Science & TechnologyS


Info

What Bitcoin Is, and Why It Matters

Tom Simonite
Te
Wed, 25 May 2011 16:39 UTC
Bitcoin
© Technology Review, MIT

Recent weeks have been exciting for a relatively new kind of currency speculator. In just three weeks, the total value of a unique new digital currency called Bitcoin has jumped four times, to over $40 million.

Bitcoin is underwritten not by a government, but by a clever cryptographic scheme.

For now, little can be bought with bitcoins, and the new currency is still a long way from competing with the dollar. But this explainer lays out what Bitcoin is, why it matters, and what needs to happen for it to succeed.

Where does Bitcoin come from?

In 2008, a programmer known as Satoshi Nakamoto - a name believed to be an alias - posted a paper outlining Bitcoin's design to a cryptography e-mail list. Then, in early 2009, he (or she) released software that can be used to exchange bitcoins using the scheme. That software is now maintained by a volunteer open-source community coordinated by four core developers.

"Satoshi's a bit of a mysterious figure," says Jeff Garzik, a member of that core team and founder of Bitcoin Watch, which tracks the Bitcoin economy. "I and the other core developers have occasionally corresponded with him by e-mail, but it's always a crapshoot as to whether he responds," says Garzik. "That and the forum are the entirety of anyone's experience with him."
Read More...
Cloud Lightning

Surprise!: Live Bacteria Help Create Rain, Snow & Hail


Live Science
Tue, 24 May 2011 14:46 UTC
Bacteria Hail
© NOAA Photo Library, NOAA Central Library; OAR/ERL/National Severe Storms Laboratory (NSSL)Large hail collects on streets and grass during severe thunderstorm. Larger stones appear to be nearly 2 to 3 inches in diameter.

Living bacteria that get whipped up into the sky may be just the spark needed for rain, snow and even hailstorms, research now finds.

Alexander Michaud of Montana State University in Bozeman, Mont., found large amounts of bacteria at the centers of giant hailstones.

Traditionally, researchers have thought that minerals or other particulates in clouds caused water droplets to glom together until they were large enough to fall as raindrops, snowflakes and hail. The new research shows that a large variety of bacteria, and even fungi, diatoms and algae, persist in the clouds and can be used as precipitation starters, a growing field of study called bioprecipitation. (In order for snow, say, to fall from clouds, particles around which ice crystals can form - called ice nuclei - are needed.)

"Minerals were thought to be the dominant ice nucleators in the atmosphere, but they aren't nearly as active as biological particles," said Brent Christner, a microbiologist studying bioprecipitation at Louisiana State University who is presenting the work today (May 24) at the General Meeting of the American Society for Microbiology in New Orleans.
Read More...
Telescope

Nearby Supernova Factory Ramps Up


NASA
Tue, 24 May 2011 17:37 UTC
Image
© NASA
A local supernova factory has recently started production, according to a wealth of new data from NASA's Chandra X-ray Observatory on the Carina Nebula. This discovery may help astronomers better understand how some of the Galaxy's heaviest and youngest stars race through their lives and release newly-forged elements into their surroundings.

Located in the Sagittarius-Carina arm of the Milky Way a mere 7,500 light years from Earth, the Carina Nebula has long been a favorite target for astronomers using telescopes tuned to a wide range of wavelengths. Chandra's extraordinarily sharp X-ray vision has detected over 14,000 stars in this region, revealed a diffuse X-ray glow, and provided strong evidence that supernovas have already occurred in this massive complex of young stars.

"The Carina Nebula is one of the best places we know to study how young massive stars live and die," said Leisa Townsley of Penn State University, who led the large Chandra campaign to observe Carina. "Now, we have a compelling case that a supernova show in Carina has already begun."

One important piece of evidence is an observed deficit of bright X-ray sources in Trumpler 15, one of ten star clusters in the Carina complex.

"This suggests that some of the massive stars in Trumpler 15 have already been destroyed in supernova explosions," said Junfeng Wang of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass, first author of a paper on this cluster. "These stars were likely between 20 and 40 times the mass of the Sun and would have exploded in the last few million years, which is very recent in cosmic terms."
Read More...
Telescope

Odd Orbits Mark Discovery of New Alien Planets


CBS News
Mon, 23 May 2011 17:05 UTC
Kepler alien planets
© Jason Rowe and Kepler teamThis illustration shows all 1,235 of the potential alien planet candidates NASA's Kepler mission has found to date. The planets are pictured crossing front of their host stars, which are all represented to scale.
Alien solar systems with multiple planets appear to be common in our galaxy, but most of them are quite different than our own, a new study finds.

NASA's Kepler Space Telescope detected 1,235 alien planet candidates in its first four months of operation. Of those, 408 reside in multiple-planet systems, suggesting that our own configuration of multiple worlds orbiting a single star isn't so special.

What may be special, however, is the orientation of our solar system's planets. Some of them are tilted significantly off the solar system's plane, while most of the Kepler systems are nearly as flat as a tabletop, researchers said.
Read More...
Evil Rays

The Invisible iPhone

Kate Greene
Technology Review, MIT
Mon, 23 May 2011 14:20 UTC
Invisible Phone
© Hasso Plattner InstitutePoint and click: The “imaginary phone” determines which iPhone app a person wants to use by matching his or her finger position to the position of the app on the screen.

A new interface lets you keep your phone in your pocket and use apps or answer calls by tapping your hand.

Over time, using your smart-phone touch screen becomes second nature, to the point where you can even do some tasks without looking. Researchers in Germany are now working on a system that would let you perform such actions without even holding the phone - instead you'd tap your palm, and the movements would be interpreted by an "imaginary phone" system that would relay the request to your actual phone.

The concept relies on a depth-sensitive camera to pick up the tapping and sliding interactions on a palm, software to analyze the video, and a wireless radio to send the instructions back to the iPhone. Patrick Baudisch, professor of computer science at the Hasso Plattner Institute in Potsdam, Germany, says the imaginary phone prototype "serves as a shortcut that frees users from the necessity to retrieve the actual physical device."

Baudisch and his team envision someone doing dishes when his smart phone rings. Instead of quickly drying his hands and fumbling to answer, the imaginary phone lets him simply slide a finger across his palm to answer it remotely.
Read More...
Question

Why are Supermassive Black Holes at Galactic Cores Spinning Faster than Ever in the History of the Universe?


The Daily Galaxy
Tue, 24 May 2011 13:43 UTC
Spinning Black Hole
© The Daily Galaxy

British astronomers have found that the giant black holes in the centers of galaxies are on average spinning faster than at any time in the history of the Universe. Dr. Alejo Martinez-Sansigre of the University of Portsmouth and Prof. Steve Rawlings of the University of Oxford made the new discovery by using radio, optical and X-ray data. They publish their findings in the journal Monthly Notices of the Royal Astronomical Society.

There is strong evidence that every galaxy has a massive black hole in its center that has masses of between a million and a billion Suns. They cannot be seen directly, but material swirls around the black hole in a so-called accretion disk before its final demise. That material can become very hot and emit radiation including X-rays that can be detected by space-based telescopes whilst associated radio emission can be detected by telescopes on the ground.

Twin jets are often associated with black holes and their accretion disks. There are many factors that can cause these jets to be produced, but the spin of the supermassive black hole is believed to be important. However, there are conflicting predictions about how the spins of the black holes should be evolving and until now this evolution was not well understood.
Read More...
Telescope

Major Astronomical Study confirms Mysterious-Dark Energy

Elvira Veksler
Business 2 Community
Tue, 24 May 2011 10:37 UTC
Image
© Unknown
A mysterious dark energy which permeates space and increases the rate of expansion of the Universe was confirmed by a major astronomical survey Thursday. The BBC has reported that the study concluded that "Dark energy makes up some 74% of the Universe and its existence would explain why the Universe appears to be expanding at an accelerating rate."
Read More...
Telescope

Galactic 'Fountain of Youth' Flows in Hubble Photo


Space
Sun, 22 May 2011 00:00 UTC
Image
© ESA/Hubble & NASAThis NASA/ESA Hubble Space Telescope image shows the edge-on profile of the slender spiral galaxy NGC 5775, which is surrounded by a halo of gas that astronomers suspect is kicked up by star explosions like a galaxy-size fountain.
A new photo from the Hubble Space Telescope has revealed what scientists have called a veritable galactic "fountain of youth," one that would turn the fictional pirate captain Jack Sparrow of the Pirates of the Caribbean films green with envy.

Journeying to the mythic Fountain of Youth is Sparrow's goal in Disney's latest installment in the adventure film franchise, Pirates of the Caribbean: On Stranger Tides. But the space fountain spotted by Hubble is no myth.

The new Hubble image shows the galaxy NGC 5775, which is located about 85 million light-years from Earth in a group of galaxies called the Virgo Cluster. NGC 5775 is a spiral galaxy that is tilted away from Earth in such a way that only its edge is visible.

This edge-on position of the galaxy has allowed astronomers to spot a vast halo of hot gas around NGC 5775, but how the material actually got there is unclear, researchers said.
Read More...
Info

Kepler Team Announces New Rocky Planet

Jason Major
Universe Today
Mon, 23 May 2011 15:45 UTC
Kepler-10c
© NASA/Ames/JPL-CaltechArtist's impression of Kepler-10c (foreground planet).
Today at the American Astronomical Society conference in Boston, the Kepler team announced the confirmation of a new rocky planet in orbit around Kepler-10. Dubbed Kepler-10c, this planet is described as a "scorched, molten Earth."

2.2 times the radius of Earth, Kepler-10c orbits its star every 45 days. Both it and its smaller, previously-discovered sibling 10b are located too close to their star for liquid water to exist.

Kepler-10c was validated using a new computer simulation technique called "Blender" as well as additional infrared data from NASA's Spitzer Space Telescope. This method can be used to locate Earth-sized planets within Kepler's field of view and could also potentially help find Earth-sized planets within other stars' habitable zones.
Read More...
Info

Giant Black Hole's Massive Jets Get Extreme Close-Up in New Photo


Space.com
Mon, 23 May 2011 13:00 UTC
Black Hole Jets
© SO/WFI (visible); MPIfR/ESO/APEX/A.Weiss et al. (microwave); NASA/CXC/CfA/R.Kraft et al. (X-ray)Merging X-ray data (blue) from NASA’s Chandra X-ray Observatory with microwave (orange) and visible images reveals the jets and radio-emitting lobes emanating from Centaurus A's central black hole.

Energetic jets spewed forth from a galaxy's supermassive black hole got a close-up in their most detailed image ever taken by Earth radio telescopes.

The picture shows jets racing away at one-third the speed of light from a huge black hole weighing 55 million times the sun's mass. Most matter falling toward a black hole becomes trapped, but some matter at the base of the jets gets ejected outward at about one-third the speed of light. In this case, the black hole sits at the center of the Centaurus A galaxy.

"These jets arise as infalling matter approaches the black hole, but we don't yet know the details of how they form and maintain themselves," said Cornelia Mueller, the study's lead author and a doctoral student at the University of Erlangen-Nuremberg in Germany.

The matter in the jets has created a pair of giant radio-emitting lobes that each stretch almost a million light-years long. That makes the Centaurus A galaxy appear almost 20 times the size of a full moon when seen in radio waves, despite being 12 million light-years away from Earth.

Read More...