3Doodler Plane

MattBdreaming

If you can draw an airplane on paper, you could be well on your way to making a (toy) plane in real life. Just check out this project from maker and blogger Matt Butchard. He created a remote controlled toy plane using a 3Doodler, a $99, pen-like, hand-held 3-D printer.

Butchard created the plane's frame with the 3Doodler, then covered the wings with this specialized tissue. So far, he's posted one solid powered test flight to YouTube. The plane definitely goes for a few seconds before stalling and crashing, which damaged it enough so that he couldn't fly it again. But the silver lining is that the 3Doodler makes the damage easy to fix.

Popular Science has covered the 3Doodler before. We even took a quick video of an early version of the pen at work, making tiny 3-D springs:

Since 3Doodler began selling its pen, users have made some pretty cool things with it. Butchard made this adorable Johnny Five, using a variety of colors that would be difficult to achieve with a desktop 3-D printer. And the store of the Museum of Modern Art recently displayed some sophisticated 3Doodler art.

[Make]

Header

Brazilian neuroscientist Claudia Vargas explains the plastic nature of the brain.

Imagine Science Films

The World Cup has drawn more than rabid soccer fans to Brazil. A team of filmmakers are on the ground in Rio de Janeiro documenting the science behind the games, including an exoskeletal kick-off, the genetics of competition, and even the biochemistry of diehard spectators.

Here's Imagine Science Films' take on Header, the latest mini-documentary in their "Field Work: World Cup" series:

Imagine Science Films teams up with neuroscientist Claudia Vargas to discuss mind and motion in Header.

Thanks to the brain, players are able to translate their thoughts into action. The first ceremonial kick-of the World Cup was made by a paralyzed teenager wearing a exoskeleton suit. This technology supports the lower body, using brain activity to trigger movements in the suit. How does the brain control our body motion? What happens in our brain/body when this communication is atrophied? Vargas explains that when motor neurons in the brain lose the ability to communicate with muscles, new pathways are forged through a phenomena called neuroplasticity. And, with an accompanying EEG headset, these neural pathways can interface with an artificial skeleton!

Not only can the brain control motion of players and exoskeleton suits, but it can anticipate the action of other players on the field. The same neurons fire both when making or observing a winning kick. But, when observing, they fire slightly before the kick is made, allowing players to predict the strategy of their rivals. How much of the game is determined by the mind rather than physical physique?

Watch the film below.

This article was created in partnership with Imagine Science Films. Watch all of the Field Work videos here.

Eggsellent

Picture of a chicken.

Pier/Getty Images

Rising global temperatures pose a major risk to world food supplies. When it comes to chickens, geneticist Carl Schmidt is working to prepare the most-dined-upon North American breeds to withstand greater heat stress in coming decades.

As Lauren Rothman reports for Modern Farmer, Schmidt and his University of Delaware team are collaborating with researchers from Iowa and North Carolina state universities to decode the DNA of chicken breeds in Brazil and Uganda that have featherless heads and necks.

These birds find baldness a virtue, not a curse, because the adaptation “allows the south-of-the-equator poultry to throw off additional body heat and stay cool in their scorching native climes,” writes Rothman.

They are generally found in small backyard flocks, Schmidt tells Rothman, rather than industrial agriculture complexes, and “are under constant selection pressure” to survive intense heat and other environmental challenges, traits he and others are eager to see introduced to North American breeds:

Schmidt’s team’s work is part of a five-year, $4.7 million climate change grant from the National Institute of Food and Agriculture. Three years into the project, the geneticists have gathered just about all the data they’ll need and will spend the next two years analyzing it: mapping the birds’ gene sequences in order to determine the best approach for getting those good, heat-resistant genes into American chickens without taking along all the genetic “baggage,” as Schmidt calls it, that’s unnecessary to duplicate in the hybrid chickens.

Once Schmidt and his colleagues have deciphered and analyzed the genetic codes of these hardy African and South American poultry, they hope American producers will crossbreed them to North American birds. It could take around 10 generations of chickens, carefully bred, to arrive at new heat-resistant breeds that can successfully reproduce on their own.

Poultry production is booming worldwide, as Rothman reports, with global food experts projecting that it will top 100 million tons in 2015, and 143 million tons by 2030. An interruption in this supply could cause a humanitarian disaster.

“My concern is feeding nine billion people in 2050,” Schmidt said. “That’s going to be a challenge. And it’s going to be made worse if the climate does continue to change.”

Click here to read the full article.

Video Editing the Old-Fashioned Way

Goram, CC BY-SA 3.0

Who needs to see two entire minutes of your kid playing with an iPad, anyway? Computer science doctoral student Bin Zhao claims he never even watches his own recordings. "I have a lot of videos on my phone, but the reality is that I almost never look back to those videos," he tells Popular Science. "The main reason is that the video itself might be five or 10 minutes long."

Zhao and his advisor, Eric P. Xing of Carnegie Mellon University, have come up with an interesting solution to this problem. They've created an algorithm that recognizes the boring parts of videos and edits them out. The final product is like a little highlight reel. Users can even specify the length of reel they want—say, 30 seconds. Much more digestible. "Our motivation is that people don't want to look at the original video," Zhao says.

Zhao and Xing aren't the first computer scientists to try to automatically recognize the interesting or important parts in a video. Many researchers and companies are working to make software that spots unusual activity in surveillance videos while it's happening. At least one company says it sells a system that can do this, but research is ongoing. An important-scene-recognizing program could also be a boon for social media companies: Imagine being able to make condensed, snappy videos to share with your Internet friends.

The new algorithm works by creating a "dictionary" to explain what it sees as it processes a video. Then, at every moment, it asks itself, "Can I explain what's happening now with my dictionary?" If the answer is no, that's an indication something new and exciting is happening in the video, so the algorithm makes note of that. The algorithm doesn't need to see the whole video before it starts putting together its highlight reel. That, along with coding techniques Zhao and Xing used, helps the algorithm work faster.

Zhao says his new algorithm is unusually fast and human-like in what scenes it decides to excerpt. It processes a one-hour video in one to two hours, versus the 10 to 20 hours similar algorithms published in the scientific literature require. To test whether the algorithm chooses "interesting" scenes like a person would, Zhao and Xing asked three people to watch videos and choose segments to highlight from the videos. The computer scientists then checked how closely the human and algorithmic choices matched. For 18 out of 20 personal videos, Zhao and Xing's algorithm made more human-like choices than the three other competing algorithms they tested. The pair also checked five security-type videos, showing situations such as people entering a subway station. They found their algorithm, plus one other, outperformed the rest. Zhao is presenting their results this week at a conference hosted by the Institute of Electrical and Electronics Engineers.

Zhao now plans to launch a startup, PanOptus, to commercialize his software. A PanOptus iPhone app and API are in the works.

Check out the algorithm at work on a video of Xing's son:

Abstract salad

Wassily Kandinsky's Painting No. 201 on the left, and a salad arranged to resemble it, on the right.

University of Oxford

The short answer: it made a big difference. The scientists presented 60 dinners with three different salads: one that resembled Wassily Kandinsky's Painting No. 201, one in which vegetables were lined up in neat rows, and another was arranged in a normal salad-heap. Diners rated the Kandinsky salad as 18 percent better than the other two, and they said they'd be willing to pay twice as much for it--before and after tasting it. 

As the scientists write in the study, which was published this month in the journal Flavour:

Besides presentation and design, many other factors can affect the perceived taste of food, such as color, the language used to describe it, and even the utensils one uses.

Non-Kandinsky Salads

The regular salad on the left, the "neat" salad on the right. All salads contained the same ingredients, but diners strongly preferred the "Kandinsky" salad.

University of Oxford

Credit: Andy Soth/QUEST Wisconsin

Why is a Wisconsin scientist using science fiction-like stories to talk about global warming?

According to Quest, the public broadcasting science series, the goal of “Yahara 2070” is to get local communities in the Yahara watershed, a 386 square-mile (1,000 square-kilometer) area surrounding Madison, into constructive discussions about adapting to the effects of climate disruption.

Rather than do it solely via the usual high-level scientific lingo, however, limnologist (fresh water scientist) Steve Carpenter worked with a writer and an illustrator to create four human-scale visions of the region's future, based on the best current scientific data and trends, as well as interviews and workshops with people living in the watershed.

Each story features characters whose thoughts and experiences frame the conditions projected in the scenario.

Wild Wisconsin

“Felix heard a loud rustle on the shoreline that startled him into alertness. Cougars are known to stalk these shores, and even though he knew the odds that one would bother to jump in after him were miniscule, he couldn’t help but feel a sense of dread as he eyed the distance between himself and the pier, where his machete lay. Then, a trumpet-like noise bellowed from the trees, and the mammoth head of an elephant emerged. Phew, thought Felix. Just an elephant.”

Copy, Jenny Siefert. Illustration, John Miller

• In the most apocalyptic vision, the “Abandonment and Renewal” scenario, dramatic temperature increases push unprepared local communities and regional government over the edge, leading to mass evacuations. The Yahara watershed re-wilds, “including animals, like elephants, who have escaped the local zoo,” and people begin to re-populate the region and create a new, low-tech way of life.
• “Accelerated Innovation,” the most utopic scenario, envisions the region using technology to adapt to changing climate conditions in time to avoid disaster, with “motherless” lab-grown meat replacing environmentally destructive animal agriculture-as-usual.

The two additional scenarios explore other community and political transformations, such as redrawing local government boundaries to align with local watersheds, the better to manage drought and water scarcity.

This project is fascinating. It's easy to imagine this approach creating constructive discussions on community resilience all over the United States. Click here to watch and read the whole thing.

Click here for more Popular Science coverage on the future of energy and other resources.

Adélie penguins

The species is found only in Antarctica.

PLOS Biology via Wikimedia Commons

Planetary temperatures warmed up naturally thousands of years ago, at the end of the last Ice Age. Some Antarctic penguin populations flourished under the changes. 11,000 years later, however, some Adélie and chinstrap colonies are turning from winners into losers: As temperatures around the western Antarctic Peninsula increase at some of the fastest rates on Earth, their population numbers are falling quickly, while gentoo penguins appear to holding their own.

What's the difference between then and now?

Looking the past to learn more about how different species might fare under today's anthropogenic climate change, researcher Gemma Clucas of the University of Southhampton, U.K., and her team collected samples of feathers and blood from 537 individual Adélie, chinstrap, and gentoo penguins, which live and breed near each other on the Antarctic Peninsula, and sequenced DNA from the samples.

By calculating the rate of genetic diversification revealed in the DNA, Clucas and her team were able to project how the different species' populations changed over time, and draw some tentative conclusions about why. Their findings are published in the June 12, 2014 edition of the open-access journal Scientific Reports.

Their findings suggest that while a certain absence of ice is important to improving the welfare of penguins, too little can tip things against them.

During the last Ice Age, the amount of ice covering land and water around the Antarctic Peninsula limited the growth of these penguin populations, because all three species need access to the sea to feed, and ice-free land for breeding. When snow and ice cover on both water and land decreased, the penguins were able to get at increased amounts of krill, minute shrimp which feed on algae growing beneath the ice. There was also more ice-free land available for nesting and raising chicks. Gentoo, chinstrap, and Adélie penguins all appear to have flourished for thousands of years under these conditions.

But with sea-ice further melting over the last half-century, krill habitat has also decreased. Most colonies of chinstraps and Adélie, which have krill-heavy diets, are losing numbers fast, while gentoo penguins, which eat a wider array of fish and squid in addition to krill, seem to be showing greater resilience to the shifting environment. Clucas and her colleagues think the more varied diet is a key:

This ‘reversal of fortunes’ for two former climate change ‘winners’ has resulted from anthropogenic impacts outside the range of natural variation that has occurred in the past. Rapid warming trends in the Antarctic Peninsula over the past 50 years has led to decreased sea ice, loss of winter habitat, and a reduction in krill stocks that is negatively affecting Adélie and chinstrap penguins, but not gentoo penguins5, 18, which apparently are not as reliant on krill17. While we know of no other examples of ‘reversal in fortunes’ as documented here, we expect many more will be identified as global warming proceeds and biodiversity declines.

The researchers don't want the findings to be taken as a sign that global warming is nothing to worry about, however. Says one report co-author in a statement, "We are not saying that today's warming climate is good for penguins. In fact, the current decline of some penguin species suggests that the warming climate has gone too far for most penguins."

Albino Lab Mouse

Wikimedia Commons

By feeding mice a genetically modified version of E. coli, a bacterium that naturally lives in human and mice guts, scientists were able to prevent the animals from gaining as much weight as mice not given the treatment. The microbes were designed to express a substance called NAPE (or N-acylphosphatidylethanolamine), which the bodies of mice and humans convert into a hormone produced when food is digested. This hormone then moves through the bloodstream to the brain, and reduces appetite. The idea is that mice with this new bug in their guts thought they were eating more than they were, without any apparent ill effects.

In the study, published in The Journal of Clinical Investigation, mice given the microbe and un-dosed animals were both put on a high-fat diet. The animals given the bacteria (in their drinking water) ate less and gained less weight, and also showed less insulin resistance, a marker for diabetes. 

The finding raises the possibility that these bacteria, which basically amount to an engineered probiotic, could be imported into humans to do the same thing. That's obviously a ways off and hypothetical at this point, since mice are not humans.

However, if the microbe could be safely used in humans, it would have several advantages of current treatments for obesity--which isn't a very high bar, to be fair, given the failure of many recent anti-obesity drugs. The bacteria appear to last in the gut for about four weeks, a long period of time between interventions that would trump taking a pill everyday, for example. The fact that E. coli naturally live in the gut is also an advantage over other probiotics, which often do not colonize the human intestines well. 

[Forbes]

Aereo Antenna Array

Aereo

Yesterday, in a 6-3 decision by the Supreme Court in ABC v. Aereo, the government ruled that Aereo's streaming of cable TV over the web is illegal. In the process, the Supreme Court majority showed its confusion over how the internet works—and technology in general—and put forth a strange interpretation of the term "public performance."

Here's how Aereo works (or worked, rather): A subscriber with an internet connection wants to watch a live television show. Rather than paying separately for TV service or even owning a digital TV antenna, however, the customer instead watches the show from a remote antenna that Aereo rents to them. That antenna streams the TV show, as freely broadcast over the air, to the Aereo subscriber via the internet. Aereo also offers the option to digitally record video of a broadcast to its server farm for future viewing (and stream that content, too). Many cable TV subscriptions provide a physical digital video recorder for viewers to save shows; Aereo does this on equipment in a warehouse that is controlled, in part, by each of its subscribers.

The case essentially came down to whether or not this streaming of broadcasts by Aereo counts as a distinct "performance," and if that infringes on the rights of broadcasters to exclusively air content. Here's the SCOTUS majority opinion on the matter, in case you speak legalese:

Does Aereo “perform”? See §106(4) (“[T]he owner of [a] copyright . . . has the exclusive righ[t] . . . to perform the copyrighted work publicly” (emphasis added)); §101 (“To perform . . . a work ‘publicly’ means [among other things] to transmit . . . a performance . . . of the work . . . to the public . . . ” (emphasis added)). Phrased another way, does Aereo “transmit . . . a performance” when a subscriber watches a show using Aereo’s system, or is it only the subscriber who transmits? In Aereo’s view, it does not perform. It does no more than supply equipment that “emulate[s] the operation of a home antenna and [digital video recorder (DVR)].” Brief for Respondent 41. Like a home antenna and DVR, Aereo’s equipment simply responds to its subscribers’ directives. So it is only the subscribers who “perform” when they use Aereo’s equipment to stream television programs to themselves.

After this part, the ruling gets weird. It looks back in time, which is a standard for a practice based on precedent, but the justices chose to highlight pieces of the past that are, well, strange.

One was Community Access TV (CATV), a cable precursor that Popular Sciencewrote about in 1970. Like Aereo, CATV allowed home viewers to watch broadcast channels, yet with higher fidelity than broadcast. Yet CATV (again, similar to Aereo) suffered a blow that changed how the law saw the service it provided; a 1976 law subjected cable companies to copyright laws in a similar way to over-the-air broadcasters.

To rule as it did on Aereo, the Supreme Court overlooked 40-some years of technological advancement since early cable television and said that, because Aereo functions somewhat like a cable company, it is one. And this is where it comes down to a definition of performance.

Copyright is big on regulating performance. It's a reason companies pay billions of dollars for exclusive rights to air rare events, like the Olympics. NBC broadcasting the Olympics is, in the eye of the law, a performance by NBC. Aereo, however, makes no content selection—its subscribers do that.

In other words: When the law defined "performance," its definition hinged on networks selecting the content they broadcast, not subscribers. And that is a major distinction from the CATV precedent, where the Court ruled that the CATV network selected programing and sent it out continuously. The ruling by Justice Stephen Breyer in ABC v. Aereo argues that emphasizing this difference "makes too much out of too little."

A Large Aereo Array

Aereo

While the Supreme Court decision ruled against Aereo by treating it like a cable company (and, in a weirder later metaphor, like a car dealership instead of a valet), the dissenting opinion better grasps how the technology works.

Justice Antonin Scalia, joined by Justices Clarence Thomas and Samuel Alito, instead dispute the definition of "performance." If a future case succeeds where Aereo failed, it will likely cite this dissent when it does.

Rather than seeing Aereo as just another cable company, and one that doesn't pay for the rights to what it broadcasts, Scalia sees Aereo more in line with the technology that enables it, i.e. as an internet provider. The violation, in this line of thinking, comes not from the company that collects broadcasts, but rather hinges on the consumers. They're the ones who use the technology and choose to watch broadcasts they haven't otherwise paid for.

Scalia writes:

Internet-service providers are a prime example. When one user sends data to another, the provider’s equipment facilitates the transfer automatically. Does that mean that the provider is directly liable when the transmission happens to result in the “reproduc[tion],”§106(1), of a copyrighted work? It does not. The provider’s system is “totally indifferent to the material’s content,” whereas courts require “some aspect of volition”directed at the copyrighted material before direct liability may be imposed.

He continues, likening the copying function of recorded and stored broadcasts to that of a copy shop:

A comparison between copy shops and video-on-demand services illustrates the point. A copy shop rents out photocopiers on a per-use basis. One customer might copy his 10-year-old’s drawings—a perfectly lawful thing to do—while another might duplicate a famous artist’s copyrighted photographs—a use clearly prohibited by §106(1). Either way, the customer chooses the content and activates the copying function; the photocopier does nothing except in response to the customer’s commands. Because the shop plays no role in selecting the content, it cannot be held directly liable when a customer makes an infringing copy. See CoStar, supra, at 550

In published response to the court decision, Aereo CEO and Founder Chet Kanojia emphasizes the Scalia dissent:

“Justice Scalia’s dissent gets it right. He calls out the majority’s opinion as ‘built on the shakiest of foundations.’ (Dissent, page 7) Justice Scalia goes on to say that ‘The Court vows that its ruling will not affect cloud-storage providers and cable television systems, see ante, at 16-17, but it cannot deliver on that promise given the imprecision of its results-driven rule.’ (Dissent, page 11)”

The dissenting SCOTUS view on this case aside, Aereo and other companies must now live with the majority view. The Electronic Frontier Foundation highlights the danger the ruling poses to other technology companies:

"With this ruling, the Supreme Court said that technology companies can't rely on the words of the Copyright Act—companies can follow the letter of the law but still get shut down if a court decides that their business is somehow similar to a cable company," said EFF Staff Attorney Mitch Stoltz. "This decision will make it harder for new independent media technologies to get launched and funded without the blessing of major media companies, and that's a loss for all of us."

The Supreme Court's ruling on Aereo, in effect, protects the broadcast rights of television and cable companies while denying future technologies the same leeway that made cable broadcasting possible in the first place. And, weirdly enough, it does it on behalf of ABC—a company that still broadcasts freely over the air.

Illustration by Jason Schneider

Taken as a whole, a cooked cadaver would yield about 81,500 calories’ worth of food, says James Cole, a lecturer on human origins at the University of Brighton in England. But that’s only if you wolfed down every part that could be consumed. To create his “nutritional template” for cannibalism, Cole used body-composition data published in the 1940s and ’50s, drawn from four dead males between the ages of 35 and 65. From these he built something like a beef chart for human beings, with caloric content listed for every cut of person-meat.

A human arm would supply about 1,800 calories, for example, while each leg would yield 7,150 calories.

Cole determined that a human arm would supply about 1,800 calories, for example, while each leg would yield 7,150 calories. The lungs, liver, and alimentary canal each provide roughly 1,500 calories, while the brain, spinal cord, and nerve trunks together account for 2,700. And what lurks in the hearts of men? Seven hundred twenty-two calories, Cole says.

Archaeologists might use the nutritional template to help settle some tricky research questions. We know that some groups of early hominins engaged in cannibalistic behavior, but it’s hard to know whether they did so for ritual and social reasons (so-called cultural cannibalism) or as an occasional source of nutrients (gastronomic cannibalism). In a cave site east of Burgos, Spain, where Homo antecessor lived one million years ago, researchers have found cut-marks on hominin bones that suggest the latter. The marks look identical to those found on the bones of animals consumed as food. Cole hopes that his work could further help distinguish these behaviors. For example, researchers might check to see if H. antecessor’s cut-marks deliberately targeted the most nutritious body parts.

The 81,500 calories in a human body may sound like a lot, but it’s paltry next to what’s found in bigger animals. A horse contains more than 200,000 calories, and a bear three times that much. And that’s just from their most appetizing parts. It’s also worth considering that about half the calories in human meat come from adipose tissue. Consuming so much fat might pose problems of its own. “I’m not a nutritionist,” says Cole, “but I would imagine that it would not be very healthy.”

This article originally appeared in the July 2014 issue of Popular Science.

Books!

Greg Friedler/Getty Images

When it comes to books, those in Russian and Chinese have the narrowest range of emotion, while books in English have the greatest. Even more emotionally wide-ranging than English books are Portuguese and Spanish tweets, and music lyrics in English. All these insights and more come from a big, new study of 10 diverse languages: English, French, German, Spanish, Chinese, Korean, Arabic, Indonesian, Russian and Brazilian Portuguese. In part, the researchers in charge of the project wanted to test whether human languages tend to be positive or negative. Languages are positive! they found… while finding plenty of other cool stuff, too.

How was a team of American engineers able to rate the emotions of world languages? For one thing, they used a lot of automation. The team used an algorithm to analyze different kinds of writing, including website text, books, tweets, TV subtitles and the New York Times (English only). The algorithm gave the researchers the 5,000 to 10,000 most commonly used words in each language and each body of writing. Then, the team paid native speakers to rate how positive each of those words were on a 10-point scale. Those measurements gave the research team an overall measurement of the "positivity" of different languages.

All the languages and writings they studied skewed more positive than neutral. None skewed negative. Nevertheless, some were more positive than others. Spanish Twitter is among the cheeriest, for example, while Chinese books are the closest to neutral.

There are many more gems to find in the paper the team wrote and posted to the paper-database arXiv. There's a whole section in which the researchers analyzed the positivity in different parts of classic novels, such as Moby Dick, Anna Karenina and The Count of Monte Cristo. The Physics arXiv Blog, which first turned us onto this cool study, has more about the book analysis. Here's one strange thing I learned from the paper: "kkkkkkkkkkkkkkkkkkkkk" represents laughter in Brazilian Portuguese. As a word, it obviously scores high on Brazilian Portuguese speakers' positivity scale. I found it curiouser that it was pretty frequently used on Twitter, and at that length, too. Who can afford all those characters?

[Physics arXiv Blog, arXiv]

ReWalk Users in London

Courtesy of Argo Medical Technologies

A motorized exoskeleton, designed to help paralyzed people walk again, just earned U.S. Food and Drug Administration approval. It is the first such device to do so.

The device, called ReWalk, straps on user's bodies and helps those with certain spinal-cord injuries to sit, stand, and walk. Users have to wear a backpack to carry the ReWalk's computer and battery. They also have to wear a wrist device with buttons to tell the motorized legs when to stand up, sit down, or start walking. But it's not like users are punching every step into their wrist controllers--ReWalk legs also respond to movements of the user's torso, so that leaning forward triggers a step. (Popular Science gave the device an Invention Award in 2009 and a Best of What's New award in 2011.)

The new FDA approval means ReWalk's maker, Argo Medical Technologies, or Argo, can now market its products in the U.S. Over the past few years, Argo and other companies that make similar products have tested their exoskeletons on people. Argo has previously sold ReWalk devices to rehabilitation centers in the U.S. but the FDA approval marks the start of sales of ReWalk devices to Americans for private use. Each device will likely cost $65,000 to $68,000, the Telegramreported in March.

The FDA's announcement about ReWalk details what it is—and isn't—cleared for. It's approved for specific spinal cord injuries, but it's not recommended for people with other severe neurological injuries. The FDA also says users should undergo training before strapping the ReWalk on, and so should a helper for the user—maybe a spouse or a home health aide. Interestingly, the announcement also says the device isn't for climbing stairs. This is a departure from some earlier news reports about the ReWalk, which showed users going up stairs in the exoskeleton.

A ReWalk Demonstration

Israeli Prime Minister Benjamin Netanyahu and U.S. President Barak Obama watch a ReWalk Demonstration in March 2013.

Courtesy of Argo Medical Technologies

Once Argo starts selling ReWalks, it will have to gather data about problems with the device that crop up and submit that data to the FDA.

The agency reviewed a few studies of the device before offering its approval. The studies included 30 volunteers altogether and assessed how far users could walk using the ReWalk and how they fared in crowded places and on uneven surfaces. In one study of 12 volunteers, all were able to walk 50 to 100 meters without help. Some reported they had an easier time going to the bathroom afterward. The FDA announcement didn't specify who ran these studies, but normally, they're paid for by companies themselves.

So, ReWalk is the first company to get FDA approval for its walking exoskeleton. Now a few companies and academic research teams that are working on similar products may soon follow. In the more distant future, companies may advance enough to try with the next generation of exoskeletons--ones that are controlled by people's thoughts, instead of by tilts of the torso or buttons on a wristband. 

Good news--there is much less nitrogen dioxide in the air over the United States than there was a decade ago, as can be seen in this remarkable animated satellite image. The images were produced by data collected by the Ozone Monitoring Instrument on NASA's Aura satellite and you can clearly see how much the levels of this pollutant have decline from 2005 to 2011.

Nitrogen dioxide can cause respiratory problems by itself, besides also reacting with "ammonia, moisture, and other compounds to form small particles," or particulates, that can worsen emphysema and other lung ailments, the EPA noted. The gas also contributes to the formation of ozone, which is an irritant and pollutant at ground level. NASA credits the improvement in air quality to improved fuel efficiency in cars and "technology to reduce emissions of nitrogen dioxide and sulfur dioxide from coal-fired power plants." Generally, levels of nitrogen (and sulfur) dioxide began declining soon after enactment of the 1990 Clean Air Act Amendments, and have continued to fall. Overall, levels of nitrogen dioxide have declined by more than 50 percent since 2000, according to the EPA.

Of course, air quality isn't perfect, and could get better. "While our air quality has certainly improved over the last few decades, there is still work to do--ozone and particulate matter are still problems," NASA atmospheric scientist Bryan Duncan said. And about 142 million people still live in areas in the United States with unhealthy levels of air pollution, NASA noted.

New York air pollution

There has been a 32 percent decrease in nitrogen dioxide in New York City between the 2005-2007 (left) and 2009-2011 (right) periods.

NASA Goddard's Scientific Visualization Studio/T. Schindler

New shrew

The newfound elephant shrew, Macroscelides micus.

Dumbacher et al / Journal of Mammology

They also have some other bizarre features--they typically give birth to twins "which hit the ground running like the calves of some types of African antelope," Reuters reported:

The scientists have named the animal Macroscelides micus. Adults measure seven inches long, including the tail, and weigh only 27 grams, about the weight of two tablespoons of sugar. And what sweet shrews they are.

A study describing the creatures was published in the Journal of Mammalogy. 

[Reuters]

Here's a roundup of the week's top drone news, designed to capture the military, commercial, non-profit, and recreational applications of unmanned aircraft.

Spy From The Past

Paleofuture recently unearthed a police drone -- from 1976. The Westland Wisp was a prototype surveillance drone designed for police work. Foreshadowing future drones, it could transmit regular video (and maybe infrared) images back to a control station. After the Wisp, Westland made two more drone helicopters, the Wideye and the Sharpeye.

The Westland Wisp

Don't mind me, just carrying around a flying police state here.

Associated Press

A Possible Private Privacy Violation

Long rumored, it appears the feared arrival of a "peeping Tom with a drone" finally happened this week. In Seattle, a woman called police after seeing a drone hovering outside her window. 

Update: It appears that while the drone was outside the window, its purpose was not capturing lewd photographs. Instead, the drone company was apparently trying to capture an aerial panoramic view for a developer.

Following Filmographer

Hexo+ is a drone that carries a camera and automatically follows a specified person. Currently a crazily well-funded project on kickstarter, the drone can fly at about 45 mph for 15 minutes. Set up with a smartphone app, the drone then follows and films a person with an attached camera. The end result? Awesome video footage of one's jogging, and one annoying flying machine closer to a future of robot smog.

Watch a video about it below:

New FAA Rules For Tiny Drones

We're living in a weird pre-regulatory limbo of drones before drone law. Particularly challenged for the Federal Aviation Administration are small drones and model airplanes, which until the past decade were largely indistinguishable. The FAA wants to keep model airplane hobbyists happy at the same time they tightly restrict all commercial uses of drones. This challenge is inherent in new guidelines the FAA put out this week for model airplane use. 

FAA Model Airplane Guidelines Detail

FAA

The most obvious impact of these rules are on drone delivery services, a common drone gimmick. More revealing is the first row, which says it's okay to have model airplane clubs but not okay for those clubs to have contests with cash prizes. It's good that the FAA is trying to regulate drones, but attempts like this to distinguish between hobbyist model airplanes and small drones have unintended consequences for both communities.

A Predator Drone Waits At Balad Air Base, Iraq. 2004

U.S. Air Force photo by Tech. Sgt. Scott Reed, via Wikimedia Commons

Back To Baghdad

The United States revealed this week that, as part of their renewed presence in Iraq, they are flying armed Predator drones as part of reconnaissance efforts there. The drones are flying from bases in Kuwait, according to the Pentagon.

In related news, Stimson Center, a DC think tank, released an in-depth study of the role of drones and targeted killing. The report, co-authored by retired Army general John P. Abizaid and defense analyst Rosa Brooks, calls into question several of the myths concerning drones at war. Perhaps the biggest finding is that we don't even know if drone strikes are working towards any strategic goals. The report states:

In recent years, US targeted strikes involving UAVs have gone from a relative rarity to a relatively common practice in Pakistan and Yemen. As the number of strikes increases, so, too, does the strategic risk. To the best of our knowledge, however, the US executive branch has yet to engage in a serious cost-benefit analysis of targeted UAV strikes as a routine counterterrorism tool. 

Did I miss any drone news? Email me at kelsey.d.atherton@gmail.com.

FOX Float Fit iCTD

Photograph by Jonathon Kambouris

Mountain bikers need suspensions with dual personalities: Barreling downhill, they want a soft suspension to absorb bumps; chugging uphill, they want stiff shocks so that their energy transfers to forward motion, not bobbing up and down. Finding that balance usually requires riders to make several manual adjustments. The Float Fit iCTD electronic suspension from California company Fox lets them make changes in half a second.

Bikers initiate a shift by rotating a switch on the handlebars. That signals two motors, one on the frame-mounted shock and one on the fork, to turn oil-regulating valves, which restrict or free internal pistons. The system is just five ounces heavier than a manual one, so there’s not a lot of extra heft to lug uphill. Fox will debut iCTD on mountain bikes from Yeti, Scott, and others next year. Riders can also retrofit it onto almost any model, so no one has to get roughed up—or lose steam—on the trail again.

FOX Float Fit iCTD

Shock travel: up to 140mm

Price:$2,000 (shocks only), $7,600 (on Yeti bike, as shown)

In Related News: Upside-Down Shocks

SRAM RockShox RS-1

Photograph by Jonathon Kambouris

At first glance, something may seem a little off about the new SRAM RockShox RS-1: It’s inverted. Unlike most bike suspension forks, the thinner piston sits underneath the fatter structural stanchion. The arrangement, standard on motor­cycles, keeps the piston bathed in oil, which helps the suspension respond better to small bumps. To compensate for the rigidity lost by moving the stanchion away from the axle, SRAM engineers developed a aluminum double axle, which stiffens the ride.

Price:$1,865

This article originally appeared in the July 2014 issue of Popular Science.

Detail Of Small Arms Of WWI Collaborative Project

Detail from the larger image. At the center is the Colt/Browning Model 1895 machine gun, used by the Dominion of Canada and the Kingdom of Belgium in World War I.

C&Rsenal

113: the number of hand-held weapons used World War I and catalogued by this crowd-sourced project. The project is incomplete, so you can add arms if you know of them.

60 percent: reduction in levels of the air pollutant nitrogen dioxide in the U.S. since 1980. The U.S. Environmental Protection Agency credits the reduction to improvements in car fuel efficiency and coal-plant technology.

$65,000 to $68,000: estimated cost of a ReWalk exoskeleton in the U.S. ReWalk devices help people with spinal-cord injuries to sit, stand and walk independently. ReWalk's maker, Argo Medical Technologies, recently received U.S. Food and Drug Administration approval to market the device in the U.S.

ReWalk Users in London

Courtesy of Argo Medical Technologies

$2,000: cost of the materials for this DIY pressurized spacesuit. Pressurized spacesuits typically cost upwards of $30,000.

DIY pressure suit

Courtesy Jev Olsen/Copenhagen Suborbitals

$142: the cost of administering one dose of contraception to a wild female elephant. Although elephant populations are still considered vulnerable worldwide, in certain regions, they've made strong comebacks. Park rangers give elephants birth control in regions where they've become too populous for the reserves in which they live.

22,000: estimated number of African elephants killed illegally in 2013.

Fruzsina Eördögh

20 seconds: how long weightlessness lasts at the top of each parabola in a zero-gravity flight.

32: the number of parabolic zero-gravity flights Popular Science assistant editor Rose Pastore took while reporting for this story. She took the flights to observe a team of Stanford University students, who were testing whether their heart imaging system would work in zero gravity. It did. Pastore reports she did not throw up.

A Boeing 727 during a parabolic flight

NASA

81,500: calories in an adult male human body. Yes, we mean if you ate one.

200,000: calories in a horse.

600,000: calories in a bear.

Robot Makes a Design with Blocks

U of Washington

In a new study, computer scientists wrote algorithms for robots to arrange blocks into designs that a human would recognize as a car, a turtle, a house, and other things. But the designs weren't programmed in. Instead, the robots learned from in-person (in-robot?) demonstrations... plus asking questions on a crowd-sourcing website called Mechanical Turk.

The combination of in-person and online, crowd-sourced learning helped robots learn tasks better than in-person demos alone, the researchers found. In addition, the crowd-sourced robot-tutoring was cheaper than hiring the same number of people to demonstrate for the robot. The researchers think that in the far future, crowd-sourcing could help robots learn useful tasks such as setting tables for meals, or loading the dishwasher. (I mean, I wish, right?)

The scientists, a team from the University of Washington, equipped their own Gambit robot with a Kinect depth sensor to help it sense the colors and locations of blocks on a table. Gambits are arms with pincer hands, so they're able to grasp objects. They're even able to move chess pieces around a board. The programmers also tried their algorithm on a Willow Garage PR2 robot, about which Popular Science has written extensively.

The robots first got demonstrations of block flowers, fish, snakes, and other things from 14 volunteers in lab. Often, these designs were too difficult for the robots to reproduce. So they also posted questions on Mechanical Turk: How would you make a car (or a person, or a baby bird) with these blocks? As the robots gathered data from hundreds of responses, they began to learn how to make something that a human would register as a "car," but still would be feasible for them to build. The robots also learned to recognize block patterns as one of the eight things they had learned about, even when some pieces were missing.

Crowd-Sourced Turtle Designs

U of Washington

All of this is pretty cool, and pretty impressive. You can learn more from a paper the researchers posted online about their work. One bonus: The paper includes pictures of the responses from Mechanical Turkers. It appears some Mechanical Turk users are surprisingly clever at turning a couple dozen blocks into convincing turtles and people. Others are surprisingly bad at the task. Luckily, the University of Washington algorithm had a way of weeding out the poor designs. It asked Mechanical Turkers to rate each others' designs, so it knew which ones were good turtles and which ones were bad ones.

The researchers presented the results of their work earlier this month, at a robotics conference hosted by the Institute of Electrical and Electronics Engineers.

Crowd-Sourced Person Designs

U of Washington

The production tax credit for renewable energy expired—most recently—at the end of 2013, and it’s unclear if Congress will renew it again. The program gives wind farms 2.3 cents for every kilowatt-hour of renewable energy they pump into the U.S. grid. Since it was enacted in 1992, the incentive has driven a sevenfold increase in the number of U.S. turbines. “Wind has grown so much that it’s approaching hydroelectric in scale,” says Gwen Bredehoeft, an analyst with the U.S. Energy Information Administration. Without the tax credit, Bredehoeft says, new turbine construction will probably stall until at least 2030, when the country will need more energy generation. Until then, this is the American wind-energy landscape. 

Katie Peek

Left: Total U.S. Wind-Energy Capacity In Gigawatts. When a renewable-energy tax credit was in place [represented by diagonal lines], energy companies raced to build new turbines. Each time the credit expired [yellow columns], construction—and hence capacity—flattened out. Right: U.S. Wind Turbines By Type.

Katie Peek

This article originally appeared in the July 2014 issue of Popular Science.