World's smallest laser unveiled

The world's smallest laser, contained in a silica sphere just 44 nanometres across, and about 10 times smaller than the wavelength of light, has been unveiled. According to a report in Nature News, the laser has been named as the 'spaser'. Whereas a laser amplifies light, using a mirrored cavity to intensify it, a spaser amplifies surface plasmons - tiny oscillations in the density of free electrons on the surface of metals, which, in turn, produce light waves. The spaser could be used as a light source for scanning near-field optical microscopes, which can resolve details beyond the reach of standard light microscopy, and in nanolithography, to etch patterns much smaller than the width of a human hair. The device also opens the door to nanoscale circuits that could process information thousands of times faster than the microelectronic chips inside today's computers. "This work has utmost significance," said Mark Stockman of Georgia State University in Atlanta, who with David Bergman of Tel Aviv University in Israel proposed the spaser concept in 2003. "The spaser is the smallest possible quantum amplifier and generator of optical fields on the nanoscale - without it, nanoplasmonics is like microelectronics would have been without a transistor," he added. According to Nikolay Zheludev, a physicist at the Optoelectronics Research Centre at Southampton University, UK, "I can think of applications in tagging large biochemical assays and in security marking, where the spaser's narrow spectral output gives better tagging capacity than existing semiconductor quantum dot emitters." Such applications are not far off, according to the US team. But, Noginov thinks that the spaser's ability to generate coherent surface plasmons may be even more important than its uses as a nanolaser, and could herald a new generation of ultrafast nanoelectronics. So far, researchers have made plasmonic circuit elements that serve as wires, resistors and capacitors, but the spaser should enable the development of amplifiers and generators. For the spaser to have realistic applications in computing, however, researchers need to find a way to make it work electrically using a semiconductor, rather than using light to pump an organic dye. That would allow the spaser to be integrated with photonic nanocircuitry. According to Stockman, such devices are about a year away. "There is already a nanolaser with electrical pumping, and its extension to the spaser is very realistic," he said.

Archaeologists discover oldest map in Western Europe

Researchers at the University of Zaragoza have unearthed what they believe is man's earliest map, dating from almost 14,000 years ago. The research team, led by archaeologist Pilar Utrilla, discovered a stone tablet in a cave in Abauntz in the Navarra region of northern Spain in 1993 but it has taken them 15 years to disentangle the mess of etched lines. The artefact found during excavation of the cave is believed to contain the earliest known representation of a landscape. Engravings on the stone, which measures less than seven inches by five inches, and is less than an inch thick, appear to depict mountains, meandering rivers and areas of good foraging and hunting. "We can say with certainty that it is a sketch, a map of the surrounding area," the Telegraph quoted Utrilla as saying. "Whoever made it sought to capture in stone the flow of the watercourses, the mountains outside the cave and the animals found in the area. "The landscape depicted corresponds exactly to the surrounding geography. Complete with herds of ibex marked on one of the mountains visible from the cave itself," she added. The research adds to further understanding of early modern human capacities of spatial awareness, planning and organised hunting. "We can't be sure what was intended in the making of the tablet but it was clearly important to those who populated the cave 13,660 years ago. Maybe it was to record areas rich in mushrooms, birds' eggs, or flint used for making tools," Utrilla said. According to the researchers, it may also have been used as a storytelling device or to plan a hunting expedition. "Nothing like this has been discovered elsewhere in western Europe," she said. The research has been published in the latest edition of the Journal of Human Evolution.

Send e-mails via mobile phone just by writing in the sky

Duke University engineering students have come up with a cell phone application that can enable users to remember things just by writing short notes in the air with their handsets, which will be automatically sent to their e-mail address. The researchers say their PhonePoint Pen application uses the built-in accelerometers in cell phones to recognize human writing. Accelerometers are the devices in phones that not only keep track of the phone's movements, but make it possible for the display screens to rotate from landscape to portrait modes depending on how the phone is rotated. These devices are always "on," so there is no additional burden on the phone to use this new application. "We developed an application that uses the built-in accelerometers in cell phones to recognize human writing," said Sandip Agrawal, electrical and computer engineering senior at Duke's Pratt School of Engineering, who with Duke graduate student Ionut Constandache developed the PhonePoint Pen. "By holding the phone like a pen, you can write short messages or draw simple diagrams in the air. Constandache said: "The accelerometer converts the gestures to images, which can be sent to any e-mail address for future reference." "Also, say you're in a class and there is an interesting slide on the screen. We foresee being able to take a photo of the slide and write a quick note on it for future reference. The potential uses are practically limitless. That this prototype works validates the feasibility of such a pen," Constandache added.

Computer hackers can use power sockets to spy on what you're typing

Computer hackers can use power sockets to scout what people are typing, warn experts. Researchers Andrea Barisani and Daniele Bianco, of Inverse Path, have revealed that poor shielding on some keyboard cables can allow hackers to identify each character typed on a computer. According to the BBC, the information passed along cables connecting keyboards to desktop PCs is leaked onto power circuits. "Our goal is to show that information leaks in the most unexpected ways and can be retrieved," the Telegraph quoted the researchers as saying. During the study, the research focused on the cables used to connect a type of keyboard, called a PS/2, to desktop PCs. They found that six wires inside a PS/2 cable were typically "close to each other and poorly shielded", thus information travelling along the data wire, when a key is pressed, leaks onto the earth wire in the same cable. The study said that picking up the voltage changes, which identify each keystroke, was made easier because data travels along PS/2 cables one bit at a time.

Web addresses exceed world's population

Internet is growing in dimensions every second, so much so that there are more addresses than there are people on Earth, claims the team behind Microsoft's new search engine Bing. Bing has put the number of web pages at "over 1 trillion", while Google had earlier indexed more than one trillion discreet web addresses. The current global population stands at more than 6.7 billion, which means that there are about 150 web addresses per person in the world. And this could mean that if a person spent just one minute reading every website in existence, then he or she would be kept busy for 31,000 years, without any sleep. "An average person would need six hundred thousand decades of nonstop reading to read through the information," News.com.au quoted Bing as saying. Mark Higginson, director of analytics for Nielsen Online, said that the global online population had jumped 16 per cent since last year. "Approximately 1.46 billion people worldwide now use the internet which represents a solid 16 per cent increase from the previous year's estimate (1.26 billion in 2007)," he said. The largest Internet population belongs to China, with 338 million users online, which is more than there were people in the US. However InternetWorldStats.com (IWS), a website that combines multiple data sources, has claimed that China's online population is more like 298 million. "With the rates of India and China still quite low, there is ample room for growth in the coming decade," said Higginson. But, measuring the online population could be tricky-there are servers, users, per capita numbers, and penetration percentages to evaluate. And thus it is difficult to find a single figure to represent the world online population. IWS combined data from the UN's International Telecommunications Union, Nielsen Online, GfK and US Census Bureau, and its latest global figures puts the number of internet users in the world at 1,596,270,108. And this is just 23.8 per cent of the estimated 6,0706,993,152 people in the world. But it changes every day. "In terms of the future, we anticipate mobile to contribute significantly to internet usage," said Higginson. According to IWS, the top 5 countries with the most internet users are:

1 - China (298,000,000 users, or 22.4 percent of their population)

2 - US (227,190,989, or 74.7 percent)

3 - Japan (94,000,000, or 73.8 percent)

4 - India (81,000,000, or 71.5 percent)

5 - Brazil (67,510,400, or 34.4% percent)

Rare Buddhist treasures unearthed in Gobi Desert

A joint Austrian-Mongolian treasure hunt team has unearthed rare Buddhist treasures, not seen for more than 70 years, in the Gobi Desert. The relics, which include statues, artwork, manuscripts and personal belongings of a famous 19th Century Buddhist master, were buried in the 1930s during Mongolia's Communist purge, when hundreds of monasteries were looted and destroyed. Michael Eisenriegler, leader of the search team, told the BBC World Service they were filled with "the most amazing Buddhist art objects". The expert said: "It is of tremendous value for Mongolian culture because Buddhism was almost extinct in the Communist times, especially in the 1930s. "I'm totally exhausted right now but I'm also totally impressed with what I've seen." The finds will be put on show at the Danzan Ravjaa Museum in Sainshand, 400km (450 miles) south of the Mongolian capital, Ulan Bator. About 20 boxes remain hidden in the desert.

Sahara desert becoming green due to climate change

Scientists are now seeing signals that the Sahara desert and surrounding regions are greening due to increasing rainfall, all thanks to the rising temperatures due to climate change. According to a report in National Geographic News, if sustained, these rains could revitalize drought-ravaged regions, reclaiming them for farming communities. This desert-shrinking trend is supported by climate models, which predict a return to conditions that turned the Sahara into a lush savanna some 12,000 years ago. The green shoots of recovery are showing up on satellite images of regions including the Sahel, a semi-desert zone bordering the Sahara to the south that stretches some 2,400 miles (3,860 kilometers). Images taken between 1982 and 2002 revealed extensive regreening throughout the Sahel, according to a new study in the journal Biogeosciences. The study suggests huge increases in vegetation in areas including central Chad and western Sudan. he transition may be occurring because hotter air has more capacity to hold moisture, which in turn creates more rain, according to Martin Claussen of the Max Planck Institute for Meteorology in Hamburg, Germany. "The water-holding capacity of the air is the main driving force," Claussen said. While satellite images can't distinguish temporary plants like grasses that come and go with the rains, ground surveys suggest recent vegetation change is firmly rooted. Throughout North Africa, new trees, such as acacias, are flourishing, according to Stefan Kropelin, a climate scientist at the University of Cologne's Africa Research Unit in Germany. "Shrubs are coming up and growing into big shrubs. This is completely different from having a bit more tiny grass," he said. In 2008, Kropelin visited Western Sahara, a disputed territory controlled by Morocco. "The nomads there told me there was never as much rainfall as in the past few years," he said. "They have never seen so much grazing land," he added. He explained it's a similar story in the eastern Sahara area of southwestern Egypt and northern Sudan, a remote desert region that he has studied for two decades. "Before, there was not a single scorpion, not a single blade of grass," Kropelin said. "Now, you have people grazing their camels in areas which may not have been used for hundreds or even thousands of years. You see birds, ostriches, gazelles coming back, even sorts of amphibians coming back," he said. According to Reindert Haarsma of the Royal Netherlands Meteorological Institute in De Bilt, the Netherlands, satellite data shows "that indeed during the last decade, the Sahel is becoming more green."