It consists of a bulk lithium cobalt cathode three millimeters long, an ionic liquid electrolyte, and has as its anode a single tin oxide (Sn02) nanowire 10 nanometers long and 100 nanometers in diameter – that’s one seven-thousandth the thickness of a human hair.
By following the progression of the lithium ions as they travel along the nanowire, the researchers found that during charging the tin oxide nanowire rod nearly doubles in length. This is far more than its diameter increases and could help avoid short circuits that may shorten battery life. This unexpected finding goes against the common belief of workers in the field that batteries swell across their diameter, not longitudinally.
YouTube user SterlingBreed captured this marvelous video. Keep Portland weird! via Geekosystem
Young first came up with the ball bearings idea when he noticed that carved stone balls were often found near Neolithic stone circles in Aberdeenshire, Scotland (map).
"I measured and weighed a number of these stone balls and realized that they are all precisely the same size—around 70 millimeters [3 inches] in diameter—which made me think they must have been made to be used in unison, rather than alone," he told National Geographic News.
The balls, Young admitted, have been found near stone circles only in Aberdeenshire and the Orkney Islands (map)—not on Stonehenge's Salisbury Plain.
But, he speculated, at southern sites, including Stonehenge (map), builders may have preferred wooden balls, which would have rotted away long ago. For one thing, wooden balls are much faster to carve. For another, they're much lighter to transport.
Zuckerberg’s creature continues to gain users around the world (almost 600 millions). Since June 2010 Facebook has stolen new important nations from local, previously strong, competitors (in 115 out of 132 countries analyzed it is market leader) especially in Europe. In particular:
- From Iwiw: Hungary
- From Nasza-Klasa: Poland
- From Hi5: Mongolia
- From Orkut (Google): Paraguay and India. Orkut remains the first social network in Brasil.
In Japan Mixi is still the most used web-based social network (Ameba that I previously mentioned it’s not a pure social networking site, but also a portal/blog-hosting provider). But if we look to mobile social networks usage the leader is Gree followeb by Mobage Town.
An electromagnetic railgun offers a velocity previously unattainable in a conventional weapon, speeds that are incredibly powerful on their own. In fact, since the projectile doesn't have any explosives itself, it relies upon that kinetic energy to do damage. And at 11 a.m. today, the Navy produced a 33-megajoule firing -- more than three times the previous record set by the Navy in 2008.[...]
Ellis says the Navy has invested about $211 million in the program since 2005, since the railgun provides many significant advantages over convention weapons. For one thing, a railgun offers 2 to 3 times the velocity of a conventional big gun, so that it can hit its target within 6 minutes. By contrast, a guided cruise missile travels at subsonic speeds, meaning that the intended target could be gone by the time it reaches its destination.
Furthermore, current U.S. Navy guns can only reach targets about 13 miles away. The railgun being tested today could reach an enemy 100 miles away. And with current GPS guidance systems it could do so with pinpoint accuracy. The Navy hopes to eventually extend the range beyond 200 miles.
Jim Oberg, a space journalist who worked at the space shuttle’s mission-control center for 22 years and specialized in rendezvous procedures, weighs in on the options for rescue. The station’s robotic arm, he explains, is usually not within range of where the astronauts work and moves too slowly to grab someone. The Soyuz vehicles need a full day to power up and undock. By then, the carbon dioxide filters in the astronaut’s spacesuit would run out, asphyxiating him. And the ISS cannot redirect its positioning rocket quickly enough to catch up to a runaway astronaut.
In a worst-case situation, the only rescue option, according to Oberg, would be for a second astronaut to link together several tethers end-to-end, attach them to the station, and then use his Safer pack to jet over to his crewmate and haul him in. Certain conditions could make a rescue easier, he says. If an astronaut floated away more or less at a right angle from the station’s orbit, orbital dynamics (which require too much math to explain here) dictate that he would float back toward the station in about an hour.
