzzfeed and the like all the time,” he notes. “It allows people to feel like there’s a nice packet of useful information that they can share with others.” We want to feel smart and for others to perceive us as smart and helpful, so we craft our online image accordingly.

A final predictor of success is the quality of the story itself. “People love stories. The more you see your story as part of a broader narrative, the better,” Berger says. Some cat lists are better than others, and some descriptions of crying teen-agers are more immediately poignant; the best underlying story, regardless of its trappings, will come out on top. That, in fact, is what the Upworthy editors have argued in response to their critics: the headlines may seem like link bait, but the stories, the curators promise, are worthwhile. “Coming up with catchy, curiosity-inducing headlines wasn’t the reason
Upworthy had those 87 million visitors,” they write. “It was because millions of members of the
Upworthy community watched the videos we curated and found them important, compelling, and worth sharing with their friends.”

Some of these features, of course, are incompatible: a list, for the most part, isn’t going to tell much of a story, and a LOLcat video or other meme isn’t usually informative. But, taken together, especially with the underlying principles of arousal and positivity in mind, the guidelines can help. “I see it as a batting average,” Berger says. “No one is going to hit a home run every time, but if you understand the science of hitting your batting average goes up.”

The irony, of course, is that the more data we mine, and the closer we come to determining a precise calculus of sharing, the less likely it will be for what we know to remain true. If emotion and arousal are key, then, in a social application of the observer effect, we may be changing what will become popular even as we’re studying it. “If everyone is perfectly implementing the best headline to pass on, it’s not as effective any more,” Berger says. “What used to be emotionally arousing simply isn’t any longer.” Those in search of evidence for this should look no further than Viralnova.com, a site that was started just eight months ago and is already the seventh most popular site on the Web, at least as measured by Facebook shares. As I type, the lead story on its front page is “Her Little Boy Has No Idea His Mother Is About To Die. What She’s Doing About That Is Amazing.”
Illustration by Adrian Tomine

As a Reformed Creationist, I Hope Bill Nye Doesn't Underestimate Ken Ham

David MacMillan

Posted: 01/23/2014 9:57 am

 

It's rare to see a prominent scientist agree to a public debate with someone from the creation science movement. Giving equal time to both sides might be a foundational principle of American dialogue, but it paints the issue as more of a controversy than it actually is. That's why it surprised a lot of people when Bill Nye, scientist and TV personality, agreed to debate the president of Cincinnati's Creation Museum, Ken Ham.

Even so, it's not hard to see why Nye has chosen to engage creationism directly. The most recent polling shows one in three Americans still won't accept that all living things evolved from a common ancestor. Creationism may be pseudoscience, but its grip on the American public is hard for a science educator like Nye to ignore.

This debate is more than academic for me. I grew up steeped in creationism. I was homeschooled with creationist curriculum, my family took us to creationist conferences, and I was deeply proud that I knew the real story about evolution and the age of the earth. I was taught there was absolutely no way the universe could be explained without creationism. Evolution was a fairy tale based on faith; creation was good science. I was taught that Christianity wasn't consistent without creationism... that all "Bible-believing Christians" rejected evolution and long ages in favor of a six-day creation and a global flood.

My proudest teenage achievement was mowing lawns to earn $1,000 so I could help build the Creation Museum. My donation earned me lifetime free admission, a polo shirt, and my name engraved in the lobby. I wrote back and forth with many prominent creationists and hotly debated origins with anyone who dared argue in favor of evolution. On two occasions I even wrote featured articles for the Answers In Genesis website... a high honor for Teenage Me.

I'm writing all this because I don't know many people who were as far into the creation science movement as I was and came out of it. After graduating high school, I went on to college and got my Bachelor's degree in physics; I now work in energy regulation. Despite four years of physics, it still took me a long time before I actually came to understand evolution, geology, and cosmology. Now, I'm always learning, always finding out new information, always excited.

Because so much of what I'd been taught was flatly false, I had to re-learn practically everything about biology, geology, and the history of science. I'm amazed by the amount of evidence I systematically ignored or explained away, just because it didn't match creation science.
Bill Nye may not understand just how difficult it is for people who were raised like me to abandon creationism. Creationism isn't just one belief; it's a system of beliefs and theories that all support each other. We believed that unless we could maintain confidence in special creation, a young planet, a global flood, and the Tower of Babel, we'd be left without any basis for maintaining our faith.

This false dichotomy makes creationism strong. As long as people think the foundation of their religious faith depends on denial of science, it takes incredible energy to make them question the simple explanations given by the creationist movement. Ken Ham claims creation science keeps people from abandoning Christianity, but it usually works in the opposite direction.

Learning the history of creationism freed me to examine the evidence for evolution. I wouldn't claim to know everything about the Bible, but I do know Ken Ham's insistence on "biblical origins" is as phony as the rest of creation science. I had never known creationism was only invented a scant 50 years ago (six-day-young-earth creationism was never a fundamentalist dogma until the 1960s). I had never known that most Christians accepted the Bible's creation account as deliberate allegory many centuries before scientists even knew the earth revolved around the sun.

I hope Bill Nye doesn't underestimate creationists. Between their strident religious confidence and the way they painstakingly dumb-down and oversimplify evidence to fit into 6,000 years, people like Ken Ham can be tough nuts to crack. We were raised with false ideas about biology, geology, and history itself. Relearning all these things from the ground up is a tall order to begin with; the influence of religious dogma only make it that much more difficult. In a debate like this one, demonstrating even the most elementary facts about evolution and the age of the universe would be a great success.

Creationism has spread an incredible amount of misinformation over the past half-century. I hope Nye can cut through the accumulated falsehoods and teach about the actual evidence. I want people to be free to learn, free to understand, free to explore the fantastic mysteries of the universe without being tied down to phony dogma that wasn't even part of Christianity until the last fifty years. I want children to learn how to trust the scientific method... and, even more importantly, how to use the scientific method so their creativity and imagination won't be wasted trying to defend pseudoscience.
The universe has so much more to offer than could ever fit into a few thousand years.

Ernst’s Law

By Edzard Ernst

Originally Published Saturday 23 November 2013

Some time ago, Andy Lewis formulated a notion which he called ‘Ernst’s law’. Initially, I felt this was a bit o.t.t., then it made me chuckle, and eventually it got me thinking: could there be some truth in it, and if so, why?

The ‘law’ stipulates that, if a scientist investigating alternative medicine is much liked by the majority of enthusiasts in this field, the scientist is not doing his/her job properly. In any other area of healthcare, such a ‘law’ would be absurd. Why then does it seem to make sense, at least to some degree, in alternative medicine? The differences between any area of conventional and alternative medicine are diverse and profound.

Take neurology, for instance: here we have an organ-system, anatomy, physiology, pathophysiology, etiology and nosology all related more or less specifically to this field and all based on facts, rigorous science and substantial evidence. None of this knowledge, science and evidence is static, but each has evolved and can be predicted to do so in future. What we knew about neurology 50 years ago, for example, was dramatically different from what we know today. Scientific discovery discoveries in neurology link up with the knowledge gathered in other areas of medicine to generate a (more or less) complete bigger picture.

In alternative medicine or any single branch thereof, we have no specific organ-system, anatomy, physiology, pathophysiology, etiology or nosology to speak of. We also have few notions that are transferable from one branch of alternative medicine to another – on the contrary, the assumptions of homeopathy, for example, are in overt contradiction to those of acupuncture which, in turn, are out of sync with those of reflexology, aromatherapy and Reiki.

Instead, each branch of alternative medicine has its own axioms that are largely detached from reality or, indeed, from the axioms of other branches of alternative medicine. In acupuncture, for instance, we have concepts such as yin and yang, qi, meridians and acupuncture points, and there is hardly any development of these concepts. This renders them akin to dogmas, and there is no chance in hell that the combination of all the branches of alternative medicine would add up to provide a sensible ‘bigger picture’.

If a scientist were to instill scientific, critical, progressive thought in a field like neurology, thus overthrowing current concepts and assumptions, they would be greeted with open arms among many like-minded researchers who all pursue the aim of advancing their field and contributing to the knowledge base by overturning wrong assumptions and discovering new truths. If researchers were to spend their time trying to analyse the concepts or treatments of alternative medicine, thus overthrowing current concepts and assumptions, they would not only not be appreciated by the majority of the experts working in this field, they would be castigated for their actions.

If a scientist dedicated decades of hard work to the rigorous assessment of alternative medicine, that person would become a thorn in the flesh of believers. Instead of welcoming him with open arms, some disappointed enthusiasts of alternative treatments might even pay for defaming them.

On the other hand, if a researcher merely misused the tools of science to confirm the implausible assumptions of alternative medicine, he would quickly become the celebrated ‘heroes’ of this field.

This is the bizarre phenomenon that ‘Ernst’s law’ seems to capture quite well – and this is why I believe the ‘law’ is worth more than a laugh and a chuckle. In fact, ‘Ernst’s law’ might even describe the depressing reality of retrograde thinking in alternative medicine more accurately than most of us care to admit.

What do readers feel? Their comments following this blog may well confirm or refute my theory.
_________________________________________________________________________________________

Edzard Ernst MD, PhD, FMedSci, FSB, FRCP, FRCPEd

Emeritus Professor, Exeter University

Dr. Ernst qualified as a physician in Germany in 1978 where he also completed his MD and PhD theses. He received hands-on training in acupuncture, autogenic training, herbalism, homoeopathy, massage therapy and spinal manipulation.

Later, he became Professor in Physical Medicine and Rehabilitation (PMR) at Hannover Medical School and Head of the PMR Department at the University of Vienna. In 1993, he moved to the UK and became Chair in Complementary Medicine at the University of Exeter. He is founder/Editor-in-Chief of two medical journals (Perfusion and Focus on Alternative and Complementary Therapies).

He has published 48 books and more than 1000 articles in the peer-reviewed medical literature. His work has been awarded with 14 scientific prizes. In 1999, he took British nationality.

His research focussed on the critical evaluation of all aspects of alternative medicine. Unlike most of his colleagues, he does not aim to promote a particular therapy. His goal is to provide objective evidence and reliable information. It is fair to say that this ambition did not endear him to many quasi-religious believers in alternative medicine.

Healthy Skepticism is republishing selections from Dr. Ernst’s blog with permission. Please visit his website at http://edzardernst.com

You Will Be Assimilated. | Neurotic Physiology

You Will Be Assimilated. | Neurotic Physiology

Jan 24 2014 Published by scicurious under Academia, Uncategorized

Blame Bashir for this one.

In a previous post, I talked about how I wasn't yet free of academia. How it's still got hooks in me, in the form of papers that need to be published, and that won't get published until I get them out. Bashir noted that it was like Borg.

Borg, for those not familiar, are characters in the Star Trek universe. The most quoted phrase is 'resistance is futile, you will be assimilated.' Borg are partially cybernetic and act as part of a "hive" controlled by a queen. Like metallic, slightly slimy looking bees. But smarter (though I have always wondered why they have to look slimy). If you get assimilated into the Borg, it's very hard to leave, they give you all these cybernetic implants that influence your thoughts and dampen your feelings. Freeing someone from the Borg is a difficult experience, with lots of surgeries to remove the implants (for example your organs have to relearn how to function on their own). Often it's lifelong, and you are never truly free.

In particular, consider the character Seven of Nine, from Star Trek: Voyager. She was integrated into the Borg when she was 6. Grew up and lived her whole life as Borg. She then ends up on the Voyager, and they begin taking away her cybernetic implants. She begins to function on her own and build a life for herself. But some of the implants, esp the cortical node, can't really be removed well. She always has difficulty with some things, especially emotions. But she has some advantages as well, she can always sense Borg activity, for example.

(Seven of Nine. Pity her, she had emotional issues and had to wear a LOT of catsuits. Source)

De-assimilating from the Borg does, in a way, remind me of academia.

Obviously academia does not give you cybernetic implants in grad school (though if they are, they'd BETTER come with the health plan and a decent increase in stipend). But leaving academia and its culture behind can be jarring. I had been in it, in some way, my whole life. I believed that it was the best place. It is, in many ways, great. But it's also very much its own world. Some other careers may be similar, but I've only experienced this one.

There are so many things about academia that I have assimilated, and that, via slow and sometimes painful surgeries, I have to get rid of. Instead of cybernetic implants, maybe I shed them in a different way. Shreds of lab coat here, a nitrile glove there. A few examples:

1. I'm learning the outside way of behaving professionally. Emails in academia could get very passive aggressive or just out and out aggressive. Thankfully, it's a minority of people who do it, but in academia, that kind of behavior (along with other kinds of bad behavior) is often allowed to perpetuate, as long as the science is good.  I know you don't do that on the outside. I know people who feel physically sick checking their email sometimes. I still catch myself questioning many emails I receive. Was it meant to be snarky? Is there another way to interpret that? What did I do? At the same time, though, I know I shouldn't need to be handled with kid gloves.
I also don't seem to know how to communicate casually, yet professionally. I alternate between hyper-formal, ultra passive prose, and one-liners. I know there's a happy medium in there somehow, but I'm still learning where it is.

2. I don't know when to quit. If you don't have every spare minute in academia filled (and by spare, I mean til at least 1am every night, a family can count as a hobby), you are not doing enough. Find more things to do. More projects, more grants, more papers. Outside, well, don't overload yourself! Because if you do, you do everything worse. Better to do less, and do it well. This is still a major, major shock to my system. My gut is always telling me to do more and more and more.

3. I don't know how to take criticism. Or rather, I know how I SHOULD take criticism. I know I do not take it well. This is odd, because I remember a time when I took criticism well. I did a lot of theater and music, it was something you HAD to take well. I took it, I improved, worked harder, fixed things, and did better. Sometime during grad school, however, criticism began to paralyze me. Every critique felt like a critique of me, as a scientist. Since a scientist was what I WAS, all criticism began to feel like criticism of me, as a person. Sometimes it was indeed phrased that way. You are careless. You are not smart enough, why don't you get this?! You are not focused.
I remember once, my aunt asked me what peer review was. I explained, and to show what I meant, handed her a review of one of my manuscripts. When she handed it back, she was on the verge of tears. She asked how they could be so mean to me. It was an accept with minor revisions. But it was full of things like "the authors do not grasp...", "the authors fail to state...", "the authors smell..." (ok, no). And I remembered when I first read that review. How my heart sank and my stomach hurt and my PI had to TELL me is was accepted. Because it surely did not say that anywhere on there.
Before academia, I would have taken criticism and said "I can be more careful, I will work on focus. Intelligence will just have to deal." But after academia...criticism still makes me work harder, but I first spend a period completely paralyzed by panic. Panic, gnawing self doubt, and shame. Why couldn't I do better? What's wrong with me? Why am I such a terrible person? Why am I not smart enough? Isn't there a way to make myself more careful, more smart? Outside of academia, I am relearning to take criticism. It is a long process.

4. When the professional is often personal. Not that there weren't professional standards in academia of course. But when all your colleagues are all your friends (and often your only friends) and are often also your significant others, well, things get mixed up. There were colleagues you couldn't work with because your friend had divorced them and it got ugly. And of course, you're all talking about work outside of work. Often, you feel like you don't know HOW to talk anything else but shop. Academia was my life. Soon you just become wrapped up in it, and everything else begins to lose importance. Outside, I've been relearning perspective.

5. You can be positive. So much of academia is based in criticism. It's important criticism. Science would not advance if we just said things looked nice and sent it along. You have to probe, you have to say "that's unacceptable with an n=3," you have to say "that explanation isn't adequate." It's incredibly important. But it also, over time, can make people really negative. Things you screw up become "how could you!?" and things you did right...well they were what you should be doing and deserve no praise. I've observed before that only academia could turn successes into mere not-failures. If you DIDN'T see something wrong with that talk you were just at, well obviously you don't know anything about the field! Too gullible!  Cynicism makes you look smart.
This isn't the case outside. I love that I can be enthusiastic about my ideas...and that's ok! Other people are too! We work with ideas and refine them, rather than ripping them apart before building them again. The net result may end up the same. But the process is so much sunnier. Even when people don't like your idea, they say "well, I don't think we're interested in that," as opposed to "how could you attempt something so stupid." People are congratulated on their achievements...and you feel they HAVE done something good. Sure, it's your job, it's what you are supposed to be doing, but you're good at it, and that deserves praise. This, above everything else, has made me happy to be where I am.

I'm sure there are others, pieces of academia that I will shed over time. But I hope I keep the positive things. Seven of Nine could sense Borg. She could also act without panic in a crisis. I hope I will keep my academic remnants, my training, my questioning, my background and my ability to do research. I hope I will keep some of my cynicism, so I remember to look for the flaws and stick to careful interpretations. There are advantages to assimilation, after all.

The psychology of political parties: Why conservatives fall in line and liberals don’t

Thursday, Jan 23, 2014 08:15 AM EST                         

Research suggests liberals suffer from a sense of false uniqueness -- and they strive to maintain their difference

Sarah Estes and Jesse Graham, Scientific American
                         

     

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(Credit: istockphoto \ Iqoncept)

This article was originally published by Scientific American.

When he was President, Bill Clinton famously (and perhaps apocryphally) complained that getting Democrats to agree on a course of action was like herding cats, while the Republicans didn’t seem to have this problem. All political parties are large coalitions of people with varied interests and beliefs, but is it possible that ideological differences between the parties could play a decisive role here?

A new paper by researchers at New York University, in press at Psychological Science, suggests that the answer is yes. A large body of psychological research has shown that people tend to overestimate how much others share their beliefs, feelings, and practices. But this new research suggests that this is not the case for those on the left end of the political spectrum – in fact, it’s quite the opposite.
Conservatives and moderates overestimated the degree to which other conservatives and moderates were like them, while liberals assumed they were more unique among party peers than they actually were. This “liberal uniqueness” perceptive bias could help to explain why it’s harder to get Democrats to fall in line than it is for Republicans.

Led by Chadly Stern, the scientists begin by contrasting the conservative Tea Party movement, which has successfully organized its own congressional caucus, with the liberal Occupy Wall Street movement, which was hobbled by its inability to reach consensus on issues both large (what’s our agenda?) and small (how should we respond to the NYPD’s request to take down signs?). While group member similarities (in goals, beliefs, preferences, and personalities) are crucial for organizational success, the authors wondered whether perceptions of in-group similarities were just as important. In other words, maybe if group members only thought they were the same, the group would function better.

 

In the first study, hundreds of people online answered forty questions about preferences and beliefs, half of them political (“America should strive to strengthen its military”) and half non-political (“I like poetry”). They then estimated what percentage of study participants who share their political beliefs (political in-group members) would agree with them on each item – in other words, if you’re a conservative, and you indicated that you liked poetry, you then estimated what percentage of other conservatives in the study liked poetry as well. Stern and colleagues then compared those estimateswith the actual figues to determine whether each participant overestimated their similarity to their political in-group (false consensus) or underestimated it (false uniqueness).

Conservatives overestimated how similar their preferences were to those of other conservatives (false consensus), while liberals underestimated how similar their preferences were to those of other liberals (false uniqueness). Political moderates also overestimated their similarity to other moderates, in line with previous findings that people in general overestimate how much other people share their preferences and beliefs. This was the case for both political (e.g., military spending) and non-political (e.g., poetry) preferences.

The second study replicated the design of the first, with one twist: everyone also filled out the Need for Uniqueness scale, with questions like “If I must die let it be an unusual death rather than an ordinary death in bed.” Again, conservatives and moderates overestimated how similar they were to their political in-group, while liberals underestimated their similarity to their political in-group.
Further, these ideological differences were in part accounted for by people’s need for uniqueness – the more you expressed the desire to be different from those around you, the more you underestimated how similar you were. This suggests that liberals think they’re unique among liberals in part because they want to be unique.

Anyone who’s ever been part of a liberal counter-cultural clique will recognize this pressure to be unique, which can easily turn into an arms race. You’ve got a tattoo? Well, my skin is nothing but tattoos. You make artisanal pickles? Well, I make artisanal horseradish. You have a pet ferret? Well, I have a pet camel. And so on. But it’s this motivation to be unique – even among other liberals – that makes liberals alike. It’s a bit like the scene from Monty Python’s Life of Brian where a crowd of hundreds chants in unison: “Yes, we are all individuals! Yes, we are all different!”

While the findings make sense in light of ideological stereotypes like the gotta-be-different liberal hipster, or the conformist conservative soldier, they might not apply as well to contemporary American politics. These days you’re more likely to hear the “herding cats” phrase in reference to John Boehner’s attempts to reconcile the Tea Party faction with the rest of the Republicans in the House. It remains to be seen whether the conservative false consensus effect can lead to any real consensus in the GOP.

Scientists build ion-selective membrane for ultra-stable lithium sulfur batteries#nRlv

Scientists build ion-selective membrane for ultra-stable lithium sulfur batteries#nRlv

Scientists build ion-selective membrane for ultra-stable lithium sulfur batteries

Dec 24, 2013

       

Credit: Tsinghua University

Advanced energy storage systems are highly desired to fill the gap between currently available battery systems and high performance electronic devices or even electric vehicles. As the commonly-used lithium ion battery systems are approaching their theoretical energy density value, lithium-sulfur batteries are considered to be one promising candidate, exhibiting much higher theoretical energy density at 2600 Wh/kg (around 3-5 times that of the lithium ion batteries). However, the practical applications of lithium-sulfur batteries are hindered by the complexity of this electrochemical system, especially the insulate nature of sulfur and the so called "shuttle effect", which means the diffusion and reaction of the cathode intermediate polysulfide with the anode side.

Researchers from Tsinghua University in Beijing, led by professors Qiang Zhang and Fei Wei, have developed a new strategy to build ultra-stable lithium-sulfur batteries based on an ion selective membrane system. With this new membrane system, the cyclic degradation of the cell was significantly reduced to 0.08 % per cycle within the first 500 cycles. Meanwhile, the coulombic efficiency of the battery can also be improved by around 10 %, which may greatly benefit the energy efficiency of the battery system. The team has published their findings in a recent issue of Energy & Environment Science.

"Designs for cathode electrode structures for a lithium sulfur battery have been widely investigated, but a design to suppress the shuttle effect based on the whole battery system has rarely been reported," Qiang Zhang said. "We employ a cation permselective membrane, which helped to 'separate' lithium ions and polysulfide ions based on their different charge nature. The electrostatic interaction allows diffusion across the membrane but prevents the permeation of polysulfide anions, which suppressed the shuttle effect." In their experiments, a facile coating method was employed to build a complete selective ion shield between the cathode and anode electrode. By using a visualized glass cell, one can clearly observe that the polysulfide was prevented from reaching the anode side when using the ion selective membrane.

Enlarge

Credit: Tsinghua University

As Prof. Zhang and Wei point out, this approach shed some light on building ultra-stable lithium-sulfur batteries by suppressing the "shuttle effect". This method is also fully applicable with other advanced electrodes. Going forward, the researchers hope to understand the other problems in the degradation of lithium sulfur cells and to build even better batteries.

 Explore further: Holistic cell design leads to high-performance, long cycle-life lithium-sulfur battery

More information: Ionic shield for polysulfides towards highly-stable lithium-sulfur batteries, Energy & Environment Science.
Journal reference: Energy & Environment Science

Provided by Tsinghua University

 Read more at: http://phys.org/news/2013-12-scientists-ion-selective-membrane-ultra-stable-lithium.html#jCp

IceCube neutrino detector is running hot

Now that we know how to find high energy neutrinos, we're seeing lots.

by Chris Lee - Jan 23 2014, 7:00am EST  

The building that houses the IceCube servers.

USAP.gov

With the IceCube detector now in operation at the South Pole, the first results are starting to come in, and boy are they interesting. IceCube monitors a volume of one cubic kilometer of ice for muons, the byproduct of neutrinos colliding with the ice. What makes IceCube different is that it is looking especially for very high energy neutrinos. In the lower energy range, neutrinos are products of things generated very locally (in astronomical terms). Although these events are interesting, they swamp those that are produced at great distances, making it difficult to use neutrinos as a window into the Universe.

However, very distant and highly energetic events should produce neutrinos with a correspondingly high energy. If we can detect them, maybe they can tell us about those high-energy events. This idea is more than 30 years old—until now, the technology has simply not been up to the task.
IceCube consists of some 8000 photomultiplier tubes (light detectors), strung out on strings, buried under the ice of the Antarctic. Each photomultiplier tube contains its own data processing computer that provides some preliminary filtering and enables event signals to be synchronized to within 2ns.
These signals are then sent to a local computing center that sits at the center of the array (yes, in Antarctica), which does more processing before sending it out to the world.

Further Reading

Coolest jobs in tech (literally): running a South Pole data center

You know it's cold when you have to heat the air used to cool your data center.

Both the instrument and neutrino physics are exquisitely well understood, so the scientists working with the detector have just a single percent uncertainty in their models and another ten percent uncertainty in the instrumentation. Considering everything, that is a fine piece of hardware. However, even buried deeply in the ice, IceCube has a devil of a time finding the neutrinos it is looking for. The instrument records 2700 cosmic rays per second, and a locally produced neutrino turns up every six minutes. The cosmic signal, in contrast is ten neutrinos... per year.
After a fairly long run and a particular type of analysis, the collaboration running IceCube was rather confused; they hadn't found any neutrinos of interest yet. So they took a look inside their processing and found a particular type of event that was being incorrectly filtered out. The problem was an assumption about the energy range they were after.
At high energies (but not too high), a neutrino will tend to collide with an atom outside the volume occupied by the detectors. The resulting high energy muon streaks off like a meteor through the ice, losing energy through radiation, production of electrons and positrons, and other things. IceCube looks for these tracks and figures out where the neutrino came from. (It should be noted that some of these neutrinos have traveled through the entire Earth before being detected.)
Once you go to even higher energies, however, neutrinos that are detected are a result of collisions from within the detector. Again the muon motors off, causing havoc, but the event track began from within the detector volume—a pattern that the researchers initially excluded. They are now actually spotting neutrinos in the 1000TeV range (The LHC operates around 14TeV).
At these energies, the particles have quite a high probability of interacting with atoms, so they don't make it through the Earth; instead, they're detected quite close to the surface of the ice. Even better, because the tracks begin within the detector volume, the energy of the neutrinos can be calculated with high accuracy
After recognizing the problem, a reanalysis produced around 30 neutrinos, and many more are expected to be reported in May. The big question is whether these neutrinos are evenly distributed across the sky (as low energy neutrinos are), or if they have specific sources. At present, there is not enough data to say. As with any small data set, it has a few blobs that look like they may be specific sources, but we should expect those to disappear as more neutrinos are detected.

Pope Francis explains why the Internet is a 'gift from God'

Keith Wagstaff NBC News    

21 hours ago

Twitter

 

Not as many followers as Justin Bieber, but not bad.

This pope has wasted no time in embracing the Internet.
A week after Jorge Mario Bergoglio was declared pope in a puff of white smoke in March, he sent out his first tweet as Pope Francis, which was retweeted 36,457 times. His account, @Pontifex, now has more than 3.5 million followers.

His predecessor, Pope Benedict XVI , also embraced social media, calling it "a great opportunity" for users to establish a "Christian-style presence" online. He started the papal Twitter account, launched a Vatican YouTube channel and even released a Facebook application called Pope2You.
Francis, despite not having a Twitter account as a cardinal, has praised the Internet as well, calling it a "gift from God" in a statement on Thursday. Still, the pope, like most people, has some reservations about our new digital age.

• This pretty much sums up Twitter: "The speed with which information is communicated exceeds our capacity for reflection and judgement, and this does not make for more balanced and proper forms of self-expression." 
• On the Internet "filter bubble": "The variety of opinions being aired can be seen as helpful, but it also enables people to barricade themselves behind sources of information which only confirm their own wishes and ideas, or political and economic interests."  
• Beware, World of Warcraft players: "The desire for digital connectivity can have the effect of isolating us from our neighbours, from those closest to us."  

Overall, however, the pope seemed bullish on the Internet. He certainly hasn't been shy in utilizing it, occasionally angering both conservatives and liberals with his 140-character messages. He angered the free-market crowd with tweets like this.

 

Some liberals, on the other hand, took offense on Wednesday when he tweeted this in support of an anti-abortion rally.

Despite the Internet's flaws, His Holiness isn't likely to cancel the Vatican's broadband plan anytime soon. The pontiff's advice: The Internet is cool, as long as it leads to good deeds IRL.

"While these drawbacks are real, they do not justify rejecting social media; rather, they remind us that communication is ultimately a human rather than technological achievement," he wrote. "It is not enough to be passersby on the digital highways, simply 'connected'; connections need to grow into true encounters."

Keith Wagstaff writes about technology for NBC News. He previously covered the tech beat for TIME's Techland and wrote about politics as a staff writer at TheWeek.com. You can follow him on Twitter at @kwagstaff and reach him by email at: Keith.Wagstaff@nbcuni.com

La. Teacher Tells Buddhist Student He's 'Stupid' And Bible is '100 Percent True'

 

By Allison Geller, Thu, January 23, 2014

 

The American Civil Liberties Union of Louisiana is suing the Sabine Parish School Board on behalf of a family who alleges that their son, a Buddhist, suffered from racial discrimination at his school. His teacher told students that Buddhists were “stupid” and led the class to laugh at him. The school regularly proselytized the Christian faith.

According to the ACLU complaint filed in the U.S. District Court in Louisiana, the main offender, science teacher Rita Roark at Negreet High School, teaches students that evolution is “impossible” while the Bible is “100 percent true.”

Roark’s science tests include questions like “"ISN'T IT AMAZING WHAT THE _____________ HAS MADE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!" According to Scott Lane, the stepfather of “C.C.,” Roark marked his test wrong when he wrote “Lord Buddha” and “belittled him in front of the entire class” when he wrote nothing.

A student stated in class that "people are stupid if they think God is not real." Roark responded, "Yes! That is right! I had a student miss that on his test," to which the whole class laughed.

C.C, who is of Thai descent, has been a Buddhist his whole life. Yet he was subject to regular Christian prayer in class, religious iconography, Bible versus scrolling on the electronic marquee in front of the building, and a large picture of Jesus over the school’s main doors.

C.C.’s parents tried to bring up their complaints with school board superintendent Sarah Ebarb. Ebarb responded, “this is the Bible belt,” and advised C.C. to “change” his religion. She also suggested that the Lanes transfer C.C. to a school where “there are more Asians.” They did, in fact, transfer him—C.C. was having such bad anxiety at that it made him physically ill—but they encountered discrimination there, too.

"The treatment this child and his family have endured is not only disgraceful, it's unconstitutional," said Heather L. Weaver, senior staff attorney for the ACLU Program on Freedom of Religion and Belief. 

The U.S. Department of Education and U.S. Department of Justice will also investigate the school board at the ACLU’s request.

Sources: ACLU (2)

A new wrinkle in the control of waves: Flexible materials could provide new ways to control sound and light

by David Chandler

Flexible, layered materials textured with nanoscale wrinkles could provide a new way of controlling the wavelengths and distribution of waves, whether of sound or light. The new method, developed by researchers at MIT, could eventually find applications from nondestructive testing of materials to sound suppression, and could also provide new insights into soft biological systems and possibly lead to new diagnostic tools.

The findings are described in a paper published this week in the journal Physical Review Letters, written by MIT postdoc Stephan Rudykh and Mary Boyce, a former professor of mechanical engineering at MIT who is now dean of the Fu Foundation School of Engineering and Applied Science at Columbia University.

While materials' properties are known to affect the propagation of light and sound, in most cases these properties are fixed when the material is made or grown, and are difficult to alter later. But in these layered materials, changing the properties—for example, to "tune" a material to filter out specific colors of light—can be as simple as stretching the flexible material.

"These effects are highly tunable, reversible, and controllable," Rudykh says. "For example, we could change the color of the material, or potentially make it optically or acoustically invisible."

The materials can be made through a layer-by-layer deposition process, refined by researchers at MIT and elsewhere, that can be controlled with high precision. The process allows the thickness of each layer to be determined to within a fraction of a wavelength of light. The material is then compressed, creating within it a series of precise wrinkles whose spacing can cause scattering of selected frequencies of waves (of either sound or light).

Surprisingly, Rudykh says, these effects work even in materials where the alternating layers have almost identical densities. "We can use polymers with very similar densities and still get the effect," he says. "How waves propagate through a material, or not, depends on the microstructure, and we can control it," he says.

By designing that microstructure to produce a desired set of effects, then altering those properties by deforming the material, "we can actually control these effects through external stimuli," Rudykh says.
"You can design a material that will wrinkle to a different wavelength and amplitude. If you know you want to control a particular range of frequencies, you can design it that way."

The research, which is based on computer modeling, could also provide insights into the properties of natural biological materials, Rudykh says. "Understanding how the waves propagate through biological tissues could be useful for diagnostic techniques," he says.

For example, current diagnostic techniques for certain cancers involve painful and invasive procedures. In principle, ultrasound could provide the same information noninvasively, but today's ultrasound systems lack sufficient resolution. The new work with wrinkled materials could lead to more precise control of these ultrasound waves, and thus to systems with better resolution, Rudykh says.

The system could also be used for sound cloaking—an advanced form of noise cancellation in which outside sounds could be completely blocked from a certain volume of space rather than just a single spot, as in current noise-canceling headphones.

"The microstructure we start with is very simple," Rudykh says, and is based on well-established, layer-by-layer manufacturing. "From this layered material, we can extend to more complicated microstructures, and get effects you could never get" from conventional materials. Ultimately, such systems could be used to control a variety of effects in the propagation of light, sound, and even heat.

The technology is being patented, and the researchers are already in discussions with companies about possible commercialization, Rudykh says.

Explore further: Light and sound fire scientists' imaginations: Researchers lead review of photonic, phononic metamaterials

   

How Grazing Cows Can Save the Planet, and Other Surprising Ways of Healing the Earth

January 12, 2014

By Dr. Mercola

Judith Schwartz is a freelance writer and author of the book Cows Save the Planet: And Other Improbable Ways of Restoring Soil to Heal the Earth. I recently met Judy at a conference held by Allan Savory of the Savory Institute in Boulder, Colorado.
The Savory Institute helps farmers to holistically manage their livestock in order to improve soil quality and heal the environment. In fact, according to Savory, an African ecologist, dramatically increasing the number of grazing livestock is the only thing that can reverse desertification (when land turns to desert).
This was Savory's first conference, and turned out to be quite a memorable event. Judy has summarized a big portion of what was presented in that conference in her book. But what made her hone in on the issue of soil health to begin with?
Surprisingly, it all began with an investigation into the economy. Around 2008, just before the economic downturn, she'd started writing about the transition movement:

"One of the things that transition initiatives were dealing with was local currencies," she says. "Looking into local currencies kind of helped me understand how local economies work and primed me to ask questions when the economic downturn hit, like 'What is money? What is wealth?'

I was on that trajectory, writing about environmental economics and new economics... Basically, it's the notion that our economy can and should serve the people the planet as opposed to the other way around.

This I fear is the scenario that we've kind of gotten stuck in – that people and the planet, meaning all of our natural systems, exist to serve the economy.

From that framework, I started looking at ecology and observed the disconnect between our financial system and the natural world, which just cannot be separate. That disconnect doesn't work."

The Environmental Impact of Conventional Farming

This led her to learn more about soil health, economical land use, and how modern agricultural practices affect our environment.
 

For example, did you know that our modern agricultural system is responsible for putting more carbon dioxide into the atmosphere than the actual burning of fossil fuels? Understanding this reveals an obvious answer to pressing global problems.

There are only three places for carbon to go: land, air and water. Our agricultural practices have removed massive amounts of valuable carbon from land, transferring it into air and water. By paying greater attention to carbon management, we have the opportunity to make a dramatic difference in this area, which is having major negative consequences to our agriculture, and the pollution of our water and air.
As explained by Judy, early this past summer, concentrations of atmospheric CO2 crossed the 400 parts per million-threshold—the highest it's been in thousands of years. According to an organization called 350.org, scientists believe our CO2 levels need to be around 350 parts per million in order to maintain favorable living conditions on earth.

Carbon management is a critical aspect of environmental health and the growing of food.
That said, CO2 levels are not constantly or continuously rising in a straight line. The level rises and falls, and this is a clue to what's going on.

"Depending on the season, depending on how much photosynthesis is happening, it dips down, and then goes up again," Judy explains. "When we've got a lot of plants, as we get towards the warmer part of the year, more photosynthesis is happening, and the CO2 levels drop slightly.

That's so important to know, because photosynthesis is key to what we're talking about.

When I talk about bringing carbon back into the soil, I'm talking about supporting and stimulating the process of photosynthesis – in other words, growing more plants. Those plants then take in the CO2. They make carbon compounds. Those carbon compounds are drawn down, and they go into the soil."

Sequestering carbon in the Earth's soils is a good thing. There's actually more carbon in our world soils than in all plants, including trees, and the atmosphere together. However, due to modern agricultural methods, we've lost between 50 and 80 percent of the carbon that used to be in the soil... This means there's plenty of "room" to put it back in.

"It's useful to understand that the notion of bringing carbon back into the soil, one thing that it does is withdraw carbon down from the atmosphere. That's hugely important," Judy says.

"Carbon is the main component of soil organic matter. That's the good stuff that you want in soil anyway for fertility. It also absorbs water. When you have carbon-rich soil, you also have soil that is resilient to floods and drought. When you start looking at soil carbon, the news keeps getting better and better."

The Importance of Holistic Herd Management

Another major factor that needs to be considered is the management of livestock. Herds raised according to modern, conventional practices contribute to desertification—turning land into desert—which, of course, doesn't support plant life and photosynthesis, thereby shifting the equation in the wrong direction. When land turns to desert, it no longer holds water, and it loses the ability to sustain microbial life and nourish plant growth...
One of the reasons Allan Savory has become so popular is his promotion of holistic herd management, which causes desert areas to convert back to grasslands that support plant life. As explained by Judy:

"It occurred to him that the land needed the animals in the same way that the animals needed the land. He began to really observe how animals functioned on land, and came to understand the really intricate dynamics, the system, that had been naturally in operation.

Basically, when grazing animals graze, they're nibbling on the grasses in a way that exposes their growth points to sunlight and stimulates growth... Their trampling [of the land also] did several things: it breaks any capped earth so that the soil is aerated. It presses in seeds [giving them] a chance to germinate, so you have a greater diversity of plants. [Grazing herds] also press down dying and decaying grasses, so that they can be better acted upon by microorganisms in the soil. It keeps the decaying process going. Their waste also fertilizes the soil."

This natural symbiotic relationship between animals, soils and plants—where each benefits the other mutually—is a powerful insight. And it's one that can be replicated with great benefit. Besides the environmental benefits, grass-fed, pastured livestock is also an excellent source of high quality meat. In fact, it's the only type of meat I recommend eating, as raising cattle in confined animal feeding operations (CAFOs) alters the nutritional composition of the meat—not to mention such animals are fed antibiotics, growth promoters and other veterinary drugs.

You Can Make a Difference in More Ways Than One  

As for recommendations for what we can do to get us going in the right direction with regards to improving not only animal and human health but the health of the planet, Judy says:

"Most recommendations are very simple. The simplest thing is to avoid having bare soil. Because when you have bare uncovered soil, the land degradation process begins. When you have bare soil, that means that the carbon is binding with oxygen and becoming carbon dioxide."

We also need to shift our focus to emphasize the biological system as a whole. Soil is not a static "thing." It's a living symbiotic system, and soil microorganisms also play a very important role in this system. When I visited Elaine Ingham at the Rodale Institute, I learned the value of compost tea for promoting beneficial soil microbes, and I now use a vortex compost tea brewing system to revitalize my own garden. Interestingly, the better you farm or garden, the less land you need. According to Judy, a biological farmer using appropriate methods can grow on 1,000 acres the same amount of food another farmer might need 5,000 acres to produce...
 

Another factor is the importance of integrating animals on the land. Most biological farmers understand this, and will tell you that in order for soil to get to its highest potential of productivity and health, there needs to be animals on the land. (According to Savory, grazing large herds of livestock on half of the world's barren or semi-barren grasslands could also take enough carbon from the atmosphere to bring us back to preindustrial levels!) But what if you're not a gardener yet, or a farmer? How can you help achieve this much needed shift?

"I think people can make a difference in all sorts of ways that people make decisions every day, such as asking yourself how the food you're buying was grown," Judy says. "Because once you start asking where the food comes from, even posing that question, will lead you to make different choices.

Apart from food, what decisions are being made in your community about the use of land? Can your community save money by working with soil rather than, say, putting in an expensive waste or water treatment plant? That's another thing, getting involved on a local level. There are all kinds of organizations that are working on different environmental and different food aspects locally and nationally, etc."

Biological Farming Solves Many Pressing Problems

My first passion and career was being a physician, then an Internet educator, and now I'm moving into high-performance biological agriculture because I really believe it's the next step in our evolution. We must shift the way we produce food because the current system is unsustainable. And while this information really is ancient, it's not widely discussed. There's only a small segment of the population that even understands this natural system, and the potential it has for radically transforming the way we feed the masses AND protect the environment at the same time.
 

I thoroughly agree with the recommendation to get involved personally, because it's so exciting. For me, it's become a rather addictive hobby. Once you integrate biological farming principles, you can get plant performances that are 200-400 percent greater than what you would typically get from a plant! What's more, not only does it improve the quantity, it also improves the quality of the food you're growing. These facts should really be at the forefront of everybody's mind when they think about farming, as it's the solution to so many pressing problems. Judy agrees, noting:

"The challenge is that we've been led to believe that our agricultural model, which is an extractive model, is the way it needs to be. But we can shift to a regenerative model. That's where we need to go."

Final Thoughts

As Judy says, there's a lot to be optimistic about, because whether we're talking about the degradation of the environment or our food supply, there are answers!

"Many people just sort of give up and say, 'I can't do anything about this.' I was speaking to someone the other day who said that her son, who just finished college, said, 'You know, it's over. We're doomed.' To me, that is just so sad. How can we let the next generation feel that way? I think that betrays a huge lack of imagination. Because when we talk about our environmental challenges, one thing we don't talk about is nature's desire to heal itself. Once we ally with that natural process, it's amazing what we can do."

Ending the burning of fossil fuels is not the one and only way for us to turn the tide on rising carbon dioxide levels. Granted, solar energy and wind power would certainly be preferable to burning fossil fuels. But even if we didn't stop burning fossil fuels, we can still reverse rising CO2 levels by addressing the way we farm, using sound, time-honored agricultural principles.

And—something else to consider—even if we completely stop burning fossil fuels but do not change agriculture, we'll still be left with problems like lands turning to desert, flooding, and drought for example. In short, we really must address how we manage our lands and soils... You can learn more about biological farming by reviewing the related articles listed in the right-hand side bar on this page. I also highly recommend Judy's book, Cows Save the Planet: And Other Improbable Ways of Restoring Soil to Heal the Earth. It's a great read for anyone wanting to learn more about this topic.

Habitability, Taphonomy, and the Search for Organic Carbon on Mars

John P. Grotzinger

Science 24 January 2014:
Vol. 343 no. 6169 pp. 386-387
DOI: 10.1126/science.1249944                        

+ Author Affiliations

Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.

1. E-mail: grotz@gps.caltech.edu

 

The quest for extraterrestrial life is an old and inevitable ambition of modern science. In its practical implementation, the core challenge is to reduce this grand vision into bite-sized pieces of research. In the search for organic remnants of past life, it is enormously helpful to have a paradigm to guide exploration. This begins with assessing habitability: Was the former environment supportive of life? If so, was it also conducive to preservation of organism remains, specifically large organic molecules?

 

The 2004 arrival of the Mars Exploration Rovers (MERs) Spirit and Opportunity provided a chance to investigate ancient aqueous environments in situ and deduce their likelihood of supporting life. Initial results confirmed what data from orbiters had long suggested—that diverse aqueous environments existed on the surface of Mars billions of years ago. The success of the MERs led to the development of the Mars Science Laboratory (MSL) mission. The Curiosity rover landed at Gale crater in 2012 and was designed to specifically test whether ancient aqueous environments had also been habitable. In addition to water, did these ancient environments also record evidence for the chemical building blocks of life (C, H, N, O, P, S), as well as chemical and/or mineralogic evidence for redox gradients that would have enabled microbial metabolism, such as chemoautotrophy?

Curiosity also has the capability to detect organic carbon, but it is not equipped for life detection.

Image taken by the Mars Hand Lens Imager of the John Klein drill hole (1.6 cm in diameter) at Yellowknife Bay reveals gray cuttings of mudstone (ancient lake sediments), rock powder, and interior wall.                                                

An array of eight ChemCam laser shot points can be seen. The gray color suggests that reduced, rather than oxidized, chemical compounds and minerals dominated the pore fluid chemistry of the ancient sediment. A cross-cutting network of sulfate-filled fractures indicates later flow of groundwater through fractures after the sediment was lithified.

CREDIT: NASA/JPL-CALTECH/MALIN SPACE SCIENCE SYSTEMS

Five articles presented in full in the online edition of Science (www.sciencemag.org/extra/curiosity), with abstracts in print, describe the detection at Gale crater of a system of ancient environments (including streams, lakes, and groundwater networks) that would have been habitable by chemoautotrophic microorganisms. The Hesperian age (<∼3.7 billion years) rocks mentioned in these articles are at the young end of the spectrum of ancient martian aqueous environments. Yet, a sixth article details a more ancient and also potentially habitable environment detected in Noachian age (>∼3.7 billion years) rocks at Meridiani Planum. A seventh article describes the present radiation environment on the surface of Mars at Gale crater and its influence on the preservation of organic compounds in rocks.

 

Opportunity landed at Meridiani Planum on 25 January 2004. Coincident with the 10th anniversary of this landing, Arvidson et al. report the detection of an ancient clay-forming, subsurface aqueous environment at Endeavour crater, Meridiani Planum. Though Opportunity does not have the ability to directly detect C or N, it has been able to establish that several of the other key factors that allow for the identification of a formerly habitable environment were in place. This potentially habitable environment stratigraphically underlies and is considerably older than the rocks detected earlier in the mission that represent acidic, hypersaline environments that would have challenged even the hardiest extremophiles. The presence of both Fe⁺³- and Al-rich smectite clay minerals in rocks on the rim of the Noachian age Endeavour impact crater were inferred from the joint use of hyperspectral observations by the Mars Reconnaissance Orbiter and extensive surface observations by the Opportunity rover. The rover was guided tactically by orbiter-based mapping. Extensive leaching and formation of Al-rich smectites occurred in subsurface groundwater fracture systems.

Grotzinger et al. show that an ancient habitable environment existed at Yellowknife Bay, Gale crater, where stream waters flowed from the crater rim and pooled in a curvilinear depression at the base of Gale's central mountain to form a lake-streamgroundwater system that might have existed for millions of years. Vaniman et al. provide evidence for moderate to neutral pH, as shown by the presence of smectite clay minerals and the absence of acid-environment sulfate minerals, and show that the environment had variable redox states due to the presence of mixed-valence Fe (magnetite) and S (sulfide, sulfate) minerals formed within the sediment and cementing rock. McLennan et al. show that lake salinities were low because of the very low concentration of salt in the lake deposits.

Elemental data indicate that clays were formed in the lake environment and that minimal weathering of the crater rim occurred, suggesting that a colder and/or drier climate was prevalent.

Ming et al. show that the thermal decomposition of rock powder yielded NO and CO₂, indicating the presence of nitrogen- and carbon-bearing materials. CO₂ may have been generated by either carbonate or organic materials. Concurrent evolution of O₂ and chlorinated hydrocarbons indicates the presence of oxychlorine species. Higher abundances of chlorinated hydrocarbons in the lake mudstones, as compared with modern windblown materials, suggest that indigenous martian or meteoritic organic C sources are preserved in the mudstone. However, the possibility of terrestrial background sources brought by the rover itself cannot be excluded.

 

These results demonstrate that early Mars was habitable, but this does not mean that Mars was inhabited. Even for Earth, it was a formidable challenge to prove that microbial life existed billions of years ago—a discovery that occurred almost 100 years after Darwin predicted it, through the recognition of microfossils preserved in silica (1). The trick was finding a material that could preserve cellular structures. A future mission could do the same for Mars if life had existed there.
Curiosity can help now by aiding our understanding of how organic compounds are preserved in rocks, which, in turn, could provide guidance to narrow down where and how to find materials that could preserve fossils as well. However, it is not obvious that much organic matter, of either abiologic or biologic origin, might survive degradational rock-forming and environmental processes. Our expectations are conditioned by our understanding of Earth's earliest record of life, which is very sparse.

 

Paleontology embraces this challenge of record failure with the subdiscipline of taphonomy, through which we seek to understand the preservation process of materials of potential biologic interest. On Mars, a first step would involve detection of complex organic molecules of either abiotic or biotic origin; the point is that organic molecules are reduced and the planet is generally regarded as oxidizing, and so their preservation requires special conditions. For success, several processes must be optimized. Primary enrichment of organics must first occur, and their destruction should be minimized during the conversion of sediment to rock and by limiting exposure of sampled rocks to ionizing radiation. Of these conditions, the third is the least Earth-like (Earth's thick atmosphere and magnetic field greatly reduce incoming radiation). Curiosity can directly measure both the modern dose of ionizing cosmic radiation and the accumulated dose for the interval of time that ancient rocks have been exposed at the surface of Mars.

 

Hassler et al. quantify the present-day radiation environment on Mars that affects how any organic molecules that might be present in ancient rocks may degrade in the shallow surface (that is, the top few meters). This shallow zone is penetrated by radiation, creating a cascade of atomic and subatomic particles that ionize molecules and atoms in their path. Their measurements over the first year of Curiosity's operations provide an instantaneous sample of radiation dose rates affecting rocks, as well as future astronauts. Extrapolating these rates over geologically important periods of time and merging with modeled radiolysis data yields a predicted 1000-fold decrease in 100–atomic mass unit organic molecules in ∼650 million years.

 

Sediments that were buried and lithified beneath the radiation penetration depth, possibly with organic molecules, would eventually be exhumed by erosion and exposed at the surface. During exhumation, organics would become subject to radiation damage as they entered the upper few meters below the rock-atmosphere interface. The time scale of erosion and exhumation, and thus the duration that any parcel of rock is subjected to ionizing radiation, can be determined by measuring cosmogenically produced noble gas isotopes that accumulate in the rock. ³⁶Ar is produced by the capture of cosmogenic neutrons by Cl, whereas ³He and ²¹Ne are produced by spallation reactions on the major rock-forming elements. Farley et al. show that the sampled rocks were exposed on the order of ∼80 million years ago, suggesting that preservation of any organics that accumulated in the primary environment was possible, although the signal might have been substantially reduced.

 

Wind-induced saltation abrasion of the rocks in Yellowknife Bay appears to have been the mechanism responsible for erosion and exhumation of the ancient lake bed sampled by Curiosity. The geomorphic expression of this process is a series of rocky scarps that retreated in the downwind direction. Understanding this process leads to the prediction that rocks closest to the scarps were most recently exhumed and are thus most likely to preserve organics, all other factors being equal. In this manner, the MSL mission has evolved from initially seeking to understand the habitability of ancient Mars to developing predictive models for the taphonomy of martian organic matter. This parallels the previous decade, in which the MER mission turned the corner from a mission dedicated to detecting ancient aqueous environments to one devoted to understanding how to search for that subset of aqueous environments that may also have been habitable.

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