Linkadelica

“Too soon fron the cave, too far from the stars. We must ignore the whispers from the cave that say, ‘Stay.’ We must listen to the stars that say, ‘Come.'”

—Ray Bradbury

Decorah Rocks

Decorah, Iowa (detail)Decorah, Iowa is a quiet sort of midwestern town. With a population of just over 8,100, the seven square miles of Decorah make up the Winneshiek County seat, right about where Route 52 crosses Highway 9. Once upon a time, the Winnebago tribe lived here after being driven from Wisconsin; the town is named after Waukon Decorah, who led Ho-Chunk Winnebago warriors alongside American forces in the Black Hawk War of 1832, and lived to see his people once again uprooted so that white American settlers could have the land. The good people of Decorah named their town after him, and then dug up what they believed was his body in 1859 in order to build over the gravesite. In 1876, they dug up the bones again, in order to renovate the courthouse.

The town is also home to Luther College and the Vesterheim Norwegian-American Museum. Each year, the town is flooded by thousands of tourists celebrating Norwegian heritage during Nordic Fest.

It is a picturesque little place in the American heartland.

And it also sits on a 470 million year-old cosmic impact crater:

An asteroid as big as a city block smashed into what is now northern Iowa about 470 million years ago, says a Smithsonian geologist, supporting a theory that a giant space rock broke up and bombarded Earth just as early life began flourishing in the oceans.

The impact dug a crater nearly four miles wide that now lies beneath the town of Decorah, said Bevan French, one of the world’s foremost crater hunters and an adjunct scientist at the National Museum of Natural History.

The asteroid that carved it would have dwarfed the estimated 55-foot-wide space rock that exploded over southern Russia on Friday.

The Decorah object smashed into bedrock with such force that it shattered tiny grains of minerals. French found this “shock quartz” in gravel from beneath the town, he told two dozen colleagues during a seminar at the museum last week.

Finding impact craters is rare, as erosion and the shifting of tectonic plates tend to erase them. The Decorah crater, if accepted by other scientists, would be just the 184th known, according to an international database at the University of New Brunswick.

But spying the evidence of the Earth’s most dramatic explosions requires only humble equipment — a simple black microscope. As sun streamed into French’s office above Constitution Avenue one recent afternoon, he placed a glass slide under the microscope’s lens and invited a reporter to peer in. A thin slice of rock from beneath Decorah sat on the slide.

Three white circles — quartz crystals no bigger than mustard seeds — popped into view. Dozens of parallel lines striped each circle: evidence of a rock-crushing pulse.

“They’re shattered,” French said of the crystals. Geologists consider shock quartz near-definitive evidence of an extraterrestrial impact.

The Decorah crater lay undiscovered until now because almost none of it peeks above ground. Instead, it is filled by an unusual shale that formed after an ancient seaway sluiced into the crater, depositing sediment and an array of bizarre sea creatures that hardened into fossils, French said.

This shale was the first clue that certain Iowans may be unknowingly living in a crater.

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The Upside of Education

Mini Cooper Countryman backflipA note for the kids: Study hard, and you, too, might make history someday. After all, backflipping a car is the sort of thing that takes all sorts of knowledge, namely in physics and engineering.

MINI and its stunt driver Guerlain Chicherit have done the impossible: executing the perfect “unassisted” backflip.

Using a heavily modified MINI Cooper Countryman, Chicherit, a French rally driver and avid skier, completed the stunt recently at a resort in Tignes, France.

The stunt qualifies for the unassisted certification because the ramp used by Chicherit was static ….

…. For his take-off, Chicherit used a static ramp similar to those used by skiers. With the ideal ramp breakover angle in place, the 34-year-old needed only two other things to record a successful attempt: an extremely light touch with the accelerator and a MINI with a suitably buoyant suspension setup.

Guerlain Chicheret backflipAssisted backflips? Those have been done before.

But this? Well, sure, it’s just a publicity stunt, but one must admit it’s pretty cool.

Copernicus

Here’s one to file under First World Problems: I use the search bar in my browser window, so I rarely see the Google home page.

Not much of a problem, is it? First world, or otherwise.

But today turns out to be the 540th birthday of Nicolaus Copernicus the Polish mathematician and astronomer who revolutionized the European view of the Universe by correctly theorizing a heliocentric solar system.

And, of course, Google marked the day with one of their festive logos.

Eoin O’Carroll explains, for The Christian Science Monitor, a bit about Copernicus’ celebrated discovery:

Google Doodle: February 19, 2013It’s astonishing to think that anatomically modern humans walked on this planet for nearly two hundred millennia before they realized that it was moving.

Then again, you can’t really blame us. Even though the equator is spinning at more than a thousand miles per hour, even though our planet is hurtling around our sun at about 66,000 miles per hour, even though our solar system and everything in it is careening around our galaxy at nearly half a million miles per hour, and even though our galaxy is whirling around at a mind-blowing 1.2 million miles an hour, the very fact that you’re not currently clinging to the ground for dear life makes it only natural to think of the Earth as 16th century astronomer Tycho Brahe did, as a “hulking, lazy body, unfit for motion.”

Nicolaus Copernicus’s book, titled “On the Revolutions of the Heavenly Spheres,” was published the year the Polish astronomer died, in 1543. It marked the beginning of an eclipse of a worldview dominated by the ideas of Aristotle, who believed that the Earth remained at rest while the sun, moon, other planets, and all the stars, which were made of an unchanging substance called aether, revolved around it in perfect circles.

Of course nothing is ever that simple. Our prehistoric ancestors observed five celestial bodies moving independently from the rest of the lights in the sky. These bodies would move slowly across the sky, loop backward for a few months, and then loop forward again. The ancient Greeks called them astēr planētēs, or “wandering stars,” and thought them to be living beings.

The looping behavior of these wanderers – whom today we know as the planets Mercury, Venus, Mars, Jupiter, and Saturn – presented a problem for ancient astronomers, many of whom would have loved nothing more than to have observed them circling above in a simple, orderly fashion, just as Aristotle said they did. But the heavens demanded a more nuanced explanation.

Happy birthday, Nicolaus.

Look Up

The BBC reports that Brecon Beacons National Park in Wales has achieved the status of international dark sky reserve; it is only the fifth site in the world to be so recognized:

Llanthony Prior, Brecon BeaconsThe park joins Mont Megantic in Quebec, Canada; Exmoor National Park in south west England; Aoraki Mackenzie in New Zealand; and NambiRand Nature Reserve in Namibia with the status.

The status means the night-sky is protected and lighting controls are in place to prevent light pollution.

The national park said it already possessed some of the UK’s darkest skies, which was ideal for stargazing ….

…. To get through the application process local astronomers conducted a survey to assess the levels of light pollution, and lighting engineers audited the existing external lighting in the national park.

Information leaflets and letters were distributed to residents living in the ‘core zone’ to help them understand the simple measures they could take, such as tilting outdoor security lights downwards instead of up, that could make difference to how dark the night sky appears.

Local communities supported the bid, with residents in Talybont-on-Usk holding their own Star Party and organising a community light switch off.

Martin Morgan-Taylor, board member of the International Dark-Sky Association, the US based organisation which awards the status, said the gradual loss of the view of the night sky was a loss of part of culture.

“Whilst no-one wants all the lights to be switched off, we can improve the lighting we use in towns and cities.

“However, the best views of the night sky come from places such as the Brecon Beacons, who have dedicated themselves to protecting and restoring the night sky for all to enjoy.”

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