When you see a flock of birds flying in formation, it might seem like their group dynamics are fairly simple: The one out front leads the way. But does the same birds always take the lead in a group? And do the birds in the back follow the overall leader, or rather the middle managers in front of them?
To find out, Tamás Vicsek and colleagues strapped backpacks equipped with GPS sensors to pigeons for a study out this week in Nature. The lightweight trackers recorded the birds on both solo flights and group flight and measured their positions five times per second. Indeed, Vicsek found, birds fly according to the group pecking order, with the leader out front. When it changed direction, its direct followers would do the same in less than a second, and then the more junior members of the group would respond to the direction of those middle managers.
But there were surprises, too. Sometimes the lead bird wouldn’t fly out front; it may have been tired from leading the pack and needed some time off. So perhaps birds are like cycling teams, occasionally trading off who carries the taxing burden of leading the group.
For more details about the study—including why it’s not as obvious as you might think that the leading bird flies in the front of the group, and why left and right matter so much to pigeons—check out DISCOVER blogger Ed Yong’s post at Not Exactly Rocket Science.
This time, Solar Impulse has really taken to the skies.
When we last left Swiss adventurer and around-the-world ballooning enthusiast Bertrand Piccard, he and his team were celebrating their first test flight of their solar-powered plane in December. However, those tests were really just “flea hop” tests to get the plane a couple feet off the ground. This time, though, Solar Impulse has completed a two-hour true test flight, a big step toward Piccard’s goal of flying the solar plane around the world.
At a military airport in the Swiss countryside, the “Solar Impulse” plane lifted off after only a short acceleration on the runway, reaching a speed no faster than 45 kph (28 mph). It slowly gained altitude above the green and beige fields, and disappeared eventually into the horizon as villagers watched from the nearest hills [AP]. Piccard says the test proved his plane—which weighs about as much as a car and runs on 12,000 solar cells with lithium batteries and electric engines as emergency backup—can not only fly, but fly straight. Since the plane will be flying without a drop of liquid fuel, he says, it must stay on its planned trajectory and conserve energy.
We gave the BBC a hard time this morning for going a little overboard in declaring the Large Hadron Collider a broken-down mess. But here’s something cool: In a new documentary, a team simulated the blast that “Underwear Bomber” Umar Farouk Abdulmutallab tried to create on Christmas Day last year. Their finding: Even if he had blown up the bomb successfully, it wouldn’t have been enough to take down flight 253 from Amsterdam to Detroit.
Dr John Wyatt, an international terrorism and explosives adviser to the UN, replicated the conditions on board the Detroit flight on a decommissioned Boeing 747 at an aircraft graveyard in Gloucestershire, England [BBC News]. Wyatt used the same amount of the explosive pentaerythritol that the bomber carried, about 80 grams, which packs about the punch of a hand grenade. They put it on the same seat and lit off a controlled explosion, which sent a shock wave through the aluminum exterior.
Thanks to a little technological ingenuity, we may soon get a look at what exactly is happening in the flying brain. In the journal Nature Neuroscience, Caltech researchers document how they managed to monitor the brain activity of fruit fly in flight.
“The challenge was to be able to gain access to the brain in a way that didn’t compromise the animal’s ability to fly, or to perform behavior,” said study researcher Michael Dickinson of Caltech. “We couldn’t just rip the brain out of the body and put it into a dish” [LiveScience]. Researchers have previously studied activity in the tiny brain of a living fruit fly, but only when it was restrained. Dickinson’s team created a way to look inside while the bug was flying around.
Until or unless we can create a Jurassic Park and build dinosaurs from DNA, the best way to study them may be to build dino models using materials like balsa wood, carbon fiber, and rubber bands.
That’s what a team did for a new study in the Proceedings of the National Academies of Sciences. To figure out how the 120-million-year-old winged dinosaurMicroraptor gui took to the skies, the researchers used a well-preserved fossil to build their own. “We went back and forth. We thought, maybe we’ll do 3-D graphics and it’ll look really cool. But it’s more accurate to do the modeling directly from the specimen,” said Dave Burnham, a paleontologist at the University of Kansas [Wired.com].
Austrian daredevil Felix Baumgartner officially announced that sometime this year, he intends to jump from a balloon at a height of nearly 23 miles, breaking the 50-year-old world record for the highest parachute jump held by retired U.S. Air Force pilot Joe Kittinger. Kittinger is the Stratos mission’s capcom (short for capsule communicator), which means that he will be the voice in Baumgartner’s helmet. Kittinger’s advice to his successor: “Have fun, enjoy it, and tell us all about it when you get down” [Scientific American].
The one-man stealth plane of the future is on the horizon–and it’s named after a conspicuously cute bird. NASA scientists will officially unveil their design for a hover-capable, electric-powered aircraft, nicknamed “the Puffin,” on Wednesday at an American Helicopter Society meeting in San Francisco.
On the ground, the Puffin is designed to stand on its tail, which splits into four legs to help serve as landing gear. As it prepares to take off, flaps on the wings would tilt to deflect air from the 2.3-meter-wide propeller rotors upward, keeping the plane on the ground until it was ready to fly and preventing errant gusts from tipping it over. The Puffin would rise, hover and then lean over to fly horizontally, with the pilot lying prone as if in a [hang] glider [Scientific American].
Air travelers around the country saw their flights delayed this morning, thanks to a computer glitch. The problem, which occured [sic] in the Atlanta-based computer system that provides data about flight plans, has forced air controllers to input the information manually, said Arlene Salac, FAA spokeswoman in New York [Reuters].
The Federal Aviation Administration tried to assure travelers that the problem wasn’t a safety concern; rather it fouled up ground stops and caused delays. The problems began a little after 5 a.m. Eastern time, and hit Atlanta’s busy airport the hardest. One passenger said that a Delta Air Lines gate agent had announced that the glitch prevented pilots from accessing flight plans, the Atlanta Journal-Constitution reported [The New York Times].
The computer problem has been fixed, though FAA spokeswoman Kathleen Bergen said she doesn’t know how many flights have been affected [MSNBC]. And today’s glitch was the second such one in 15 months.
The seeds that twirl down from maple trees every spring can fly as far as a mile, with each wing-shaped seed spinning like a whirligig on the air. Studies have shown that the seed’s whirling, called auto-rotation, gives it extra lift, but why this occurs has never been explained. It took an aerospace engineer, David Lentink of the Wagenigen University in the Netherlands, to figure it out [The New York Times].
Lentink and his colleagues first studied how a model of a maple seed moved in a tank of oil, and then filmed a real seed falling through a smoke-filled wind tunnel, which allowed them to observe the air currents around the seed. The images the team obtained showed that a swirling maple seed generates a tornado-like vortex that sits atop the front leading edge as the “helicopter” spins slowly to the ground. This leading edge vortex lowers the air pressure over the upper surface of the maple seed, effectively sucking the wing upward to oppose gravity [Live Science].
A hummingbird in love can perform aerial stunts that put fighter pilots to shame. In a new study, researcher Christopher Clark captured the male hummingbird’s daring dives with cameras that can capture 500 frames per second. To get the footage, Clark set out a caged female, or even a stuffed female on a stick, to inspire birds to dive right in front of his video cameras [Science News].
In the study, published in the journal Proceedings of the Royal Society B, Clark observed the Anna’s hummingbird, a tiny bird native to the American southwest. In the male’s courtship display he dives down dramatically with his wings pressed to his sides, and then dramatically stretches out his wings and tail feathers to break his momentum and bring him swooping back up into the sky. Clark says that the maneuver sets some records. When measured relative to the length of their bodies, the birds’ top speed, he said, was “greater than [that] of a fighter jet with its afterburners on, or the space shuttle during atmospheric re-entry” [BBC News].
Researchers have learned the universal secret behind the graceful, aerial turns executed by everything from insects to cockatoos. And it’s a surprisingly simple process: To turn left, all a bird has to do is flap its right wing a little bit harder than the left wing. To end the turn, the bird simply returns to flapping its wings in unison [Discovery News]. Researchers hope to duplicate the simple set of motions to create more nimble and acrobatic flying robots.
Though the dynamics probably can’t work at large scales — building-sized robotic birds won’t ever be as agile as a swallow — they could be harnessed in small drones used by explorers or the military. Compared to the average hummingbird or fruit fly, such craft are now clumsy and unstable. “The results will inform all future research into maneuvering flight in animals and biomimetic flying robots” [Wired], wrote biomechanicist Bret Tobalske in a commentary.
Paleontologists believe that majestic pterosaurs ruled the skies during the Jurassic and Cretaceous periods, soaring overhead on their leathery wings while dinosaurs stomped over the ground below. But researchers recently began wondering how exactly those “winged lizards” lifted off, as some of them weighed more than 500 pounds and were as tall as a giraffe. Last year, researchers tried to figure out how they got off the ground by looking at the largest bird now flying, the albatross. They concluded that anything much bigger couldn’t get off the ground the same way [AP], because the wing muscles wouldn’t be able to generate enough lift. But researcher Mike Habib now says pterosaurs shouldn’t be compared to birds. “The catch is that they are not built like birds,” Habib said [AP].
Habib thinks he has the answer to the pterosaurs’ launching maneuver. When the pterosaurs’ strong wings were folded they created “knuckles” that the animals rested on in four-legged stance, he says, which allowed them to take off in a motion akin to leap-frogging. The back legs kicked off first, Habib says, and then the front legs gave a mighty push to propel them into the air. This procedure would negate the need for launching aids that other paleontologists have suggested, like strong winds, a downslope, or a cliff to jump from. “Using all four legs, it takes less than a second to get off of flat ground, no wind, no cliffs,” Habib said. “This was a good thing to be able to do if you lived in the late Cretaceous period and there were hungry tyrannosaurs wandering around” [LiveScience].
An unmanned, solar-powered plane has unofficially broken the record for the longest uninterrupted flight, staying aloft for 82 hours and 37 minutes; it flew through the nights by drawing energy from batteries that it recharged during the day. Engineers for the high-tech aircraft, the Zephyr, say that the three-day flight is just the beginning of what it can do. [T]he aircraft’s designers, at the defence firm QinetiQ, in the UK, think the plane could fly indefinitely. “We think the aircraft, in future, will be capable of weeks or months duration,” said Paul Davey [Guardian].
The flight was a demonstration for the U.S. military, which is interested in using the craft for reconnaissance and battlefield communications. But the Zephyr didn’t officially break the record for the longest flight because representatives from the world air sports federation weren’t on hand to observe the feat. The flight beats the current official world record [for an uncrewed flight] of 30 hours, 24 minutes set by the US robot plane Global Hawk in 2001 [Telegraph].
80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles on the day's most compelling topics.
80beats is written by Veronique Greenwood and Valerie Ross. This team darts through each day's science news faster than the ruby-throated hummingbird that beats its wings 80 times per second. Send ideas, tips, suggestions, and complaints to [azeeberg at discovermagazine dot com].