Saturday, 19 January 2013

RPMFusion Error GPG Key retrieval failed: [Errno 14] .....Solved

If you are using FEDORA18 and are having some problem with this error .....

"RPMFusion Error GPG Key retrieval failed: [Errno 14]"..............

Here is the Solution....:)


Just write the below code in terminal....

su -c 'yum localinstall --nogpgcheck'

Dats it...your problem is solved...:D

Saturday, 12 January 2013

World's Smallest Snake...

The world's smallest snake—and perhaps the smallest possible snake—has been discovered on the Caribbean island of Barbados, a new study says.

At about ten centimeters long (less than four inches), the diminutive reptile might easily be mistaken for an earthworm, and could comfortably curl up on a U.S. quarter, researchers say.

A second new species, only slightly larger, was found on the neighboring island of St. Lucia.

Genetic tests and studies of the snakes' physical features identified the animals as new species, said biologist Blair Hedges of Penn State university, who led the study team.

Both new species belong to a little-known group of known as thread snakes—also called worm snakes and slender blind snakes. Short and slender, thread snakes burrow in the soil and live on a diet of insect larvae.

Death Valley's Rolling Stone...

This is Racetrack Playa in Death Valley California. This area has been the centre of scientific controversy for decades. Why? At this location an amazingly large number or rocks and boulders (some weighing up to half a tonne) have been regularly moving across the surface, without any human or animal interference, and they are not just moving a small distance; one travel path was recorded at 880.73 metres!

Some scientists have proposed that the movement is caused by strong winds accompanied by the development of surface ice when temperatures fall. It is hypothesised that the development of ice allows the wind to move the rocks with less difficultly. This hypothesis, however, is commonly refuted. The hypothesis cannot account for rocks starting side by side and moving at different rates and in disparate directions, and sliding rock trails vary in direction and length. Some rocks which start next to each other start out travelling parallel, but one may abruptly change direction to the left, right, or even back the direction it came from. Length also varies because two similarly size and shaped rocks could travel uniform, then one could burst ahead or stop dead in its tracks.

Another hypothesis proposed is that another force is present; electromagnetism. Air passing through the valley is positively-charged, since it has passed over the highest mountains in the Lower 48 to get into the valley, and since positive charge increases with altitude. The electric charge in the air induces an opposite charge in the Earth, creating an electrostatic potential between them. Dolomite, being composed of calcium, magnesium, and sometimes with traces of iron, is a good conductor. Being in contact with the surface, it will be negatively charged, and will therefore be attracted to the positive charge in the air above. Sticking up above the perfectly flat playa, the rocks will concentrate the lines of force on themselves, accentuating the effect. The electric force will then exert an uplifting force on the rock, reducing the friction caused by gravity, and allowing it to travel more easily.

This hypothesis is also widely discredited. A team of interns from NASA’s Lunar and Planetary Science Academy went to Racetrack Playa last year to investigate. They found that there are no electromagnetic or radiation anomalies that would account for the movement, and they also found no patterns in the mass, direction and orientation in the moving stones.

There are several other explanations offered by the scientific community, but as of yet, none are set in stone!! ;)


The Blue Dragon (Glaucus atlanticus) is one of the world’s rarest and most beautiful mollusks. The normal size of this species is up to about 3 cm, depending on the animal's age. It is silvery grey on its dorsal side and dark and pale blue ventrally. It has dark blue stripes on its face. It has a tapering body which is flattened and has six appendages which branch out into rayed cerata. Its radula bears serrated teeth on their blades.

The Blue Dragon is distributed throughout the world's oceans, in temperate and tropical waters. Regions where this slug is found include the East and South Coast of South Africa, European waters, the east coast of Australia and Mozambique. This species floats upside down on the surface tension of the ocean.

Atlanticus preys on other, larger pelagic organisms: the dangerously venomous Portuguese Man o' War Physalia physalis; the by-the-wind-sailor Velella velella; the blue button Porpita porpita; and the violet snail, Janthina janthina. Occasionally, individual Glaucus become cannibals given the opportunity.

Wrinkles On Wet Hands Help Us Grip Better..

Scientists have an answer to the pressing question of why hands and feet get wrinkled after too much time in the bath: Pruniness may have evolved to make it easier to handle wet objects.

The smooth skin of human hands and feet becomes furrowed after extended periods in water. Though often assumed to be a result of water passively seeping into the skin, the phenomenon is actually caused by the nervous system constricting blood vessels. As early as the 1930s, surgeons noticed that no wrinkling occurred if a finger nerve had been severed, so furrowing has been used as a medical indicator of nerve function. But what evolutionary purpose wrinkling serves, if any, remained a mystery.

In 2011, a team of researchers proposed that the grooves in wet fingers might function as “rain treads” that improve grip by channeling water away, much like car tires on a wet road do. Now, researchers at Newcastle University in England have tested that theory.

The researchers had 20 volunteers manipulate objects with smooth fingers or digits shriveled by immersion in warm water for 30 minutes. The experimenters measured how long it took people to transfer the objects between a water-filled container and a dry one, or between two dry ones, with wrinkled versus unwrinkled fingers. The objects were glass marbles and fishing weights of various sizes.

All the participants transferred the wet objects (but not the dry ones) faster when their hands were pruney. The results suggest furrowed fingertips make it easier to handle moist items more efficiently, the scientists report online January 8 in Biology Letters.

Friday, 11 January 2013

How NASA's Flying Lab Stays Connected to Earth...??

Mars and Antarctica have a lot in common—they're both cold, inhospitable places with terrible broadband service. The crew of Operation IceBridge, NASA's airborne survey of glaciers and ice shelves in the Arctic and Antarctic works with networking constraints similar to those of the Curiosity rover, keeping in contact with its ground crew at worse-than-dialup speeds using the lowest-bandwidth method possible: Internet Relay Chat.

In February of 2010, after seven years of operation, the final laser sensor on NASA's Ice, Cloud, and Land Elevation Satellite (ICEsat) failed. With its replacement not slotted to be launched until 2015, NASA launched Operation Ice Bridge to conduct aerial surveys to fill in the gap. Flying 500 meters above the surface in a precisely-planned pattern over the Antarctic ice sheets, the OIB aircraft—operated by the National Suborbital Education and Research Center at the University of North Dakota—carries ice-penetrating radar, a gravimeter for measuring variations in the density of the ice below, and an Airborne Topographic Mapper—a laser altimeter that combines GPS data with laser measurements to build a precise record of the elevation of the ice sheets.

But because of the poor satellite coverage in the Antarctic, the refitted vintage Douglas DC-8 airliner can't use the Inmarsat BGAN service it normally uses for voice and data communication channels. "Like most high bandwidth satellite systems, the constellation is in geosynchronous orbit," David Van Gilst, NSERC's network engineer, told Ars in an e-mail interview. "So once you get past 72-73 degrees latitude the satellites are so low in the sky as to be problematic. Past 80 degrees latitude, they're below the horizon."

Bandwidth is a big enough problem for the land-based scientists in the Antarctic, who get about 10 hours a day of broadband (with some aggressive management of ground station dishes) from NASA's Tracking and Data Relay Satellite-F (TDRS-F) and the re-purposed GOES-3 weather satellite. But it's not practical for OIB's flying laboratory (operated by the National Suborbital Education and Research Center at the University of North Dakota) and other science on the move to try to lock in on TDRS or GOES-3; the only real option is to use the Iridium satellite network—the satcom equivalent of dial-up. Iridium's 66 low-orbit satellites zip around Earth in near-polar orbits (inclined at 86.4 degrees relative to the equator). Since they orbit at just 470 miles or so above the Earth—much closer than even the GPS satellite network, let alone geosynchronous communications satellites—they don't require directional antennas or the kind of broadcast power needed for most satellite communications. But the tradeoff is that the satellites quickly pass in and out of range, and connections have to be passed off from one to the other. While Iridium advertises data rates of up to 10 kilobits per second, the best that they usually can manage over a single connection is a quarter of that.

So Operation Ice Bridge squeezes all it can out of Iridium the old-fashioned way—by multiplexing over PPP Multilink. The DC-8 is equipped with an array of Iridium-based modems, each of which dials into a modem on a land line at NASA's Ames Research Center in San Jose. By aggregating the connections, the OIB flying lab gets about 9600 bits per second of bandwidth. "We've experimented with as many as 8 channels," said Van Gilst, "but with Iridium's lower level of reliability (modems will tend to hang up and have to redial periodically, particularly on a moving, banking aircraft) and the relatively high latency, PPP starts to see diminishing returns beyond 4 or 6 channels."

Over that BBS-worthy bandwidth, Operation Ice Bridge pushes and pulls three main types of data. One of them is IRC chat, which allowed for the crew on the DC-8 to coordinate with the ground crew in Punta Areas, Chile, and has also been used during the summer to coordinate with weather forecasters for thunderstorm-chasing over Kansas. During the latest Antarctic mission, IRC was also used to communicate with students in 49 school classrooms in the US and Chile. One IRC server is aboard the aircraft and another at the ground station, reducing the number of connections that need to be handled over the narrow IP network pipe. The DC-8 also sends back an ASCII-based telemetry stream over the Iridium connection, providing the aircraft's location as well as some meteorological sensor data. "This data is of interest to weather modeling groups," Van Gilst said, "as there is often not a lot of in-situ measurement data available. And simply knowing where the aircraft is via a Google Earth KML is extremely helpful, allowing ground crew to return to the airport to receive the aircraft when we're about to return." Another stream of data that comes over the multiplexed Iridium channels is a feed of weather and satellite data from the ground station. "The OIB missions generally do not need much in the way of real-time situational awareness data, as the flight plans are fixed at takeoff," said Van Gilst, "but the scientists have found it helpful to have access to model run data while we're returning to base in order to get a jump on planning the next day's flight." Other missions flown by NASA's Earth Science Division—such as the ARCTAS atmospheric monitoring mission in the Arctic in 2007—have changed their flight plans in mid-air based on updated satellite data; in the case of ARCTAS, the data would be used "to chase forest fires in Northern Canada, locating flare ups from GOES and MODIS satellite data," Van Glist said.

Millau Viaduct, France The Tallest Bridge Ever

The Millau Viaduct is a cable-stayed road-bridge that spans the valley of the river Tarn near Millau in southern France. Designed by the French structural engineer Michel Virlogeux and British architect Norman Foster, it is the tallest bridge in the world with one mast's summit at 343.0 meters above the base of the structure. It is also the 12th highest bridge in the world, with a 270 meters drop from the bridge road to the valley below. The 2460 meters long bridge is a stunning architectural and design feat. And it is beautiful to look at as well.

The first plans were discussed in 1987 and by October 1991 the decision was made to build a high crossing of the Tarn River. In late 2001, the first stone was laid. By spring 2002, the first piers of the Millau Viaduct were rising skywards. At the same time, the anchorage points of the deck (the abutments) were appearing. A few weeks were all it took to carry out the earthworks. Twelve months after the work began, the pier "P2" went higher than 328 feet. A year later, on December 9, 2003, the concrete work was completed on time and the record for the tallest pier in the world was set at 804 feet.

The first work on the steel deck of the bridge commenced in the summer of 2002, and on March 25, 2003, the first deck section, which was 561 feet long, was driven out into open space. Seventeen others followed suit, at an average rate of one rolling out every four weeks. And on May 28, 2004, the joining of the north and south sections of the deck took place. On 28 May 2004, at exactly 2:12 p.m., the junction--or "clavage"--of the north and south sections of the deck took place 886 feet above the River Tarn.

The rest of the bridge's construction went swiftly. Just 24 hours after the junction of the two sections, the first installation of the towers began, followed quickly by the addition of 154 stays intended to support the bridge's deck. By the end of September 2004, the deck's surface was laid. And on December 16, 2004, the first traffic crossed the Millau Viaduct.

The bridge's construction cost up to €394 million, with a toll plaza 6 km north of the viaduct costing an additional €20 million. The builders, Eiffage, financed the construction in return for a concession to collect the tolls for 75 years, until 2080. However, if the concession is very profitable, the French government can assume control of the bridge in 2044.

The project required about 127,000 cubic meters of concrete, 19,000 tonnes of steel for the reinforced concrete and 5,000 tonnes of pre-stressed steel for the cables and shrouds.

Suitcase that Wirelessly Follows Its Owner....

This suitcase is equipped with receivers that communicate with the smartphone in order to make the luggage follow its owner wirelessly, moving on caterpillar tracks based on compressed air.

Dubbed the Hop, the suitcase tries to follow the user at a specific distance. However, in case the distance is too great and the signal is lost, the suitcase instantly locks itself and the user receives a vibration on their phone that informs about it.

Another interesting feature is that the several suitcases can be programmed to follow one another.

There are 3 different bits of tech in the valise that receive, identify and triangulate signals captured from the user's smartphone. The relative location of the suitcase relative to the smartphone is estimated with the help of a microcontroller.

The Moon...

The only natural satellite of the Earth and the 5th largest among all the satellites in the solar system, the Moon is a great celestial body in our solar system which the universe has bestowed upon us. With an appearance that is calm and ever-fascinating, Moon has been a subject matter of interest for many since the ancient times and has a strong relevance in our mythologies, cultures, arts and calendars. The day Galileo observed Moon closely through his telescope; he would not have imagined that one day a human would set foot on the grounds of this glowing element in the sky above our heads. But then, he may not have imagined lots of things science is discovering about the Moon today. Here is an entire section to feed your curiosity for the Moon and related facts. Take a glance! 

Fast Facts 

Distance From Sun: 147 million kilometres
Average Distance From Earth: 384,400 km
Mean Radius: 1737.5 km
Mean Circumference: 10,917.0 km
Volume: 21,971,669,064 km3
Mass: 7.34 x 1022 kg
Density: 3.344 g/cm3
Surface Area: 37,936,694.79 km2
Surface Gravity: 1.624 m/s2
Length of Day: 27.322 Earth days
Length of Year (Orbital Period): 0.074803559 Earth years
Average Orbit Velocity: 3,680.5 km/h
Orbit Inclination: 5.16 degrees
Orbit Circumference: 2,413,402.16 km
Average Temperature: -233°C/123 °C (Min/Max)

Curiosity's Dust Removal Tool....

NASA's Mars rover Curiosity has completed first-time use of a brush it carries to sweep dust off rocks.

           Nearing the end of a series of first-time uses of the rover's tools, the mission has cleared dust away from a targeted patch on a flat Martian rock using the Dust Removal Tool.

The tool is a motorized, wire-bristle brush designed to prepare selected rock surfaces for enhanced inspection by the rover's science instruments. It is built into the turret at the end of the rover's arm. In particular, the Alpha Particle X-ray Spectrometer and the Mars Hand Lens Imager, which share the turret with the brush and the rover's hammering drill, can gain information after dust removal that would not be accessible from a dust-blanketed rock.

Choosing an appropriate target was crucial for the first-time use of the Dust Removal Tool. The chosen target, called "Ekwir_1," is on a rock in the "Yellowknife Bay" area of Mars' Gale Crater. The rover team is also evaluating rocks in that area as potential targets for first use of the rover's hammering drill in coming weeks.

Smartphones as Secure and Versatile Keys...

Researchers have developed a new software that makes the technology of opening car and home doors using smartphone apps more secure and versatile.

Researchers from the Fraunhoffer Institute for Secure Information Technology SIT in Darmstadt, Germany, will be demonstrating their ShareKey software, a solution to popularise the method.

"In essence, ShareKey offers two new functions: users can issue digital keys remotely and assign these keys certain user permissions. For instance, I can grant the building superintendent access to my apartment for a short period so that he can open the door for the gas meter to be read while I'm at work," said Alexandra Dmitrienko from the SIT.

"The solution is built around modern security technologies and can be easily integrated into existing access control systems," Dmitrienko said in a statement. ShareKey sends electronic keys directly to the user's mobile phone, in the form of a QR code attached to an e-mail or MMS. "Recently, users of parcel stations have fallen victim to phishing attacks. Equally, hackers continue to target their efforts on smartphones. In light of this, the big challenge was to protect the electronic keys without compromising the intuitive operation of such devices," said Dmitrienko.

ShareKey works using the Near Field Communication (NFC) transmission standard, which allows data to be exchanged wirelessly over short ranges of up to a few centimeters.
"To open a door, all you need to do is hold your mobile phone close to the lock," said Dmitrienko. NFC interface and door locks only operate within a narrow bandwidth and have limited computing power.

Scientists at the SIT have equipped ShareKey with particularly resource-efficient communication protocols. Electronic keys are reliably protected on the smartphone from malware and unauthorised access. This is achieved by leveraging advanced technologies which keep sensitive data on the smartphone separate from other data and apps. Communication between the mobile phone and a central server is protected by established security protocols.

How Google's self-driving car works...

                          The longtime dream of sci-fi fans-cars smart enough to drive themselves-is still many years off. That doesn't keep Google from trying. Its seven custom-equipped self-driving cars have logged more than 200,000 miles on the road without crashing. Well, one suffered a dent when a human driver rear-ended a Prius. So far the cars are officially legal only in Nevada-liability issues need to be worked out. More likely the technology will appear piecemeal in new vehicles. For instance, most car companies already offer accident-warning alarms.
                         Google says the sophisticated operating system that guides the cars makes them safer than if a human driver were behind the wheel. The vast majority of car accidents are caused by human error. Self-driving cars an also travel closer together, which would cut down on traffic congestion.

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