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The weird, black, spidery things of Mars

See those weird, black, spidery things dotting the dunes in this colorized photo taken by the Mars Reconnaissance Orbiter in 2010? Yeah. Nobody knows what the hell those things are.

What we do know about them just underlines how incredibly unfamiliar Mars really is to us. First spotted by humans in 1998, these splotches pop up every Martian spring, and disappear in winter. Usually, they appear in the same places as the previous year, and they tend to congregate on the sunny sides of sand dunes — all but shunning flat ground. There’s nothing on Earth that looks like this that we can compare them to. It’s a for real-real mystery, writes Robert Krulwich at NPR. But there are theories:

Scientists from the U.S. Geological Survey, from Hungary, from the European Space Agency have all proposed explanations; the leading one is so weird, it’s transformed my idea of what it’s like to be on Mars. For 20 years, I’ve thought the planet to be magnificently desolate, a dead zone, painted rouge. But imagine this: Every spring, the sun beats down on a southern region of Mars, morning light melts the surface, warms up the ground below, and a thin, underground layer of frozen CO2 turns suddenly into a roaring gas, expands, and carrying rock and ice, rushes up through breaks in the rock, exploding into the Martian air. Geysers shoot up in odd places. It feels random, like being surprise attacked by an monstrous, underground fountain.

“If you were there,” says Phil Christensen of Arizona State University, “you’d be standing on a slab of carbon dioxide ice. All around you, roaring jets of carbon dioxide gas are throwing sand and dust a couple hundred feet into the air.” The ground below would be rumbling. You’d feel it in your spaceboots.

Read the rest of Robert Krulwich’s post — and check out some spectacular photos of the things — at NPR

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Todd Akin on the scourge of doctors giving abortions to non-pregnant women

[Video Link] Salon: Among “abortionists,” Akin said in a floor speech in 2008, “you find that along with the culture death go all kinds of other lawbreaking: the not following good sanitary procedure, giving abortions to women who aren’t actually pregnant, cheating on taxes, all these kinds of things.” Later in the video Akin also accuses death culture doctors of killing imaginary unicorns.

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Quadcopters playing catch

The ETH Zurich quadcopter folks have added to their already impressive collection of videos of cooperative, autonomous quadcopters doing exciting things (previously) with this video of the adorable little gizmos throwing and catching balls together.

To toss the ball, the quadrocopters accelerate rapidly outward to stretch the net tight between them and launch the ball up. Notice in the video that the quadrocopters are then pulled forcefully inward by the tension in the elastic net, and must rapidly stabilize in order to avoid a collision. Once recovered, the quadrotors cooperatively position the net below the ball in order to catch it.

Because they are coupled to each other by the net, the quadrocopters experience complex forces that push the vehicles to the limits of their dynamic capabilities

Cooperative Quadrocopter Ball Throwing and Catching – IDSC – ETH Zurich

(via JWZ)

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Ask science: Does sugar really make children hyper?

“Why aren’t my kids hyper after binging on sugar?” asked Gillian Mayman at Mind the Science Gap, a blog featuring the work of various Master of Public Health students from the University of Michigan.

The punchline: “A review of 12 separate research studies found that there was no evidence that eating sugar makes kids hyper.”

The post is great, but greatest of all? The animated GIFs used to illustrate it. (via @Boraz)

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Guerrilla Grafters covertly add fruit-tree branches to ornamental trees

The Guerrilla Grafters are a group of rogue artists who roam San Francisco, covertly grafting fruit-tree branches onto ornamental trees to create a municipal free lunch. John Robb calls it “resilient disobedience.”

How can you improve the productivity of your community even if the officials are against it?

One way is through resilient disobedience. For example, there’s a group of gardeners in San Francisco that are spreading organic graffiti across the city. How? By grafting branches from fruit trees onto ornamental trees that have been planted along sidewalks and in parks.

They are using a very simple tongue in groove splice that’s held together with annotated electrical tape. Good luck to them.

Personal Biochar Kilns, Portable Factories, DiY Septic Tank Cleaning, and Guerrilla Grafting

(via Warren Ellis)

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Black American sign language and American sign language are different languages

I’ve been fascinated by the history and development of sign language for a while now. Highly linked to local Deaf cultures, individual sign languages have deep roots in the home-made systems people came up with in order to communicate with one another and with their families at times when Deaf people were often a lot more socially isolated than they are today. That means that each sign language is unique — even British and American sign language aren’t at all the same thing. English is spoken in both countries, but the cultural history that gave birth to sign was sufficiently different to produce two completely different languages that are unintelligible to one another. (Meanwhile, American sign language is much closer to French, because it also has roots in a system imported from France in the 19th century.)

In that case, it was a physical distance that lead to the development of two different sign languages. But, within the United States, the same thing happened because of social distance. Turns out, there is a Black American sign language that is distinctly different, as a language, from ASL. Its roots lie in segregation, and especially in separate-and-not-at-all-equal school systems. Ironically, though, that meant sign language had a more prominent place in black schools for much of the 20th century. At white schools, up until the 1970s and 1980s, students were heavily pressured to speak and lip-read, rather than sign — because it was thought to be better. Meanwhile, at black schools, sign language continued to be heavily used, growing and changing. By the late 1960s, the two systems were almost completely different languages.

Carolyn McCaskill remembers exactly when she discovered that she couldn’t understand white people. It was 1968, she was 15 years old, and she and nine other deaf black students had just enrolled in an integrated school for the deaf in Talledega, Ala.

… The teacher’s quicksilver hand movements looked little like the sign language McCaskill had grown up using at home with her two deaf siblings and had practiced at the Alabama School for the Negro Deaf and Blind, just a few miles away. It wasn’t a simple matter of people at the new school using unfamiliar vocabularly; they made hand movements for everyday words that looked foreign to McCaskill and her fellow black students.

…So, McCaskill says, “I put my signs aside.” She learned entirely new signs for such common nouns as “shoe” and “school.” She began to communicate words such as “why” and “don’t know” with one hand instead of two as she and her black friends had always done. She copied the white students who lowered their hands to make the signs for “what for” and “know” closer to their chins than to their foreheads. And she imitated the way white students mouthed words at the same time as they made manual signs for them.