Archive for April 2006

Interstellar deathray not likely to hit Earth – Interstellar deathray not likely to hit Earth

Doomsayers and Chicken Little-types can now strike “deathray from a star” from their list of possible ways to die.

A new study finds that the chances of a gamma ray burst going off in our galaxy and destroying life on Earth are comfortingly close to zero.

Gamma ray bursts, or GRBs, are focused beams of gamma radiation emitted from the magnetic poles of black holes formed during the collapse of ancient, behemoth stars. They can also form when dead neutron stars merge with each other or with black holes.

It’s been speculated that if a GRB went off near our solar system, and one of the beams hit Earth, it could set off a global mass extinction.

But in a new study to be published in the Astrophysical Journal, researchers found that GRBs tend to occur in small, metal-poor galaxies and estimated that the likelihood of one occurring in our own metal-rich Milky Way is less than 0.15%.

Black holes are actually ‘green’ – Black holes are actually green

A new study finds that the supermassive black holes at the hearts of some galaxies are the most fuel efficient engines in the universe.

“If you could make a car engine that was as efficient as one of these black holes, you could get about a billion miles out of a gallon of gas,” said study team leader Steve Allen of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University. “In anyone’s book, that would be pretty green.”

The finding, made using NASA’s Chandra X-ray Observatory and announced in a media teleconference Monday, is giving scientists insights into how supermassive black holes generate energy and how they affect the galaxies where they make their homes.

Some (atomic) fundamentals may change as time goes by – Some (atomic) fundamentals may change as time goes by

“The fundamental things apply, as time goes by,” sings Sam, the pianist in Casablanca. But maybe Sam didn’t mean that to apply over 12 billion years.

A new study in the journal Physical Review Letters suggests that over the lifetime of the cosmos, some fundamental things may not be so fundamental.

The study, led by physicists Wim Ubachs and Elmar Reinhold of the Free University of Amsterdam, the Netherlands, suggests that “mu,” the mass ratio of two atomic particles — the proton and the electron — “could have decreased in the past 12 billion years.”

At that’s an interesting notion to physicists, who rely on this fundamental constant to understand the structure of the atoms inside stars, planets and people. In more technical terms, mu sets the scale of the “strong” nuclear force, one of the four fundamental forces in the universe (gravity, electromagnetism and the weak force that governs radioactivity are the others.) The strong force binds the sub-atomic particles called quarks to one another inside protons. As fundamental stuff goes, that’s pretty fundamental.

Measured today, the ratio indicates that a proton weighs (just roughly speaking here) 1836.15267261 times more than an electron.

Call me nerdy, but I find this pretty fascinating. Wanted to get this up before work. Blah 🙁 . Click article link for more, along with some quasar pics.

Layout Transparency

Yes yes… I never mentioned that this blog is best viewed in Firefox, or most browser other than MSIE, as the transparency doesn’t properly function. I always forget to fix it since I don’t use IE, nor do my friends. I browsed to my blog one day from work and was like, damn, still gotta fix that. Just needs some CSS alpha trans code and whatnot… a fix will come some time soon, when I find time.

Scientists process more photos from Mars – Scientists process more photos from Mars

Scientists have processed more than a dozen new photos taken by the Mars Reconnaissance Orbiter, which arrived at the Red Planet last month, including its first color image.

The crisp test images released Friday revealed pocked craters, carved gullies and wind-formed dunes in Mars’ southern hemisphere. The diverse geologic features show the importance of water, wind and meteor impacts in shaping the Martian surface, scientists said.

The orbiter, the most advanced spacecraft ever sent to another planet, reached Mars on March 10 and slipped into an elliptical orbit. Over the next six months, it will dip into the upper atmosphere to shrink its orbit, lowering itself to 158 miles above the surface.

Last month, the orbiter beamed back the first view of Mars from an altitude of 1,547 miles. Those first test images were meant to calibrate the high-resolution camera aboard the spacecraft. The latest images were taken at the same time, but scientists spent several weeks processing them.

The Reconnaissance Orbiter will begin collecting data in November, and scientists expect the resolution of those images to be nine times higher.

Read article for further information and pics.

Water on Mars?

UC Davis News & Information ::

Cracks and fins in the sand in an American desert look very similar to features seen on Mars and may indicate the recent presence of water at the surface, according to a new study by researcher Greg Chavdarian and Dawn Sumner, associate professor of geology at UC Davis.

“Recent, as in ongoing now,” Sumner said.

Images from the Mars rover “Opportunity” show patterns of cracks across the surface of boulders and outcrops. Some of these cracks are associated with long, thin fins that protrude from the surface.

Those features look very similar to cracks and fins that form on the sulfate-rich sands at White Sands National Monument in New Mexico. The desert national park has a similar geological environment to the area of Mars visited by Opportunity, Sumner said.

See article for image.

Nearby Dust Clouds in the Milky Way

HubbleSite – Nearby Dust Clouds in the Milky Way – Image – 4/4/2006

NASA’s Hubble Space Telescope has photographed dense knots of dust and gas in our Milky Way Galaxy. This cosmic dust is a concentration of elements that are responsible for the formation of stars in our galaxy and throughout the universe. These dark, opaque knots of gas and dust are called “Bok globules,” and they are absorbing light in the center of the nearby emission nebula and star-forming region, NGC 281. These images were taken with Hubble’s Advanced Camera for Surveys in October 2005. NGC 281 is located nearly 9,500 light-years away in the direction of the constellation Cassiopeia.

Global warming 247M years ago? – Expert says it was hotter 247M years ago

John Roth shined his flashlight on a black streak flowing through the cream-colored marble forming the walls of the Oregon Caves.

The graphite line is graphic evidence of dramatic global warming that consumed so much oxygen that it nearly wiped out all life on the planet 247 million years ago, said the natural resources specialist for the Oregon Caves National Monument.

“It was the biggest extinction by far of all time,” he said. “Geologists and paleontologists all agree on that. … The extinction that killed the dinosaurs about 65 million years ago, that wasn’t anything compared to this.”

Scientists aren’t certain what caused the episode some 247 million years ago. They estimate that temperatures ranged in the low 100s year-round for thousands of years, he said.

“Its kind of scary that we don’t know for sure what caused the worst catastrophe of life on this planet,” he said.