popular science usa - september 2013

boards and eight types of sensors. Recently, Quin persuaded his parents

to let him convert the family garage into a hackerspace where he and his friends could work on projects together. Now devoid of automobiles, it contains a long workbench littered with safety goggles, soldering irons, and a $30 toaster oven that Quin uses to manufacture circuit boards. Nearby, a stack of plastic drawers holds wires, LED lights, and other parts. Quin also uses the space to teach monthly workshops on such topics as how to hack a Wii Nunchuk game controller so that it interfaces with the Google Earth fl ight simulator. In the spring, he returned to Maker Fairethis time, as a featured speaker.

E VERYONE WHO has met Quin agrees that, both technically and personally, he stands out. Quin is extremely over-the-top self-moti-vated and driven, says Tara Tiger Brown, executive director of LA Makerspace. Quins biography on Twitter sums this up as well: Im a 12-year-old maker that loves Arduino and electronics. I run my own electronics company selling @ArduSensors and will be going to MIT in 7 years.

But Quin embodies a groundswell of preteen inven-tors enabled by cheap hardware, free soft ware, and the proliferation of hackerspaces around the countrysome, such as Maker Kids in Toronto and LA Maker-

50 / POPUL AR SCIENCE / SEPTEMBER 2013

space in California, designed with young hackers in mind. Hes a bellwether for a whole generation of kids, many who havent even been identifi ed yet, says Jeff Branson, SparkFuns educational outreach coor-dinator. Were seeing more and more kids like Quin getting together and teaching each other.

Another young maker at the forefront of this trend, Super-Awesome Sylvia (Sylvia Todd, age 12), has a YouTube show that has more than 1.5 million views. In recent episodes, she taught her audience how to build squishy circuits with LEDs and a heart-beat-sensor pendant using LilyPad, an Arduino micro-controller board designed for textiles. At the White House Science Fair in April, she showed President Obama her WaterColorBot, a robot that paints.

Both SparkFun and Adafruit Industries, another DIY-electronics retailer, have expanded their educa-tion teams to reach the next Quin and Sylvia where they study or play. There is a worldwide demand from young people to learn more, share more, and become the next generation of scientists and engineers, says Limor Fried, Adafruits founder. To encourage them, Adafruit now makes skill badgesa geeky nod to traditional Boy Scout and Girl Scout merit badgesawarding profi ciency in areas such as soldering, programming, and successfully using Ohms law.

Inspired by Adafruits badges, a nonprofi t organi-zation called the Hacker Scouts formed in Oakland, California, in 2012. It promotes a network of guilds (rather than troops) designed to teach and mentor children ages 8 to 15. New hackerlings master basic skills, such as sewing, woodworking, and simple use of the Linux operating system, and then work in crews on more complicated projects. The guilds have spread to 11 cities in the U.S. Another national organization, Maker Corps, has begun training 18- to 22-year-olds to become mentors to kids and young teenagers both online and in physical makerspaces.

FIRST, an organization started by inventor Dean

In an episode of Super-Awesome Mini Maker Show, Sylvia Todd [above] describes a coppertastic build for etching copper jewelry or circuit boards; it has nearly

300,000 views on YouTube. Sylvia started the series with her dad in 2010; she now has 20 episodes that feature entry-level, open-source projects for kids.

Quin acts and functions like both a grownup and a preadolescent male, Mike Hord, a design engineer at SparkFun Elec-tronics, observes.

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Kamen, has also rapidly expanded. It uses robotics programs to get students from kindergarten through high school excited about engineering. This year 2,546 teams from around the world competed in its fl agship event, the FIRST Robotics Competitiona 300 percent increase from 10 years ago, according to Kevin OConnor, a robotics engineer who helps design the annual challenge.

A 2011 study published in the journal Science Education showed that high-school seniors who express an interest in pursuing science, technology, engineering, and math (STEM) are three times more likely to complete college degrees in those subjects. The key to getting students to that tipping point, says lead author Adam Maltese, an assistant professor of science education at Indiana University, seems to be exposing them early to a STEM experience that sparks their interest, then providing them with a way to main-tain ita formula that Quin has already mapped out.

T HE DAY AFTER his Arduino class at Deezmaker, Quin climbs into the backseat of the family car. While his dad steers onto Highway 101 toward their home near San Luis Obispo, California, Quin digs into his back-pack and pulls out a Rubiks cube. He solves it in 16 seconds. Then he turns on his parents iPad and starts typing. He explains that hes been rethinking K12 educationand that he has come up with a much better system. He calls it the New Qtechknow School.

School is pretty boring, but it could be a lot more interesting and interactive, he says. More hands-on and more mentoring. According to his plan, three schoolsgrades K3, 48, and 912would sit side by side on one campus so that older students could mentor younger ones at least once a day. Quins been helping other students with math for several years. Its fun to teach other kids, and little kids look up to older kids, he says thoughtfully. It helped me learn

when I was young because it was fun. Plus, he points out, the older kids would get experience teaching, which would help them decide whether to pursue an education degree in college. Not surprisingly, the teachers at the New Qtechknow School would focus heavily on science and engineering.

In the meantime, Quin is making sure his current school system can provide more hands-on education. In March, he and his father visited Raynee Daley, the assistant superintendent of business services in his school district, and suggested that teachers use electronics kits in their classes. Daley didnt know anything about Arduino, but Quin impressed her with a demonstration of his FuzzBot and other projects. I knew this kid was absolutely brilliant, she says. And I believe that hands-on learning is critical.

Daley appealed to the superintendent, and he agreed to let Quin present to a broader group; more than a dozen principals and teachers showed up for his lunch-time electronics lesson. I looked around the room and saw everybody, except maybe the robotics guy, with their mouths open, amazed, Daley says. This fall, the school district will bring a SparkFun education team to train some of the teachers. By August 2014, when Quin will enroll as a freshman, Arroyo Grande High School hopes to have a DIY-electronics program. Quin has made us all think diff erently about what the future of education could be like, Daley says.

A couple hours into the car ride home, Quin is still typing on his iPad, tweaking his plan to overhaul the U.S. education system. But suddenly his dreams turn more immediate and visceral. He fi res up the browser and searches for the nearest In-N-Out Burger. Then he makes a plea identical to that of kids everywhere: Can I get two orders of French fries, Mom?

QUIN IS A BELLWETHER FOR A WHOLE GENERATION OF KIDS, MANY WHO HAVENT EVEN BEEN IDENTIFIED YET.

Quin experiments with an age-old form of DIY elec-tronics: licking a nine-volt battery to feel a shock.

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Go/Do/LearnTHE EDUCATION ISSUE


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he first massive open online course, or MOOC, launched in September 2008 at the University of Manitoba in Winnipeg. Via the

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The courses arent quite substitutes for traditional edu-cation; at Coursera, one of the largest MOOC providers, 80 percent of students already hold a bachelors degree, and only 10 percent finish the courses they start, according to co-founder Andrew Ng. But MOOCs can help students build the skills to become almost anythingor anybody.

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STORY BY JEFFERSON MOK

ILLUSTR ATION BY BEUTLER INK

The clusters represent the number of courses available through early 2014 at nine of the largest MOOC providers. Every course appears as a dot. The clusters for iTunes U and Udemywhere educators create their own classesinclude only their most popular courses.

S O U R C E S : C O D E C A D E M Y , C O U R S E R A , E D X , I T U N E S U , K H A N A C A D E M Y , O P E N 2 S T U D Y , S A Y L O R , U D A C I T Y , A N D U D E M Y .

Reaction Engines Skylon spacecraft would make short hauls into orbit, come back, and be ready to do it again two days later.


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A new type of engine could usher in an era of aff ordable spaceplanes Story by Nicole Dyer Illustration by Nick Kaloterakis

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A Y T O O R B I TA N D B A C K

at the Culham Science Center in Oxfordshire, England. When the engine screams to life, columns of steam billow from the vent, giving the impression of an industrial smokestack. Engineer Alan Bond sees something more futuristic. Were looking at a revolution in transportation, he says. For Bond, the engine represents the beginning of the worlds fi rst fully reusable spaceship, a new kind of craft that promises to do what no space-faring vehicle ever has: off er reliable, aff ordable, and regular round-trip access to low Earth orbit.

Bond and the engineers at Reaction Engines, the aerospace company he founded with two colleagues in 1989, refer to the future craft as the Skylon. The vehicle would have a fuselage reminiscent of the Concorde and take off like a conventional airliner, accelerate to Mach 5.2, and blast out of the atmosphere like a rocket. On the return trip, Skylon would touch down on the same runway it launched from.

Bonds Synergistic Air-Breathing Rocket Engine (Sabre)part chemical rocket, part jet enginewill make Skylon possible. Sabre has the unique ability to use oxygen in the air rather than from external liquid-oxygen tanks like those on the space shuttle. Strapped to a spacecraft, engines of this breed would eliminate the need for expendable boosters, which make launching people and things into space slow and expensive. The Skylon could be ready to head back to space within two days of landing, says Mark Hempsell, future-programs director at Reaction Engines. By comparison, the space shuttle, which required an external fuel tank and two rocket boosters, took about two months to turn around (due to damage incurred during launch and splashdown) and cost $100 million. Citing Skylons simplicity, Hempsell estimates a mission could cost as little as $10 million. That price would even undercut the $50 million sum that private spacefl ight company SpaceX plans to charge to launch cargo on its two-stage Falcon 9 rocket.

The engine produces incredible heat as it pushes toward space, and heat is a problem. Hot air is diffi cult to compress, and poor compression in the combustion chamber yields a weak and ineffi cient engine. Sabre must be able to cool that air quickly, before it gets to the turbocompressor. In November, Reaction Engines hit a critical milestone when it successfully tested the prototypes ability to inhale blistering-hot air and then fl ash-chill it without generating mission-ending frost. David Willetts, British minister for universities and science, called the achievement remarkable.

The Skylon concept has also impressed the European Space Agency (ESA), which audited Reaction Engines

designs last year and found no technical impediments to building the craft. The bigger challenge may be securing funding. While ESA and the British government have invested a combined $92 million in the project, Bond and his crew plan to turn to public and private investors for the remaining $3.6 billion necessary to complete the engine, which they say could be ready for fl ight tests in the next four years. Building the craft itself would require a much heftier investment: $14 billion.

THE QUEST FOR a single-stage-to-orbit spaceship, or SSTO, has bedeviled aerospace engineers for decades. Bonds own exploration of the topic began in the early 1980s, when he was a young engineer working with Rolls-Royce as part of a team tasked with developing a reusable spacecraft for British Aerospace. Thats when he came up with the idea of a hybrid engine. But the team struggled to fi gure out how to cool the engine at supersonic speeds without adding crippling amounts of weight. By the time the plane hits Mach 2 or so, the air becomes very hot and extremely diffi cult to compress, Bond says. Rolls-Royce and the British government, doubtful that an easy and economical solution existed, canceled the programs funding.

NASA and Lockheed Martin, meanwhile, had their own plans for a fully reusable spacecraft, the VentureStar, intended as an aff ordable replacement for the partially reusable space shuttle. The VentureStar demonstrator, called X-33 (which graced the cover of this magazine in 1996), was a squat, triangular rocket that would take off vertically and glide back to Earth just as the shuttle did. Eliminating the expendable rockets needed to boost the shuttle into space could theoretically reduce the cost of launches from $10,000 per pound to $1,000 per pound. But by 2001, after sinking more than $1 billion into the project, the agency pulled the plug, citing repeated technical setbacks and ballooning costs. We backed off because we felt it was better to focus our eff orts on other, less costly ways to get payloads to orbit, says Dan Dumbacher, NASAs deputy associate administrator for exploration systems development, who spent two years working on the X-33.

With the shuttle now retired, and companies such as SpaceX under contract to resupply the International Space Station (ISS), NASA has doubled down on expendable boosters as a means of sending humans and probes well beyond Earths orbit. NASAs new platform for deep-space exploration, the Space Launch System, will be the most powerful rocket ever built. The agencys focus on space exploration, and the need for big rockets to achieve it, means NASA no longer needs to build its own platforms just to get cargo into orbit. From a pure technical perspective, wed all love to go do SSTO, Dumbacher says. But were focused on making sure we get humans farther into space, and thats an expensive proposition.

Expendable rockets make sense for missions beyond low-Earth orbit. They can haul more cargo and more fuel than single-stage craft. Rockets also off er reliabilityon average, only one out of 20 launches fail, in part because they suff er no wear and tear from repeated use. Finally, rockets come


A disembodiedjet engine, attachedto a hulking air vent, sits in an outdoor test facility

with fewer R&D costs, as much of the technology has existed since the 1960s.

But for routine missions to the ISS, or to park a small observational satellite in orbit, aff ordability becomes a critical consideration. SpaceX CEO Elon Musk told an audience at the National Press Club in 2011 that private spacefl ights would need to follow a model closer to that of airlines. If planes were not reusable, very few people would fl y, he said. SpaceX plans to make rocket stages reusable, but there are drawbacks to that, too: While it is possible to recover rocket stages, designing bits and pieces to survive reentry in good working order adds a level of complexity and cost.

Hempsell says Skylon could potentially make 100 fl ights annuallywhich, if true, could in its fi rst year recoup the money spent in R&D and construction, leaving only expenses like fuel, maintenance, and overhead. And Bonds engine technology, aside from keeping a launch vehicle intact from start to fi nish, off ers another advantage: supersonic aviation. It could enable an aircraft to fl y anywhere in the world in under four hours, says Bond.

WHEN AIR STRIKES an engine at fi ve times the speed of sound, it can heat up to nearly 2,000 degrees Fahrenheit. Bleeding off that heat instantly, before the air reaches the turbocompressor and then the thrust chamber, was the most onerous technical challenge for Reaction Engines engineers. Bonds solution is a heat exchanger that works by running cold liquid helium through an array of tubes with paper-thin metal walls. As the scorching-hot air moves through the exchanger, the chilled tubing absorbs the energy, cooling

the air to minus 238 degrees Fahrenheit in a fraction of a second. Bond says his exchanger could handle about 400 megawatts of heat (equivalent to a medium-size natural-gas plant). If it were in a power station, it would probably be a 200-ton heat exchanger, he says. The one weve built is about 1.4 tons.

For rocket scientists, nothing matters more than weight. Each pound you put into orbit requires about 10 pounds or so of fuel to get it there, says NASAs Dumbacher. The challenge with the SSTO has always been to get the craft as light as possible [and generate] as much thrust as possible. Bond estimates that Skylon would weigh about 358 tons at takeoff and hold enough hydrogen fuel to carry itself and about 16.5 tons of payloadabout the same capacity as most operational rocketsinto orbit.

If and when the engine passes fl ight tests, one of Reaction Engines plans is to license the technology to a potential partner in the aerospace industry. Bond hopes the recent success of the heat exchanger will inspire interest. After 30 years of research, it has certainly inspired him. It represents a fundamental breakthrough in propulsion technology, he says. This is the proudest moment of my life.


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T H E S A B R E E N G I N E : H O W I T W O R K SAir traveling at Mach 5 enters the engine and passes through a heat exchanger. There, a network of paper-thin metal tubes fi lled with liquid helium chill the 2,000oF air to 238oF almost instantly. That chilled air fl ows into the turbocompressor, then into the thrust chambers, where its mixed with liquid hydrogen and ignited to produce thrust for the spacecraft.

C O N C E P T S & P R O T O T Y P E S

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DOWNEDW O R L D W A R I I C O M B A T P I L O T S H A V E B E E N L O S T A T T H E B O T T O M O F T H E P A C I F I C O C E A N F O R N E A R L Y 7 0 Y E A R S . N O W A U T O N O M O U S R O B O T S H A V E B E E N D E P L O Y E D T O F I N D T H E M .


S T O R Y B Y A N D Y I S A A C S O N

An engineer uses high-frequency sonar to image the fuselage of a

Corsair near Palau. Dozens of World War II aircraft lie in the waters surrounding the island chain.

N A BRIGHT morning in mid-March, Pat Scannon stands on the deck of a 40-foot catamaran looking for an airplane hidden in the waters of Palaus western

lagoon. A limestone ridge thick with veg-etation juts into the cloudless blue sky be-hind him. His quick-dry clothing, coupled with a red bandanna knotted around his neck, befi ts Scannons role as an amateur archaeologist. He has spent the past 20 years making annual wreck-hunting trips to Palau, about 500 miles from the Philip-pines, to fi nd aircraft that had been shot down during one of World War IIs fi erc-est battlesplanes that may still be hold-ing their pilots. His organization, Bent-Prop Project, works to repatriate their remains to the U.S. To guide the search, Scannon ordinarily relies on interviews

with Palauan elders, military records, and maps hand-drawn aft er the war. But on this trip, he has a new tool at his disposal.

Two technicians in a nearby Boston Whaler cradle a small, torpedo-shaped craft , then lower it into the water. Scan-non watches as its nose tilts down and its rear propeller pushes it beneath the surface. Out of sight, the autonomous underwater vehicle (AUV), an ocean-ographic workhorse called a Remus, begins gliding through the lagoon in a pattern that resembles the long, linear passes of a mowed lawn. From roughly 10 feet above the seafl oor, its side-scan sonar sends out acoustic waves that build a two- dimensional map. The strength of the refl ected waves also helps distinguish metal from mud or coral.

For a group like BentProp, the use of advanced oceanographic instruments is a huge technological leap forward and one it couldnt aff ord on its own. The vehicles come from the University of Cal-ifornia, San Diegos Scripps Institution of Oceanography and the University of

things during their searches.When Terrill and Scannon met through

a mutual friend on the island, a collabora-tion seemed natural. BentProp could fi nd planes in a tricky marine environmentwith steep terrain, fast currents, and cor-al headswhile Scripps tested circulation models and advanced imaging systems. If were able to use those techniques on natural environments, theres nothing to say we cant apply it to the man-made ob-jects on the seafl oor, Terrill says.

Scripps and the University of Dela-ware shipped 60 packages of equipment to Palau, including underwater vehicles, cameras, various types of sonar, and, for aerial surveys, an autonomous hexacop-ter drone that had been rebuilt to survive sea spray and aquatic landings. The man-groves growing along the shore around Palau are so dense that aluminum wreck-age from aircraft has been found sitting on top of the tree canopy about 30 feet up.

This year, Scannon has his eye on a major prize: a B-24 that he believes had been shot down in Palaus western reef.

That September, the U.S. Marines landed on the island of Peleliu. Although they ultimately won that battle, it came at a terrible cost: 10,000 Japanese and 1,700 Americans were killed in actionthe highest casualty rate of World War IIs Pacifi c Theater. And between the be-ginning of the air campaign and the end of the war, BentProp estimates, 200 U.S. aircraft were shot down inside Palaus barrier reef. Some 40 to 50 planes and 70 to 80 airmen have never been recovered.

Scannon, a medical doctor and found-er of a biotechnology company, fi rst visit-ed Palau in 1993 as a recreational scuba diver. He came with a group looking for a Japanese naval vessel that had been sunk by George H.W. Bush, who fl ew torpedo bombers during the war. Aft er the group found it, Scannon hired a local guide to take him to other wreck sites, where he eventually discovered the wing of a B-24. When he researched Palaus history at home, he realized there must be many more planes in ruins around the islands. Palauans knew of them but didnt know


With the oceanographers help, he hopes, BentProp could fi nd it. On land our major technology was a machete, and underwater it was scuba tanks, he says. The ability to extend our mission is, like, I dont know how to describe it. Its like starting out walking, and suddenly youre in a supersonic jet.

BY THE 1920s, Palau had grown into a thriving Japanese port for goods and ser-vices en route across the Pacifi c. Recog-nizing the strategic location, Japan estab-lished an airfi eld there, and aft er World War II broke out, it began to shore up its defensesbuilding hundreds of bunkers and caves to defend the islands from an American attack . General MacArthur, who wanted to secure islands to the east as he prepared to invade the Philippines, ordered that attack in 1944. The U.S. be-gan with a furious air campaign that was designed to knock out Japanese vessels clustered in Palaus western lagoon and adjacent harbors, and clear the way for an amphibious assault.

Delaware, which received a grant from the U.S. Offi ce of Naval Research. The funding enables oceanographers to test new technologies while helping BentProp locate World War II airmenan eff ort they named Project Recover.

The lead scientist is Eric Terrill, direc-tor of the Scripps Coastal Observing Re-search and Development Center. Board shorts and sandals make the athletic oceanographer look more surfer than scientist he even brought a board on the research vessel for what he calls wave sampling. For the past few years, Ter-rills team has used a Remus to study the ocean circulation around Palau.

Historically, on unmanned underwa-ter platforms, you might spend the better part of your experimental time just ensur-ing the sensors were functioning, tracking the vehicle navigation, and charging bat-teries, he says. The systems now have matured to where we can run them hard, like outboard motors. The oceanographic community is engineering new sensors for them and having them do smarter

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anything about them, he says. He was particularly gripped by the thought that many airmen couldnt have survived the impact. These people died defending us, he says. And they deserve to be honored and, if possible, brought home.

So began Scannons quest. He re-turned to Palau for the next few years by himself, chasing leads. Then in 1996, he formed BentProp and recruited volun-teers, roughly half of whom are retired and active-duty military members, to help him search. Combing the jungle and sur-rounding waters, they located debris from more than fi ve dozen aircraft .

Last year, local spear fi shermen diving on Palaus western barrier reef stumbled

across one of the most impressive fi nds: an intact plane. They alerted the owner of a dive shop, who passed photos of the wreck along to BentProp. Scannons team eventually identifi ed the plane as an American Corsair. It had sustained some damage to its left forward wing root, but the wing fl aps were down, and the cano-py had been locked open, suggesting that the pilot had ditched. It had been sitting there unknown for 65 years, Scannon says. It gave us great hope that there were other intact airplanes out here that no one has seen.

BentProp calculates that eight Amer-ican planes, including a B-24 bomber, remain hidden in Palaus western lagoon.

HIGH-TECH IMAGERS [1] Eric Terrill [left] and Billy Middleton of the Scripps Institution of Oceanography prepare to launch a Remus autonomous underwater vehicle in Palaus western lagoon. [2] The team also deploys an Echoscope, a 375kHz multibeam sonar, to image the seafl oor under the research vessel. [3] The sonar produces a real-time display showing the fuselage of a Japanese fl oatplane. [4] Equipped with GoPro HD cameras, the Remus surveys the wreck of an American Corsair. [5] Algorithms developed by Autodesk fuse those images into a 3-D model of the planes nose.

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The B-24, in particular, would be a tre-mendous discovery. It carried 10 to 11 men, including a pilot and co-pilot, gun-ners, bombers, a radioman, and a naviga-tor. Of the four B-24s BentProp suspects were shot down near Palau, two were found aft er the war. BentProp located a third in 2004; the organization notifi ed the Department of Defenses Joint POW/MIA Accounting Command, and the re-mains of the eight men onboard (three had parachuted out, only to be appre-hended and executed) were repatriated to Arlington National Cemetery.

Mission photographs from World War II show the fourth, a Consolidated B-24 Liberator, on a path toward the western lagoon. Two of its crew had bailed out midair, landing in Malakal Harbor to the east, where the Japanese took them into custody; the rest presumably went down with the plane. We have very, very good information about what heading

EXPEDITION PREP [1] Mark Moline [left] of the University of Delaware pilots a remotely operated vehicle while Eric Terrill of Scripps adjusts sonar and video displays of a sunken Japanese warship. [2] The team consults historical documents at its command center at the Coral Reef Research Foundation. [3] The archival information helps the team plan transects for autonomous underwater vehicles (AUVs) . [4] Scripps engineer Billy Middleton offl oads data from the Remus AUV after each mission. [5] Flip Colmer volunteers in BentProps search for downed aircraft and airmen. [6] Joe Maldangesang [left] and Pat Scannon [right] of BentProp with Scrippss Shannon Scott [center] study various warplanes fl own into battle over Palau. [7] Scott prepares the handheld Shark Marine Navigator system, which contains sonar, lights, and cameras. [8] The machines Blueview sonar allows divers to fi nd targets in very-low-visibility water.

dation, but their unoffi cial headquarters is an open-air bar called the Drop Off , originally built for the production crew of CBSs Survivor: Palau. Several days into the expedition, they head there for dinner and order a round of local Red Rooster beers. As they wait for their food, Mark Moline, an oceanographer from the Uni-versity of Delaware, opens a Toughbook laptop and scrolls through sonar images produced by the Remus.

they were on during the bombing mis-sion, and we have very good information about what heading they took leaving, Scannon says, on the deck of the research vessel during this years expedition. So bringing the two of those together essen-tially brings you right here.

THE OCEANOGRAPHIC teams offi cial command center in Palau is on the second fl oor of the Coral Reef Research Foun- AN

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Grainy and reddish, the sonar imag-es look like transmissions from Mars. Some show deep scours; others, shadowy trenches. The team have given the fea-tures names like Homer Simpson, Cry-ing Baby, and SpongeBobs Grave. Aft er identifying promising targets in scans, they will have to investigate in person, diving to the various sites to determine if the features are purely biological, like coral heads, or actual wrecks.

Moline pauses on an image with an ob-long shape. On closer inspection, it seems to have intact wings and a tail. We got a plane! Moline announces. Everyone springs up and huddles around the screen, snapping photos with their phones. Their excitement attracts the attention of a Japanese man dining at the other end of the long communal table, who cranes his neck for a peek at the computer. Moline abruptly shuts the laptop; World War II wrecks attract dive tourists and salvagers.

The next morning, at the coral-reef lab, Terrill debriefs Scannon and the Bent-Prop group. Paul Reuter, a Scripps pro-grammer, projects Google Earth onto a wall. Reuter had used an archival map of observed plane crashes to mark Google Earth layers with known wreck sites; he then added a layer with intriguing objects that had turned up in the sonar images.

Terrill uses a laser pointer to indicate the newest fi nd. The hard edges provide bright scatter, he says. Theres a long shadow here and here. He then shift s his pointer to a spherical object about 45 me-ters away and wonders if it could be the pontoon of a fl oatplane.

If thats intact, it tells me it was a low-speed impact, perhaps ditching, says Daniel OBrien, a former skydiver and Hollywood stuntman who now volun-teers for BentProp. My fi rst impression is thats a Zeroa long-range fi ghter aircraft . There are rounded edges at the tail. But if it is a fl oatplane, the only U.S. airplane it could be would be amphibious. The shape looks like a Kingfi sher. Flip Colmer, a former Navy pilot who now fl ies for Delta, also with BentProp, reach-es for the book Floatplanes in Action and begins fl ipping through color pictures.

The Kingfi sher, OBrien explains, was typically fl own for observation and to res-cue downed pilots. If they were in this deep, it would have been on a risky en-deavor. There werent anti-aircraft along

the ridge. But existing ships that were still moored had anti-aircraft . So for him to come in and land here, it would have been to pick somebody up.

During World War II, fl oatplanes in Pa-lau oft en fl ew rescue operations. As they scooped airmen from the water, another plane provided cover overhead. BentProp knew that two Kingfi shers on reconnais-sance missions had disappeared during the war, and the western lagoon seemed the most likely location for them to have ended up. The identifi cation number painted on the planes exterior would have degraded by now; to confi rm the exact craft , divers would try to recover a stamped metal plate riveted to the in-side of the cockpit. Its our holy grail, OBrien tells me.

Colmer cautions the group about jump-ing to conclusions. The Japanese also fl ew seaplanes. If theres any primer left on the interior of the cockpitwhich will last longer than straight paintthats one way to take a peek at it, he says. U.S. airplanes used lime-green zinc chromate; the Japanese had a red primer. The team will have to get a close look.

GUIDED BY GPS coordinates from the AUV, Pat Colin, director of the Coral Reef Research Foundation, pilots the vessel across the lagoon to the approximate lo-cation of the mystery plane. Then Terrill lowers a device called an Echoscope over the side. As we creep along the surface, an onboard computer displays 3-D imag-es of the seafl oor in real time.

While side-scan sonar provides a gen-eral impression of contours along the bottom, it doesnt directly measure the elevations of features. The Echoscope, or multibeam volume imaging sonar, does, enabling oceanographers to map topog-raphy accurately and in high enough res-olution to distinguish man-made objects. Terrill describes it as the oceanographic seafl oor-mapping equivalent of ultra-sound sonar used to look inside the hu-man body. Using the two technologies in tandem helps to narrow wide-area search-es and then pick out targets from clutter on the seafl oor, so that human divers maximize their time at the correct site.

With the boat now directly over the plane, the dive teams begin to suit up.

THE VESSELS that typically explore the oceans are professionally engineered. But in Palau, eight students from the Advanced Underwater Robotics team at Michigans Stockbridge High School also deployed a remotely operated vehicle (ROV). The 40-pound craft successfully dived to 140 feet towing a video-camera system and sonar that it used to image several unknown shipwrecks and a Corsair plane.

A local BentProp volunteer had read about the team in 2011 and reached out to the students for assistance. They set to work on building a ROV, using 3-D computer-aided-design software and soldering and electronics skills learned in class. Because Stockbridge, located in a rural community, doesnt have a swimming pool, they tested the craft in a cattle trough. The team also raised $45,000 to pay for the ROV parts and the trip 7,000 miles across the world. The class is run more like a small business or research team than a traditional classroom, says teacher Robert Richards, a retired Army sergeant. Were focused on building a robot and doing a mission.

The team represents the last level of a robotics program that starts in elementary school. Stockbridge also integrates the Palau project into the curriculum for grades 3 through 12, so 300 kids learn about subjects like island biology and World War II Pacifi c Theater history. Next year, the students hope to return to Palau for a third fi eld tripthis time, with an autonomous vehicle and hexacopters.

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CONTINUED ON PAGE 77

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CUSTOM KICKSDenton initially shod the Mantis in modified go-kart tires. They worked out really well, he notes, but they werent very grippy. So he fabricated custom rubber feet, modeling the hexagonal pattern after off-road tires. Now he alternates shoes based on the terrain.

n 2007, Matt Denton stopped on the side of the road near his home

in Hampshire, England, to watch an excavator dig. The machines had fas-cinated him since childhood, but after years of designing control systems for animatronic Hollywood creatures, Denton saw the shovel-tipped boom through a more imaginative lens. It was effectively the shape of a leg, he says. So I started to wonder: Would it be possible to buy six of them and attach them to a chassis? Four years later, Denton can lumber around in a

I

Grow bacteria into photographic fi lm PAGE 70

E D I T E D B Y D A V E M O S H E RS E P T E M B E R 2 0 1 3 H 2 0 @ P O P S C I . C O M

P O P S C I . C O M @ P O P S C I

WARNING We review all our projects

before publishing them, but ultimately your safety is your responsibility. Always wear protective gear, take proper

safety precautions, and follow all laws and regulations.

PLUS: 3-Dprint an

invisibility cloakPAGE 72

STORY BY GREGORY MONE

PHOTOGR APHS BY MAT T DENTON

TIME 3 yearsCOST $250,000


two-ton, nine-foot-tall robo-walker he calls the Mantis.

Denton, who helped engineer the hippogriff (an eagle-headed flying horse) in the Harry Potter films, had also built walking hexapods for the movies and for fun, but they were no bigger than a radio-controlled toy car. He wanted the Mantis to be the size of an SUV. Unable to afford the proj-ect alone, he sketched out a design, used toy excavator arms to construct a scale model, and courted financial backers with the mock-up. No one bit. A few months later, a friends wealthy

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H 2father heard about Dentons quixotic mission and, inspired by his vision, agreed to bankroll it.

Denton asked his friend Josh Lee, a mechanical engineer, to help him build the Mantis. The pair spent the first few weeks studying hydraulic actuatorsthe artificial muscles that would move the robots legs. Meanwhile, Denton adapted software to drive the giant hexapod from code he wrote for his toy-size models. He and Lee then drew up plans for the robots central chassis and six legs, built and tested one appendage, and contracted a fabrication company to make the rest. When the aluminum-and-steel legs arrived at Dentons workshop, however, he realized that some of the holes needed to bolt the pieces together were missing and oth-ers were poorly machined. Impatient, Denton spent a week correcting the flaws himself. We had to make it work, he says.

Although Denton had a working pro-totype by 2011, the Mantis weighed too much and moved too slowly. To cut its mass by 400 pounds, he removed one of the four joints in each leg. The joints had enabled better mobility on different terrain, but the Mantis moved well enough without them. Denton also streamlined the chassis, which houses the hydraulic system, diesel engine, electronics, and the pilots chair.

When the moment arrived to drive it, Denton wouldnt climb inside. I was too scared, he says. To allay his fears, he performed 100 hours of Wi-Fienabled testing over six months. His first time out was terrifying, but the Mantis operated as expected, and he slowly grew more comfortable in the cockpit. Now Denton shows off his creation at festivals. Some criticize its slow pacethe Mantis hasnt cracked two miles per hourand Denton is uncertain if it has a future in movies, construction, or elsewhere. But adolescent spectators understand it instantly. Kids love it, he says. They want to get in and stick some lasers on it.

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In high school, Hajime Sakamoto was so obsessed with humanoid robots in the anime TV series Gundam, he assembled toy models of the machines. Today, the 46-year-old roboticist wants to build a full-size, 59-foot-tall automaton. For now he has made a pair of legs that stand 11.5 feet [above]. Sakamoto hopes to add a torso later this year, climb into the 13-foot-tall walker, and ride around. Sarah Jacoby

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CONTROLSA pilot selects one of several gait patterns from a touchscreen control panel. One mode designed for rough terrain instructs the robot to pick each leg up before swinging it forward. Manipulating the joystick can direct the machine to creep forward, backward, or crab-walk to the side. Twisting the joystick forces the Mantis to turn in place.

SAFETYShould an emergency arise, Denton says, we have two big red buttons. One sits right next to the pilot in the cockpit, the other at the back of the machine (where one of Dentons friends walks in step with the Mantis, making sure no animal or bystander falls beneath its feet). Both buttons kill the power and freeze the robot where it stands.

SENSINGOnce a foot touches the ground, force sensors alert an onboard computer. Only then can the next leg in a walking sequence swing forward. A ball joint in the ankle allows the foot to pivot and plant itself on uneven ground; if the foot meets a ledge, however, another sensor tells the computer to find a more secure spot. Denton hopes to place ultrasonic sensors in each leg so the robot can scan the ground before stepping down.


T W O M O R E R I D E A B L E R O B O T S

Artist Scott Parenteau designed his geodesic Walking Pod for shelter and transportation at Burning Man, an annual weeklong festival in Nevadas Black Rock Desert. The 1,800-pound dome crawls on two sets of six legs powered by batteries. Parenteau hopes his RV art inspires new mobile-home designsand perhaps even nomadic colonies on Mars.Lillian Steenblik Hwang

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COLUMN BY THEODORE GR AY PHOTOGR APHS BY MIKE WALKERH2H O W 2 . 0 / G R A Y M A T T E R

WARNING: Mixing flammable powders with pure oxygen is dangerous, and blowouts occurred with this setup. Do not attempt.

mixes air into wine as its poured (for anyone who thinks aerating wine makes it taste better).

My favorite trick is to turn a garden-hose-variety Venturi pump into a flamethrower. Instead of using water, I attach a tank of pure oxygen and blow it through. The gas can suck up powdered spices and convert them into sparkling pillars of fire. Pretty much any fine organic powder burns, thanks to a large flammable surface area; Ive succeeded with cinnamon, garlic, black pepper, onion, cumin, powdered sugar, and even bread flour. About the only disappointment in my kitchen was chili powder, which makes a pathetic little flame. So much for extra heat.

When you blow air across the top of a straw dipped in soda, liquid rises up the tube. This might seem strange, but a Venturi pumpnamed after the Italian physicist who invented ittakes advantage of the same effect, simply by virtue of its shape.

Any high-velocity, high-pressure jet of liquid or gas creates suction in its wake. As molecules zoom by, nearby material rushes in to fill the void. So if you force a jet through a constricted section of tubing, you can make a pump with no moving parts.

Most Venturi pumps use three openings: one for the jet, one for suction, and the last as an exit. The devices are great for shallow-water wells in rural areas because they require no electricity, motors, or bearings to work at the bottom of the well. Plus, a metal Venturi pump can last decades in water.

The pumps can also mix dissimilar materials. A jet of gas can suck up liquid, so you can use compressed air, a pump, and a garden hose, for instance, to empty a flooded basement. Another example: the Vinturi, a funnel-like contraption that

Vacuum Power

Flame OnA jet of burning

cinnamon shows just how fl ammable fi ne

organic powders can be in a stream of

pure oxygen.

Below is a cutaway view of a plastic Venturi pumpdesigned to suck up water with a garden hoseattached to the end of a cutting torch. Coincidentally, its a perfect fi t. High-velocity gas (or water, in the original application) rushing out of the small nozzle creates suction that pulls liquid up through the lower hose connection.

I N S I D E L O O K

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A pump that goes from blow to suck with no moving parts

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[left], founder of POPULAR SCIENCE, circa 1886

A B C

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STORY BY Z ACH ZORICH

PHOTOGR APH BY DAN BR ACAGLIA

H O W 2 . 0 / B I O H A C K S

The enzyme converts an agar additive called S-gal

into dark pigment. Without signaling molecules, no

pigment formsso E. coli in darkness turn black and

lit-up cells stay clear.

These signaling molecules normally

latch onto DNA inside the bacteria, then turn

on a gene that produces the enzyme beta-

galactosidase.

Proteins on the bacterias surface work together to detect red light. When light is present, the

proteins prevent unique signaling molecules from forming within the cells.

Melt 15 milliliters of agar mixture in a microwave (about one minute on high) in the smaller container. Let cool until warm to the touch.

Add the bacteria. Mix vigorously, but do not create bubbles.

INSTRUCTIONS

In their basic setup, red light shines through a printed trans-parency thats taped to the bottom of an agar-filled petri dish. Only bacteria growing in the transparencys shadows produce pigment. Voigt and his team borrowed two proteins from blue-green algae to give E. coli this new ability. The proteins detect red light and turn off a gene that makes black pigment.

Jeff Tabor, a bioengineer at Rice University who collabo-rates with Voigt, is now engineering light-sensitive strains of E. coli to produce red and green pigments. If anyone can coax these bacteria to produce blue pigment, he says, the world could see its first bacterial pixelthe foundation of microbial television screens.

MATERIALS1. Agar mixture:

100 mL luria broth agar 30 mg S-gal 50 mg iron ammonium sulfate 1 g low-melting-point agarose

2. 30 L Voigts bacteria3. Two sterile, microwave-safe containers with lids:

One to hold 100 mL agar One to hold 15 mL agar

4. Six 9-cm-diameter petri dishes 5. Plastic wrap6. Clear tape7. 9-cm-diameter designs printed onto transparencies (sized to fi t the round petri dishes)

Note: Most biotech companies ship supplies only to registered laboratories. Fortunately, most do-it-yourself and community biology labs qualify.

Pour the mixture into a petri dish and quickly cover with a lid. Let it cool until solid, about 20 minutes.

Remove the lid, cover the petri dish with plastic wrap, and cut three narrow slits in the plastic.

Tape the transparency to the bottom of the petri dish, fl ip it over, and shine red light down onto the transparency for one to three days. (Make sure the light doesnt melt the agar, as this will kill the bacteria.)

TIME 1 to 3 daysCOST About $50 for six bacterial photosDIFFICULTY

Grow a PhotoUse microbes to make black-and-agar still lifes

icrobes arent known for their artistic merit, but that hasnt stopped

scientists from using bacteria to fi nd their inner Ansel Adams. Bioengineer Chris Voigt and his team at the Massachusetts Institute of Technology have hacked a harmless strain of Escherichia coli so that it produces black pigment in darkness or, in red light, remains transparent. The result: an organism that behaves like fi lm.

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INSTRUCTIONS

1. Find a 3-D printer, preferably one that builds objects in thin layers of plastic (a process called fused deposition modeling). If you dont own a 3-D printer, cant borrow one, or lack the funds to buy onetypically $500 or moreyou can pay an online company (such as Shapeways or RedEye on Demand) to print a design for you.

2. Download Urzhumovs design file at popsci.com/microwavecloak and print it out. (The default thickness is 1 centimeter, but it can expand as tall as a 3-D printer allows.)

3. To use the invisibility cloak, line the disks inner ring with aluminum foil, lay it on a flat surface, and put an object 5.4 inches long or less inside. Any microwaves shining on the disks outer edge wont reveal your precious property.

STORY BY PAVITHR A S. MOHAN

H O W 2 . 0 / S I M P L E P R O J E C T O F T H E M O N T H

3-Dprint your own invisibility cloak to live a sci-fi dream

he invisibility cloak Harry Potter brandishes against dark lords and nosy

professors is now a realityat least in microwave light. Duke University engineer Yaroslav Urzhumov has designed a plastic disk that makes a small object placed in its hollow center invisible to frequencies from 9.7 to 10.1 GHz (close to the range used by radar speed guns). Holes in the doughnut-shaped cloak can eliminate an objects shadow and decrease its ability to scatter light. In effect, the cloak guides the microwave beams around the object so they cant bounce backrendering it invisible. Until scientists can scale up, however, it might be useful only for getting toy cars out of a speeding ticket. CO

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TIME 3 to 8 hoursCOST About $100DIFFICULTY
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H2

o youve got yourself a bitcoin. Congratulations! Its value was hovering around

$100 at press time. But what can you do with your newly acquired digital riches? Quite a lot, as it turns outespecially if you have a penchant for projects.

More and more vendors who cater to makers accept bitcoin, a digital currency thats created and maintained by its own extensive virtual network. Bitcoins add little or nothing to overhead because they carry no inherent processing fees and cant be traced. This translates to savings on tools and materials for projects.

CryptoPrinting.com, for example, will 3-Dprint custom designs for prices the company claims are about 20 percent cheaper than its competitors.

Bitcoinstore.com off ers a wide variety of electronic parts, such as Arduino microcontrollers, power supplies, and cameras. Go to Spendbitcoins.com for a list of other sites that take part in the blossoming mini economy, including virtual marketplaces like Coingig.com, where bitcoin owners can independently buy and sell items from one another.

Want a bit more coin? Success isnt easy, but all you need to mine the currency is a computer thats properly confi gured to help anonymously secure and verify others bitcoin transactions (for a great guide on mining, see popsci.com/bcmining). If your computer miner pays for itself, then you can start saving up for all your geekiest workshop desires.

S

A S K A G E E K / H O W 2 . 0

Use this crypto-currency to fund ambitious projects

My Friend Gave Me a Bitcoin. Now What?

STORY BY JACK DONOVAN ILLUSTR ATION BY MICHELLE MRUK

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This is the entrance to our 418-acre estate in Shohola, Pa.a gorgeous property on top of a mountain we bought overlooking the Delaware River. Most of our business profits go to this property to support 3,000 boy scouts, girl scouts and disadvantaged youngsters.

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About John Ellis Water The 83 year old inventor is a Choate School, Lafayette College Engineering graduate,

Douglas Aerospace and Honeywell Engineer that discovered the

KEY to a HYDROGEN ECONOMY. In the past, it took too much

power to split the water molecule into hydrogen and oxygen. He has

found a way to do it using very little power. If you click on the two

red click here spots at the top of www.johnellis.com, it explains it. Watch a VIDEO

adding ONLY 20 DROPS of water from his home water machine to ordinary water that

saps your energy! UCLA Med Center M.D. stating the hydrogen bond angle change

to 114: You cant argue with measurable results. Nothing is even close to your water

for Blood Flow (94% water) to the extremities! Washington Post investigative article:

10,000 people/day, cures anything! www.WaterCuresAnything.com

THE CANCER VIRUS ANSWER?

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Who would know better than the founder of the American Cancer Society?

Now, after almost 40 years in business, we have developed machines that are the State of The Art! PROOF: Watch the Video at www.WaterCuresAnything.com and you will see that if you add only 20 DROPS of this water to ordinary water it takes less energy to split water into into hydrogen and oxygen (like The Body Electric, that also splits water into hydrogen and oxygen providing more energy to keep you alive)! In the past, it took too much energy to split ordinary water (with a Hydrogen Bond Angle of 104.5 degrees) into hydrogen and oxygen to make hydrogen a feasible energy source. However, by using this patented method of heating and cooling, it increases the measurable hydrogen bond angle to 113.8 degrees (tunneling electron microscope) so less energy is required. Trucks require 30 amps of power to split ordinary water by electrolysis. WATCH THE AMMETER in the Video. The power gradually drops from 30 amps to almost ZERO (less than 1 amp) while producing plenty of hydrogen! A revolutionary discovery that will allow the world to Go Green without eventually running out of the energy sources that produce pollutants that are destroying the environment and us! A scientist called from Zurich, Switzerland: I have had your E5 machine exactly 24 hours. I have elephantitis in my legs. I lost all that water weight and bought the first pair of ordinary shoes I have worn in years. Then, using only 100 watts of power, I couldnt believe how much hydrogen your water can produce! It violates Faradays Law! Why is that? This discovery is explained in the Answer to Cold Fusion by Jon Christian Ryter. READ IT and you will realize if you buy a machine from us, you will be the first in line to buy one of these electrolyis units that can be used to heat your home, produce electricity and (later) power your car for pennies!! Since the electrolysis units are inexpensive and the world wide demand is so great, you wont have to wait years to buy one if you are already a water machine customer. An M.D. who was doing blood flow studies at the UCLA MEDICAL SCHOOL: Nobody can argue with something you can measure. We can measure the ability of blood (94% water) to go through a membrane into the cells to the extremities. Nothing is even close to your water!

Your Hydrogen Bond Angle is 114 degrees! We knew that it was saving diabetics from amputation and the Washington Post sent reporters to investigate and write an article on our website as far back as 1/27/92 when we were developing these machines. A man in Mexico (our Mexican Patent 239719) was running our water into a well giving it away: 10,000 people/day, cures anything! Scientists ranging from the Los Alamos Nuclear Lab to Lawrence Livermore called the Ad Manager at The Washington Times (we have advertised there every week for 17 years) with an apology about the impossible results: We are wrong. He is right. He has changed the properties of water! Shills for the water industry with no degrees in this field cant argue with the results because they are MEASURABLE and yet you will see a Water Scam Report that violates the FTC Order C-3220. We filed our complaint with Joel Winston at the FTC and he sent us the final Order that we used in our older literature. Now, we are about ready to file again: Look at the VIRUS & BACTERIA DESTRUCTION CHART on our website. Each one has a different Destruction Time and NONE allow enough time to destroy them and change WATER PROPERTIES! DOLE FOODS tested our water on mold spores for 9 months and sent us a 7 page contract because a Dow Chemical caused serious problems! Go to JEWISH VIRTUAL LIBRARY/BIOTERRORISM and you will see that mold spores in small amounts dispersed by airplane could kill 1/3 of the population while also contaminating our water supplies!! Do you see why the DOLE results are important? 7 Muslims, MIT Chemical Engineers ignoring the No Trespassing Signs, were caught at 1 AM at the Boston reservoir! You know they have my machines and have read the Associated Press testing (2/10/08) about 57 drugs in municipal water supplies! Thousands of wells have been returned to purity using only 10 gallons of my water on each well, so you know they can reverse this technology to contaminate our water supplies with deadly consequences! Read the letter on the town letterhead from LaSalle, CO! ONLY 1000 gallons of our light tap water treated over 10 million gallons of e-coli in an untreatable 5 acre waste lagoon avoiding fines of $10,000/day from the State! No other water product can do that and our countertop machines produce TWO types of water! Learn more...it may save your life!

Watch an online video of John Ellis, 83 year old Inventor

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THE WORLDS BEST WATER PURIFIER (332 FDA Approved Tests because it REPURIFIES water 100s of times/gal! NOT ONCE!!).Ordinary products violate FTC Order C-3220 as a result of tests on our older versions and complaint filed with the FTC in 1987!

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FYI

H O W F O R C E F U L I S A S N E E Z E ?QUESTION

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S H O R T A N S W E R About as strong as a cough

A N S W E R S B Y D A N I E L E N G B E R

S E P T E M B E R 2 0 1 3

HAVE A BURNING SCIENCE QUESTION?E-mail it to fyi@popsci .com, or tweet @popsci hashtag #PopSciFYI.

P O P S C I . C O M


A long-standing estimate pins the velocity of a sneeze at roughly 100 meters per sec-ond, or 224 miles per hour, but that appears to be a gross exaggeration. The figure origi-nates from a mid-century researcher named William Firth Wells, who analyzed the size of airborne droplets from a sneeze and then inferred the speed at which air must travel across a liquid surface to form them. Wells figure has been repeated for many years but never directly tested in the lab. I think people have been waiting for someone to come along and debunk it, says Julian Tang, a medical virologist at the Alberta Provincial Laboratory for Public Health in Edmonton.

For a study published this year, Tang and his colleagues used high-speed cameras to take pictures of pepper-induced sneezes from six volunteers. The team captured each sneeze by positioning the volunteers in front of a concave mirror and then shining an LED beam toward it. The warm air from the

sneeze has a different refractive index than the cooler ambient air, so the reflected LED bends differently. The camera records the changes, and scientists can map the sneeze.

The study found that a sneezes maxi-mum velocity is nowhere near 100 meters per second but instead reaches a high of 4.5 meters per second, or 10 miles per hour. Thats comparable to the velocity of air expelled by coughingand a violent cough can push up a larger volume of air, which requires even more force. The sneeze is really coming from your upper respiratory tract, Tang explains.

Tang, who did his study in Singapore, acknowledges that his numbers might have come out differently if hed chosen different subjects. All my data is from these rather slim Asian students, he says. If somebody did this in the North American setting, with the bigger body frames that they have here, they might find higher velocities.

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For the entomophiles who keep insects as pets, this question will seem a little silly. Some bugs appear aggressive, and others, shy; some venture into the open, others hide by the wall. But beyond casual observa-tion, researchers are still learning the dimensions of an insects personality and how individuals of the same spe-cies might diff er in temperament.

Last year, a group based at the University of Illinois looked at novelty-seeking tendencies in honeybees. The scientists found that bees that routinely searched for new

D O I N S E C T S H A V E P E R S O N A L I T I E S ?

QUESTION

L O N G A N S W E R

nest sites also had a very strong tendency to scout for food. That suggests particular individuals are programmed in such a way, whether through genetic or other factors, that they manifest wanderlust and an inclination to explore.

Most people think that insects are very similar and behave in the same ways, says Enik Gyuris, a biologist at the University of Debrecen in Hungary, but she has found diff erently. In her studies of fi re bugs, Gyuris uses a battery of behavioral tests to measure three distinct personality traits: bold-

ness, activity, and explorativeness. In a recent study, she put each bug into an open vial and then placed it at the center of a two-foot-wide circular arena. The boldest bugs emerged quickly, while the timid ones hid for 10 minutes. Once the bugs left the vial, their tendency to move in diff erent directions and investigate new objects served as an index of their explorative-ness. Our results show that there are personality diff erences between the individuals of the fi re bug, Gyuris wrote, as we found that they behave consistently over time.

S H O R T A N S W E R

Yes, and some love to travel.
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Terrill fi lls his scuba tank with nitrox to allow himself more time to explore the aircraft 100 feet below. Shannon Scott, an engineer from Scripps, descends with Terrill, Colmer, and OBrien. He carries a handheld sonar that displays acoustic images on an LCD screen, allowing the divers to zero in on the fl oatplane even in fi ve-foot visibility. About 20 minutes later, OBrien surfaces. Well, its not a Kingfi sher, he says.

Aft er descending to the plane, OBrien noticed that the windscreen on the cock-pit was located behind the wing. In King-fi shers, it was situated in front. Hed also detected a subtle distinction in the shape of the fuselage n

popular science usa - september 2013

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