The Promise of the World’s Smallest Lasers

October 2009

By Grace V. Jean

About the thickness of a hair and the length of a few millimeters, quantum cascade lasers long have been a laboratory curiosity that only scientists could understand and operate. But recent advances in power efficiency, design and high temperature functionality have pushed this class of semiconductor lasers closer to real-world utility. One day they may provide the military with directional infrared countermeasures, target illumination, chemical warfare sensing and search-and-rescue capabilities, technologists say.

Quantum cascade lasers, as the name infers, employ quantum mechanics principles to convert electrical power into optical energy. Though these devices are fabricated in the same way as their traditional diode counterparts, with thousands of thin layers of materials, quantum cascade lasers produce energy in a different way.

Semiconductor lasers typically require electrons and “holes” to generate light energy. Quantum cascade lasers need only the electrons, which gain atom-like properties when confined into very narrow spaces.

Atoms have specific energy levels to which they can be excited. When they relax, they “fall” to a lower level and emit a photon. Electrons in the laser act the same way. Lining up multiple energy levels in a descending “staircase” causes electrons to cascade continuously and produce a photon at every step.

The material composition in a traditional semiconductor laser determines the energy wavelength that is produced. For example, a carbon dioxide laser emits light at approximately 10.6 microns.

In quantum cascade lasers, the wavelength is dictated not by material but by the size of the energy level positions, or “belts.” Technologists can control the wavelength by increasing or decreasing the size of the belts.

“Now I don’t have to go to exotic materials,” says Kumar Patel, founder and president of Pranalytica Inc. based in Santa Monica, Calif.

Most semiconductor lasers must be cryogenically cooled in order to function. Even when cooled, they generate only milliwatts of power, which renders them inefficient for practical use. “That’s why this field remained fallow for many, many years,” says Patel.

The high-power quantum cascade lasers produced by Pranalytica can generate watts of power and run on continuous operation at room temperature. “They’re different from any other semiconductor laser that ever existed before,” Patel says. “Because I can tailor the energy level positions, I can make the system operate at room temperature.”

But quantum cascade lasers have had a problem: They typically don’t work very efficiently. “If you wanted one watt of power output, the laser would consume 50 watts,” explains Patel.

Under a Defense Advanced Research Projects Agency program, the company sought to produce 20 milliwatts of continuous wavelength and power with an initial goal of attaining 40 percent wall plug efficiency. The team achieved 3 watts of power output with 15 percent efficiency. It may not have hit the target, but Patel says the laser is sufficient for practical applications, such as protecting airplanes from shoulder-fired missiles.

Heat-seeking sensors on such missiles can lock onto the gasses discharged by airplane engines. If a laser could shoot the same wavelength at the sensor, it would disable the guidance system and send the missile veering off-course. Lasers that have attempted the feat previously could not produce the wavelength required to blind the sensor. The quantum cascade laser developed by Patel’s company can.

In a demonstration in February, the laser burned a small hole through a business card placed in close proximity. The same technology fired over longer distances will disable the seeker on shoulder-fired missiles, Patel says. Several defense contractors are testing the laser in their developing countermeasure systems, he adds.

The laser also has utility for infrared illumination. Current target illuminators have short ranges because a substantial amount of the light disperses as it travels through the air. Another problem is that the laser’s wavelengths can be seen by enemies using commercial viewers.

Those cameras cannot detect the quantum cascade laser emission, so the company has produced a battery-operated laser that can illuminate a target up to 2 miles away. Only NATO allies and U.S. forces have technologies that can see this kind of light, Patel points out.

The same laser technology also can be incorporated into a beacon to help the military locate downed pilots and troops. “Having a quantum cascade laser as a source increases the range so significantly that it becomes a viable device for search and rescue,” says Patel. “If you’re at 4.6 microns or longer, you can see [it] from space.

There are no natural sources of radiation at that wavelength.”


http://www.nationaldefensemagazine.org/archive/2009/October/Pages/ThePromiseoftheWorld%E2%80%99sSmallestLasers.aspx

How Self Reliance Can Get You Through Any Disaster

Our complex world is more disaster-prone than ever—but there’s plenty we can do about it. Self-reliant, community-minded individuals (with appropriate skills) can help people get through a major event when all else fails. Instapundit’s Glenn Reynolds tells us how.

(Illustration by Paul Blow)

Here’s a simple truth: It’s better to bend than to break, and it’s best to be prepared for the worst. This age-old wisdom is going by a new name in slide-rule circles: “Resilience engineering” starts with the insight that it’s smart to design and maintain systems so they have some give. That means building technologies that offer extra capacity to handle sudden loads, plenty of warning when normal operations are beginning to break down, backup systems in case things do go wrong, diverse digital architectures so that a single bug doesn’t produce widespread failure, and decentralization so that when (not “if”) communication breaks down things don’t grind to a halt.

Resilience engineering as an academic idea was born in response to the 2003 space shuttle Columbia disaster. The spacecraft disintegrated on re-entry because thermal panels had been damaged by a piece of foam that broke off during the launch. But investigators identified a larger issue: NASA had responded to budget cuts in the 1990s by adopting a “faster, better, cheaper” approach, launching more missions with fewer resources. Safety margins gradually narrowed, information sharing withered and overconfidence ballooned without anyone really noticing. The organization had become brittle and prone to disaster.

When a system looks solid year after year, it’s easy to become complacent, like the generals behind France’s old Maginot Line—which, after all, was pretty good at keeping the Germans out, though useless once they found another way in. It’s just a short step from complacency to pure arrogance: Why worry about lifeboats when the Titanic is unsinkable? Resilience is about having enough lifeboats anyway.

NASA’s not the only institution where financial pressures can lead to brittle operations. When you squeeze the slack out to cut costs, you’re left with systems that have no real margin for error. Modern, “just-in-time” manufacturing methods allow factories to save money by eliminating stockpiles of parts and materials—but if transportation is interrupted, those superefficient assembly lines shut down in a hurry. This doesn’t mean that just-in-time delivery should go away, but the people in charge had better have a backup plan: early-warning systems and a plan to temporarily switch manufacturing sites, perhaps, or a short-term supply of parts always kept in reserve in case of emergencies.

Often, technologies become so tightly coupled that when one piece goes down, it produces a cascade of failures. In his 1988 book, The Collapse of Complex Societies, anthropologist Joseph Tainter suggested that it was increasing complexity that really toppled the Mayan and Roman empires. The northeastern blackout of 2003 didn’t bring about the end of our civilization—but it was serious. The problem started when a single power line brushed against some overgrown trees, then quickly spread to affect 50 million people. One proposal for adding resilience to the electrical grid is called “distributed energy,” with homes, businesses and municipalities producing at least a portion of their own electricity.

Resilience engineering is a specialized field, but it simply takes some common sense to apply its principles to the ordinary world. For instance, when the power goes out, traffic signals go down. This causes accidents and traffic jams—often exacerbated by people who decide to leave work or home in favor of finding someplace where there might be lights and a/c. During the 2003 blackout, New York City streets were gridlocked by traffic-signal failure, causing some to abandon their cars and walk, which, of course, made the congestion even worse.

Happily, there’s a simple solution to that one: Battery backups for traffic signals. The batteries may only last a few hours, but that’s a huge improvement. Most blackouts are over by then, and even if the backup power does run out, there’s enough time for traffic to disperse and police officers to arrive. The system fails gracefully rather than catastrophically. California’s Sacramento County, New York City and many smaller communities have started installing battery backups. And when New York experienced outages in 2006, many traffic lights continued working.

Backup power for cellphone systems can be equally important, but here things aren’t going as well. After studying the aftermath of Hurricane Katrina, the Federal Communications Commission ordered mobile providers to install backup power for all cell towers, but the industry resisted and the requirement was dropped. This means that cellphones, which many rely on in emergencies, aren’t as reliable in a crisis as they should be.

The Public Option

When it comes to large-scale emergencies, the country has a hidden weapon—and we can do more with this resource. I’m talking about a populace filled with self-reliant, community-minded individuals. During a major crisis, on the order of Katrina or a serious California earthquake, relief services can be overwhelmed. When individuals are prepared to look after themselves for a while, with food, water and medicine on hand, and alternative sources of heat or power, it makes a big difference. The government can’t take care of everybody at once. If disaster-relief staffs don’t have to worry about you, they can take care of others—which means that being self-reliant can actually help your community.

Often, government officials worry about the public panicking in a widespread disaster. But they have that backwards. In studies of more than 500 emergencies, the University of Delaware’s Disaster Research Center found that panic rarely occurred. In fact, people consistently jump in to help themselves and their neighbors. Research by scholars like Kathleen Tierney, who directs the Natural Hazards Center at the University of Colorado at Boulder, shows that the true first responders are often the people on the scene when a disaster strikes. They save lives by administering first aid, getting people out of hazardous areas and spreading warnings. Volunteers improvised the water-based evacuation of lower Manhattan on Sept. 11, called an American Dunkirk by some, that moved masses of people out of the danger zone.

A self-reliant attitude is good, but skills help mightily, too. Citizen training is available through the Red Cross, Community Emergency Response Teams and Neighborhood Emergency Response Teams. One underappreciated resource is the amateur radio community. Acquire a ham radio license (American Radio Relay League, ) and you can become a major resource if a disaster strikes. It’s fun, too.

In the meantime, architects, engineers, regulators and government officials should take heed, and think about creating systems that don’t leave us hanging when things go wrong. Because, inevitably, they will.

http://www.popularmechanics.com/science/worst_case_scenarios/4330416.html

How to Move Heavy Objects With Simple Tools

Big loads don’t always call for big machines. Basic know-how backed by simple tools can move almost anything. Here’s how to move boulders, lift fences and haul logs without relying on heavy machinery.

The human race is industrious, but we don’t like to work any harder than we have to. The details are lost to history now, but somebody, somewhere, noticed that sliding a mammoth haunch was less tiring than carrying it. (In fact, I’m willing to bet that he noticed it slid even better fur side down.) Whether you’re bringing home dinner or tearing up a concrete sidewalk, easier is still better. And while some jobs might require a backhoe or a winch, you can do a lot with basic levers and rollers, built in a few minutes using some hand and power tools. The crummiest 2 x 4 stud, properly applied across a fulcrum, moves a 150-pound rock with about 10 pounds of force. The improved version of this lever is even more capable. We’ll take brains over brawn any day, and the basic methods we show here will help you easily move the rocks, slabs, stumps, rubble and tree branches that you’re likely to encounter.

Sleds and Ramps

Slippery Slope (top): Sure, you can buy nice ramp hardware that mounts to construction lumber, but you can easily make your own from steel flat stock. Use carriage bolts to attach it to 2 x 12s.

Problem Solver (bottom): Somewhere between ramps and steps is the step ramp. Just face-nail short pieces of 2 x 12 lumber to create a versatile load mover.

Sleds and ramps are simple to build, and they are often the best way to move heavy stones. A stone sled is a plywood platform bolted and screwed to a pair of 2 x 4 runners. Its low stance allows you to easily roll or pivot the load onto it. To get big stones off, pivot a bar against the side rails.

Good-quality aluminum ramps are widely used to get ATVs in and out of pickups, but rough loads can wreck them. After all, they weren’t designed to withstand tumbling rocks, stumps or chunks of concrete. Instead, consider building stout ramps from 2 x 12s. The lumber needs to be a minimum of 10 feet long—this will produce an angle of about 17 degrees, for a typical pickup-bed height. That doesn’t sound very steep, until you push a loaded wheelbarrow up it. Improve traction by applying some paint to the ramp surface, preferably stuff you would have otherwise thrown away. Sprinkle dry sand on the wet paint or use antiskid paint additive ($7 to $15 per container). Improve traction by stiffening it with a 2 x 4 spine nailed vertically on edge to its bottom surface.

A “step ramp” sounds oxymoronic, but it’s well-suited to its name—a hybrid between ramps and steps. Build a pair. Each consists of extremely shallow steps made from 2 x 12 chunks face-nailed together. They nest together nicely and tuck unobtrusively into the corner of a shed.

In rare instances, a load forms its own transport. Years ago, the owner of a tree company showed me an old-time Yankee trick. To move a big pile of brush, place a Y-shaped branch on the ground, curved side down, and stack the brush on it. The branch’s stem forms a convenient handle, and the curved trunk acts like a sled runner.

Rollers

The Can, Can: Any round trashcan rolls on its bottom edge. Plastic ones also slide nicely.

Dolly, Wood: Bolt a piece of 3/4-inch plywood to four heavy-duty dollies. No plywood? Use construction lumber and cross cleats.

Pipe Line: PVC pipe (Schedule 40) and construction lumber team up to move heavy loads. This technique is particularly well-suited to soft or wet terrain.

If sliding is easier than carrying, rolling is easier than sliding. Tip a rubble-filled garbage can onto its corner and you’ve created an effective way to move rubble around a remodeling job. The can’s large diameter lets you apply a surprising amount of torque.

Everybody knows the trick of rolling a heavy load on pipes. The method works better when you roll the pipes over lumber, not on ground. Also, putting the load itself on lumber makes for a smoother action.

If you need to move a big load like a chest freezer over a smooth surface, make yourself a four-wheel dolly. Moving companies are likely to own varied dollies—with raised ends, raised sides or flush platforms. For a homeowner, a couple of smooth-platform dollies are the most useful. You can always make riser blocks as needed to suit the bottom surface of the load you’re rolling. Use swivel-plate caster wheels, not the pin types designed to be installed in furniture legs. The casters should be rated for at least 150 pounds each. That might strike you as overkill, but keep in mind that the caster rating is based on an evenly distributed load moved over an ideal surface. That almost never happens. So the real-world carrying capacity of the caster is much less. Large wheels (4 or 5 inches) roll more easily over rough surfaces than 2- or 3-inch wheels, though they are slightly more difficult to load, since they make the dolly a couple of inches taller.

Levers

Bar Exam: A heavy-duty shovel’s back forms the perfect fulcrum for a wrecking bar. Face the two tools in the same direction, and get the bar tip under the load. Then just step down on the bar.

Rock, Roll: To get the most from your fulcrum, keep it from moving by staking it in place with rebar.

Lever Lift: It’s easy. Use hefty wood screws or even bolts to attach a bent piece of steel flat stock to the end of a 2 x 4.

Simple levers are all around us, from wrecking bars to pieces of lumber to shovels and tree branches.

The chisel-tip (or pinch-point) wrecking bar is one of my favorite load movers. To get the most out of it, pivot it against a firm, angular fulcrum—the best is a piece of 4 x 4 staked in place with 2-foot-long pieces of rebar.

For hands-free prying, the bar teams up nicely with my other favorite, a heavy-duty shovel. The shovel's back forms a curved fulcrum for the bar. Lay the shovel face down in the same direction as the bar, then get the bar tip under the load. You can step on the bar's end to lift the load, leaving your hands free to work.

A Johnson bar is a wheeled lever. It's a favorite among movers and millwrights, and one of the best contraptions for moving stuff ever invented. The one I made lacks wheels, but it's no less useful. Take a 1 1/2 x 48–inch piece of mild-steel flat stock and clamp the end in a machinist's vise. Then put a stubby 30-degree bend in its end. Bore a row of countersunk holes through the flat stock and attach the metal to the edge of an 8-foot-long 2 x 4 using No. 10 wood screws. Now cut a fulcrum radius on the bottom corner of the 2 x 4. Hook the end of the flat stock under a load, and when you pry back you'll be astonished at the way the load just floats off the ground.


http://www.popularmechanics.com/home_journal/how_to/4328372.html?page=1

Technologies to Help Aircraft Avoid Mid-Air Collisions

October 2009

By Grace Jean

Recent flight tests of newly developed technologies are proving that it is possible to fly manned and unmanned aircraft safely in the same airspace.

“We’re attacking the three or four real key enabling technologies,” says Reece Clothier, project manager of the Smart Skies Project, a three-year research and development project in Australia that is focused on integrating unmanned systems into civilian airspace. It is being funded in part by the Queensland State Government Smart State Funding Program.

His team, in collaboration with Boeing Research and Technology in the United States and Australia and the Australian Research Center for Aerospace Automation (ARCAA) — a joint venture between the Commonwealth Scientific and Industrial Research Organization and the Queensland University of Technology, is helping to develop and test technologies in three areas: global aircraft separation management, aircraft tracking and onboard detection systems for collision avoidance of dynamic and static obstacles.

Boeing’s airspace separation management system concept, called the automated dynamic aerospace controller, or ADAC, employs algorithms to track aircraft and resolve potential conflict situations. It can be located anywhere on the planet to provide four-dimensional separation assurance service to aircraft flying around the world.

The mobile aircraft tracking system, a portable air traffic control radar under development by Boeing Research and Technology Australia, is capable of detecting and tracking aircraft in a five- to 10-nautical mile range. It can transmit traffic information to the ADAC, to local air traffic control and to other airspace monitors.

Finally, the detect, sense and act system is seeking to help unmanned systems perceive and avoid moving and stationary obstacles.

The team completed a full month of flight-testing of the automated dynamic airspace controller (ADAC) in July in Kingaroy, Australia, at a remote test range about four hours northwest of Brisbane. The trials were conducted with up to seven aircraft — three live aircraft including two unmanned systems, and four simulated aircraft including one flown at Sheffield University in the United Kingdom. The aircraft were linked via Iridium satellite and Telstra NextG communications networks to the ADAC separation system, located in Palmdale, Calif.

“We wanted to demonstrate that it could be anywhere,” Clothier says at the Association for Unmanned Vehicle Systems International symposium in Washington, D.C.

In one scenario, a fixed-wing unmanned system and a drone helicopter were put on a collision course. For safety reasons, their actual flight paths were separated by altitude. The ADAC system altered their flight paths to keep them flying safely. In another scenario, the ARCAA airborne systems laboratory — a modified Cessna 172R aircraft — was flown in a range of conflict scenarios with a varying number of simulated aircraft, says Clothier. Pilots in the Cessna flew “hands-off” and monitored onboard displays as the ADAC transmitted separation commands directly into the autopilot system.

The team in December 2010 intends to demonstrate all the technologies in trials that will separate 30 manned and unmanned aircraft, simulated and real, flying within a 10 nautical mile area of the range.

“In the final flight trial campaign, we hope to fly a real conflict scenario between two of the UAS platforms,” Clothier says in an email to National Defense. “We would remove the altitude safety buffer and actually fly the two aircraft at each other relying on the automated airspace separation management system to detect and resolve the conflict.”


http://www.nationaldefensemagazine.org/archive/2009/October/Pages/TechnologiestoHelpAircraftAvoidMid-AirCollisions.aspx

Machine That Predicts Terrorists’ Intent Showing Progress

November 2009

By Austin Wright

Metal detectors screen for the means to commit a crime. The Department of Homeland Security is developing technology that screens for the intent to do so.

The department’s Future Attribute Screening Technology, or FAST, uses body scanners to sense the fear in your eyes — and in your skin, your heartbeat and even your movements. The system places these and other variables into an algorithm that may be able to determine whether the sum of certain bodily signals is the result of hostile intent, or just someone having a bad day.

Robert P. Burns, deputy director of the Homeland Security Advanced Research Projects Agency, says the technology could help security officers at checkpoints decide which travelers should be called aside for secondary questioning. The technology is still years from completion, he adds.

About 5 percent of Homeland Security’s science and technology budget goes toward these reach-for-the-sky endeavors that could have game-changing effects on national security if they succeed. The agency also is developing technologies that would detect drug-trafficking tunnels from above ground, reduce the likelihood of massive power outages and strengthen levees. “We go after the projects or ideas that other people don’t want to go after because they are incredibly high-risk and could fail,” says Burns, a 1981 Naval Academy graduate who spent 21 years in the private sector. “We’re really pushing the envelope in terms of science and technology.”

The FAST project, which began in 2006, involves 40 to 50 developers from several organizations and so far has cost the agency $20 million. It combines research from a number of academic fields into a futuristic model for stopping crime before it happens. Project collaborators from Draper Laboratory, a Massachusetts-based not-for-profit research company, have been working with the agency to translate decades’ worth of physiological studies into algorithms that gauge people’s involuntary bodily signals.

“We look at a series of physical cues or behavioral cues that you give off that are a direct relation to your physical and emotional thought processes,” Burns says. “You can’t base anything on any one of these signals. It’s the compilation that we look at and that come together.”

The technology could be described as a more comprehensive, less intrusive polygraph exam. Already, privacy advocates are expressing concern. The Electronic Privacy Information Center, a Washington-based think tank, plans to push for laws that would ensure that the federal government doesn’t keep records of the FAST system’s measurements, and the American Civil Liberties Union is exploring its legal options for trying to halt the project.

“We think that it’s an invasion of privacy to read someone’s physiological bodily functions without their permission,” says Jay Stanley, a spokesman for the ACLU. “It’s nobody’s business what my pulse rate is. It’s a profound invasion of human dignity.”

Burns counters that the system was designed as a way to help checkpoint security guards make better-informed decisions about which travelers to call aside for further questioning — and not as an Orwellian device for keeping medical tabs on unassuming citizens. He says he worked with Homeland Security’s privacy office to make sure the program adheres to all federal laws. “The system does not record or maintain your information,” Burns says. “Once any issues are resolved, the information is dumped.”

The program’s long-term goal is to allow the public to move with greater freedom through airports, border checkpoints and government buildings, he adds. But in its current form, the FAST system can scan only one traveler at a time, and it requires that each person answer a series of questions. Computer software compares physiological measurements taken during questioning to measurements taken before questioning.

“This is a case where technology has finally caught up to the theory, and each of our sensors has a specific theory behind it,” Burns says. The system relies mainly on low-cost, widely available equipment. “We should have something that’s reasonably cheap.”

In 2007, Burns left his job as an executive at American Systems, a technology consulting and engineering firm, to become manager of the FAST program. In mid-2009, he was tapped to become deputy director of Homeland Security’s entire advanced-projects agency. The former submarine officer is loud and animated as he describes what he says have been the most fulfilling two years of his professional life. “I was raised to value duty, honor and country,” he says.

“Being a public servant works really well for me.”

In addition to FAST, he oversees several cutting-edge, often-secretive projects. Department researchers are developing contact-less fingerprint scanners, liquid-explosive detection devices and software to help public-safety officials make snap judgments during disasters. Another project, the resilient tunnel, aims to seal leaks and smother fires in commuter tunnels that run under rivers and other bodies of water.

University and private researchers collaborated on the tunnel project in an effort to develop gigantic deployable airbags capable of withstanding extreme water pressure. If the project succeeds, airbags would be able to keep cracking tunnels temporarily intact, giving rescue workers more time to search for trapped survivors. And in the event of a tunnel fire, airbags would be able to seal off the entrances and deprive the fire of oxygen.

“We needed to find a way to protect tunnels, because today’s safeguards are super expensive,” Burns says. “If we’re able to bring some of these projects forward, they could truly change the game.”

The FAST system has the potential to catch terrorists and their accomplices before they ever get the chance to launch their attacks, he says. Agency researchers showcased FAST at a September technology exhibition in Cambridge, Mass. They tested the system’s ability to identify study participants who planned to commit a crime.

Some of the participants were given items that, if smuggled into the exhibition, would have been capable of causing a major disruption. Others were told to enter the exhibition hall, locate a hidden device and set it off. In both cases the items were inert, a fact that was unknown to the participants. Burns declines to discuss the items, the hidden device or the study’s findings. Such information, he says, could compromise future experiments.

“We’re doing amazingly well, but this is not ready for prime time,” he says. “We would like, in fiscal year 2011, to have a single prototype that we can take to an operational location and perhaps test and do further data collection in a real-world environment.”

At the exhibition, study participants, including some who were part of a control group, walked single-file through a security checkpoint. A guard asked them a series of questions. Meanwhile, a laser measured their heart and respiratory rates, an eye tracker measured their blink rates and pupil dilation, a thermal camera measured the heat on their skin and a reconfigured Nintendo Wii Balance Board measured their fidgeting. Nearby computers processed the data, and the system’s software recommended to the security guard which participants should be taken aside for follow-up questioning.

“We’re looking at the combination of those factors,” Burns says. “We’ve got to make sure that whatever system is developed doesn’t cause false readings. I want to make sure that if you’re running late to catch your mass transit and you’re carrying a large backpack, that I don’t pull you over for secondary questioning because you’re hot and sweaty. If you’ve had a bad day and are a little terse, I don’t want to pull you over because you’re grumpy.”

So far, the results show that “we’ve made great progress,” he says.

Paul Ekman, a prominent psychologist and a consultant on the FAST project, says he’s skeptical of the technology. Over the past 40 years, Ekman has pioneered the study of human emotions and their effects on facial expressions. He is ranked 59th on the Review of General Psychology’s list of the 100 most eminent psychologists of the 20th Century.

Ekman was glad to offer recommendations to project researchers, but he says he doubts the system will ever outperform human observers. “I’m a little dubious, but data could convince me,” he says. Ekman runs a company that trains security workers to detect signs of malicious intent in people’s behaviors, such as body posture and facial twitches that last a quarter of a second. The premise of the Fox television show “Lie to Me” is based on his research.

“Whether the FAST project will succeed in being practically useful is unknown at this point,” he says. “Also, testing the technology is very difficult. You can’t get the stakes high enough, because of ethical constraints.”

People’s physiological behaviors change in measurable ways only when the cost of failure is high, and the agency’s experiments lack strong negative consequences for the mock criminals, he says. Also, he adds, innocent people sometimes display physiological behaviors that would make them appear malicious, while criminals might be able to train themselves not to display those behaviors.

“You can’t, in my view, simulate a terrorist.”

http://www.nationaldefensemagazine.org/archive/2009/November/Pages/MachineThatPredictsTerrorists%E2%80%99IntentShowingProgress.aspx