Popular ScienceJanuary 2014的目錄

ITOOK A JOB at Popular Science in 2006, fresh from a yearlong stint as a health and fitness editor. On my first day, in a story meeting, I confidently and casually praised the life-extending virtues of resveratrol, a compound found in red wine I'd been reading about that morning, and suggested we run a story about it. At that point, I'd mostly worked in publishing environments where the staff simply nodded at the ideas of the highest-paid person in the room. But no one was nodding. Instead, they were silent. “Resveratrol is unproven,” Martha Harbison, our senior editor, told me flatly. I opened my mouth to speak, but she was already laying out, in a rising voice, the rickety case I was about to make, and then she dismantled it…

For years, automakers have worked to push fuel economy beyond 100 miles per gallon. Reaching that mark typically meant three things: cutting weight, maximizing aerodynamics, and improving powertrain efficiency. In 1999, Volkswagen engineers got close with the Lupo 3L, a three-cylinder coupe that could go 78.4 miles on one gallon of diesel. Not satisfied, VW tasked star engineer Ulrich Hackenberg, whose résumé includes work at Bentley and Bugatti, with breaking the 100mpg barrier. Hackenberg's team crushed that goal—and then some. In tests, their new XL1 got a mind-bending 261 mpg. The team designed nearly every part of the XL1 from scratch. To trim weight and add strength, they replaced some steel components, such as the chassis, with carbon-fiber ones. To reduce drag, they removed side-view mirrors and sculpted the body…

Call it the curse of the picture window. Big panes may light up a home, but they also let in enough heat to drive up the temperature by several degrees, raising cooling costs. Self-tinting windows solve the problem, darkening or turning opaque on command, but they are expensive and require custom installation. California start-up SONTE has developed an alternate approach: an affordable after-market tinting treatment. SONTE film works like an ultrathin LCD TV. It consists of a layer of conductive liquid-crystal polymer sandwiched between layers of PET plastic. Users trim the film to the size of the window and smooth it onto the glass. A semipermanent adhesive holds the film in place. Each kit comes with a quarter-size clip, which attaches to a corner of the film and plugs into…

More than 1,000 working satellites orbit Earth. As space becomes increasingly crowded, there's a greater chance that the satellites' radio signals could overlap. To avoid that problem, which disrupts communications, satellite antennas must transmit only within a narrow frequency band. The radio-frequency anechoic chamber at the Technical University of Denmark (DTU) is one of the best places in the world to accurately calibrate antennas. A steel Faraday cage surrounding the chamber blocks interference from external sources, such as Wi-Fi and broadband networks. Inside, foam pyramids stop a satellite's own radio waves from bouncing around, to ensure that a receiver in the chamber measures only the signals coming directly from the antenna and not reflections. (The pyramids dissipate the signals as they travel from tip to base.) Engineers then use the…

A SINGLE film can come from many sources of inspiration, but part of the idea for the movie Her came 10 years ago, when writer and director Spike Jonze was interacting with an online chatbot. More specifically, it came midway through the conversation, when things got weird. “You're not very interesting,” the bot told him. The filmmaker wasn't charmed, but he was intrigued. Instead of seeming blandly, vaguely human, Jonze says, “it was sassy and had an attitude and a point of view of the world.”…

One of Europe's newest solar- and biofuel-power stations is a former Hamburg air-raid shelter called the Energiebunker. The 138-foot-tall structure was inaugurated last year and is scheduled for completion in 2015. It holds equipment that will generate electricity for 1,000 households and heat for 3,000, creating 95 percent less carbon-dioxide emissions from heating than oil and gas boilers. Six years ago, Tel Aviv University researchers found 10 species of endangered bats in abandoned bunkers on Israel's Jordanian border. It's a quiet home—much of the area is an off-limits minefield. The scientists added wire mesh and roughed-up cement for better bat grip and insulation. Internet provider Bahnhof turned a Cold War-era, nuclear-bomb-proof bunker 98 feet below the streets of Stockholm into its exceptionally secure headquarters and data center. The newly renovated…

Single bio-inspired drones are useful, but dozens can work together to accomplish a complex task. Vijay Kumar, an engineer at the University of Pennsylvania, teamed up with Arizona State University biologist Stephen Pratt to apply three lessons learned from ant swarms to fleets of quadrotors. In nature, ants act autonomously. Engineers traditionally use a centralized system to choreograph movement in swarms, Kumar says. As a swarm grows larger, the control algorithms become increasingly complex. Instead, Kumar tries to program his aerial vehicles with a common set of instructions; the quadrotors divide up tasks and assume complementary roles. Individual ants are interchangeable. “If I want to scale up my swarm, maintain the predictability of its behavior, and make it robust, the gang has to be able to perform the task if…

This year, the U.S. Army will build mobile decontamination labs called Field Deployable Hydrolysis Systems (FDHS) that can rapidly neutralize bulk chemical-warfare agents such as sarin. The technology could be particularly useful in a country like Syria, which does not have the proper facilities to destroy its chemical-weapons supplies. STEP ONE: Dilute a given amount of chemical-weapon agent with water in the lab's titanium tank, then add bleach (sodium hypochlorite) and lye (sodium hydroxide). STEP TWO: Heat titanium tank with mixture to just about boiling for three hours. In that time, the bleach, water, and lye will hydrolyze 99.9 percent of the chemical agent. STEP THREE: Transfer the byproducts into a tanker for shipment to a regular hazardous-waste facility, where they will be further processed.…

CANCER PRESENTS many bedeviling issues, starting with diagnosis. Tissue biopsies, the only surefire test for most cancers, are invasive and painful and can cause infection. They also tend to be performed after symptoms have developed, and that's often too late. A new diagnostic tool may make identifying some diseases much easier. Within the body, tiny sacs called exosomes travel through fluids, such as blood, urine, and saliva. They shuttle genetic material and proteins between cells, playing an important role in cellular communication. “We like to think of it as the body's Federal Express system,” says James McCullough, CEO of Exosome Diagnostics. McCullough's company developed a test to capture those messengers and analyze the RNA they contain, flagging mutations that point to the presence of malignant cells. Another company, Caris Life…

In 1900, the U.S. death rate from infectious disease was 40 times higher than it is today. But despite the progress made last century, some illnesses have begun to reappear. “We are facing a perfect storm of vulnerability,” says Tom Frieden, director of the Centers for Disease Control, citing increasing travel and food trade, failure to vaccinate against preventable diseases, and poor antibiotic management as causes. Cases of pertussis, or whooping cough, have climbed in the U.S. for several reasons. For one, the vaccine adopted in the 1990s wears off faster than the previous vaccine did. Better diagnostic tests in the U.S. may also contribute to the higher prevalance. Measles was eliminated in the U.S. in 2000, but cases still pop up when unvaccinated people pick up the highly contagious…

Gy It's extremely rare to experience prolonged sideways G-force in an air- or spacecraft. Only a flat spin or a T-bone collision tends to produce it. Gy can move or even dislodge organs. Gx This is the classic lips-peeled-back G-force. It looks gruesome, but it's the most tolerable: In the 1950s, U.S. Air Force Colonel John Stapp showed a human can survive more than 45 Gx. Gz The vertical G-force arises when the craft performs loops. It induces tunnel vision and unconsciousness when too much G-force drains blood from the head.…

GRAEME OBREE doesn't own a car. And why would he? The Scottish racing cyclist built a bike in his kitchen that can travel at highway speeds. Last year, it even broke a world record. Obree is no cycling novice. In 1993, he broke the world record for distance biked in an hour: He cycled 32 miles in 60 minutes on a closed track. Another cyclist broke the record later that year, but in 1994 Obree reclaimed the title. “Winning is almost like a drug you keep needing more of,” he says. So Obree kept competing. And after winning two races in 2007, at age 42, he gained the confidence to try something few people had ever attempted: to build the planet's fastest human-powered vehicle. It would have to exceed 82.819…

(good idea) Belt sanders may smooth floors and strip paint, but YouTube user wyldediver demonstrates how they can also breathe new life into dull blades. To sharpen yours, start with a 150-grit belt. Slowly run one side of the blade across the belt a few times using light pressure (the sharp edge should point down at an acute angle to the belt). Next, sand the other side. Turn off the sander, swap in a 240-grit belt, and sharpen again. Repeat the cycle for 400-grit, 20-micron, and finally 9-micron belts. Buff away any flecks with a leather sanding belt treated with polishing compound. (bad idea) Long nails? Callused feet? You'll need help, just not from this power tool. Sanding belts move upwards of 1,000 rpm, so contact could leave you abraded…

short answer It's not impossible. long answer It's very hard to figure out when the influenza virus first started making animals sick. Studies of the history of major human epidemics suggest the flu has been around for at least a thousand years. “The certainty diminishes as we go further back into the past,” says David Morens, of the National Institute of Allergy and Infectious Diseases. “We can say for certain that influenza has been around since 1918 because we have the 1918 virus. Before that time, we have to speculate or make an educated guess.” By looking for clues in contemporary accounts of disease outbreaks, Morens has concluded, with 95 percent certainty, that humans were getting the flu as far back as 1510 A.D. His confidence drops to about 80…

Several of the world's largest desalination plants sit along the coast of the United Arab Emirates. Every year, they deliver 115 billion gallons of potable water to more than 550,000 people in Dubai alone. But the plants have had to slow or shut down production more frequently over the past decade because of an unexpected disturbance: massive algal blooms in the Gulf of Oman and the Persian Gulf. The algae, known as red tide, clog pipes and filters at the plants. For warning of an approaching bloom, local authorities now consult data from a European Space Agency project, which began in 2012. When a passing satellite captures an image of an algal bloom (and software scans for the algae's chlorophyll, represented by the intensity of redness), officials alert plant managers,…

Even though skiers are spending more time hiking into the backcountry, their boots are still geared to traditional lift-access runs. Most alpine boots have cuffs and uppers that are single, rigid pieces, which makes walking in them awkward and painful. And boots made specifically for trudging through snow are so flexible that they're harder to control when skiing downhill. With stronger materials and adjustable cuffs, manufacturers are creating a new, adaptable breed of boot—one that offers comfort on the way up without sacrificing support on the run down.…

The Novaerus air-filtration system uses a cold plasma field to destroy virtually 100 percent of airborne pathogens. Removing them from the air decreases surface contaminants as well. Scientists at Microsearch Laboratories in the U.K. fed a variety of pathogens through the intake vent of the system. They then analyzed the samples after they passed through the output vent. The Novaerus killed all but 0.001 percent of bacteria cells, bacterial spores, mold, and yeasts. It also destroyed all but one-billionth of a percent of viruses. The system draws air into the unit and through a plasma field, which, among other stressors, bombards the targets with UV radiation.…

“I made the Digital Chocolatier, a machine that builds chocolates layer by layer, from the bottom up. Four tubes hold nuts or chocolate. The chocolate tubes are heated for melting. For each layer, a servomotor positions the correct tube, and a valve releases the contents. Chocolate's hard to work with—it clogs—and we had to fabricate the parts because existing chocolate valves are too big for home use. Printing takes about a minute, and a thermoelectric plate and heat sink cool the printed treat. This machine is the first step toward a 3-D food printer. I'm convinced it's possible to create things you couldn't do by hand—for example, a cake that's chocolate and gradually swirls into a lemon pie. That's something we can do on a computer with a digital image…

Moon dust is dangerous. Each mote is like a tiny shard of glass—there's no wind or rain to soften the edges of lunar soil. During the Apollo missions, it jammed equipment and got stuck in the seals of space suits, causing a serious loss of pressure. Martian dust poses its own hazards. On the Red Planet, swirling dust storms have covered rovers' solar panels, significantly reducing their power while they waited for a favorable gust of wind. And if these kinds of space dust get into an airlock, forget it: It can be toxic or irritating to the lungs and could endanger astronauts' health on long missions. An electric charge can zap the stuff right off. NASA scientists proposed the idea in a 1967 paper, but the space agency didn't…

Nature spent millions of years perfecting flapping-wing flight. Now engineers can reproduce it with machines. Five years ago, Richard Guiler and Tom Vaneck were sitting at a bar a few blocks from their office, trying to take their minds off work. For nearly a year, the two engineers had been struggling to develop a durable drone that could dodge objects, navigate inside buildings, and fly in stormy weather. They'd tried fixed-wing models, but adding enough sensors to effectively detect obstacles made them too heavy to fly. They'd tried helicopters, but the rotors kept getting tangled in branches and electrical wires. They'd even built a motorized balloon; all it took was a gentle gust of wind to blow it off course. As they sat nursing their beers, Guiler and Vaneck watched…

IN JANUARY 2013, the Lunar Reconnaissance Orbiter received a historic transmission: an image of the Mona Lisa. It was the first time scientists used a laser to send data to the moon, a feat that promises to exponentially increase the flow of information to and from space. For the past 50 years, spacecraft have relied on radio waves to communicate with Earth. But radio has limitations. Airwaves are crowded. Signals degrade with distance, so transmissions require power-hungry generators and large antennas. Focused laser light operates in wavelengths 10,000 times shorter than radio, pumping out more waves—and more information—each second. Lasers maintain signal strength across large distances, so transmitters require less power. And spacecraft carrying smaller receivers would be cheaper to launch. In October, the Lunar Atmosphere and Dust Environment Explorer…

THE DOMESTIC-DRONE age will officially begin by year's end. That's when the Federal Aviation Administration (FAA) will issue a draft rule regulating the use of drones under 55 pounds in U.S. airspace, a category that includes most commercial models. But the devices will be in the air before then. Flight tests planned for 2014 will shape the future of unmanned aircraft for years and perhaps decades to come. At press time, groups from 24 states were competing to house six sanctioned test sites, where drone models and flight protocols will be evaluated. And although the FAA is expected to be restrictive in its initial guidelines—likely requiring constant line of sight between pilots and unmanned aerial systems (UAS), as well as an altitude ceiling of 400 feet—the testing at those sites…

UNITED STATES Federal funding for basic research and development in 2013 was down 8 percent from the previous year and 16 percent from its peak in 2010. Congressional 2014 budgets don't restore much, and sequestration caps could make money tight for the next decade. With research grants harder to come by, science in the U.S.—and the innovation and growth that result from it—will probably slow, according to Matt Hourihan, director of the budget program at the American Association for the Advancement of Science. FEDERAL RESEARCH & DEVELOPMENT SPENDING, 2004–2014…

BIG THINGS HAPPENED IN 2013 TOO. TWELVE HEADLINES FROM POPSCI.COM: february 11 “Mars Rover Curiosity Has Become the First Robot to Drill Another Planet” february 15 “Videos: Space Rock Explodes Over Russia” march 4 “5 Things You Should Know About the Baby Cured of HIV” march 13 “ALMA, Earth's Largest Telescope, Is Officially Open for Business” march 14 “New Results Confirm: The Particle Believed to Be the Higgs Boson Really Is the Higgs Boson” april 22 “Apply Now for a One-Way Trip to Mars” may 14 “X-47B Takes Off from an Aircraft Carrier” june 13 “U.S. Supreme Court Rules on Gene Patents” august 5 “The First Lab-Grown Hamburger Is Served” september 6 “NSA Has Secretly Been Hacking, Cracking, and Circumventing Encryption for Years” september 12 “Voyager 1 Has Entered Interstellar…

ON A COLD, GRAY DAY in central London, Alastair Parvin is staring at a coffeepot, or what used to be one before he took it apart to clean it. The appliance lies strewn across an office table, a wreck of wet steel and springs. Parvin co-founded WikiHouse, an open-source construction system that could transform how people design and construct buildings. But rebuilding a percolator seems to have him stumped. After a few failed attempts, Parvin reconstructs the machine, produces coffee, and shows me around the maker space he shares on one floor of a mid-20th-century skyscraper. It's a sprawling landscape of desks, sofas, and bulletin boards with a plywood house frame rising from within the common area. It's also an apt manifestation of WikiHouse itself: occupants taking back architecture on…

POSTURE Obree cut up a saucepan and crafted the pieces into a shoulder brace. STRUCTURE Steel-and-manganese poles make for a strong yet lightweight frame. Obree joined the pieces with silver because he could easily melt the metal at home with a plumber's torch. POWER Boomerang-shaped bars allow horizontal pedaling at the back of the bike. SPEED & SAFETY A shell made of lightweight Kevlar and fiberglass reduces drag while protecting Obree from wipeouts. A small window helps him see the road as he breathes through a snorkel.…

Tollbooth plazas aren't the only locations that scan car tags like the E-ZPass. One wary driver in New York City modified his tag to sound off during activation. “I drove around [Manhattan] and realized, Wow, this is being read everywhere!” he says. Car tags “listen” for a wireless signal from an electronic reader. When that signal is strong enough, a tag draws power from an onboard battery to broadcast its serial number. Here's how to keep tabs on your tag's activity. For full instructions and an in-depth story, visitpopsci.com/ezhack. INSTRUCTIONS TIME 2 hours COST About $55 DIFFICULTY Cut open a car tag, and snip the battery's negative lead. (The circuit added after this step will detect any drain on the battery during a scan.) Build the circuit shown at popsci.com/ezhack…

The astronaut on Popular Science's February 1982 cover introduced a new kind of space traveler: the mission specialist. Until then, NASA had required astronauts to be certified jet pilots. Mission specialists focused on tasks other than flight, such as conducting scientific research or repairing equipment, and some worked as physicians or engineers on Earth. More than 120 civilians have since traveled to space on NASA missions. Today's private industry will open low Earth orbit to even more people. But like the early explorers, they will have to train rigorously. To see if you're up to it, turn to page 54. Man In April 1961, the Soviet cosmonaut Yury Gagarin orbited Earth aboard Vostok 1, spending 89 minutes in space. Woman Valentina Tereshkova, chosen because of her parachuting expertise, orbited Earth…

The robot of the popular imagination, whether it's R2D2 or Rosie, just works. But in reality, making a robot just work takes a lot of hard work. Many would-be roboticists give up when faced with a soldering iron, an Arduino board, and lines of code. The EZ-Robot kits make constructing and coding modular, so anyone can build a custom bot in 30 minutes or less. Builders assemble their EZ-Robots physically and digitally. They attach motors and appendages to a controller board that contains a processor and a Wi-Fi radio. Alongside their creation, users configure their robot with the EZ-Builder PC software, selecting from more than 200 behaviors (dancing, chatting), which sync to the bot over Wi-Fi. Advanced users can code their own robotic quirks and even download plans to 3-D—print…

Photographers typically have two options when shooting underwater: double the size of their D-SLR with an expensive submersible housing or opt for a waterproof point-and-shoot with the image quality of, well, a point-and-shoot. Mirrorless interchangeable-lens cameras, such as the Nikon 1 AW1, produce D-SLR—quality images minus the delicate moving parts of D-SLRs themselves. The compact internals allow engineers to ruggedize and seal the camera without adding much bulk. When a lens zooms, small crevices between the stacked components open. The entire AW1 lens is enclosed in a sealed barrel. As the camera zooms—up to 27.5 millimeters—all the parts remain protected. The lens mount on the AW1 is raised about six millimeters above the camera body. Lenses slip over it and into a groove in the housing. A greased rubber O-ring…

ON CHICAGO'S gang-embattled South Side, a shooting can incite swift retaliation, which spawns even further violence. That's what may have happened in September in Cornell Square Park when gunmen opened fire on a basketball court just hours after one of them had been wounded in a separate incident. When officers can't connect the dots between people fast enough, it's nearly impossible to get ahead of crime. In Cornell Square Park, the fallout wounded 13, including a three-year-old boy. Gang violence is generally not random. It's usually related to territorial disputes or personal rifts—that is, to geographic, cultural, and social connections. Some police departments have had marginal success monitoring social networks like Facebook for clues about where bloodshed might erupt next. But a new kind of software being used in Chicago…

The film Her, which opens across the country this month, tells a love story between a man and some software. It may seem far-fetched, but researchers say it's plausible. If so inclined, they could stitch together existing systems into one irresistible romance algorithm. Here's how a lovebot could seduce you. A program that asks lots of questions stays more in control of the conversation and is more likely to produce convincing, relevant replies. Software that attempts to answer a person's questions risks revealing just how little it knows about the world (and human emotions)—ruining the effect. That's why inquisitiveness is one of the most common and successful cheats for chatbots, dating back to Eliza, a program built at the Massachusetts Institute of Technology in the '60s. Its persistent queries were…

The Dutch police are training rats to sniff out drugs and gunpowder. A global commission officially changed the atomic weights of 19 chemical elements, including molybdenum, cadmium, selenium, and thorium. A Duke University team showed that monkeys with electrodes implanted in their brains could control two virtual arms at once, using just their thoughts. Archaeologists recovered five cannons off the North Carolina coast from a 1718 shipwreck captained by the infamous pirate Blackbeard. A Centers for Disease Control and Prevention report found that each year two million Americans get infections that are antibiotic-resistant. DARPA awarded Boston Dynamics $10 million to make its robotic pack mule LS3 quieter and more bulletproof. Korean researchers genetically engineered E. coli to produce gasoline.…

Using high-speed videography, scientists observed the precise motion of an insect's wings and identified the aerodynamic forces at play—insight that now informs the design of microdrones. As a wing flaps, a tornado-like spiral of air forms along its leading edge. This vortex causes air pressure to drop briefly above the wing; higher pressure pushes the wing from below. The wing rotates in preparation to flap in the opposite direction. This rotation creates forces similar to backspin on a tennis ball, pulling a faster stream of air over the top surface. As the wing moves in the opposite direction, it collides with the swirling vortex of air created by the previous stroke, a principle called wake capture. Depending on the angle of the wing as it hits the wake, it can…

ON OCTOBER 7, 2013, at the Swiss Federal Institute of Technology in Lausanne, one of the most ambitious brain-research projects in history officially kicked off. The Human Brain Project—backed by 1.2 billion euros and more than 250 researchers—aims to create the first complete computer simulation of the human brain. Over the course of a decade, everything we know about the organ's biology will be modeled. Eventually, virtual neurons will even be subjected to virtual drugs. The Human Brain Project is one element in a larger, interdisciplinary surge in brain research that has pulled engineers, data theorists, and other non-neuroscientists into various efforts. In the U.S., the government-led Brain Initiative plans to deliver its own “first”: a detailed map of all brain activity. The future potential ranges from the borderline poetic—watching…

FUKUSHIMA, JAPAN Last August, the Tokyo Electric Power Company (Tepco) admitted that a tank at the earthquake-crippled Fukushima nuclear power plant had leaked more than 300 tons of contaminated water into the ground. To prevent groundwater from carrying it to the ocean, Tepco announced plans to build an underground ice wall in 2014. STEP ONE: Install pipes three to five feet apart into the earth around the power plant. STEP TWO: Pump chilled coolant (calcium-chloride brine) into the pipes, and circulate it continuously through a refrigeration station. STEP THREE: Frozen ground around each pipe joins to form a wall of ice, blocking water flow.…

IT HASN'T EXACTLY been a banner year for privacy. Revelations of the National Security Agency's mass-surveillance efforts underscored the obvious need for better data security. Recent breakthroughs in quantum cryptography could provide just that: spyproof encryption that's no longer lodged in laboratories or stuck at industrial-grade price points. Quantum key distribution (QKD) is an essentially unbreakable encryption protocol that exploits one of quantum physics' more head-spinning principles—that simply observing information changes it. In a QKD-based system, a randomly generated key is encoded on light particles and shared through fiber-optic cables before being used to encrypt sensitive data. Any attempt to detect the key en route will alter its photons, indicating that the transmission has been intercepted and a new key is necessary. So far, QKD has remained tethered to fiber-optic…

SENDING PEOPLE to space has always involved a frank assessment of their defects, and in the early days, it was a matter of finding people without any. First it was fighter pilots—calm in a crisis, physically perfect, unquestioning in their execution of mission control's instructions. Then, as it became clear that space was more than a military objective, space agencies began to train scientists for flight, placing otherwise reasonable researchers into fighter jets and swimming pools and screening them relentlessly for defects of vision, circulation, or character. Now a new category of space traveler is headed beyond the stratosphere. Not the combat pilots and astrophysicists who train for at least two years just to get a shot at a trip, but the rest of us, with our carry-on bags, our…

Follow these five easy steps to design and build a home from scratch. Install Google SketchUp, a free 3-D—modeling program, and download the plug-in for WikiHouse (wikihouse.cc/guide/download). Choose a home design from the WikiHouse library, and click “make this house” in SketchUp to generate cutting files for its components. Use a CNC mill (or hire a machine shop) to cut the beams, panels, and other pieces from a sheet material such as plywood. Match the pieces to form a frame, and connect them with pegs. Raise the frame, and screw on the walls, roof, and floor panels. Plumb and wire the structure, and add insulation, windows, and cladding to weatherproof it. Now your new WikiHouse is ready for occupants.…

You don't need to be a paleontologist or travel through remote canyons to find exquisite fossils. The teeth, shells, and bones of ancient animals could lurk in a creek, quarry, or on a beach near you. Once you find a good location—the map below shows a bunch of spots—you'll need to separate fossils from surrounding soil. A mesh-lined letter tray works in a pinch, but the best option is to build your own sifter. We like this rig made from 1/4-inch chicken wire and 1-inch-by-2-inch planks. Wood floats, so your sieve won't sink, and the wire can catch shark or ray teeth, small bones, and even ammonite casts. It works best in water, where erosion has done most of the hard work; unwanted sand, dirt, and pebbles will wash out…

short answer Yes, but it's complicated. long answer At the yearly Rottnest Channel Swim in Western Australia, participants often smear their bodies with animal fat for insulation against the 70-degree water. But their own body fat also helps to keep them warm, like an extra layer of clothing beneath the skin. When scientists studied aspects of the event in 2006, they found that swimmers with a greater body mass index (BMI) appear to be at much lower risk of getting hypothermia. The same effect has been demonstrated in hospitals where patients who've suffered cardiac arrest are treated with “therapeutic hypothermia” to stave off brain injury and inflammation. Studies have shown that it takes longer to induce hypothermia in obese patients than in their leaner counterparts. The extra fat seems to…