HomeLatest ThreadsGreatest ThreadsForums & GroupsMy SubscriptionsMy Posts
DU Home » Latest Threads » n2doc » Journal
Introducing Discussionist: A new forum by the creators of DU


Profile Information

Gender: Do not display
Home country: USA
Current location: Georgia
Member since: Tue Feb 10, 2004, 12:08 PM
Number of posts: 34,064

About Me

Environmental Scientist

Journal Archives

The Flaming Skull Nebula.

By Phil Plait

Photo by T.A. Rector (University of Alaska Anchorage) and H. Schweiker (WIYN and NOAO/AURA/NSF)
Planetary nebulae are among my favorite objects in the sky. When a star a bit more massive than the Sun starts to die, it blows off a super solar wind of gas. As it ages more, this wind it blows speeds up, slamming into the stuff previously ejected, carving it into weird and amazing shapes. Eventually, the entire outer layers of the star blow off, exposing the star’s hot, dense core. This floods the surrounding gas with ultraviolet light, causing it to glow.

Once it starts to emit light, the gas cloud becomes visible to us on Earth, and we can see the weird forms it can take. This structure can be quite fantastic, depending on how exactly the star was spinning as it blew off those winds, what angle we see this at, and the chemical composition of the gas.

In the case of the planetary nebula Sh2-68, though, we have an added factor: motion. The star at the heart of this nebula is moving rapidly through space, and it happens to be in a location in our galaxy where there is more gas and dust between stars than usual. So as it moves, the gas it blows off is itself blown back, like a dog’s hair is blown back when it sticks its head out of a car window.

The image above, taken by my friend Travis Rector using the KPNO 4-meter telescope, shows this in detail. The blue gas is oxygen (which is slightly false-color here; this flavor of oxygen is actually more greenish), and the red is hydrogen. The star itself is the blue one right in the center of the blue gas.

I could go into great detail about the overall shape of the gas, the cavities in it, the actually quite interesting physics of how the gas interacts with the interstellar gas … but c’mon. Seriously.

The nebula looks like a giant screaming head with its hair aflame streaking across the galaxy!



Infographic: An Astounding Map of Every River in America


Nelson Minar didn’t really mean to create a piece of art. When the California-based software engineer began working on All Rivers, a gorgeously detailed look at the waterways in the 48 contiguous states, it was really just a practice in computer nerdery. Minar, a self-described “computer nerd at heart,” simply wanted to create a vector map (a map consisting of Geographic Information System data) using open source data. “The single All Rivers map was just me goofing around to see what it’d look like,” he told Wired.

It looks pretty cool. Inspired by Ben Fry’s All Streets poster, Minar’s version shows a vast web of blue veins spreading across the United States. River-rich areas like Mississippi are dense with blue, but more surprisingly, so are notoriously dry areas like Nevada and Arizona.

To create All Rivers, first Minar gathered information from NHDPlus (National Hydrography Dataset) and put it in a database. He extracted the Strahler number, a measure of how significant a creek is, to determine how large the rivers would appear on the map. From there he built a web server that would allow him to serve the flowline data as vector map tiles, and finally he wrote a JavaScript program that did most of the cartography work for him.

Minar kept All Rivers pretty simple, using only the Strahler number as a variable. But he says it’s possible to gather more information to include on future maps. “To be a useful hydrography map, it should have information on river volume, size, seasonality, etc,” he said. “That’s a lot of data to cram into a single picture. I don’t know how to do that and make it look good.”


Take the Impossible “Literacy” Test Louisiana Gave Black Voters in the 1960s

By Rebecca Onion

This week’s Supreme Court decision in Shelby County v. Holder overturned Section 4(b) of the 1965 Voting Rights Act, which mandated federal oversight of changes in voting procedure in jurisdictions that have a history of using a “test or device” to impede enfranchisement. Here is one example of such a test, used in Louisiana in 1964.

After the end of the Civil War, would-be black voters in the South faced an array of disproportionate barriers to enfranchisement. The literacy test—supposedly applicable to both white and black prospective voters who couldn’t prove a certain level of education but in actuality disproportionately administered to black voters—was a classic example of one of these barriers.

The website of the Civil Rights Movement Veterans, which collects materials related to civil rights, hosts a few samples of actual literacy tests used in Alabama, Louisiana, and Mississippi during the 1950s and 1960s.

In many cases, people working within the movement collected these in order to use them in voter education, which is how we ended up with this documentary evidence. Update: This test—a word-processed transcript of an original—was linked to by Jeff Schwartz, who worked with the Congress of Racial Equality in Iberville and Tangipahoa Parishes in the summer of 1964. Schwartz wrote about his encounters with the test in this blog post.
Most of the tests collected here are a battery of trivia questions related to civic procedure and citizenship. (Two from the Alabama test: “Name the attorney general of the United States” and “Can you be imprisoned, under Alabama law, for a debt?”)

But this Louisiana “literacy” test, singular among its fellows, has nothing to do with citizenship. Designed to put the applicant through mental contortions, the test's questions are often confusingly worded. If some of them seem unanswerable, that effect was intentional. The (white) registrar would be the ultimate judge of whether an answer was correct.



Sen. Warren’s Bill Gets Cold Shoulder as Student Loan Rates Spike Monday

by Lauren McCauley

Despite the groundswell of support behind Senator Elizabeth Warren’s (D-Mass.) popular student loan proposal, Senate leaders have dismissed the legislation opting instead to let student interest rates double Monday as they pack their bags for a Fourth of July holiday recess.

Because of Congressional inaction, students will be left in the lurch as federal Stafford loans spike to 6.8 percent.

The Warren bill proposes to tie student loan interest rates to the same “discounted rates” given to big banks from the Federal Reserve, lowering student loan rates to 0.75 percent and saving students thousands of dollars.

“We subsidize bankers whose excesses blew up the economy, why not subsidize kids struggling to pay for the education we say they need?” writes Robert Borosage. However, he adds that the legislators “dismiss the Warren proposal out of hand.”

With more support than any other proposal, petitions backing the bill have received over a million signatures and presidents from more than 25 colleges have backed the legislation. A recent poll conducted by Public Policy Polling found that 60 percent of respondents backed Warren’s idea, including 56 percent of Republicans.

However, despite the widespread popularity, the bill has been systematically ignored by Congress and has not yet come up for a vote.



Night parrot confirmed alive again after 30 years?

A LIVE NIGHT PARROT has reportedly been photographed in western Queensland for the first time since the species was discovered more than 150 years ago.

With a loosely estimated population of less than 250 individuals across central Australia, the last living night parrot specimen was collected in 1912 at Nicol Spring in Western Australia.

The species has since famously avoided detection, save a handful of sightings and two dead specimens, the most recent of which was a decapitated young female picked up by a ranger in Queensland's Diamantina National Park in 2006.

A pair of biologists reported seeing several night parrots at a well in the Pilbara, WA, in 2005, but they were not able to photograph them or collect samples.



Sunday's Doonesbury- We're Still There

After Stonewall: The First-Ever Pride Parades, In Vintage Photos

by Maria Popova

In the early morning hours of June 28, 1969, violent protests and street demonstrations took over the streets of New York after a police raid of Stonewall Inn, the now-legendary Greenwich Village gay bar. Known as the Stonewall Riots, these protests are commonly considered the tipping point at which the LGBT community coalesced into political cohesion and the birth of the modern gay rights movement. On that June morning, equality for all seemed a distant but necessary dream — a dream that has finally become reality a day shy of 44 years later.

In Stonewall: The Riots That Sparked the Gay Revolution (public library), David Carter contextualizes the remarkable delta of progress that the Stonewall Riots precipitated:

It was only a few decades ago — a very short time in historical terms — that the situation of gay men and lesbians was radically different from what it is today. At the end of the 1960s, homosexual sex was illegal in every state but Illinois. Not one law — federal, state, or local — protected gay men or women from being fired or denied housing. There were no openly gay politicians. No television show had any identifiably gay characters. When Hollywood made a film with a major homosexual character, the character was either killed or killed himself. There were no openly gay policemen, public school teachers, doctors, or lawyers. And no political party had a gay caucus.

In 1970, to mark the first anniversary of the Stonewall uprisings, the very first Gay Pride marches took place in New York, Los Angeles, San Francisco, and Chicago.

Digging through the New York Public Library archives, I unearthed some goosebump-inducing photos of the first-ever Pride parades around the world:



Danziger Toon: Voting Rights

Sums up the attitude of all too many folks I run into down here in Savannah...

Toon- Cutting Carbon the Healthy Way

Luxury Hotel Being Built In An Abandoned Chinese Quarry

by Megan Willett

Construction has officially begun on a £345 million ($528 million) resort project in an abandoned quarry in China's Songjiang District, The Daily Mail reports.

Known as the Songjiang Shimao Hotel, the resort is part of a larger development plan to turn the area into a theme park, according to Li Xuyang, a senior manager for the Shimao Group.

Atkin, the British firm that designed the hotel, wanted to make sure it blended in with the landscape. They are planning to build an eco-friendly roof with grass and trees that uses natural resources for power.

Two of the building's 19 stories will be underwater with aquarium-style walls, so guests can look out into the quarry. The other 17 stories will be built inside the cave, which is at the base of the Tianmenshan Mountain, according to The Daily Mail.

Read more: http://www.businessinsider.com/chinese-quarry-hotel-under-construction-2013-6
Go to Page: « Prev 1 ... 466 467 468 469 470 471 472 473 474 475 476 ... 925 Next »