Submarines fly

GUILLEMOTS and gannets do it. Cormorants and kingfishers do it. Even the tiny insect-eating dipper does it. And if a plan by the Pentagon's Defense Advanced Research Projects Agency (DARPA) succeeds, a remarkable airplane may one day do it too: plunge beneath the waves to stalk its prey, before re-emerging to fly home.

The DARPA plan, announced in October 2008, calls for a stealthy aircraft that can fly low over the sea until it nears its target, which could be an enemy ship, or a coastal site such as a port. It will then alight on the water and transform itself into a submarine that will cruise under water to within striking distance, all without alerting defences.

DARPA, which has a $3 billion annual budget, has begun to study proposed designs. In the next year or so it could begin allocating funding to developers. Though the agency itself is unwilling to comment, Hawkes and others working on rival designs have revealed to New Scientist how they would solve the key problems involved in building a plane that can travel under water - or, to put it another way, a flying submarine.

The challenges are huge, not least because planes and submarines are normally poles apart. Aircraft must be as light as possible to minimise the engine power they need to get airborne. Submarines are heavyweights with massive hulls strong enough to resist crushing forces from the surrounding water. Aircraft use lift from their wings to stay aloft, while submarines operate like underwater balloons, adjusting their buoyancy to sink or rise. So how can engineers balance the conflicting demands? Could a craft be designed to dive into the sea like a gannet? And how will it be propelled - is a jet engine the best solution, both above and below the waves?

That may have been because the navy had already commissioned another aircraft manufacturer, Convair, to build what became known as the "subplane". It dispensed with heavy floats, relying instead on its streamlined fuselage, like the hull of a flying boat, to land on the water. In a paper in the September 1964 issue of Naval Institute Proceedings (p 144), hydrodynamics engineer Eugene Handler at the US Bureau of Naval Weapons claimed this flying sub would be ideal for attacking Soviet shipping in the Baltic, Black and Caspian seas. Convair drew up detailed designs and even built scale models which were tested in water tanks. Though the results looked promising, the project never made it any further; it was cancelled by Congress in 1966.

So is DARPA's new project destined for a similar fate? "What the Americans want sounds incredibly ambitious," says UK Royal Navy commander Jonty Powis, head of NATO's submarine rescue service. "If they achieve half of what they want from this machine they will be doing well." Others are more optimistic, especially in the light of advances in engineering and materials science since the last attempt - notably in lightweight carbon fibre composites and energy-dense batteries. "There's probably no reason why it can't be done," says Hawkes.

Hawkes admits that an awful lot of power will be needed to get the Super Falcon airborne, and only jet engines have enough oomph to do the job. Polmar agrees, and points out that the piston engines used in conventional light planes are ruled out for other reasons: they would fail if any water leaked into the cylinders. "You cannot immerse a reciprocating engine and expect it to work," he says. But protect a jet engine against saltwater corrosion and position it high on the craft so the spray doesn't enter the intake during take-off and landing, and it will work fine. Russian aircraft maker Beriev has proved this with its Be-200 amphibious plane.Others are already thinking along these lines. Last year, aircraft manufacturer Airbus patented a hybrid electric jet engine for airliners which can be powered by both conventional kerosene and electricity. Most jet engines have an electric starter motor, and this motor could spin the turbine's shaft under water, Hawkes suggests. The blades would rotate more slowly than normal, he says, and the engine won't be particularly efficient. "But I believe this could work perfectly well."

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First piloted solar

A solar powered aircraft masterminded by a Swiss adventurer has made history as the first manned plane to fly around the clock on the sun's energy, bringing a step closer the dream of perpetual flight.

The aircraft, built by Swiss company Solar Impulse, also broke the records for highest altitude and longest duration for a piloted solar flight.
The craft took off at 6:51 local time yesterday morning from the Payerne airbase in Switzerland.
Its power was collected by 12,000 solar panels built into its 63-metre wingspan. During the hours of bright sun, batteries siphoned off some energy to power the plane through the night.
The craft climbed to a height of 8564 metres, which it reached about ten hours into the flight. When the sun began to fade around 7:30 in the evening, the plane began a slow descent to around 1500 metres, where it stayed from 11 pm until sunrise.
After 26 hours in the plane, Borschberg landed it at 9:00 this morning.
This is the last milestone for Solar Impulse's prototype aircraft. Its first was the "flea hop" of last December: a short flight around one metre from the ground.
The company's dreams for the next plane are bigger. To be constructed in 2011, its objectives are to cross the Atlantic, and then to circumnavigate the globe on solar power alone, by 2013. For such missions, let's hope they consider a more adventurous name for the plane than its current moniker: HB-SIB.
"The flight was really zen. It's very peaceful, during this time you have the time to think and to concentrate," he explained.
Piccard revealed that Solar Impulse had emerged from darkness with three hours of energy left in its batteries, a far bigger margin than expected.
The first prototype, shaped like a giant dragonfly, is clad with solar panels across a wingspan of 63 metres, the size of an Airbus A340 airliner.
The solar cells and nearly half a tonne of batteries provide energy for four small electric motors and propellers - the "power of a scooter", as the crew put it - and weigh little more than a saloon car.
The team is driven by a desire to demonstrate that clean energy is technically feasible and should be developed and used more widely for transport, in the household and at work.

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Robot arm punches human to obey Asimov's rules

SAAC ASIMOV would probably have been horrified at the experiments under way in a robotics lab in Slovenia. There, a powerful robot has been hitting people over and over again in a bid to induce anything from mild to unbearable pain - in apparent defiance of the late sci-fi sage's famed first law of robotics, which states that "a robot may not injure a human being".

But the robo-battering is all in a good cause, insists Borut Povše, who has ethical approval for the work from the University of Ljubljana, where he conducted the research. He has persuaded six male colleagues to let a powerful industrial robot repeatedly strike them on the arm, to assess human-robot pain thresholds.

It's not because he thinks the first law of robotics is too constraining to be of any practical use, but rather to help future robots adhere to the rule. "Even robots designed to Asimov's laws can collide with people. We are trying to make sure that when they do, the collision is not too powerful," Povše says. "We are taking the first steps to defining the limits of the speed and acceleration of robots, and the ideal size and shape of the tools they use, so they can safely interact with humans."

Povše and his colleagues borrowed a small production-line robot made by Japanese technology firm Epson and normally used for assembling systems such as coffee vending machines. They programmed the robot arm to move towards a point in mid-air already occupied by a volunteer's outstretched forearm, so the robot would push the human out of the way. Each volunteer was struck 18 times at different impact energies, with the robot arm fitted with one of two tools - one blunt and round, and one sharper.

The volunteers were then asked to judge, for each tool type, whether the collision was painless, or engendered mild, moderate, horrible or unbearable pain. Povše, who tried the system before his volunteers, says most judged the pain was in the mild to moderate range.

The team will continue their tests using an artificial human arm to model the physical effects of far more severe collisions. Ultimately, the idea is to cap the speed a robot should move at when it senses a nearby human, to avoid hurting them. Povše presented his work at the IEEE's Systems, Man and Cybernetics conference in Istanbul, Turkey, this week.

"Determining the limits of pain during robot-human impacts this way will allow the design of robot motions that cannot exceed these limits," says Sami Haddadin of DLR, the German Aerospace Centre in Wessling, who also works on human-robot safety. Such work is crucial, he says, if robots are ever to work closely with people. Earlier this year, in a nerve-jangling demonstration, Haddadin put his own arm on the line to show how smart sensors could enable a knife-wielding kitchen robot to stop short of cutting him.

"It makes sense to study this. However, I would question using pain as an outcome measure," says Michael Liebschner, a biomechanics specialist at Baylor College of Medicine in Houston, Texas. "Pain is very subjective. Nobody cares if you have a stinging pain when a robot hits you - what you want to prevent is injury, because that's when litigation starts."

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IBM Launches Five-Year Effort To Develop Quantum Computing

IBM is breathing new life into a quantum computing research division at its Thomas J. Watson Research Center, reports New York Times. The computer giant has hired alumni from promising quantum computing programs at Yale and the University of California-Santa Barbara, both of which made quantum leaps in the past year using standard superconducting material.

Groups at both universities have been using rhenium or niobium on a semiconductor surface and cooling the system to absolute zero so that it exhibits quantum behavior. As the Times reports, the method relies on standard microelectronics manufacturing tech, which could make quantum computers easier and cheaper to make.

The Santa Barbara researchers told the Times they believe they can double the computational power of their quantum computers by next year.

Quantum computing uses spooky action at a distance to conduct superfast calculations. Rather than using transistors to crunch the ones and zeroes of binary code, quantum computers store data as qubits, which can represent one and zero simultaneously. This superposition enables the computers to solve multiple problems at once, providing quick answers to tough questions. But observing a qubit strips it of this duality — you can only see one state at a time — so physicists must figure out how to extract data from a qubit without directly observing it. That’s where quantum entanglement comes in handy; two qubits can be connected by an invisible wave so that they share each other’s properties. You could then watch one qubit to see what its twin is computing.

None of this is simple, however; there are several competing methods for making the qubits, including laser-entangled ions, LED-powered entangled photons, and more. Google is working with a Canadian firm called D-Wave that has claimed 50-qubit computers, although skeptics have questioned that number. In most systems, the number of entangled qubits remains small, but Yale researchers believe they will increase in the next few years, the Times says.

Even better: with all this practice, physicists are getting a lot better at controlling quantum interactions. Their precision has increased a thousand-fold, one researcher said. That’s good news for anyone studying quantum mechanics.

[New York Times]

Quantum Computer Courtesy D-Wave

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Nurse Robot Gives Human A Sponge Bath

Cody Tenderly Removes Blue Candy From the Test Subject's Arm

Perhaps in the past we’ve held back from having robots administer sponge baths for fear that they would just be too forceful. Now there’s Cody – a robotic nurse proven to be gentle enough to bathe humans.

Presented by researchers from the Georgia Institute of Technology, Cody can be operated by a human, telling it where on the body to clean. It uses a camera and laser range finder to gather data before removing debris. Cody’s arm joints are slightly stiff, lessening the force of impact, and it is programmed to never exceed a specific threshold of pressure.

Cody was tested on lead researcher Chih Hung King, who had bits of blue candy stuck to his arms and legs. With a gentle caress of its washcloth-clad hand, the robot successfully cleaned the test subject’s various limbs. King’s reaction to the experiment was generally positive:

“In the beginning I felt a bit tense, but never scared. As the experiment progressed, my trust in the robot grew and my tension waned. Throughout the experiment, I suffered little to no discomfort.”

Bizarre though it may seem, the wiping of the blue candy (seen below) represents a pretty useful development in healthcare robotics. With a serious nursing shortage facing the country, any innovation that helps relieve nurses’ heavy workload will likely result in better patient care. And for bedridden patients, a robot helper could make maintaining personal hygiene less uncomfortable than receiving a sponge bath from a human.

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