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On 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 Palau's western lagoon. A limestone ridge thick with vegetation juts into the cloudless blue sky behind him. His quick-dry clothing, coupled with a red bandanna knotted around his neck, befits Scannon's role as an amateur archaeologist. He has spent the past 20 years making annual wreck-hunting trips to Palau, about 500 miles from the Philippines, to find aircraft that had been shot down during one of World War II's fiercest battles-planes that may still be holding their pilots. His organization, BentProp 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 after 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. Scannon watches as its nose tilts down and its rear propeller pushes it beneath the surface. Out of sight, the autonomous underwater vehicle (AUV), an oceanographic 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 seafloor, its side-scan sonar sends out acoustic waves that build a two-­dimensional map. The strength of the reflected 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 couldn't afford on its own. The vehicles come from the University of California, San Diego's Scripps Institution of Oceanography and the University of Delaware, which received a grant from the U.S. Office of Naval Research. The funding enables oceanographers to test new technologies while helping BentProp locate World War II airmen-an effort they named Project Recover.

The lead scientist is Eric Terrill, director of the Scripps Coastal Observing Research 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, Terrill's team has used a Remus to study the ocean circulation around Palau.

"Historically, on unmanned underwater platforms, you might spend the better part of your experimental time just ensuring the sensors were functioning, tracking the vehicle navigation, and charging batteries," 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 things during their searches."

When Terrill and Scannon met through a mutual friend on the island, a collaboration seemed natural. BentProp could find planes in a tricky marine environment-with steep terrain, fast currents, and coral heads-while Scripps tested circulation models and advanced imaging systems. "If we're able to use those techniques on natural environments, there's nothing to say we can't apply it to the man-made objects on the seafloor," Terrill says.

Scripps and the University of Delaware shipped 60 packages of equipment to Palau, including underwater vehicles, cameras, various types of sonar, and, for aerial surveys, an autonomous hexacopter drone that had been rebuilt to survive sea spray and aquatic landings. The mangroves growing along the shore around Palau are so dense that aluminum wreckage 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 Palau's western reef. With the oceanographers' help, he hopes, BentProp could find 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 don't know how to describe it. It's like starting out walking, and suddenly you're in a supersonic jet."

By the 1920s, Palau had grown into a thriving Japanese port for goods and services en route across the Pacific. Recognizing the strategic location, Japan established an airfield there, and after World War II broke out, it began to shore up its defenses-building 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. began with a furious air campaign that was designed to knock out Japanese vessels clustered in Palau's western lagoon and adjacent harbors, and clear the way for an amphibious assault.

These people died defending usThat 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 action-the highest casualty rate of World War II's Pacific Theater. And between the beginning of the air campaign and the end of the war, BentProp estimates, 200 U.S. aircraft were shot down inside Palau's barrier reef. Some 40 to 50 planes and 70 to 80 airmen have never been recovered. Scannon, a medical doctor and founder of a biotechnology company, first visited 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 flew torpedo bombers during the war. After 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 Palau's history at home, he realized there must be many more planes in ruins around the islands. "Palauans knew of them but didn't know anything about them," he says. He was particularly gripped by the thought that many airmen couldn't have survived the impact. "These people died defending us," he says. "And they deserve to be honored and, if possible, brought home."

So began Scannon's quest. He returned to Palau for the next few years by himself, chasing leads. Then in 1996, he formed BentProp and recruited volunteers, roughly half of whom are retired and active-duty military members, to help him search. Combing the jungle and surrounding waters, they located debris from more than five dozen aircraft.

Last year, local spear fishermen diving on Palau's western barrier reef stumbled across one of the most impressive finds: an intact plane. They alerted the owner of a dive shop, who passed photos of the wreck along to BentProp. Scannon's team eventually identified the plane as an American Corsair. It had sustained some damage to its left forward wing root, but the wing flaps were down, and the canopy 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 American planes, including a B-24 bomber, remain hidden in Palau's western lagoon. The B-24, in particular, would be a tremendous discovery. It carried 10 to 11 men, including a pilot and co-pilot, gunners, bombers, a radioman, and a navigator. Of the four B-24s BentProp suspects were shot down near Palau, two were found after the war. BentProp located a third in 2004; the organization notified the Department of Defense's Joint POW/MIA Accounting Command, and the remains of the eight men onboard (three had parachuted out, only to be apprehended 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 they were on during the bombing mission, and we have very good information about what heading they took leaving," Scannon says, on the deck of the research vessel during this year's expedition. "So bringing the two of those together essentially brings you right here."

The oceanographic team's official command center in Palau is on the second floor of the Coral Reef Research Foundation, but their unofficial headquarters is an open-air bar called the Drop Off, originally built for the production crew of CBS's 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 University of Delaware, opens a Toughbook laptop and scrolls through sonar images produced by the Remus.

Grainy and reddish, the sonar images look like transmissions from Mars. Some show deep scours; others, shadowy trenches. The team have given the features names like Homer Simpson, Crying Baby, and SpongeBob's Grave. After 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 oblong 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 BentProp group. Paul Reuter, a Scripps programmer, 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 find. "The hard edges provide bright scatter," he says. "There's a long shadow here and here." He then shifts his pointer to a spherical object about 45 meters away and wonders if it could be the pontoon of a floatplane.

"If that's intact, it tells me it was a low-speed impact, perhaps ditching," says Daniel O'Brien, a former skydiver and Hollywood stuntman who now volunteers for BentProp. "My first impression is that's a Zero"-a long-range fighter aircraft. "There are rounded edges at the tail. But if it is a floatplane, the only U.S. airplane it could be would be amphibious. The shape looks like a Kingfisher." Flip Colmer, a former Navy pilot who now flies for Delta, also with BentProp, reaches for the book Floatplanes in Action and begins flipping through color pictures.

The Kingfisher, O'Brien explains, was typically flown for observation and to rescue downed pilots. "If they were in this deep, it would have been on a risky endeavor. There weren't 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, floatplanes in Palau often flew rescue operations. As they scooped airmen from the water, another plane provided cover overhead. BentProp knew that two Kingfishers on reconnaissance missions had disappeared during the war, and the western lagoon seemed the most likely location for them to have ended up. The identification number painted on the plane's exterior would have degraded by now; to confirm the exact craft, divers would try to recover a stamped metal plate riveted to the inside of the cockpit. "It's our holy grail," O'Brien tells me.
Colmer cautions the group about jumping to conclusions. The Japanese also flew seaplanes. "If there's any primer left on the interior of the cockpit-which will last longer than straight paint-that's 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 location 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 images of the seafloor in real time.

While side-scan sonar provides a general impression of contours along the bottom, it doesn't directly measure the elevations of features. The Echoscope, or multibeam volume imaging sonar, does, enabling oceanographers to map topography accurately and in high enough resolution to distinguish man-made objects. Terrill describes it as "the oceanographic seafloor-mapping equivalent of ultrasound sonar used to look inside the human body." Using the two technologies in tandem helps to narrow wide-area searches and then pick out targets from clutter on the seafloor, 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. Terrill fills 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 O'Brien. He carries a handheld sonar that displays acoustic images on an LCD screen, allowing the divers to zero in on the floatplane even in five-foot visibility. About 20 minutes later, O'Brien surfaces. "Well, it's not a Kingfisher," he says.

After descending to the plane, O'Brien noticed that the windscreen on the cockpit was located behind the wing. In Kingfishers, it was situated in front. He'd also detected a subtle distinction in the shape of the fuselage near the tail.

I strap on a scuba tank and jump into the water with Scannon, who wants to see for himself. We follow a rope line, pinching our noses on the way down to equalize pressure, until we arrive at the fuselage. It lays on a bed of thick sediment that our fins kick up into dusty clouds. Long, gangly strands of black coral grow up and through the corroded metal. The front motor and propellers have broken away from the body of the plane, so that it now resembles a chewed-off cigar or the burnt end of a firecracker. Scannon waves me over to the cockpit and places my hand on the gun mount. It held a 7.7mm machine gun, Scannon later explains to me, developed by the Japanese navy.

The next day, BentProp compares the aircraft in the western lagoon with a hundred different vintage planes. Eventually, the team determines that the wreck has all the characteristics of a Kawanishi E15K1 Shiun, code-named Norm by the Allies. The high-speed reconnaissance floatplane had a single engine, contra-rotating propellers, and a center pontoon that could be jettisoned during an attack. It also had a flattened beaver tail around the vertical stabilizer, an aft cockpit machine gun, and no wing armaments. According to BentProp, the Japanese manufactured nine prototypes; six were brought to Palau for combat testing, and all were shot down by U.S. forces.

Though it isn't an American plane, Scannon is pleased with the discovery. "It's a very unusual aircraft, one of the rarest archaeological planes you will find," he says. "And there's a very high likelihood that the remains are still on it." BentProp alerts the Palauan government, which will notify the Japanese embassy.

Of more than 60 aircraft BentProp has identified in Palau-half of which are Japanese-the team has recovered just one metal plate stamped with a serial number: that of the American Corsair discovered by the spear fishermen. That plate revealed the Corsair's story.

On November 21, 1944, a young Marine captain named Carroll McCullah set off from the American airfield to finish off a Japanese vessel that had been bombed earlier. On the way back, he and his wingman strafed four Japanese ammunition dumps; an explosion at the last one sent shrapnel into the oil cooler of his plane. McCullah placed a distress call and made for the island's western reef. Then he tightened his seat belt, locked the canopy back, and turned off the plane's engine switch. Placing his left hand on the cockpit coaming, he braced for impact.
"There was no shock," McCullah later wrote in a mission report. He launched his life raft and swam across the reef, where a rescue aircraft swept down to pick him up. For the rest of his life,
McCullah-who, after his rescue, went back to the base, had a brandy, and then flew another mission the next day-retold the story of that landing. "And many other ones," his son, Patrick, told me by phone from Florida, where McCullah lives (with dementia) at age 92. "His tales were tall, but they were true."

Today, McCullah's plane rests intact on the seabed, with its nose up against the edge of the reef, like a car driven up onto a curb and abandoned. But time has turned the craft into a relic: corrosion has gnawed at the metal, and the reef has crept into the propellers and the engine; a large, bulbous coral head has taken up occupancy in the cockpit. Originally painted blue, with a white star-and-bar symbol, the aircraft has been scoured to bare aluminum.

Scripps wants to use its technology to document this chapter of the Corsair's story too, before it ends altogether. "We're not only here to find and detect underwater objects, but to get a snapshot of the state of those objects that may be corroding or eroding away in time," Terrill says. "There's a whole new field in trying to baseline-capture all the detail we can about these historic artifacts. I'm calling it digital preservation."

Suzanne Finney, an American archaeologist working with Palau's Bureau of Arts and Culture, joins us for the 45-minute boat ride to the site of the Corsair. Marine archeology rarely gets to benefit from such advances, she says. "Most of the work I've done, you've got a tape measure and some string and a dive slate and a pencil, and you're taking photographs and measurements by hand. And that's what you do." With data from the robotic vehicles, Palau can add downed aircraft to an inventory of the country's rich underwater sites, something previously unattainable for an office that can barely afford to buy gas for a boat. "There are a lot of wrecks in water that's inaccessible to diving," she says, "so you need remote-sensing equipment." By the time the expedition ends, the AUV has scanned 18.9 square kilometers of the seafloor at slightly better than 10cm resolution, an area that would have taken scuba divers a decade to explore. The sonar also revealed what Terrill says could be a new species of coral.

When we reach the Corsair, engineers lower the Remus, now equipped with GoPro HERO3 HD cameras, into the water, and it once again begins a methodical sweep. Back in California, Terrill and his team will use the thousands of captured images, plus hundreds of photos taken by human divers, to build a 3-D reconstruction of the plane. Terrill is beta-testing algorithms developed by Autodesk for the company's new cloud-based, reality-capture software, called ReCap; the software has been designed to model aboveground areas like historic sites and factory floors, and Terrill is evaluating how well it works in an aquatic environment, where light is distorted. "Man-made structures underwater are an ideal testbed for that," he says. "If it pans out, it'll be a great archaeological tool to baseline a lot of these wrecks."

Scientists and naval historians could use such technology to document how wreck sites decay. Oceanographers and biologists studying living structures such as coral reefs could also benefit from it; 3-D models would enable them to detect how ocean acidification and events like typhoons alter reefs over time. And, of course, Scannon hopes that one day AUVs will lead him to his biggest find, the final B-24, so that a perfect replica of it, too, can be recorded for posterity. For now, it still lies somewhere in the lagoons surrounding Palau, concealed by water and time.

This article originally appeared in the September 2013 issue of Popular Science.

The U.S. invasion of Iraq combined with the American-led war in Afghanistan provided a great profit opportunity for the body armor manufacturer DHB Industries, which offered the military a needed, life-saving product. David H. Brooks, DHB's founder and then-CEO, took this opportunity to instead inflate his company's value through false claims of larger inventory, squirrel away wealth through falsified tax forms, trade on insider knowledge, exploit the patriotism of people who thought they were investing in American soldiers, and then skip out on the company that bears his name right before revelations of his fraud sent the stock price tumbling down to pennies a share. Yesterday he was sentenced to 17 years in prison.

Brooks's fraud fortunately didn't involve making sub-par armor. The Interceptor Body Armor DHB produced has largely been replaced by the "Improved Outer Tactical Vest," made by (among others) Brooks's former company, since renamed Point Blank Solutions, Inc.

[NYT]

GPS is really good at finding where people are, typically with a margin of error of just a few meters. That's fine if you're using GPS for driving directions, but if you're, say, a drone operator, you might want to navigate the sky more precisely, as a few feet can mean the difference between flying between buildings and crashing into them. Created by Swift Navigation, the Piksi (pronounced "pixie") GPS receiver could give unmanned aerial vehicles a GPS signal accurate to an inch. The project has already received nearly six times its initial funding goal on Kickstarter.

Fergus Noble and Colin Beighley, the guys behind Swift Navigation, have experience in drones, specifically with work on wind turbines attached to flying kites. Knowing the precise location of a kite as it flies in circles is important, because the kite will fly autonomously for months and needs to self-correct back to a designated course in case anything sends it off-track. Knowing precisely where it is within inches is much better than being off by several feet. This was an especially acute need with some small prototypes flying in circles not much bigger than regular GPS margin of error.

Unfortunately, the available technology to track such kites is super expensive. For example, the trade publication GPS World names the Sokkia GRX2 as a low-cost possibility, and it costs $14,500. That might be low cost for the Pentagon or Exxon Mobil, but for most everyone else it's a little pricey. Faced with that, Noble and Beighley set out to create their own version.

The Piksi is a Real-Time Kinematic (RTK) GPS receiver, best explained in reverse. The receiver part means it gets signals from satellites in Earth's orbit. These satellites transmit a signal of their own location in orbit, with a time signature, down to Earth. A receiver uses the signals from four or more satellites to pinpoint a spot on Earth. Wherever the signals overlap on Earth, that's where the receiver is, and this makes the GPS system. However, the size of the waves transmitting the signal mean that the spot of overlap is several feet.

RTK works from a disparity in the length of the code transmitted and the length of the wave carrying the signal. The signal itself travels in a wave, with the location information coded in segments 985 feet long. The waves making up that code are much smaller than the whole code, with each wave about 7.5 inches from peak to peak.

Piksi uses this information to create a more precise measurement. In communication with another RTK receiver for reference, the RTK GPS system, like one in use on a drone, compares the difference in number of wavelengths between the reference point and the system itself. Since the reference point is a known location, this cross-checking of wavelengths, combined with clever algorithms, lets the RTK receiver pin the location down to within inches.

To make this clever system available at just $900, the Piksi uses open-source software and a two-receiver check system. Cheaper, commercially available processors also help bring costs down. Noble also tells Popular Science that another reason for high competitor costs is simply "that the market can bear it." With the billion-dollar budgets of oil companies and military clients, prices in the thousands of dollars are hardly notable.

For real-world applications, imagine a crop-dusting robot that flies low and precisely over every single row of corn, or a small drone that carries packages from rooftop to rooftop with the precision of a carrier pigeon.

Watch their pitch below:

Looking for a nice long-form article to read this weekend? We recommend you head over to BuzzFeeᴅ and check out this feature on the history of MSG-the much and unfairly maligned naturally occurring ingredient in so many of our favorite foods. The piece, written by former PopularScience.com head honcho John Mahoney, dives deep into the science and history of monosodium glutamate. It should give you plenty of ammo the next time your older relatives refuse to eat at your favorite Chinese restaurant due to a mistaken belief that MSG causes headaches or other illness. An excerpt:

It's a great piece; the history of MSG and anti-MSG fervor is a heady mix of chemistry, racism, and taste, all folded up into the history of American food and the several renaissances it's seen in the past five or six decades. Read it here.

"Remind me not to forget…" I often say to my roommate. My phone charger. The sandwich I made to take to work. The bill I need to put in the mail.

The way our brain handles remembering to remember something, called prospective memory, has been somewhat of a mystery to scientists. New research probes how our brain processes the intention to act at a certain point in time--like remembering to grab something before walking out the door or to take a pill at a certain time--finding that it involves two distinct brain processes.

If you really don't want to forget something as you leave the house, put it by the door.Researchers from Washington University in St. Louis instructed study subjects to lie in an fMRI scanner and organize words that popped up on a screen into different categories by pushing two buttons. Meanwhile, they had to remember to push a third button if a special target (either a specific word or syllable) appeared.

The participants showed different patterns of brain activation depending on what they were trying to remember. If the target they were trying to identify was like the other words they were seeing, remembering involved a different process than when the target was something unrelated to their main task.

When the target in question was only a syllable something that had nothing to do with categorizing words ("tor"), the participants had to constantly remind themselves to push the target button. That method is called a top-down brain process.

By contrast, when the target was a full word like "table"--similar to the words participants were already seeing as part of the categorization task--the participants weren't forced to pay attention so rigorously. Instead, the participants used a different set of brain regions to spontaneously remember to press the button when the word popped up. Because the participants were already paying attention to different words on the screen, "table" triggered a reminder, sort of like putting something important near the door so you can't help but see it as you leave.

This suggests that two different neural routes control how we remember to remember something. The researchers write that this could be a practical adaptation to keep the brain from being constantly overwhelmed, since the top-down, attentive approach to prospective memory requires a lot of brain power.

In short: Science says if you really don't want to forget something as you leave the house, just put it by the door.

The study is published online in Psychological Science.

[Association for Psychological Science]

Throughout their 23-year history, automatic guitar tuners have remained stubbornly complex systems that cost thousands of dollars and require tedious professional installation. Chris Adams, CEO of Tronical in Hamburg, Germany, has figured out a way around these problems. Using an off-the-shelf microprocessor, custom tuning algorithms, and six lightweight motors, Adams developed the first system that musicians can retrofit onto nearly any guitar's headstock-without any wiring, drilling, or soldering. Once attached, his $299 TronicalTune can make an instrument pitch-perfect in about five seconds.

ATTACH

The TronicalTune consists of a three-inch computer and six motorized tuning pegs, which screw onto the headstock in place of the existing pegs. On traditional tuning pegs, strings thread through holes-a technique that can cause breakage when strings rub against the edges. TronicalTune uses a gentler method: The strings coil around rods on the pegs.

TUNE

After selecting from 12 presets (e.g., standard, open E), a user strums all six strings at once. A piezoelectric sensor picks up the vibrations, and a processor separates out the tones of each string. When it detects an off-pitch note, it signals the servomotor in the peg to turn, tightening or loosening the string to adjust the pitch. Once all six strings are tuned, the system turns itself off.

REFINE

Different guitar bodies and strings create slight variations in timbre, so Adams programmed the TronicalTune to grow accustomed to a guitar over the course of 10 to 20 tunings. The processor tracks the overtones and adjusts its tuning accordingly.

TronicalTune

Tuning Time: 3-10 seconds
Weight: 9 ounces
Price:$299

This article originally appeared in the August 2013 issue of Popular Science. See more stories from the magazine here.

For any garage-ista ready to tackle molecular biology, the centrifuge is an essential laboratory tool. Its super-rapid spin supplies the right G-forces to neatly separate biological materials-including cells, proteins, and DNA-from a liquid. University-grade centrifuges sell for about $2,000, but synthetic biology enthusiast and inventor Cathal Garvey figured out how to build one with a Dremel tool and a 3-D-printed wheel. The combination can spin samples up to 33,000 rpm, creating forces 50,000 times stronger than Earth's gravitational pull.

The 3-D-printed wheel looks deceptively simple, with six slots for standard 1.5-microliter Eppendorf tubes, oriented horizontally. Garvey says his early prototypes often deformed, which cracked and shot off tubes like oversize plastic bullets. "People said I was mad," Garvey says. Yet he prevailed, reshaping the wheel's slots to safely cradle the tubes' thick rims. "I've never had a tube eject since," he says. Still, Garvey advises using extreme caution-and proper eye protection-when running what he's dubbed the Dremelfuge.

INSTRUCTIONS

1) Download schematics for the Dremelfuge wheel here. Two designs are available; pick the one that fits a Dremel 300 (not a standard drill).

2) 3-D-print the wheel in ABS plastic, using hexagonal infill to strengthen it. (PLA is another common printing material, but Garvey says it tends to shatter under high G-forces.) If you lack a 3-D printer, order the wheel from Shapeways.com for about $50.

3) Screw a rotary-tool disc holder into the wheel's axis, and attach it to a Dremel.

4) Fit any tubes containing a biological sample into the wheel, ensuring each has a counterweight: a tube on the opposite side with an equal amount of liquid. Otherwise, they might damage the wheel and the Dremel and make a mess.

5) Hold the Dremelfuge in a Styrofoam cooler, and let 'er rip! The foam will absorb the impact if a tube pops off.

WARNING: Use shatterproof eye protection, and operate the Dremelfuge inside a sturdy container, as the device can throw off hunks of plastic at dangerously high speeds.

TEST RUN

The cells lining your inner cheeks constantly slough off into saliva but are too small to see individually-which makes them perfect candidates for testing the Dremelfuge.

1) Swab a Q-tip inside your mouth for about 10 seconds to grab some cheek cells.

2) Dip the cotton tip repeatedly in a tube filled with isotonic saline solution to dislodge the cells. (Make your own solution from salt and distilled water, or buy wound wash at a pharmacy.)

3) Fill a second tube to the same level as the other one. Insert the tubes in opposite slots in the 3-D-printed wheel.

4) Run for one minute at the Dremel's second setting (about 10,000 rpm). You'll see a whitish pellet at the bottom of the tubes. Voilà! Isolated cheek cells.

THE DREMELFUGE

Time: 1 hour

Cost: $50 or less

Difficulty: 1/5

This article originally appeared in the August 2013 issue of Popular Science. See more stories from the magazine here.

Yesterday the CIA declassified a 400-page document about Area 51, the secret facility in the Nevada desert that has fascinated armchair historians and tormented conspiracy theorists for decades.

The site, about 50 miles northeast northwest of Las Vegas, has been associated with a number of legends and rumors: about strange aircraft, experimental weapons, weather control, and especiallyaliens. So many alienconspiracytheories.

Area 51, it turns out, was just test site that housed spy planes, most notably the U-2. Introduced in 1957, the U-2 could travel as far as 7,000 miles, at an altitude of 70,000 feet, and stay airborne for up to 12 hours. U-2s are still in service with the U.S. Air Force today, and the old film cameras have been replaced U-2s used to carry have been replaced by digital cameras. In fact, some public land has weird, barcode-like patterns on it, built for U-2 camera tests.

Why is the CIA involved? Before spy satellites, U-2s flew over the Soviet Union to collect information about the USSR's nuclear program. This was intelligence by airplane, conducted secretly and with huge consequences on the international stage. In 1960, a U-2 was shot down by Russia, spoiling a diplomatic meeting and escalating Cold War tensions. Later, in 1962, a U-2 took photos of what looked like preparations for nuclear weapons in Cuba, sparking the Cuban Missile Crisis. This is all old history by now, but when the CIA first classified the U-2 program and chose to keep Area 51 a secret, it was state-of-the-art technology, and an incredibly important test site for collecting secrets.

The declassification of the CIA's documents won't deter any conspiracy theorists; the kind of person who thinks the government creates weather machines for mind control will have no qualms believing the government also falsifies documents to cover up evidence of the same.

2 pounds: the weight of the olinguito, an adorable carnivorous mammal species just discovered in South America

20 millikelvins: the temperature at which scientists recently achieved reliable, on-demand quantum teleportation

700 miles per hour: the speed at which Elon Musk's proposed Hyperloop railway system would shoot passengers across the country

50 million years: the amount of time these two galaxies will be colliding, spewing superheated gas and x-rays into space

3,467 miles: the slice of Mars captured in a new radar image from the Mars Express orbiter

17 years: the prison term this ex-chief of a U.S. military supplier just earned for insider trading, fraud, lying to auditors, and obstruction of justice (eesh)

$15,000: the funding three college students need to build an electricity-free light bulb powered by bacteria

6 percent: the portion of medical marijuana studies from the past year that investigated the drug's benefits, rather than its harms

165 million years: the age of a newly discovered fossil with preserved hair residue-evidence that fur evolved long before the rise of modern mammals

3 inches: the height of a goofy-looking leaping robot that can control its landing by moving its tail in midair

18: the number of whiskers on the autonomous Shrewbot research robot

$900: the price of a new GPS receiver that offers navigation accurate to an inch

67: the documented number of uncontacted people living in the rainforest of Brazil. Government workers recently captured rare footage of one isolated tribe.

$1,325: the price of a paddleboard made from coconut husks

Never. We're probably stuck with our appendix, pinky toes, tailbone and just about all of our other evolutionary holdovers. Wisdom teeth may eventually go, but major changes like losing an appendage (teeth included) take millions and millions of years - who knows if humans will even be around that long. What's more, most of our seemingly useless vestiges are actually helpful.

The coccyx, or tailbone, "is an attachment point of a number of muscles at the pelvis. We need it for upright locomotion. It would be catastrophic if it went away," says Kenneth Saladin, an anatomist and physiologist at Georgia College and State University. The appendix, which helped our distant ancestors digest grass, has slowly evolved to take on a new purpose. Research led by William Parker and R. Randall Bollinger of Duke University has shown that the appendix now serves as a kind of "safe house" for the microbes that aid in digestion. "Each of us has 900 to 1,600 species of bacteria in our gut to make sure we have a healthy immune system," says Stephen Stearns, an evolutionary-biology professor at Yale University. "If one takes over, or they all get flushed out by a disease, then the appendix works like a holding tank for the good bacteria." Even the pinky toe helps keep our balance and diffuses impact throughout the foot when we run.

There are only a handful of truly useless parts of our body, but these are hanging on too. As Saladin puts it, "since vestiges like the muscles behind our ears have very little impact on reproductive success, there's no way to select against them." In other words, the ability to earwiggle doesn't interfere with having kids. Wisdom teeth were, like the appendix, good when we were eating lots of plants, but today only about 5 percent of us have jaws large enough for these extra molars. "Wisdom teeth are probably on their way out," Stearns says, "but it will take a long time."

The silliest of all vestiges is the male nipple. "Those don't have a function," Stearns says, "but they won't disappear either." All embryos, male and female, begin developing according to the female body plan. Only around the sixth week of gestation do the genes on males' Y chromosomes kick in. "The basic developmental plan has the two nipples there, so you can't get rid of them genetically because that would mess up the breasts of females." And nobody wants that.

This article originally appeared in the February 2011 issue of Popular Science magazine.

By using a special type of film that takes a physical impression of moving water, photographer Moses Hacmon created these totally astounding images. He calls the series "Faces of Water," and after hearing that, it's hard not to see some actual faces in the photos, which is a nice thing to think about the next time you drain a glass.

Hacmon's raising money at crowdfunding site USA Projects to make larger versions of the prints, but you can enjoy these computer-sized versions until the 4-by-8-foot versions are (hopefully) available.

[USA Projects via Xaxor]

Ever wonder where those beautiful, bright photos of amoebas and bacteria and other tiny weird stuff come from? Somebody's got to take and process those photographs, and our friends over at Popular Photography found one of those very people. Dennis Kunkel, who holds a Ph.D in botany, is a go-to stock photographer for researchers, news publications, museums, textbook publishers, and more--anytime you've got something weird and tiny you want to see, Kunkel's your man. Head over to PopPhoto to see how he does it.

On the afternoon of August 19, 1812, about 400 miles southeast of Halifax, Nova Scotia, the USS Constitution knocked the masts off the British warship HMS Guerriere. The battle earned the U.S. ship the nickname "Old Ironsides," in no small part due to the density of American oak, which repelled cannon shots better than the less-dense oak from Europe. Today the USS Constitution, with 215 years of service, is the longest-serving warship in the U.S. Navy.

Pictured above is the original sail plan for the USS Constitution from 1797. Pretty majestic, right?

Back in the 1790s, the U.S. faced an uncertain world of revolutions, rising superpowers, and piracy off the coasts of Africa. The Naval Act of 1794 created the first U.S. Navy ships since the Revolutionary War, including the USS Constitution.

Two very important and competing threats influenced the construction of the USS Constitution. The first was pirate attacks against American merchant ships in the Mediterranean. To outgun these pirates, the ship carried 44 heavy cannons.

The second challenge was the threat of the more-established European navies, which maintained much larger warships than those of the U.S. Called "ships of the line," they were massive, heavily armed, and held hundreds of crewmen and marines. The USS Constitution was built to outgun any ship the same size or smaller, and at the same time to sail faster than any bigger ship.

Crucial to those goals was a narrow body and a lot of sails: 42,710 square feet of sail on three masts, to be exact.

Today, the USS Constitution is both a commissioned naval vessel and a living museum in Boston Harbor.