An ultra-powerful laser can turn regular incandescent light bulbs into power-sippers, say optics researchers at the University of Rochester. The process could make a light as bright as a 100-watt bulb consume less electricity than a 60-watt bulb while remaining far cheaper and radiating a more pleasant light than a fluorescent bulb can.

The laser process creates a unique array of nano- and micro-scale structures on the surface of a regular tungsten filament—the tiny wire inside a light bulb—and theses structures make the tungsten become far more effective at radiating light.

The findings will be published in an upcoming issue of the journal Physical Review Letters.

“We’ve been experimenting with the way ultra-fast lasers change metals, and we wondered what would happen if we trained the laser on a filament,” says Chunlei Guo, associate professor of optics at the University of Rochester. “We fired the laser beam right through the glass of the bulb and altered a small area on the filament. When we lit the bulb, we could actually see this one patch was clearly brighter than the rest of the filament, but there was no change in the bulb’s energy usage.”

The key to creating the super-filament is an ultra-brief, ultra-intense beam of light called a femtosecond laser pulse. The laser burst lasts only a few quadrillionths of a second. To get a grasp of that kind of speed, consider that a femtosecond is to a second what a second is to about 32 million years. During its brief burst, Guo’s laser unleashes as much power as the entire grid of North America onto a spot the size of a needle point. That intense blast forces the surface of the metal to form nanostructures and microstructures that dramatically alter how efficiently light can radiate from the filament.

In 2006, Guo and his assistant, Anatoliy Vorobyev, used a similar laser process to turn any metal pitch black. The surface structures created on the metal were incredibly effective at capturing incoming radiation, such as light.

“There is a very interesting ‘take more, give more’ law in nature governing the amount of light going in and coming out of a material,” says Guo. Since the black metal was extremely good at absorbing light, he and Vorobyev set out to study the reverse process—that the blackened filament would radiate light more effectively as well.

“We knew it should work in theory,” says Guo, “but we were still surprised when we turned up the power on this bulb and saw just how much brighter the processed spot was.”

In addition to increasing the brightness of a bulb, Guo’s process can be used to tune the color of the light as well. In 2008, his team used a similar process to change the color of nearly any metal to blue, golden, and gray, in addition to the black he’d already accomplished. Guo and Vorobyev used that knowledge of how to control the size and shape of the nanostructures—and thus what colors of light those structures absorb and radiate—to change the amount of each wavelength of light the tungsten filament radiates. Though Guo cannot yet make a simple bulb shine pure blue, for instance, he can change the overall radiated spectrum so that the tungsten, which normally radiates a yellowish light, could radiate a more purely white light.

Guo’s team has even been able to make a filament radiate partially polarized light, which until now has been impossible to do without special filters that reduce the bulb’s efficiency. By creating nanostructures in tight, parallel rows, some light that emits from the filament becomes polarized.

The team is now working to discover what other aspects of a common light bulb they might be able to control. Fortunately, despite the incredible intensity involved, the femtosecond laser can be powered by a simple wall outlet, meaning that when the process is refined, implementing it to augment regular light bulbs should be relatively simple.

Guo is also announcing this month in Applied Physics Letters a technique using a similar femtosecond laser process to make a piece of metal automatically move liquid around its surface, even lifting a liquid up against gravity.

This research was supported by the U.S. Air Force Office of Scientific Research.

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Warning: Language

F Twitter from Shane Nickerson on Vimeo.

Uses of the phrase “Up in this bitch”, in order of appropriateness.

Semi-autonomous robots that can navigate and map drug-smuggling tunnels could be the greatest weapon to emerge from the government’s attempt to stamp out the trade in illicit substances across its borders.

Using special intelligence software developed at Idaho National Laboratory that can be mounted on different machines, the iRobot and Foster Miller robots use lasers to situate themselves in the dark tunnels that have been bored beneath the line that divides Mexico from the United States.

The subterranean passageways are a tough environment for Border Patrol to police. The agents know nothing beyond that there’s a hole in the ground. Some tunnels turn out to be crude holes. Others can reach three-quarters of a mile long and be part of a complex distribution infrastructure.

“They are not places you want to send people, especially ones that are claustrophobic, so it’s a perfect application for robotics,” said INL roboticist David Bruemmer, who has spent a decade developing the software the robots run. “That’s where we’ve really found a niche for the capabilities that we have.”

High-tech border surveillance has taken off since both the Sept. 11 attacks and the surge in illegal immigrants over the last decade. Tech is playing a bigger and bigger part in Border Patrol efforts because it’s simply too expensive to have agents everywhere. But for every high-tech solution, say, the controversial “virtual fence” that will begin construction soon in Arizona, there’s a low-tech countermove: mole tech.

In Arizona, more than 30 tunnels have been discovered just since 2006, when Congress passed the Secure Border Fence Act, which called for the construction of more than 700 miles of fence across California, Arizona, New Mexico and Texas.

Near San Diego, 32 tunnels have been discovered since Sept. 11, 2001. Before the heightened vigilance that came in the aftermath of the attack, only two tunnels had been discovered in eight years. Now, there’s a special multi-agency task force in the area dedicated to stopping the tunneling operations. In the past, officers have found them more-or-less by chance.

“We’ve discovered people coming out of the ground on camera footage,” said Jerry Conlin, a Border Patrol agent and spokesman for San Diego. “We’ve had others where we had an agent witness someone disappearing into the ground.”

At the end of 2007, a canine unit picked up a scent and followed it to a storage facility near Tecate, Mexico. Agents eventually pulled 13,700 pounds of marijuana out of the tunnel they found on the premises.

“With our increased operational control, it has literally forced them to go underground,” Conlin maintained. “We disrupted the traditional smuggling routes.”

That’s created a new need for ways of fighting the subterranean drug trade. Sophisticated geological techniques for detecting tunnels offer one solution, but once you’ve found a tunnel, you’ve got to figure out what’s down there. That’s where Bruemmer’s bots — running what his lab calls the Robotic Intelligence Kernel — come into play.

In December, they brought a sensor-loaded Talon robot to a tunnel that the Department of Homeland Security had seized. Though it had been entered, the government agents knew little about the space. Victor Walker, another roboticist at INL, accompanied the bot to the border near Arizona.

“They brought us to this warehouse,” Walker said. “There was a grate in the ground around back. Just a drain. I did not expect that. The Talon is a pretty big robot. You pulled it up and it dropped down about 10 feet below the warehouse.”

This anteroom to the tunnel was dark and damp, and about the size of a large bedroom. In the corner, was a shaft that dropped fifty feet down to the tunnel proper, which ran about 90 meters. They lowered the robot down with wires and, after a few technical hiccups, traversed the muddy hole. It output chemical readings, video, and a map like the one you see below, which can be stuck into Google Maps.

“We hooked it up with a chemical sensor. We were able to map those chemicals to the map. You could see as it was going along,” Walker said. “Within a few minutes, we were able to task it down and get the video back so [Homeland Security officials] could look at it.”

The INL robots aren’t the only ones being used by government officials, nor is the border the only place where robotic border inspectors might be used. Canadian robot maker Inuktun specializes in pipe inspecting robots operated by human beings. Most of the more than 1,000 bots they’ve sold are used by utilities checking out their sewer pipes or water mains. In recent years, however, they’ve seen requests from government agencies to repurpose their bots for subterranean inspection.

“I don’t think anyone has ever built a robot to go into a tunnel, but if you’ve built a bot to go into a nasty sewer pipe, it translates fairly well to going into a tunnel,” Dobell said. “There are a lot more of these cross border tunnels than people think.”

The company’s president, Colin Dobell, said that he could not reveal the names of the organizations that he’s working for, but that he knew they’d been deployed.

“I can tell you that they have been used in tunnels and have been used in tunnels that go across borders,” Dobell said.

The INL bots, though, use a fundamentally different control paradigm. Dobell’s bots are teleoperated, meaning there’s a human with a joystick driving them around. Bruemmer’s are a kind of hybrid bot that share control between the operator and the robot. Operators tell Bruemmer’s robots where to go, but the robots drive.

In the tunnel application, the robots use their lasers to locate themselves within the space and help human operators controlling them with a standard joystick or a Wiimote from running them into walls.

“In the Arizona tunnel, there was less than an inch involved on each side,” Bruemmer said. A teleoperator without some guided motion couldn’t do it.”

Most importantly, though, they can go exploring and mapping autonomously. Inside tunnels, you can’t always communicate via the standard means with the robots. If they go deep and far enough away from the operator, they’ll lose communications contact. In that case, the operator can set a time limit for autonomous exploration, which, when it expires, will send the robot back into communications range to phone home the data it’s found. That information is integrated into the operator’s heads-up display, and then the robot can be sent a-roving again.

Robots might not be serving us drinks yet, but they are evolving to suit our real needs. And slowly but surely we’re learning how to take advantage of robots’ potential.

“It’s all about the man-machine interface. Like Windows just provided this simple user-understood interface, I think that’s what we’re really trying to do with robots,” he said. “Forget about trying to make robots massively intelligent.”

Image: Jason Slater/Foster Miller.

From a cave in southwestern Germany, archaeologists have unearthed the oldest known piece of figurative art. More than an ancient artistic impulse, it may signify a profound change in modern human brains.

Carved from ivory and depicting a woman with exaggerated sexual features, the pinkie-sized sculpture is 36,000 years old, or about 5,000 years older than the next-earliest piece of figurative art.

Though 77,000-year-old carvings have been found in South Africa, they consist of cross-hatched lines. Such abstractions are relatively simple compared to representational art, which requires high levels of cognition to both conceive and make.

Perhaps not coincidentally, the rise of figurine-carving modern human cultures in Europe coincided with the decline of Neanderthals. Some anthropologists suspect that humans of the era experienced a leap in mental abilities, fueled by random genetic mutation or the neurological nourishment of language and culture.

“The advent of fully representational, ‘figurative’ art seems at present to be a European phenomenon, without any documented parallels in Africa or elsewhere earlier than about 30,000 years ago,” writes University of Cambridge archaeologist Paul Mellars in a commentary accompanying the discovery, published Wednesday in Nature.

“How far this ‘symbolic explosion’ associated with the origins and dispersal of our species reflects a major, mutation-driven reorganization in the cognitive capacities of the human brain — perhaps associated with a similar leap forward in the complexity of language — remains a fascinating and contentious issue,” he wrote.

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