Πέμπτη 22 Ιανουαρίου 2015
Τετάρτη 21 Ιανουαρίου 2015
Our Favorite Penguin Pictures: Fuzzy Chicks, Expert Divers, More
Admiring the View
Photograph by Joel Sartore, National Geographic
A colony of gentoo penguins perch on a rocky cliff on Danco Island, Antarctica.
In honor of Penguin Awareness Day, we decided to dive into the National Geographic photo archive to look at the bird with the iconic tuxedo coat and characteristic waddle. (See more penguin pictures.)
All 17 species of penguins, which range in size from the 3.3-pound (1.5 kilogram) little blue penguin to the 88-pound (40 kilogram) emperor penguin, live in the Southern Hemisphere.
Flightless and comically awkward on land, they spend the majority of their time in the water, and their bodies are streamlined for swimming.
Keep clicking to see our favorite penguin pictures.
—Text by Anna Lukacs, photo edit by Sherry L. Brukbacher
Published January 20, 2015
Penguin Pair
Photograph by Frans Lanting, National Geographic
A pair of macaroni penguins nestle in the grass on South Georgia Island.
Eighteenth-century British explorers thought the bird's yellow crest feathers resembled the flamboyant "macaroni" hat that was popular at the time.
With nine million breeding pairs, macaroni penguins are the most populous of the penguin species. (Also see "Emperor Penguins Counted From Space—A First.")
Published January 20, 2015
Ready for Its Close-Up
Photograph by Tom Murphy, National Geographic
The vivid colors of a king penguin on South Georgia Island (map) are evident in this tight shot.
King penguins are often confused with emperor penguins. Both are tall birds, but emperors are the largest of all penguins—an average bird stands some 45 inches (114 centimeters) tall.
The distinct, bright orange pattern on their head and chest distinguishes the king penguins; they also live further north than their Antarctic counterparts.
Published January 20, 2015
Royal Huddle
Photograph by Michael Melford, National Geographic
A colony of king penguins mingle on the beach at St. Andrews Bay, South Georgia Island.
Although their preferred habitat is warmer than that of emperor penguins, king penguins have four layers of feathers and huddle together for warmth. (Read more about king penguins in National Geographic Magazine.)
Published January 20, 2015
Walk Like a Penguin
Photograph by Bill Curtsinger, National Geographic
Photographer Bill Curtsinger waddles alongside a group of chinstrap penguins in Antarctica.
Chinstrap penguins are related to Adélie and gentoo penguins, which are part of a group commonly known as brush-tailed penguins. The chinstrap is the only one with a distinctive, all-white face. (Read about the evolution of penguin species.)
Published January 20, 2015
Tangled
Photograph by Frans Lanting, National Geographic
A gentoo penguin lies entangled in a fishing net on a Falkland Islands (map)beach in 2011.
Net fishing is just one threat facing penguin populations—a decline in krill, their main food source, is also causing their numbers to decline.
Published January 20, 2015
Pair Scale Dawn Wall - Most Difficult Rock Climb Ever
Two US free climbers reached the top of an iconic rock formation in Yosemite National Park on Wednesday, after spending nearly three weeks inching up a sheer 2,950-foot-high cliff face.
Tommy Caldwell and Kevin Jorgeson began their record-breaking climb up the Dawn Wall of El Capitan, a massive rock face seen by millions of tourists every year, in late December.
Photos: Dawn Wall and Other Climbs on Edge of (Im)Possibility
The daring pair have been documenting the climb -- in which they use only their hands and feet, albeit attached with ropes to catch them if they fall -- on social media, followed by two photographers.
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With no muscles in our fingers or toes, how come humans are able to climb every mountain? Or, climb some of them anyway!
They have slept suspended in bivouac-style tents attached to the rock, which towers above Yosemite Valley and is some three times as big as France's Eiffel Tower and even bigger than world's tallest building, the Burj Khalifa in Dubai.
"This is not an effort to conquer. It's about realizing a dream," Jorgeson tweeted on Tuesday, ahead of the final push.
Photos: The World's 'Eight-Thousander' Mountains
They pair -- 36-year-old Caldwell and 30-year-old Jorgeson -- finally scaled the last few hundred feet to stand atop the granite monolith by mid-afternoon Wednesday, live TV pictures showed.
Caldwell's wife and Jorgeson's girlfriend hugged them as they were sprayed with champagne, local media reported.
Hackers Don't Need Wi-Fi to Steal Your Data
GALLERY
The researchers are tracing leaks of electromagnetic radiation that are byproducts of various electronic components of computer hardware, including computer processors and capacitors.
Some of the signals are created when you type at the keyboard and can be picked up with the right kind of electronic eavesdropping equipment.
In their recent study, the Georgia Tech researchers developed a way to measure the strength of the emissions and offer ways for hardware and software designers to plug those electronic holes.
So far, these kinds of leaks are not overly exploited by hackers.
“If you are comparing this to Internet attacks, it is less of a problem,” said Alenka Zajic, assistant professor of electrical and computer engineering at the Georgia Institute of Technology.
“But they are very hard to detect. With any sort of Internet attack, you will find the attacker. With this one you just need to be close by and there’s no way to know who took your data.”
Cool Jobs: Hacker
Zajic and her colleagues say they were able to pick up keystroke information from laptops using just an AM radio and a cellphone. “You could probably hide it under the desk,” Zajic said. “It’s just a matter of motivation.”
These side-channel emissions can also be measured from hidden antennas in a briefcase, while acoustic emissions from the device’s electronic capacitors, can be picked up by tiny microphones.
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