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    Hand 'Em Over

    City of Johns Creek, Georgia

    All states now have a 0.08 percent legal limit, but the U.S. National Transportation Safety Board says you're drunk at 0.05 percent blood-alcohol content.

    The U.S. National Transportation Safety Board is recommending a new, lower limit for what's considered driving drunk. The board, which has no regulatory authority, wants states to set the blood-alcohol limit at 0.05 percent for driving. All 50 states now have limits of 0.08 percent.

    After reviewing decades' worth of studies, the board concluded that people still have impaired attention, perception, reaction time and other functions important to driving at the lower blood-alcohol limit. The board also decided that the U.S. hasn't done enough yet to reduce drunk driving fatalities. About 173,000 people are injured every year in drunk-driver crashes and 10,000 people die, according a report the board published. About 30 percent of traffic deaths in the U.S. in 2011 were alcohol-related.

    There's no magic number at which drinkers become dangerous drivers, of course. There's a smooth relationship between blood alcohol levels and risk of crashing that starts with even a 0.01 percent blood alcohol level. (Check out the graph on page 21 in the report.) The new 0.05 percent limit the board chose is associated with a 38 percent increased chance of a crash. A 0.08 percent blood alcohol level is associated with a 169 percent increased crash risk.

    The board looked at studies of several other anti-drunk-driving measures, too. Based on its reviews, it wants more police-run sobriety checkpoints, more breathalyzer car locks for people who have been convicted of drunk driving, and more specialized drunk driving courts to deal with-and rehabilitate-repeat offenders, who are much more likely to be involved in fatal crashes than other drunk drivers.

    The American Beverage Institute, a restaurant industry group, opposes the new recommended blood-alcohol limit. NBC News quoted the institute's managing director, Sarah Longwell, as calling it "ludicrous."

    "Moving from 0.08 to 0.05 would criminalize perfectly responsible behavior," she said. "Further restricting the moderate consumption of alcohol by responsible adults prior to driving does nothing to stop hardcore drunk drivers from getting behind the wheel."


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    This is what high-frequency trading looks like

    Nanex via YouTube

    Check out how much money you're not making.

    Something to think about as the millisecond tick by today: how much money you're not making from the slight discrepancies between the values of securities on the world's international exchanges. Developed by suburban Chicago-based financial data company Nanex, this visualization shows, at highly reduced speed, the automated trading activity that took place on Johnson and Johnson's stock May 2. The timescale bas been altered so that each millisecond of trading time is represented as roughly one second in the visualization, so it's slowed down about 1,000 times.

    The bottom box shows what's known as the National Best Bid and Offer, or the standard by which all these automated exchanges are supposed to know what the best bid and offer are on a given stock at any given time so a buyer and seller can meet at the best place. All of that other noise? Those are changes in JNJ's stock price quote being bounced around from various global exchanges (each of the other boxes rimming the circle represents a different stock exchange). The different shapes represent different quote changes, but the point is: look at all those quote changes! Every millisecond!

    This is largely the result of high frequency trading, or HFT, in which computer algorithms are constantly trying to find small price discrepancies for the same stock on different exchanges, which are caused by the fact that so much trading is happening so quickly that each exchange can't always keep up with the rapidly changing price of any security. If an algorithm can spot a millisecond-level opportunity in which a stock is--for the blink of an eye--worth more on one exchange than another, it can make a quick buck (this is called abitrage, and it's how HFT turns a profit).

    So the underlying value of the stock doesn't matter--HFT generally just exploits pricing opportunity, and in turn the high volume of trading it produces helps to further create delays in the connections between exchanges, which helps create even more opportunities for abitrage. Sounds unfair? Well, it is. Don't you wish you'd thought of it first?


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    And without it, could I do everything a five-toed human does?

    Walking, running and skipping with just four toes may be easier than you think.

    "If you're born without a pinky toe or have an accident and it's removed, you can completely do everything you wanted to do," Dr. Anne Holly Johnson, instructor in orthopaedic surgery at Harvard Medical School, says.

    So why do we have pinky toes?

    The answer goes back to the evolutionary history of humans, explains Dr. Anish Kadakia, assistant professor in orthopaedic surgery at Northwestern University.

    "Primates use their feet to grab, claw, to climb trees, but humans, we don't need that function anymore," Kadakia says. "Clearly we're not jumping up and down trees and using our feet to grab. We have toes embryologically, evolutionary for that particular reason because we descended from apes, but we don't need them as people."

    While our feet no longer help us grab, they help us stand--especially important are the bones that connect our toes to our ankle.

    We owe our balance to the 26 bones that make up the hindfoot, midfoot and forefoot. The forefoot contains the toes. The big toe has two major bones and the rest have three little bones. The toes connect to the midfoot by five long bones called metatarsals, one for each toe. The metatarsals are similar to our knuckles. The hindfoot connects to the midfoot by cuneiform and cuboid bones. These are connected to the ankle bone, the talus.

    Though all the bones in the foot come together to form the structure of the foot, the main bones responsible for our balance are the metatarsals, explains Dr. Wenjay Sung, attending physician at White Memorial Medical Group.

    "We walk like a tripod fashion, where the big toe knuckle, the fifth toe knuckle and the heel, have a tripod walking ability," Sung says. "If you remove one part of that tripod, you lose balance."

    So even though the pinky toe itself has no functional value, removing the metatarsal would make running, walking and skipping nearly impossible.

    This story was produced in partnership with Northwestern University's Medill School of Journalism. For more FYIs, go here.


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    Tavis Coburn

    In the future, when machines run our lives, we'll need a way to keep tabs on all those helper bots. Two researchers have come up with a solution.

    The trickiest part of a future filled with helpful robots (think Roombas, but for everything) is keeping track of them all. Researchers at Wayne State University published a clever solution to this problem.

    In a paper titled "LOBOT: Low-Cost, Self-Contained Localization of Small-Sized Ground Robotic Vehicles," computer scientists Guoxing Zhan and Weisong Shi lay out a technique for ground robots to share location information. (No, LOBOT doesn't stand for anything.)

    First, a robot minion has to figure out where it is. To accomplish this, the LOBOT system uses a GPS receiver, a 3-axis accelerometer, a magnetic field sensor, and multiple motor rotation sensors. Because the GPS sensor is extremely energy-intensive, it only infrequently checks the absolute position of the machine. The magnetic field sensors, accelerometer, and motor rotation sensors keep the location information up-to-date by helping to calculate the robot's change in position relative to its previously determined GPS location. Together, these processes give a good approximation of the robot's absolute location.

    If this GPS-and-accelerometer strategy sounds familiar, it should: That's how cell phones determine location. The researchers specifically used an unlocked HTC Legend smartphone for the parts, and even powered the LOBOT location system from the phone's battery. Below is a LOBOT system assembled from a Lego robotics kit and a smartphone, attached to a small tracked robot:

    Besides the fact that it would be fairly cheap to attach LOBOT systems to your Roomba army, the best part is that it all works with existing infrastructure. GPS is unlikely to go away any time soon, so a LOBOT standard for robots allows them to be tracked and integrated into the world as it is, without needing any major changes.

    Which means more robots, sooner. This is a pretty great future.

    The paper appears in the the April issue of IEEE Transactions on Parallel and Distributed Systems.


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    Samsung Galaxy S4, With Skin


    Today at Google's I/O conference, stock Android seemed like a pricey luxury. Why?

    Today at the 2013 Google I/O conference in California, Google announced that the company would begin selling the Samsung Galaxy S4, the newest in the most successful Android phone line on the planet, themselves. When you buy a Galaxy S4 from your wireless carrier or a retail store, it comes with a skin called TouchWiz and a two-year contract. With Google, you'll pay more, but you won't get stuck with either the skin or the contract.

    The developers in the audience cheered when Hugo Barra, the head of Android at Google, showed a Galaxy S4 with stock Android. Then the cheers died out, suddenly and awkwardly, when Barra noted the price for this special phone: $649. One person gave a sad whistle. Barra chuckled and changed the subject to the Chromebook.

    The audience was excited because stock Android--the version of Android that comes on Google's own Nexus devices, the so-called "pure" Android that is created with no input from any other company--is excellent. Google has spent years hiring some of the best user-interface designers in the business (they've poached several from competing companies) and turning Android into a streamlined and fantastically competent operating system. Hell, they even created their own font (it's called Roboto, and it looks a bit like Helvetica). Stock Android is fast, clean, and simple--the best version of Android you can get.

    The other benefit to stock Android is receiving updates quickly. Android is updated frequently, with major new versions arriving about once per year, but the only devices that receive those updates as soon as they're ready are the ones with stock Android. If you're using anything but a Nexus, you're going to have to wait. The update might come in a few weeks, a few months, or it might just...never come.

    The Nexus phones aren't that popular; they're sometimes sold exclusively through Google, and they never have the weight of promotion that a flagship Samsung, HTC, or Motorola phone has. According to the Guardian, the Nexus 4--the latest Nexus phone, which we ranked as the best smartphone of 2012--sold a paltry 400,000 units in its first quarter. Samsung shipped (not sold, but still) 6 million Galaxy S4 units in the phone's first 15 days. If you have an Android phone, chances are you're having an inferior experience. Check out our Galaxy S3 review for why--the hardware manufacturers who slap skins and features on their phones are just not as good at this game as Google.

    What Google needs is a self-destruct button. A built-in way for any Android device to delete whatever skin it came with and revert to clean, cool stock Android.

    * * *

    The odd thing about this inability to revert is in the meaning and execution of "open source." Android is open source, which means the hardware manufacturers are free to use it as they see fit, even if that means making it worse. But there's a paradox in that the openness enables a lockdown. Google has been tentative, nervously promoting stock Android as if it's an also-ran and not the default. "It's Google's version of Android," said Barra. But shouldn't that be the base? Shouldn't every other version be a version of that?


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    Human Blastocyst

    A human embryo at the blastocyst stage

    Open i beta

    The process that created Dolly the sheep in 1996 has now been proven successful in humans.

    Scientists have made an embryonic clone of a person, using DNA from that person's skin cells. In the future, such a clone could be a source of stem cells, for super-personalized therapies made from people's own DNA.

    It's unlikely that this clone could develop into a human, say the scientists, a team of biologists from the U.S. and Thailand. The team plans to publish a paper in the future detailing why not, Nature reported. Previously, the team conducted this entire process, including a technique called somatic cell nuclear transfer, in monkeys. Those monkey embryo clones always died before they could grow into adult monkeys.

    "While nuclear transfer breakthroughs often lead to a public discussion about the ethics of human cloning, this is not our focus, nor do we believe our findings might be used by others to advance the possibility of human reproductive cloning," Shoukhrat Mitalipov, the clone research's lead scientist, said in a statement. Mitalipov is a biologist who studies cells and development at the Oregon Health and Science University.

    This is a feat that's been a long time coming. The world even got a bit of a tease of it nearly a decade ago, in 2004 and 2005, when Woo Suk Hwang of Seoul National University said he'd made human clones. It turned out Hwang was lying.

    Now, Mitalipov and his team have made clones using the same basic technique that created Dolly the cloned sheep in 1996. The scientists took skin cells' nuclei-the centers of the cells, where the cells keep their DNA-and transplanted them into eggs that had their own genetic material removed. They then grew the eggs for a few days, harvested the daughter cells that appeared, and created a cell line, or a colony of cells that reproduces stably. The stem cells in the cell line could become several different types of adult cells, just like natural stem cells.

    In the future, stem cells made in this way will compete with another method of creating personalized stem cells. Researchers previously showed they are able to transform adult skin cells directly into stem cells, with no stop for a transfer into an egg along the way. Such cells are called induced pluripotent stem cells, or iPSCs, and they don't require the creation of embryos.

    Want to learn more? Mitalipov and his colleagues published a paper about their work today in the journal Cell. Nature has great reporting on the breakthrough, with a little more scientific nitty-gritty.


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    Kepler Space Telescope

    Kepler is designed to look for Earth-like planets orbiting Sun-like stars in a temperate "Goldilocks zone," where temperatures are right for liquid water. It stares at a patch of around 156,000 stars in the constellations Cygnus and Lyra and notes teeny blips in their brightness, which could indicate planets passing in front of the stars' faces.


    A critical failure in Kepler's alignment may spell the end for the storied planet hunter.

    The diversity of the phenomena of nature is so great, and the treasures hidden in the heavens so rich, precisely in order that the human mind shall never be lacking in fresh nourishment.
    --Johannes Kepler

    The storied Kepler space telescope, finder of scorched baby Mercuries, a real Tatooine, gigantic Jupiters and possible other Earths, might be on its last planet-hunting breath. The telescope put itself into safe mode yesterday and its control wheels may have failed, meaning it cannot properly point at the stars. NASA says the telescope is not dead, but they are not sure they can keep it going, either.

    "I think the most interesting, exciting discoveries are coming in the next two years. The mission is not over," said William Borucki, Kepler's chief scientist and the man who conceived it decades ago. "But the mission is not taking data. There is a reasonable possibility that we will be able to mitigate that problem. I don't think I'd be a pessimist, here."

    Kepler, which orbits the sun trailing 40 million miles behind the Earth, is controlled by four gyroscopic reaction wheels, which keep it parked in the right direction. It stares at a patch of 150,000 stars between the constellations Cygnus and Lyra, looking for blips in brightness that indicate a planet passing in front of them. This type of search requires incredible pointing precision, and that's where the wheels come in. The reaction wheels keep Kepler in place despite the pressure of the solar wind.

    Launched in 2009 on a $600 million mission that's already been extended through 2016, the telescope has been experiencing issues with one of the wheels for some time. Wheel No. 2 has been turned off for a while, and earlier this year, managers on Earth noticed another stuck wheel, so they put Kepler in park and hoped the kink would work itself out. On May 12, Kepler put itself into safe mode when it noticed it was drifting out of position. When NASA woke it up Tuesday, May 14, telemetry indicated wheel No. 4 wasn't moving, despite commands for it to spin.

    Scientists need at least three working wheels to keep Kepler pointed with extreme precision, as carefully as the Hubble Space Telescope. Without them, it might be able to hang out in a "point rest state" and do other types of astronomy, but that's not clear yet. NASA managers said they were trying to think of ways to fix it--maybe ordering the wheels to wiggle around, or spin like you might spin a stuck car tire--but they're not sure it will work.

    "I wouldn't call Kepler down and out just yet," said John Grunsfeld, NASA's associate administrator for science and a former astronaut.

    Kepler has been phenomenally successful, finding more than 2,700 planet candidates and 130 definite planets. In some respects, Kepler bridged the emotional void between the end of the space shuttle and the landing of the Mars rover Curiosity. During that gap, NASA still had an awe-inspiring, romantic explorer to share with the public--and with scientists.

    "When we started out, we didn't know virtually every star in the sky had planets around them," said Paul Hertz, NASA's astrophysics director. "Now we know that."

    Even if it can't be fixed, Kepler's discoveries will continue rolling in. It has a list of 2,740 planet candidates, which can be verified with ground telescopes or with Kepler's own data. Granted, those self-checks would be better if the telescope had another couple years to stare at the same stars. But it has an enormous archive of data, so no matter what happens to it now, Kepler findings will not cease for some time.

    Borucki said he has at least two years of work to do with the data he already has.

    Though NASA managers and scientists said they are not counting Kepler out, their words Wednesday were certainly fitting of a eulogy.

    "For me, it goes back to sitting on my porch, looking at the stars and wondering what's out there. And now we know, because of Kepler," Grunsfeld said.

    Go here to check out some of Kepler's current highlights.


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    Torrey Pines Logic Beam 100

    Torrey Pines Logic

    A new device protects soldiers by detecting and locating optical glass.

    U.S. defense contractors spend a lot of resources developing robots that help the Pentagon's various services keep an eye on their enemies, but San Diego-based Torrey Pines Logic is developing a small robotic sidekick that helps friendly forces know if they are being watched. The Beam 100 Optical Detection System sends out pulses of lasers that can detect various optical lenses out to roughly one kilometer, or nearly 1,100 yards, letting forces know if there's someone out their with a telescopic lens, a camera, or even a rifle scope pointed in their direction.

    Designed to help protect forward operating bases or special operators trying to avoid detection, the system emits laser pulses into its surrounding environment via a panning, swiveling head that maintains 360-degree coverage. When the pulses reflect off of glass, the returning pulses are detected and analyzed for certain signatures indicative of optical glass--lenses, essentially--used in telescoping or camera devices. The signature analysis discards noise from other glass, like bottles, window glass, or other non-optical surfaces.

    The result is a system that, if it works as well as Torrey Pines Logic says it does, only detects objects of interest, like telescoping observation lenses or weapons optics. The system then uses further software-based analysis to geolocate the objects of interest and alert the user as to their whereabouts. Considering its a laser device, it could also potentially be tweaked to incapacitate or otherwise blind the offending optical object (or person), but laser weapons and countermeasures that cause actual damage to human eyes are prohibited under international convention. So we're not advocating that. We're just noting that it probably could be done.

    [Defense Tech]


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    New Google Maps, a totally new GChat, new features for Android, and more.

    Google announced a bunch of stuff today at the annual I/O conference in California. The announcements are mostly updates--nothing as exciting as the introduction of Google Glass or a new tablet--but there are lots of changes that'll affect how you compute, and that give an idea of how Google plans to evolve in the near future. Here's what we saw:

    Maps Can Think. One of Google's best tactics of late is taking what it knows about you--which is a lot, eeee--and not just presenting it to you, but analyzing and predicting what you want to know. When you search for "Sur La Table" on your phone, your results now show a white box that gives you the address and store hours--exactly what you probably want to know. And the new Google Maps works the same way.

    Maps now adjusts based on your use. It uses the data it has on you to suggest things to do in the area you've selected, personalized just for you. Clicking on any individual item changes the map to show related items, making those brighter and less related items duller. Directions now have more detail in the different options; public transit directions now show the different number of transfers, for example.

    Sync Your Stuff. Android's notifications system has been about two or three years beyond Apple since the launch of the first Android phone. For every step Apple takes, Google takes one a step further. Apple uses the swipe-down-from-the-top motion to trigger a notifications shade? Android allows you to swipe them individually to close, or head straight to your settings menu from there. The latest is syncing: swipe to dismiss a notification on your phone, and that'll be carried over to any other Android or Chrome device, so you don't need to dismiss things multiple times. Smart.

    Another Music Subscription. Google introduced the awkwardly named Google Play Music All Access service, which is...exactly like Spotify, or Rdio, or Zune, or Rhapsody. Ten bucks a month, listen all you want. We love these services, but Google made no effort to move things forward with this offering, so we're not sure who's going to use it. Why use Google Play when you've already got Spotify and Rdio on your phone?

    Google Insists You Want Voice Search. Google spent a long time today discussing the improvements made to voice search. (We're iffy on its potential.) Google Glass relies on it already, but now Google wants you to have a full-on conversation with your computer, tablet, and phone, as well. You talk to it by saying "Ok, Google." Read more about that here.

    Chat Is Now Hangouts. GChat might be ubiquitous among the under-30 set, but Google's approach to chat has been confusing. Google Chat, Google Talk, Gmail, Google Hangouts, Video Chat--lots of different services, unnecessarily confusing. Now it's all one thing: Google Hangouts. It's available for Android, iOS, and on your computer as a Chrome extension, and looks like a more powerful, cleaner version of GChat. You can drop photos and videos easily, switch to video chat in the same window, and Google has apparently hand-drawn hundreds of new emoji, if you're into that kind of thing. More on that here.

    Google+ Is Still Alive. Google redesigned Google+, with a new multi-pane design and fancy animations, though we doubt that'll get anyone to use it who doesn't already. The best part? Photos are well-attended; they'll upload automatically, highlight and autocorrect exposure and color, and attempt to group them based on content, so all photos of a certain party will be together.


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    Water found deep in an Ontario mine could have been isolated and untouched for the last billion years.

    José Manuel Suárez via Wikimedia

    Scientists may have discovered the oldest free-flowing source of isolated water ever known.

    Scientists digging around roughly one-and-a-half miles below the Earth's surface in an Ontario mine may have just discovered the oldest free-flowing source of isolated, untouched water ever known. Though they don't know if anything has been living in this water, it contains both methane and hydrogen-key ingredients for life-and has likely been isolated in rock down there, untouched by Earth's atmosphere, for a staggering 1 billion years.

    Or perhaps even longer. While tiny, micrometer-scale deposits of water have been found in minerals tens of millions of years old (the water was trapped there when the minerals formed, so it has been trapped for at least that long), free-flowing water living in interconnected pockets, cracks, and pores deep in the Earth's crust has never been dated as older than a few tens of millions of years old. When the scientists discovered the water in the Ontario mine, they felt lucky to have found undisturbed water that they thought was maybe even hundreds of millions of years isolated.

    But an analysis of the water, which was found in 2.7-billion-year-old sulphide deposits within the copper and zinc mine, is full of isotopes that the researchers are fairly certain have not been in contact with Earth's atmosphere for at least 1 billion years, and possibly as long as 2.64 billion years.

    Given the water also contains the ingredients for life, the researchers are now examining carefully extracted samples of the water to see if they contain microbial life or whether they might have in the past. The findings, whatever they may be, could have big implications for Mars, which we know once had surface water and very well might be full of deposits of untouched, isolated water like this beneath its barren surface.

    Correction: An earlier version of this post contained a typo, stating that some micrometer-scale deposits of water had been dated "tens of billions" of years old. Which means they would predate the existence of the universe. It was supposed to read "tens of millions." The copy has been corrected to reflect this. PopSci regrets having accidentally attempted to undo decades of important cosmological research.



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  • 05/16/13--06:05: Light Duty
  • March to the Heat

    Soldiers walk on a treadmill in the tropical chamber.

    Courtesy of the U.S. Army

    The Army fires up a sunshine simulator.

    Each year, some 20 soldiers experience Afghanistan's 118°F heat for the first time not in the field but in a lab in Natick, Massachusetts. For six decades, the Doriot Climatic Chambers has created everything from deserts to blizzards to test equipment before real-world deployment-and it's the U.S.'s only military lab that uses human volunteers to do it.

    The chambers are divided into two areas: tropic and arctic. Josh Bulotsky, the electrical engineer who manages the lab, can control every aspect of each climate. Two 500-horsepower cooling systems and a heater create -70°F to 165°F temperatures; dehumidifiers and water misters produce 10 to 90 percent humidity; sprinkler heads simulate rain; and a snow machine makes winter storms. In the chambers, soldiers sometimes walk on treadmills that fit five people (to simulate a group march). And to track their health, they can swallow telemetry pills that relay their core temperatures to lab technicians. In January, the lab added the sun: eighteen 1,500-watt metal-halide vapor lamps so bright that it's impossible to look straight at them-perfect for testing portable solar panels. Brutal as the tests are, better that the troops and their equipment fail now than on the other side of the world.


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    A reconstruction of <i>Homo neanderthalensis</i> at Neanderthal Museum, Mettmann, Germany

    Wikimedia Commons

    It's a fact of the archaeological record: Modern humans survived and Neanderthals did not. Why? And what does it teach us about our own survival?

    Neanderthals were humans who went extinct between 20,000 and 30,000 years ago. Though there is some debate about who these people were, there is no question that there are none left. All that remains of the hundreds of Neanderthal groups that roved across Europe and Central Asia are a handful of ambiguous funeral sites, bones, tools, and pieces of art-along with some DNA that modern humans inherited from them. How can we avoid meeting the Neanderthals' fate? That depends on what you think wiped out these early humans in the millennia after they met H. sapiens.

    By 40,000 years ago, humans had spread in waves across most of the world, from Africa to Europe, Asia, and even Australia. But these humans were not all perfectly alike. When some groups of H. sapiens poured out of Africa, they walked north, then west. In this thickly forested land, they came face-to-face with other humans, stockier and lighter skinned than themselves, who had been living for thousands of years in the cold wilds of Europe, Russia, and Central Asia. Today we call these humans Neanderthals, a name derived from the Neander Valley caves in Germany where the first Neanderthal skull was identified in the nineteenth century.

    Neanderthals were not one unified group. They had spread far enough across Europe, Asia, and the Middle East that they formed regional groups, something like modern human tribes or races, who probably looked fairly different from each other. Neanderthals used tools and fire, just as H. sapiens did, and the different Neanderthal groups probably had a variety of languages and cultural traditions. But in many ways they were dramatically unlike H. sapiens, leading isolated lives in small bands of 10 to 15 people, with few resources. They had several tools, including spears for hunting and sharpened flints for scraping hides, cutting meat, and cracking bones. Unlike H. sapiens, who ate a wide range of vegetables and meat, Neanderthals were mostly meat-eaters who endured often horrifically difficult seasons with very little food. Still, there is evidence that they cared for each other through hardship: fossils retrieved from a cave in Iraq include the skeleton of a Neanderthal who had been terribly injured, with a smashed eye socket and severed arm, whose bones had nevertheless healed over time. Like humans today, these hominins nursed each other back to health after life-threatening injuries.

    Roughly 10,000 years after their first meeting with H. sapiens, all the Neanderthal groups were extinct and H. sapiens was the dominant hominin on Earth. What happened during those millennia when H. sapiens lived alongside creatures who must have looked to them like humanoid aliens?

    A few decades ago, most scientists would have answered that it was a nightmare. Stanford's Richard Klein, who spent years in France comparing the tools of Neanderthals and early H. sapiens, lowered his voice a register when I recently asked him to describe the meeting between these hominin groups. "You don't like to think about a holocaust, but it's quite possible," he said. He referred to the long-standing belief among many anthropologists that H. sapiens exterminated Neanderthals with superior weapons and intellect. For a long time, there seemed to be no other explanation for the rapid disappearance of Neanderthals after H. sapiens arrived in their territories.

    Today, however, there is a growing body of evidence from the field of population genetics that tells a very different story about what happened when the two groups of early humans lived together, sharing the same caves and hearths. Anthropologists like Milford Wolpoff, of the University of Michigan, and John Hawks have suggested that the two groups formed a new, hybrid human culture. Instead of exterminating Neanderthals, their theory goes, H. sapiens had children with them until Neanderthals' genetic uniqueness slowly dissolved into H. sapiens over the generations. This idea is supported by compelling evidence that modern humans carry Neanderthal genes in our DNA.

    Regardless of whether H. sapiens murdered or married the Neanderthals they met in the frozen forests of Europe and Russia, the fact remains that our barrel-chested cousins no longer walk among us. They are a group of humans who went extinct. The story of how that happened is as much about survival as it is about destruction.

    The Neanderthal Way of Life

    We have only fragmentary evidence of what Neanderthal life was like before the arrival of H. sapiens. Though they would have looked different from H. sapiens, they were not another species. Some anthropologists call Neanderthals a "subspecies" to indicate their evolutionary divergence from us, but there is strong evidence that Neanderthals could and did interbreed with H. sapiens. Contrary to popular belief, Neanderthals probably weren't swarthy; it's likely that these early humans were pale-skinned, possibly with red hair. We know that they used their spears to hunt mammoths and other big game. Many Neanderthal skeletons are distorted by broken bones that healed, often crookedly; this suggests that they killed game in close combat with it, sustaining many injuries in the process. They struggled with dramatic climate changes too. The European and Asian climates swung between little ice ages and warmer periods during the height of Neanderthal life, and these temperature changes would have constantly pushed the Neanderthals out of familiar hunting grounds. Many of them took shelter from the weather in roomy caves overlooking forested valleys or coastal cliffs.

    Though their range extended from Western Europe to Central Asia, the Neanderthal population was probably quite small-a generous estimate would put it at 100,000 individuals total at its apex, and many scientists believe it could have been under 10,000. By examining the growth of enamel on Neanderthal teeth, anthropologists have determined that many suffered periods of extreme hunger while they were young. This problem may have been exacerbated by their meat-heavy diets. When mammoth hunting didn't go well, or a particularly cold season left their favored game skinny or sick, the Neanderthals would have gone through months of malnutrition. Though Neanderthals buried their dead, made tools, and (at least in one case) built houses out of mammoth bones, we have no traditional evidence that they had language or culture as we know them. Usually such evidence comes in the form of art or symbolic items left behind. Neanderthals did make art and complex tools after meeting H. sapiens, but we have yet to find any art that is unambiguously Neanderthal in origin.

    Still, there are intriguing hints. A 60,000-year-old Neanderthal grave recently discovered in Spain suggests that Neanderthals may have had symbolic communication before H. sapiens arrived. Researchers discovered the remains of three Neanderthals who appeared to have been gently laid in identical positions, their arms raised over their heads, then covered in rocks. The severed paws of a panther were found with the bodies, heightening the impression that the discovery represented a funeral ritual complete with "burial goods," or symbolic items placed in the graves. Erik Trinkhaus, an anthropologist at Washington University in St. Louis, says this site shows that Neanderthals might have had symbolic intelligence like modern humans.

    Gravesites like these have led many scientists, including Trinkhaus, to believe that Neanderthals talked or even sang. But we haven't found enough archaeological evidence to sway the entire scientific community one way or the other.

    By contrast, the H. sapiens groups who lived at the time of first contact with Neanderthals left behind ample evidence of symbolic thought. Bone needles attest to the fact that H. sapiens sewed clothing, and pierced shells suggest jewelry. There are even traces of red-ochre mixtures found in many H. sapiens campsites, which could have been used for anything from paint or dye to makeup. Added together, these bits of evidence suggest that H. sapiens groups weren't just using tools for survival; they were using them for adornment. And culture as we know it probably started with those simple adornments.

    Looked at from the perspective of Neanderthals, then, there might have been a vast gulf between themselves and the newly arrived H. sapiens. The newcomers not only looked different-they were taller, slimmer, and had smaller skulls-but they probably chattered in an incomprehensibly complex language and wore bizarre garments. Would Neanderthals have tried to communicate with these people, or invited them to a dinner of mammoth meat?

    There was a lot more than hanky-panky going on.For anthropologists like Klein, who spoke about a Neanderthal holocaust, the answer is an emphatic no. He's part of a school of anthropological thought that holds that H. sapiens would have met the Neanderthals with nothing but hate, disgust, and indifference to their plight. After those Neanderthals watched H. sapiens arrive, the next chapter in their lives would have been marked by bloodshed and starvation as H. sapiens murdered and outhunted them with their superior weaponry. Neanderthals were so poor, and had such a small population, that their extinction was inevitable.

    This story might sound familiar to anyone versed in the colonial history of the Americas. It's as if H. sapiens is playing the role of Europeans arriving in their ships, and Neanderthals are playing that of the soon-to-be-exterminated natives. But Klein sees a sharp contrast between Neanderthals and the natives that Europeans met in America. When H. sapiens arrived, he asserted, "there was no cultural exchange" because the Neanderthals had no culture. Imagine what might have happened if the Spanish had arrived in the Americas, but the locals had no wealth, science, sprawling cities, nor vast farms. The Neanderthals had nothing to trade with H. sapiens, and so the newcomers saw them as animals.

    Neanderthals may have had fleeting sexual relationships with H. sapiens here and there, admitted Klein, but "modern human males will mate with anything." Tattersall agreed. "Maybe there was some Pleistocene hanky-panky," he joked. But it wasn't a sign of cultural bonding. For anthropologists like Klein and Tattersall, any noncombative relationships forged between the two human groups were more like fraternization than fraternity.

    But there is a counter-narrative told by a new generation of anthropologists. Bolstered by genetic discoveries that have revealed traces of Neanderthal genes in the modern human genome, these scientists argue that there was a lot more than hanky-panky going on. Indeed, there is evidence that the arrival of H. sapiens may have dramatically transformed the impoverished Neanderthal culture. Some Neanderthal cave sites hold a mixture of traditional Neanderthal tools and H. sapiens tools. It's hard to say whether these remains demonstrate an evolving hybrid culture, or if H. sapiens simply took over Neanderthal caves and began leaving their garbage in the same pits that the Neanderthals once used. Still, many caves that housed Neanderthals shortly before the group went extinct are full of ornaments, tools, and even paints. Were they emulating their H. sapiens counterparts? Had they become part of an early human melting pot, engaging in the very cultural exchange that Klein and Tattersall have dismissed?

    Extermination and Assimilation

    The complicated debate over what happened to Neanderthals can be boiled down to two dominant theories: Either H. sapiens destroyed the other humans, or joined up with them.
    The "African replacement" theory, sometimes called the recent African origins theory, holds that H. sapiens charged out of Africa and crushed H. neanderthalensis underfoot. This fits with Klein's account of a Neanderthal holocaust. Basically, H. sapiens groups replaced their distant cousins, probably by making war on them and taking over their territories. This theory is simple, and has the virtue of matching the archaeological evidence we find in caves where Neanderthal remains are below those of H. sapiens, as if modern humans pushed their Neanderthal counterparts out into the cold to die.

    In the late 1980s, a University of Hawaii biochemist named Rebecca Cann and her colleagues found a way to support the African replacement theory with genetic evidence, too. Cann's team published the results of an exhaustive study of mitochondrial DNA, small bits of genetic material that pass unchanged from mothers to children. They discovered that all humans on Earth could trace their genetic ancestry back to a single H. sapiens woman from Africa, nicknamed Mitochondrial Eve. If all of us can trace our roots back to one African woman, then how could we be the products of crossbreeding? We must have rolled triumphantly over the Neanderthals, spreading Mitochondrial Eve's DNA everywhere we went. But mitochondrial DNA offers us only a small part of the genetic picture. When scientists sequenced the full genomes of Neanderthals, they discovered several DNA sequences shared by modern humans and their Neanderthal cousins.

    Besides, how likely is it that a group of H. sapiens nomads would attack a community of Neanderthals? These were explorers, after all, probably carrying their lives on their backs. Neanderthals may not have had a lot of tools, but they did have deadly spears they used to bring down mammoths. They had fire. Even with H. sapiens' greater numbers, would these interlopers have had the resources to mount a civilization-erasing attack? Rather than starting a resource-intensive war against their neighbors, many H. sapiens could have opted to trade with the odd-looking locals, and eventually move in next to them. Over time, through trade (and, yes, the occasional battle) the two groups would have shared so much culturally and genetically that it would become impossible to tell them apart.

    This is precisely the kind of thinking that animates what's called the multiregional theory of human development. Popularized by Wolpoff and his colleague John Hawks, this theory fits with the same archaeological evidence that supports the African replacement theory-it's just a very different interpretation.

    Wolpoff's idea hinges on the notion that the ancestors of Neanderthals and H. sapiens didn't leave Africa as distinct groups, never to see each other again until the fateful meeting that Klein described with such horror. Instead, Wolpoff suggests, humans leaving Africa 1.8 million years ago forged a pathway that many other archaic humans walked-in both directions. Instead of embarking on several distinct migrations off the continent, humans expanded their territories little by little, essentially moving next door to their old communities rather than trekking thousands of kilometers to new homes. Indeed, the very notion of an "out of Africa" migration is based on an artificial political boundary between Africa and Asia, which would have been meaningless to our ancestors. They expanded to fill the tropical forests they loved, which happened to stretch across Africa and Asia during many periods in human evolution. Early humans would have been drifting back and forth between Africa, Asia, and Europe for hundreds of thousands of years. It was all just forest to Neanderthals and H. sapiens.

    If scientists like Wolpoff are right-and Hawks has presented compelling genetic evidence to back them up-then H. sapiens probably didn't march out of Africa all at once and crush all the other humans. Instead, they evolved all over the world through an extended kinship network that may have included Neanderthals as well as other early humans like Denisovans and H. erectus.

    It's important to understand that the multiregional theory does not suggest that two or three separate human lineages evolved in parallel, leading to present-day racial groups. That's a common misinterpretation. Multiregionalism describes a human migration scenario similar to those we're familiar with among humans today, where people cross back and forth between regions all the time. For multiregionalists, there were never two distinct waves of immigration, with one leading to Neanderthals, and the other packed with H. sapiens hundreds of thousands of years later. Instead, the migration (and evolution) of H. sapiens started 1.8 million years ago and never stopped.

    Many anthropologists believe that the truth lies somewhere in between African replacement and multiregionalism. Perhaps there were a few distinct waves of migration, such anthropologists will concede, but H. sapiens didn't "replace" the Neanderthals. Instead, H. sapiens bands probably assimilated their unusual cousins through the early human version of intermarriage.

    Perhaps, when Neanderthals stood in the smooth stone entries to their caves and watched H. sapiens first entering their wooded valleys, they saw opportunity rather than a confusing threat. In this version of events, our ancient human siblings may have had few resources and lived a hardscrabble life, but they were H. sapiens' mental equals. They exchanged ideas with the newcomers, developed ways of communicating, and raised families together. Their hybrid children deeply affected the future of our species, with a few of the most successful Neanderthal genes drifting outward into some of the H. sapiens population. Neanderthals went extinct, but their hybrid children survived by joining us.

    Whether you believe that humans exterminated or assimilated Neanderthals depends a lot on what you believe about your own species. Klein doesn't think Neanderthals were inferior humans doomed to die-he simply believes that early H. sapiens would have been more likely to kill and rape their way across Europe in a Neanderthal holocaust, rather than making alliances with the locals. As his comment about the sexual predilections of modern men makes clear, Klein is basing his theory on what he's observed of H. sapiens in the contemporary world. Tattersall amplified Klein's comments by saying that he thinks humans 40,000 years ago probably treated Neanderthals the way we treat each other today. "Today, Homo sapiens is the biggest threat to its own survival. And [the Neanderthal extinction] fits that picture," he said. Ultimately, Tattersall believes that we wiped out the Neanderthals just the way we're wiping ourselves out today.

    Hawks, on the other hand, described a more complicated relationship between H. sapiens and Neanderthals. He believes that Neanderthals had the capacity to develop culture, but simply didn't have the resources.

    Modern humans carry Neanderthal genes in our DNA."They made it in a world where very few of us would make it," he said, referring to the incredible cold and food scarcity in the regions Neanderthals called home. Anthropologists, according to Hawks, often ask the wrong questions of our extinct siblings: "Why didn't you invent a bow and arrow? Why didn't you build houses? Why didn't you do it like we would?" He thinks the answer isn't that the Neanderthals couldn't but that they didn't have the same ability to share ideas between groups the way H. sapiens did. Their bands were so spread out and remote that they didn't have a chance to share information and adapt their tools to life in new environments. "They were different, but that doesn't mean there was a gulf between us," Hawks concluded. "They did things working with constraints that people today have trouble understanding." Put another way, Neanderthals spent all day in often fatal battles to get enough food for their kids to eat. As a result, they didn't have the energy to invent bows and arrows in the evening. Despite these limitations, they formed their small communities, hunted collectively, cared for each other, and honored their dead.

    When H. sapiens arrived, Neanderthals finally had access to the kind of symbolic communication and technological adaptations they'd never been able to develop before. Ample archaeological evidence shows that they quickly learned the skills H. sapiens had brought with them, and started using them to adapt to a world they shared with many other groups who exchanged ideas on a regular basis. Instead of being driven into extinction, they enjoyed the wealth of H. sapiens' culture and underwent a cultural explosion of their own. To put it another way, H. sapiens assimilated the Neanderthals. This process was no doubt partly coercive, the way assimilation so often is today.

    More evidence for Hawks's claims comes from Neanderthal DNA. Samples of their genetic material can reveal just what happened after all that Pleistocene hanky-panky. A group of geneticists at the Max Planck Institute, led by Svante Pääbo, sequenced the genomes of a few Neanderthals who had died less than 38,000 years ago. After isolating a few genetic sequences that appear unique to Neanderthals, they found evidence that a subset of these sequences entered the H. sapiens genome after the first contact between the two peoples. Though this evidence does not prove definitively that genes flowed from Neanderthals into modern humans, it's a strong argument for an assimilationist scenario rather than extermination.

    Our lineage is a patchwork quilt of many peoples and cultures who intermingled as they spread across the globe.A big question for anthropologists has been whether H. sapiens comes from a "pure" lineage that springs from a single line of hominins like Mitochondrial Eve. The more the genetic evidence piles up, however, the more likely it seems that our lineage is a patchwork quilt of many peoples and cultures who intermingled as they spread across the globe. Present-day humans are the offspring of people who survived grueling immigrations, harsh climates, and Earth-shattering disasters.

    Most anthropologists are comfortable admitting that we just don't know what happened when early humans left Africa, and are used to revising their theories when new evidence presents itself. Klein's influential textbook The Human Career is full of caveats about how many of these theories are under constant debate and revision. In 2011, for example, the anthropologist Simon Armitage published a paper suggesting that H. sapiens emerged from Africa as early as 200,000 years ago, settling in the Middle East. This flies in the face of previous theories, which hold that H. sapiens didn't leave Africa until about 70,000 years ago. The story of how our ancestors emerged from their birthplaces in Africa turns out to be as complicated as a soap opera-and it likely includes just as much sex and death, too.

    Who Survived to Tell the Tale?

    Whether humans destroyed Neanderthals or merged with them, we're left with a basic fact of anthropological history, which is that modern humans survived and Neanderthals did not. It's possible that members of H. sapiens were better survivors than their hominin siblings because Neanderthals didn't exchange symbolic information; they were too sparse, spread out, and impoverished to achieve a cultural critical mass the way their African counterparts did. But it seems that Neanderthals were still swept up into H. sapiens' way of life in the end. Our Neanderthal siblings survive in modern human DNA because they formed intimate bonds with their new human neighbors.

    Svante Pääbo, who led the Neanderthal DNA sequencing project, recently announced a new discovery that also sheds light on why H. sapiens might have been a better survivor than H. neanderthalensis. After analyzing a newly sequenced genome from a Denisovan, a hominin more closely related to Neanderthals than H. sapiens are, Pääbo's team concluded that there were a few distinct regions of DNA that H. sapiens did not share with either Neanderthals or Denisovans. Several of those regions contain genes connected to the neurological connections that humans can form in their brains. In other words, it's possible that H. sapiens' greater capacity for symbolic thought is connected to unique strands of DNA that the Neanderthals didn't have. "It makes a lot of sense to speculate that what had happened is about connectivity in the brain, because... Neanderthals had just as large brains as modern humans had," Pääbo said at a press conference in 2012 after announcing his discovery. "Relative to body size, they had even a bit larger brains [than H. sapiens]. Yet there is something special that happens with modern humans. It's sort of this extremely rapid technological cultural development and large societal systems, and so on." In other words, H. sapiens' brains were wired slightly differently than their fellow hominins. And once Neanderthals merged with H. sapiens' communities, bearing children with the new arrivals, their mixed offspring may have had brains that were wired differently, too. Looked at in this light, it's as if H. sapiens assimilated Neanderthals both biologically and culturally into an idea-sharing tradition that facilitated rapid adaptation even to extremely harsh conditions.

    Early humans evolved brains that helped us spread ideas to our compatriots even as we scattered to live among new families and communities. It's possible that this connectedness-both neurological and social-is what allowed groups of H. sapiens to assimilate their siblings, the Neanderthals. Still, our storytelling abilities are also what allow us to remember these distant, strange ancestors today.

    Humans' greatest strength 30,000 years ago may have been an uncanny ability to assimilate other cultures. But in more recent human history, this kind of connectedness almost did us in. Once human culture scaled up to incorporate unprecedentedly enormous populations, our appetite for assimilation spread plagues throughout the modern world, almost destroying humanity many times over. And it spawned deadly famines, too. Humanity's old community-building habits can become pathological on a mass scale. Thousands of years after the merging of Neanderthals and H. sapiens, the practices that helped us survive in pre-ice age Europe became, in some contexts, liabilities. They wiped out whole civilizations and made it necessary for us to change the structures of human community forever.

    Excerpted with permission fromScatter, Adapt, and Remember: How Humans Will Survive a Mass Extinctionby Annalee Newitz. Copyright © 2013 by Annalee Newitz. Published by arrangement with Doubleday, an imprint of The Knopf Doubleday Publishing Group, a division of Random House, Inc. and Penguin Group (Canada), a division of Pearson Canada, Inc.


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    MARS shot and Clay Center Observatory

    The industry and the F.A.A. say the climate effects of flying civilians into space will be negligible, but some scientists fret about the accumulation of black carbon in the stratosphere.

    Virgin Galactic proudly touts the fact that each of the passengers who will fly into sub-orbital space on its SpaceShip2 will emit less carbon dioxide than a typical air passenger on a flight from New York to London. But some scientists say carbon dioxide emissions are irrelevant to measuring the greenhouse gas footprint of the nascent space tourism industry. The big threat from the scaling-up of space travel, they say, comes from something called black carbon-a type of particulate matter that, when hurled into the stratosphere, builds up for years, absorbing visible light from the sun. According to one study, black carbon emitted into the stratosphere by rockets would absorb 100,000 times as much energy as the CO2 emitted by those rockets.

    "There's one issue and it's simple: you don't want to put black carbon in the stratosphere. Period," says Darin Toohey, a professor of atmospheric and oceanic sciences at the University of Colorado, Boulder. Industry insiders say otherwise. Who's right?

    Black carbon should be familiar to anyone who's ever idled behind a diesel truck or sat by a wood stove: it's what makes soot black. Formed from the incomplete combustion of fossil fuel, biofuel, and biomass, it is emitted directly into the atmosphere and absorbs about a million times more energy than CO2. According to one study, it is Earth's second largest contributor to climate change, after carbon dioxide. The reason black carbon doesn't wreak more havoc on the environment is that it has a short lifetime in the lower atmosphere-precipitation washes away black carbon emissions from planes and other sources within a matter of weeks.

    Not so in the stratosphere, which begins as low as 5 miles above the Earth and rises up to about 31 miles. Rockets need to scream through the stratosphere to the point 62 miles above the sea level, where space is conventionally said to begin. They are also the only direct source of human-created compounds above 12 miles. Because there is no rain or other atmospheric factors to wash out the black carbon in the stratosphere, black carbon would linger for 5 to 10 years or more. Moroever, rockets produce over 1,000 times more black carbon per unit of fuel than standard aircraft.

    So in 2010, Toohey and Martin Ross, the head of the Center for Launch Emissions Analysis and Research at Aerospace Corporation, and Michael Mills of the National Center for Atmospheric Research,crunched the numbers to estimate the black carbon effects of a hypothetical 1,000 flight-per-year industry. They measured the black carbon's "radiative forcing" - a metric for how much extra energy the Earth and its atmosphere absorb from a given manmade or natural phenomena. The radiative forcing from the black carbon that rockets placed in the stratosphere was up to 100,000 times greater than that of the CO2 released by the rockets. (In contrast, the radiative forcing of the black carbon placed for just a few weeks into the atmosphere by jets is less than 1/10 of that of its carbon dioxide).

    How this extra heat in the stratosphere would effect climate is less clear, but it would definitely cause some climate change - both warming and cooling. The computer model showed a complicated pattern in which a ring-shaped cloud of black carbon would form at the latitude of the launch site, leading to shade that would cause cooling there, with corresponding warming in other places. Polar regions warmed or cooled by up to 5 degrees, depending on the season. The heating also caused ozone to radiate throughout the stratosphere, causing lower levels in some places and increases in others. The point of the study was not to say a warmer stratosphere is disastrous, but rather that 1,000 launches per year will have a significant climate change effect - and that the industry should have to study and explain the implications. After all, proposals to doctor the climate by deliberately injecting particles into the atmosphere have generated international outcry. Without meaning to, and without fully understanding the effects, Ross says, a growing space tourism industry will function like an experiment in engineering the climate. "At some point, the particles put into the stratosphere by rockets begin to look at little bit like geo-engineering," says Ross.

    Here's where space tourism comes into play: The number of space launches annually around the world numbers around 70 today, but that figure could rise drastically, as private companies jockey to turn space tourism into routine adventure travel. The aerospace research firm Futron forecasts that by 2021 the space tourism market will consist of 13,000 potential customers, with possible revenues of roughly $650 million per year. Assuming the business is successful, commercial space travel might very well reach 1,000 launches per year some time in the next decade - XCOR alone plans to ramp up to four launches per day, as part of its "Southwest airlines" model. That creates 1,000 opportunities to shoot black carbon directly into the stratosphere. The amount of black carbon emitted during combustion on Earth, or in the trophosphere, where airlines fly, tends to be low, because of the relatively rich supply of oxygen. Once you get into the stratosphere, where low pressure leads to less oxygen, black carbon can amount to as much as 5% of the products of combustion.

    The Federal Aviation Administration (F.A.A.), the organization responsible for assessing environmental impacts and deciding whether to grant licenses to launch vehicles into space, says the effects of black carbon in the stratosphere are unclear. "Although black carbon is known to be a short-term climate forcer, research on the potential climate change impacts of black carbon from rockets is in a very early stage, and any projections of impacts are speculative," writes George Nield, the F.A.A.'s associate administrator for commercial space transportation, in an email.

    The space-tourism industry has downplayed black carbon's potential harm. Virgin Galactic declined repeated inquiries to comment. Andrew Nelson, the chief operating officer of XCOR Aerospace, which is currently selling $95,000 tickets for sub-orbital flights, says that the blend of kerosene and liquid oxygen in his XR-5K18 rocket engine powering its Lynx suborbital spaceplane will emit much less in the way of "aromatic" hydrocarbons than traditional kerosene-based rocket fuel. And he says the XR-5K18 will burn much more cleanly than the solid rocket boosters used in the Space Shuttle or "hybrid" rocket engines, which burn both solid and liquid propellant.

    "XCOR will have di minimus impact on our environment," Nelson says. "Our fuels are almost completely free of particulate matter. [They have ] 20-40 times less aromatics than traditional rocket fuels, and hundreds, if not thousands of times less particulate matter than hybrids or solids. So the concern about carbon or other particles is moot for us."

    Toohey still wants to see peer-reviewed studies of the actual interaction of XCOR and other engines with the stratosphere. "I have not seen any publications that confirm (or refute) the claims of particle-free emissions from combustion of any fuel in the upper atmosphere," Toohey says. "So I think it is fair to say that we need studies to benchmark the emissions of all rocket types in order to be able to assess their impacts."


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    Not so easy to fake.


    Unlike the commonly deployed social smile, distressed expressions-anger, fear, sadness, and occasionally surprise-prove much more difficult to display on command.

    We've all done our fair share of faking it. Whether it's a canned excited response when that one particularly eccentric aunt gives you a Christmas sweater for the fifth year in a row, or a friendly smile when greeting someone you don't particularly like - putting on a good face often seems like the socially appropriate thing to do. Unfortunately not all expressions are so easy to fake.

    Unlike the commonly deployed social smile, distressed expressions-anger, fear, sadness, and occasionally surprise-prove much more difficult to display on command.

    These expressions cause tension throughout the face as one part of the brain tries to control an expression caused by another part of the brain. These expressions also rely on antagonistic muscle groups, pulling parts of the face in opposing directions.

    For example, sadness often involves both an expression of sadness and the desire to control that expression. "The tug of war over your face creates the quivering lip," says Dr. Mark Frank, professor in the Department of Communication at the University of Buffalo.

    Similarly, when a face demonstrates fear, surprise pulls the eyebrows up while stress knits the brows together, resulting in the inner corners of the eyebrows raising slightly.

    "Fear involves more muscles in the top of the face than other emotions," Dr. David Matsumoto, director of Humintell, says. "We have much less neural connection to the forehead, the eyebrows and the upper eyelids than to the lower muscles in the face, so it becomes hard for us to voluntarily control them."

    Your best bet is to fake the emotions of the people around you.
    Facial expressions are different from reactions, adds Dr. Hillel Aviezer, a professor in the Department of Psychology at the Hebrew University of Jerusalem. A reaction like a knee jerk is in response to sensory stimuli and activates motor responses, bypassing the brain. In contrast, body cues and facial expressions demonstrating emotion are brain based, meaning they can be controlled to a certain extent, even if we aren't very good at it.

    "Recreating the expression without feeling the emotion can be tricky. Many people are poor posers of expressions; they simply don't know what to move where," he says.

    Not to mention, it's almost impossible to imitate unique characteristics of sadness or fear, like tears or sweat.

    Your best bet is to fake the emotions of the people around you. We tend to read our own emotions onto those around us, according to Dr. Aviezar. So if you're with a group of happy people, they might have a harder time identifying your false smile.

    But emotion isn't all in the face. Recent studies revealed that while our basic understanding of emotional expression comes from the face, we demonstrate a lot of what we're feeling through the rest of our body as well. When we feel particularly intense emotions the body becomes a better indicator for emotion, especially in the context of victory and defeat.

    So understanding body cues might be the key to recreating particularly difficult emotions. Think about obvious cues, like covering your eyes or throwing your arms up in surprise. "Fear is arguably on of the most poorly recognized emotions from the face," Aviezer continued. "However, in real life, the face appears with a body and with a context--so we end up doing pretty well."

    This story was produced in partnership with Northwestern University's Medill School of Journalism. For more FYIs, go here.


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    Transcranial Stimulation

    This is an image of a different type of transcranial stimulation than the type researchers studied below. The transcranial random noise stimulation study below required headgear that was about as involved as this.

    S. Plontke on Open i beta

    Well, it's one way of getting better at math.

    What if a painless zap to the brain could improve your ability to do math? Would you do it?

    It may sound weird, but a new, small study of 25 people has shown that something like this may work. Researchers from the U.K. and Austria found that something called transcranial random noise stimulation helped people learn certain arithmetic faster. The effect still appeared when the researchers tested their study volunteers again six months later.

    The stimulation required volunteers to get electrical stimulation through their scalps. They get bursts of electrical currents in random frequencies, which seems to make brain cells more excitable. For this study, they received stimulation over a part of the prefrontal cortex that's important for arithmetic. The researchers gave 13 of their volunteers stimulation over five days, while they put the rest of their volunteers into the same scalp setup without actually running the stimulation.

    After five days, those who got the stimulation learned arithmetic more quickly compared to those who hadn't been stimulated. The speedier learning applied both to learning math facts, which didn't require understanding, and to doing math calculations, which required people to understand the operations they performed. At the same time, measures of blood flow to the brain showed differences between the volunteers who received stimulation and the volunteers who didn't.

    Six months later, the researchers asked their volunteers to come into the lab again, without warning. Only 12 volunteers-six who had been stimulated, six who had not-agreed. The researchers tested those folks and found that the volunteers who received stimulation training still performed better on some tests and had improved blood flow to part of the brain that received stimulation.

    The improved volunteers could even generalize their learning. They did well not only on math problems they had already seen, but also on problems that used the same principles, but weren't exactly the same. Only one effect had faded away: All the volunteers performed about equally on memorizing math facts.

    Of course, it will take a lot more than 25 people to prove this new brain stimulation technique truly works for a variety of people. Meanwhile, the researchers have an idea about why transcranial random noise stimulation works. It may help brain cells fire more simultaneously, according to Cell Press, which published the paper today in its journal, Current Biology.


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  • 05/16/13--09:30: How NASA Could Save Kepler
  • Kepler Might Be On It's Last Leg


    Scott Hubbard, former director of the NASA Ames Research Center, speculates on how NASA could revive the ailing space telescope.

    Yesterday NASA officials confirmed that the exoplanet-hunting Kepler space telescope had suffered a mechanical failure, throwing into question the telescope's ability to continue its mission.

    But Kepler is not dead just yet. Speaking to Stanford News Service, consulting professor of aeronautics and astronautics Scott Hubbard--the former director of NASA Ames Research Center who was present during much of Kepler's construction--says that there are still a couple ways mission handlers might be able to revive Kepler and get its photo-detector array pointed back at the more than 100,000 stars it monitors for signs of orbiting exoplanets.

    The problem: Kepler contains four gyroscope-like reaction wheels that spin within the telescope to keep it perfectly steady when observing this huge field of faraway stars. At least three of these wheels must be functioning for Kepler to maintain a steady field of view. One of these wheels failed about a year ago, and now a second has also locked up, causing Kepler to cease operations. On May 12, Kepler entered safe mode, when it realized it was drifting out of position. NASA mission operators woke Kepler up on the 14th and tried to get the newly stuck wheel moving again, but to no avail.

    So where to go from here? Hubbard offers a couple of potential solutions:

    There are two possible ways to salvage the spacecraft that I'm aware of. One is that they could try turning back on the reaction wheel that they shut off a year ago. It was putting metal on metal, and the friction was interfering with its operation, so you could see if the lubricant that is in there, having sat quietly, has redistributed itself, and maybe it will work.
    The other scheme, and this has never been tried, involves using thrusters and the solar pressure exerted on the solar panels to try and act as a third reaction wheel and provide additional pointing stability. I haven't investigated it, but my impression is that it would require sending a lot more operational commands to the spacecraft.

    Even if mission operators can't get Kepler working again, the telescope survived its planned mission lifetime and leaves behind an 18-month backlog of data in the pipeline that still needs to be analyzed. So sure, this might be the end of Kepler's active mission, but scientists will be making discoveries based on Kepler for a long time to come.

    [Stanford News Service]


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    D-Wave Quantum Computer


    Why not use a crazy sci-fi technology (quantum computing) to solve a classic crazy sci-fi problem (artificial intelligence)?

    Google announced today a partnership with NASA and D-Wave to launch a lab to solve artificial intelligence problems with the aid of quantum computing.

    Quantum computing is in its infancy, but it's still very tough to wrap one's head around. Here's one way to think of it: traditional computers complete calculations based on bits. A bit can have either of two values--zero or one--at any given point. But quantum computers use something called qubits, which aren't constrained by a binary nature--they can be zero, one, or anything in between, or several values, all at the same time. That makes them very valuable to calculate probability, or likelihood--anything that has more than one possible answer--because they can figure out a bunch of different calculations at the same time.

    That gives quantum computers the possibility to be much faster than traditional computers. We're talking orders of magnitude faster.

    Google and NASA specifically want to study machine learning, a branch of artificial intelligence. Machine learning is highly complex, a very nearly creative task. Quantum computing has some pretty amazing possibilities for machine learning, since it can come up with many different possible analyses of data simultaneously.

    The new lab will consist of a quantum computer from D-Wave, housed at NASA's Ames Research Center and staffed by researchers "from around the world." Google says a few experiments are already underway, and that one of their earliest discoveries is that machine learning is best arrived at with a combination of quantum and traditional computing. We'll keep an eye on this lab--there are bound to be some fascinating discoveries. Read more about it over at Google's blog.


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    Crime Scene?


    Florida state attorneys have decided not to file felony charges against a 16-year-old whose science experiment was actually not boring.

    Good news coming out of Florida this week: 16-year-old Kiera Wilmot won't be charged with dual felonies for conducting a science experiment on school grounds at her public school in Bartow, Fla., the Florida State Attorneys office has announced. The announcement comes after 195,000 people from across the country signed an online petition demanding the charges be dropped.

    On April 22 in the hours before school started, Wilmot mixed a household chemical with aluminum foil inside a water bottle and placed the cap on it as part of a science experiment. She reportedly expected the reaction to create a little smoke, but instead the bottle popped with a firecracker-like sound and produced more smoke than anticipated.

    No one was injured and no property was damaged, but nonetheless the school administration phoned the police, who arrested Wilmot for "possession/discharge of a weapon on school grounds" and "discharging a destructive device"--charges that could have led to Wilmot finishing high school in a juvenile facility and entering her adult life with a record. Wilmot has an outstanding school record and her principal describes her as both a "good kid" and one who has no record of being in any kind of serious trouble.

    Her story set off a wave of criticism in the science community and led to an online petition supporting Wilmot--and encouraging scientific curiosity among American youth in general. Whether it was the public outrage or a bout of common sense that seized Florida's State Attorneys office, the felony charges have been dropped and Wilmot is free to continue being a high school student genuinely curious about science and the world around her.


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    Remotely Piloted Jetstream


    Up, up, and away-without a pilot.

    The great thing about robots is that they take boring, repetitive tasks from humans, which frees up our superior minds for more creative endeavors (like building more robots.) Flying a commercial airplane, much like driving down long stretches of undifferentiated Eurasian steppe or piloting a cargo helicopter back and forth over the same route, typically consists of a few moments of human input mixed in with long stretches of automated tedium.

    As such, it was only a matter of time before machines took over the cockpit: Last month, a robot plane safely carried passengers 500 miles from England to Scotland and back again, the British consortium operating the plane revealed Monday.

    Dubbed "the Flying Test Bed," the plane is a normal 19-seat Jetstream-the kind a corporate executive might fly in-that was converted to fly autonomously. The group behind the plane is Autonomous Systems Technology Related Airborne Evaluation and Assessment (Astraea), a business consortium funded by the British government and private businesses.

    The test flight wasn't completely autonomous-a human pilot onboard entered the cockpit to steer the plane through take-off, and then later the landing. The majority of the flight, however, that long tedium of maintaining a plane at cruising altitude, was in control of the remote pilot, with autonomous systems doing much of the actual flying.

    While this was a test flight, it didn't interrupt normal air traffic, and it's 500-mile round-trip between Warton, England, and Inverness, Scotland, occurred in regular commercial airspace, shared with other airplanes.

    Next up for the plane? Testing weather avoidance systems over the Irish sea and then using a system based around infrared sensors to test obstacle avoidance on emergency landings. Following that, Astraea is planning to test systems that can communicate with air traffic controllers and sense and avoid other aircraft.

    The next big goal for robotics is commercial airplanes that can autonomously take off and land themselves. Earlier this week, the U.S. military showed off a drone nearly at this point, and technology is improving fast.

    With each boring task taken over by autonomous machines, the future becomes a little bit more more exciting for us creative humans.


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    Belatchew's STRAWSCRAPER vision for Södermalm's South Tower in Stockholm, Sweden

    Belatchew Arkitekter

    The, erm, splashy future of skyscrapers

    In the future, all buildings will resemble massive toilet brushes. Perhaps not, but that's the net-zero energy future of skyscrapers envisioned by Belatchew Arkitekter in an idea called STRAWSCRAPER which, in spite of the toilet brush comparison, is actually pretty cool. The general idea here is to give tall buildings a skin of piezoelectric fibers that harvest energy to power the building from the wind.

    Belatchew's model for this concept is Södermalm's South Tower in Stockholm, Sweden, which was completed in 1997 but at only 26 stories rather than the originally planned 40 stories (the architect who designed the building apparently left the project after losing control of the design). Belatchew's STRAWSCRAPER would return the building to its original proportions, extending it 14 stories skyward by way of adding huge vertical rods covered in piezoelectric filaments. The other 26 stories would also be sheathed in piezoelectric ribs that would ripple in the breeze, thus creating electricity.

    Piezoelectricity is, simply put, an electric charge that builds up as the result of mechanical stress. Think of it as a small jolt of electricity generated by the flexing of a material. With piezoelectric fibers, even a light breeze would generate power. That in turn could keep the building running without pulling energy from the grid.

    And, being the brainchild of an architecture firm, there's an aesthetic aspect to STRAWSCRAPER as well. Covered in these functional fibers, buildings--once static monoliths--become undulating, rippling, living things in the urban landscape. Like trees. Or cleaning implements.

    [David Report]


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