SuperMAN Options

[ABLAT Staff]

Scientists gain insight into invisibility through a complex superlens
By Roger Highfield, Science Editor
(Filed: 03/05/2006)



The Klingons used it to make their Bird of Prey spacecraft invisible. The Romulans used cloaking too and variants of this stealth technology hid the nasty alien in the Predator films and have been mentioned in Star Wars, Doctor Who and more besides.


Scriptwriters will be pleased to discover that this science fiction idea is deemed today to be closer to science fact than we realised, according to a paper published in the Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences.

Prof Graeme Milton, of the University of Utah, and Nicolae-Alexandru Nicorovici, of the University of Technology, Sydney, announce that "we have found that cloaking might be realised". The "making of an object invisible through some cloaking device is commonly regarded as science fiction", said Prof Milton.

But with Dr Nicorovici he outlines how to do it with the help of materials with bizarre optical properties that were first postulated in 1968 by Victor Veselago, a physicist working at the General Physics Institute of the Russian Academy of Sciences in Moscow.

His work remained obscure until six years ago, when his mathematical fantasy was realised by the creation of superlenses that can make objects placed near them invisible."

When an object is bathed in light of one colour, Prof Milton and Dr Nicorovici predict that light becomes trapped near the lens and "almost exactly cancels the light incident on each molecule in the object, so it has essentially no response to the incident light. Numerically we see that the molecule is effectively invisible".

By looking through a superlens at the object "one would only see the back half of it".

http://www.telegraph.co.uk/news/main.jhtml...03/winvis03.xml

[ABLAT Staff]

Scientists teleport two different objects
POSTED: 7:13 a.m. EDT, October 5, 2006

LONDON, England (Reuters) -- Beaming people in "Star Trek" fashion is still in the realms of science fiction, but physicists in Denmark have teleported information from light to matter bringing quantum communication and computing closer to reality.

Until now scientists have teleported similar objects such as light or single atoms over short distances from one spot to another in a split second.

But Professor Eugene Polzik and his team at the Niels Bohr Institute at Copenhagen University in Denmark have made a breakthrough by using both light and matter.

"It is one step further because for the first time it involves teleportation between light and matter, two different objects. One is the carrier of information and the other one is the storage medium," Polzik explained in an interview on Wednesday.

The experiment involved for the first time a macroscopic atomic object containing thousands of billions of atoms. They also teleported the information a distance of half a meter but believe it can be extended further.

"Teleportation between two single atoms had been done two years ago by two teams, but this was done at a distance of a fraction of a millimeter," Polzik, of the Danish National Research Foundation Center for Quantum Optics, explained.

"Our method allows teleportation to be taken over longer distances because it involves light as the carrier of entanglement," he added.

Quantum entanglement involves entwining two or more particles without physical contact.

Although teleportation is associated with the science-fiction series "Star Trek," no one is likely to be beamed anywhere soon.

But the achievement of Polzik's team, in collaboration with the theorist Ignacio Cirac of the Max Planck Institute for Quantum Optics in Garching, Germany, marks an advancement in the field of quantum information and computers, which could transmit and process information in a way that was impossible before.

"It is really about teleporting information from one site to another site. Quantum information is different from classical information in the sense that it cannot be measured. It has much higher information capacity and it cannot be eavesdropped on. The transmission of quantum information can be made unconditionally secure," said Polzik whose research is reported in the journal Nature.

Quantum computing requires manipulation of information contained in the quantum states, which include physical properties such as energy, motion and magnetic field, of the atoms.

"Creating entanglement is a very important step, but there are two more steps at least to perform teleportation. We have succeeded in making all three steps -- that is entanglement, quantum measurement and quantum feedback," he added.

http://www.cnn.com/2006/TECH/science/10/04...reut/index.html

[ABLAT Staff]

Disappear into thin air? Scientists take step toward invisibility.
By Peter N. Spotts | Staff writer of The Christian Science Monitor

Flip a switch and make something disappear? It's been the stuff of science fiction for decades. Now, two Duke University scientists and their colleagues have built the world's first device to render an object invisible.

At least, it's invisible to microwaves.

But researchers say the work demonstrates that, in principle, objects could be made to disappear from radar, cameras, and other detection devices. The trick? A new class of engineered substances called metamaterials.

These materials could someday add muscle to microscopes, reduce the size and increase the capability of radar, sonar, and other remote-sensing devices, and cloak or shield objects, researchers add. The rudimentary microwave cloaking device was reported in Friday's edition of the electronic journal Science Express.

It's hard to overstate "how amazing this whole field is," says Nathan Myhrvold, former chief technology officer for Microsoft Corp., who now heads Intellectual Ventures, a company in Bellevue, Wash., that focuses on inventions.

Metamaterials exhibit electrical and magnetic properties not found in natural materials. In essence, they respond to radiation - whether microwaves or visible light - in new ways. The US military's current stealth technology makes a plane hard to detect by radar. In theory, metamaterials could make it disappear.

The cloaking device, announced Friday, looks deceptively simple. "It's a compelling example of what we can do" with key properties that metamaterials exhibit, says David Smith, a Duke University professor of electrical and computer engineering who is one of the field's two founding fathers.

In essence, the device consists of tiny copper antennas etched on thin, nested cylinders of circuit-board material. In the center, the team put a small object that would send microwaves flying helter-skelter if they struck it. A microwave beam slipped past this array of antennas and the target it encircled, much like ocean swells flow past a small offshore rock poking through the surface. The microwaves slipped by the setup virtually unaffected.

Potential applications range from improving cellphone technology to shielding people and equipment from disruptive forms of radiation.

The field of metamaterials is still in its infancy, Dr. Smith says. In 1967, Russian physicist Victor Veselago showed that it was possible in principle for matter to appear to display oddball traits.

Light could appear to move backward. A reed would appear to bend back out of a batch of metamaterial, rather than continue in the same general direction, as it would in water. A lens made from this theoretical material would perfectly reproduce the tiniest details of the object behind it - at least over very short distances - in ways no traditional lens can.

In the late 1990s, physicist John Pendry of London's Imperial College began making metamaterials. By tailoring their designs, researchers could give these materials unique electrical and magnetic properties that their constituents - like the copper and fiberglass in Smith's device - couldn't hope to match individually.

In 2000, Smith found a combination of metamaterials that displayed the oddball optical properties Dr. Veselago's calculations predicted.

While Smith and his colleagues are working to cloak a three-dimensional object, others are looking to perfect superlenses.

In May, a team led by physicist Xiang Zhang of the University of California at Berkeley unveiled the first crude superlens using ultrahigh-frequency sound waves.

The hope, he says, is to develop devices, such as ultrasound imagers and sonar, that are smaller and lighter and render objects in far more detail than today's devices can.

http://www.csmonitor.com/2006/1020/p02s01-stss.html

[ABLAT Staff]

Mathematic Theory to Increase Power of Invisibility Cloak
2006-12-26 19:12:49

The theorists who first created the mathematics that describe the behavior of the recently announced "invisibility cloak" have revealed a new analysis that may extend the current cloak's powers, enabling it to hide even actively radiating objects like a flashlight or cell phone.

Allan Greenleaf, professor of mathematics at the University of Rochester, working with colleagues around the globe, has announced a mathematical theory that predicts some strange goings on inside the cloak—and that what happens inside is crucial to the cloak's effectiveness.

In October, David R. Smith, associate professor of electrical and computer engineering at Duke University, led a team that used a circular cloaking device to successfully bend microwaves around a copper disk as if the disk were invisible. In 2003, however, Greenleaf and his colleagues had already developed the mathematics of invisibility.

"We were working on improving the mathematics behind tumor detection," says Greenleaf. "In the final section to one paper, we spelled out a worst-case scenario where a tumor could be undetectable. We then wrote a couple of additional articles describing when this could happen. At the time, we didn't think further about it because it seemed extremely unlikely that any tumor would be covered with the necessary material to be hidden that way."

This past summer, however, Greenleaf and his colleagues learned about a paper that researchers at Duke and Imperial College had published in the journal Science, which used nearly identical equations to give a theoretical proposal for a cloaking device. Once Greenleaf and his colleagues saw that their results could also be used to show how to "hide" an object, they decided to analyze and improve the proposed cloaking device, using the techniques they had developed in their earlier work. They knew that a crucial question would be: What was going on inside the cloaked region?

Smith, a physicist, gave a description of why the cloaking device should work. Greenleaf, as a mathematician, knew that to have any hope of extending and improving the cloaking, it was important to fully understand its mathematical underpinnings. Then, in October, Smith published another paper, describing how he and his team actually built a cloaking device. This made it even more crucial to carefully analyze the underlying structure.

Greenleaf and his collaborators used sophisticated mathematics to understand what must be happening inside the cloaked region. Everything seemed fine when they applied the Helmholtz equation, an equation widely used to solve problems involving the propagation of light. But when they used Maxwell's equations, which take the polarization of electromagnetic waves into account, difficulties came to light.

Maxwell's equations said that a simple copper disk like the one Smith used could be cloaked without a problem, but anything that emitted electromagnetic waves—a cell phone, a digital watch, or even a simple electric device like a flashlight—caused the behavior of the cloaking device to go seriously awry. The mathematics predicts that the size of the electromagnetic fields go to infinity at the surface of the cloaked region, possibly wrecking the invisibility.

Their analysis also revealed another surprise: a person trying to look out of the cloak would effectively be faced with a mirror in every direction. If you can imagine Harry Potter's own invisibility cloak working this way, and Harry turning on his flashlight to see, its light would shine right back at him, no matter where he pointed it.

Greenleaf's team determined that a more complicated phenomenon arises when using Maxwell's equations, leading to a "blow up" (an unexpected infinite behavior) of the electromagnetic fields. They determined that by inserting conductive linings, whose properties depend on the specific geometry of the cloak, this problem can be resolved. Alternatively, covering both the inside and outside surfaces of the cloaked region with carefully matched materials can also be used to bypass this problem.

"We should also keep in mind that, given the current technology, when we talk about invisibility, we're talking only about being invisible at just a narrow range of wavelengths," says Greenleaf. "For example, an object could be rendered invisible at just a specific wavelength of red; it would be visible in nearly every other color."

Smith's team at Duke is also working on improving their cloaking device. On Dec. 6, Smith and Greenleaf met for the first time and talked about Greenleaf's new math.

"Allan has been looking at the problem much more generally, and deriving the conditions for when true invisibility is or is not possible," says Smith. "We are very interested in what he and his colleagues come up with!"

Greenleaf and his coauthors are now working to confirm the relationship between their work and experiments. Some of the equations do not have solutions, so they are looking at what the physical consequences are, and whether a cloak's effectiveness would be compromised. Since any physical construction is only an approximation of the mathematical ideal that Greenleaf's team analyzes, Greenleaf says it would also be very interesting to understand the extent to which small errors in the construction degrade the cloaking effect.

http://www.ccnmag.com/news.php?id=4683

[ABLAT Staff]

Pentagon to Merge Next-Gen Binoculars With Soldiers' Brains
Sharon Weinberger 05.01.07 | 2:00 AM

Darpa says a soldier's brain can be monitored in real time, with an EEG picking up "neural signatures" that indicate target detection.
Image: Darpa
View Slideshow

U.S. Special Forces may soon have a strange and powerful new weapon in their arsenal: a pair of high-tech binoculars 10 times more powerful than anything available today, augmented by an alerting system that literally taps the wearer's prefrontal cortex to warn of furtive threats detected by the soldier's subconscious.

In a new effort dubbed "Luke's Binoculars" -- after the high-tech binoculars Luke Skywalker uses in Star Wars -- the Defense Advanced Research Projects Agency is setting out to create its own version of this science-fiction hardware. And while the Pentagon's R&D arm often focuses on technologies 20 years out, this new effort is dramatically different -- Darpa says it expects to have prototypes in the hands of soldiers in three years.

The agency claims no scientific breakthrough is needed on the project -- formally called the Cognitive Technology Threat Warning System. Instead, Darpa hopes to integrate technologies that have been simmering in laboratories for years, ranging from flat-field, wide-angle optics, to the use of advanced electroencephalograms, or EEGs, to rapidly recognize brainwave signatures.

In March, Darpa held a meeting in Arlington, Virginia, for scientists and defense contractors who might participate in the project. According to the presentations from the meeting, the agency wants the binoculars to have a range of 1,000 to 10,000 meters, compared to the current generation, which can see out only 300 to 1,000 meters. Darpa also wants the binoculars to provide a 120-degree field of view and be able to spot moving vehicles as far as 10 kilometers away.

The most far-reaching component of the binocs has nothing to do with the optics: it's Darpa's aspirations to integrate EEG electrodes that monitor the wearer's neural signals, cueing soldiers to recognize targets faster than the unaided brain could on its own. The idea is that EEG can spot "neural signatures" for target detection before the conscious mind becomes aware of a potential threat or target.

Darpa's ambitions are grounded in solid research, says Dennis McBride, president of the Potomac Institute and an expert in the field. "This is all about target recognition and pattern recognition," says McBride, who previously worked for the Navy as an experimental psychologist and has consulted for Darpa. "It turns out that humans in particular have evolved over these many millions of years with a prominent prefrontal cortex."

That prefrontal cortex, he explains, allows the brain to pick up patterns quickly, but it also exercises a powerful impulse control, inhibiting false alarms. EEG would essentially allow the binoculars to bypass this inhibitory reaction and signal the wearer to a potential threat. In other words, like Spiderman's "spider sense," a soldier could be alerted to danger that his or her brain had sensed, but not yet had time to process.

That said, researchers are circumspect about plans to deploy the technology. One participant in last month's Darpa workshop, John Murray, a scientist at SRI International, says he thought the technology was feasible "in a demonstration environment," but fielding it is another matter.

"In recent years the ability to measure neural signals and to analyze them quickly has advanced significantly," says Murray, whose own work focuses on human effectiveness. "Typically in these situations, there are a whole lot of other issues (involved) in building and deploying, beyond the research."

It's unclear what the final system will look like. The agency's presentations show soldiers operating with EEG sensors attached helmet-style to their heads. Although the electrodes might initially seem ungainly, McBride says that the EEG technology is becoming smaller and less obtrusive. "It's easier and easier," he says.

But getting the system down to a target weight of less than five pounds will be a challenge, and Darpa's presentations make it clear that size and power are also issues. But even if EEG doesn't make it into the initial binoculars, researchers involved in other areas say there are plenty of improvements to existing technology that can be fielded.

For example, another key aspect of the binoculars will detect threats using neuromorphic engineering, the science of using hardware and software to mimic biological systems. Paul Hasler, a Georgia Institute of Technology professor who specializes in this area and attended the Darpa workshop, describes, for example, an effort to use neural computation to "emulate the brain's visual cortex" -- creating sensors that, like the brain, can scan across a wide field of view and "figure out what's interesting to look at."

While some engineers are mimicking the brain, others are going after the eye. Vladimir Brojavic, a former Carnegie Mellon University professor, specializes in a technology that replicates the function of the human retina to allow cameras to see in shadows and poor illumination. He attended last month's workshop, but he said he was unsure whether his company, Intrigue Technologies, would bid for work on the project. "I'm hesitant to pick it up, in case it would distract us from our product development," he says.

According to the Darpa presentations, the first prototypes of Luke's Binoculars could be in soldiers' hands within three years. That's an ambitious schedule, and an unusual one for Darpa, note several workshop attendees, who also say they expect fierce competition over the project. The list of attendees at the meeting ranged from university professors to major contractors. Spokespeople for Lockheed Martin and Raytheon both confirmed interest in the program, but declined to say whether they would bid on it.

Once fielded, Darpa indicates the measure of success lies with the military. According to information the agency provided to industry, initial prototypes would go to Special Forces. If the military asks to keep the binoculars after the trials, "that's exactly what you want here," Darpa wrote. "That's success."

Why all the rush? "I have to wonder if they aren't under pressure from Congress to make a contribution (to the war on terrorism), or if DOD is really leaning on them to come up with some stuff," suggests Jonathan Moreno, a professor of ethics at the University of Pennsylvania, whose recent book, Mind Wars, looks at the Pentagon's burgeoning interest in neuroscience. Darpa did not respond to press inquiries about the program.

Despite the fast schedule, McBride, of the Potomac Institute, thinks the idea is doable. "It's a risky venture, but that's what Darpa does," he says. "It's absolutely feasible."

http://www.wired.com/gadgets/miscellaneous...7/05/binoculars

[ABLAT Staff]

In A First, Scientists Develop Tiny Implantable Biocomputers

Science Daily — Researchers at Harvard University and Princeton University have made a crucial step toward building biological computers, tiny implantable devices that can monitor the activities and characteristics of human cells. The information provided by these "molecular doctors," constructed entirely of DNA, RNA, and proteins, could eventually revolutionize medicine by directing therapies only to diseased cells or tissues.

"Each human cell already has all of the tools required to build these biocomputers on its own," says Harvard's Yaakov (Kobi) Benenson, a Bauer Fellow in the Faculty of Arts and Sciences' Center for Systems Biology. "All that must be provided is a genetic blueprint of the machine and our own biology will do the rest. Your cells will literally build these biocomputers for you."

Evaluating Boolean logic equations inside cells, these molecular automata will detect anything from the presence of a mutated gene to the activity of genes within the cell. The biocomputers' "input" is RNA, proteins, and chemicals found in the cytoplasm; "output" molecules indicating the presence of the telltale signals are easily discernable with basic laboratory equipment.

"Currently we have no tools for reading cellular signals," Benenson says. "These biocomputers can translate complex cellular signatures, such as activities of multiple genes, into a readily observed output. They can even be programmed to automatically translate that output into a concrete action, meaning they could either be used to label a cell for a clinician to treat or they could trigger therapeutic action themselves."

Benenson and his colleagues demonstrate in their Nature Biotechnology paper that biocomputers can work in human kidney cells in culture. Research into the system's ability to monitor and interact with intracellular cues such as mutations and abnormal gene levels is still in progress.

Benenson and colleagues including Ron Weiss, associate professor of electrical engineering at Princeton, have also developed a conceptual framework by which various phenotypes could be represented logically.

A biocomputer's calculations, while mathematically simple, could allow researchers to build biosensors or medicine delivery systems capable of singling out very specific types or groups of cells in the human body. Molecular automata could allow doctors to specifically target only cancerous or diseased cells via a sophisticated integration of intracellular disease signals, leaving healthy cells completely unaffected.

Benenson and Weiss worked in collaboration with undergraduate Keller Rinaudo, postdoctoral researcher Leonidas Bleris, and summer intern Rohan Maddamsetti, all at Harvard, and with Sairam Subramanian, a graduate student at Princeton. Their research is supported by Harvard University and a center grant from the National Institute of General Medical Sciences. The results will be published in the journal Nature Biotechnology.

Note: This story has been adapted from a news release issued by Harvard University.

http://www.sciencedaily.com/releases/2007/...70521140917.htm

[ABLAT Staff]

Scientists close in on “cyborg-like” memory chips
Trendwatch
By Wolfgang Gruener
Tuesday, May 29, 2007 16:15

Tel Aviv (Israel) – Two scientists from the Tel-Aviv University have shown that information can be stored in live neurons. The research results provide a new way to help understand how our brain learns and store information, but also indicate that a “cyborg-like integration of living material into memory chips” could become a reality in the foreseeable future.

The experiment published on May 16 in Physical Review E, is based on the idea that linking neurons can result in spontaneous, coordinated firing. Itay Baruchi and Eshel Ben-Jacob of Tel-Aviv University said that they were able to create additional firings by using a special protocol of local chemical stimulations, which created multiple, rudimentary memories stored in the neuron network.

Neuron network with electrodes © Itay Baruchi and Eshel Ben-Jacob

To create stored memory in the neurons, the researchers introduced a chemical stimulant into the culture at a specific location. The stimulant induced a second firing pattern, starting at that location. The new firing pattern in the culture along coexisted with the original pattern. 24 hours later, they injected another round of stimulants at a new location, and a third firing pattern emerged. The scientists used an array of electrodes to monitor the firing patterns in a network of linked neurons, which revealed that the three memory patterns persisted, without interfering with each other, for more than 40 hours.

Previously published researched already indicated that coordinated neuron firing, referred to as synchronized bursting events, could be viewed as “memory templates” or “precursers of memory-related activity modes in task-performing in vivo networks.” However, Baruchi and Ben-Jacob are apparently first to actually “store” information in a cultured neuron network for an extended period of time.

Baruchi and Ben-Jacob concluded that chemical signaling mechanisms might play a “crucial role in memory and learning in task-performing [living] networks.” With some imagination, the experiment resulted in a chemically operated neuro-memory chip – which could show a way towards a memory chip that not only includes “dead”, but also living material.

http://www.tgdaily.com/content/view/32230/113/

[ABLAT Staff]

Self-Healing Materials Can Mimic Human Skin Healing Again And Again

by Staff Writers
Champaign IL (SPX) Jun 12, 2007

The next generation of self-healing materials, invented by researchers at the University of Illinois, mimics human skin by healing itself time after time. The new materials rely upon embedded, three-dimensional microvascular networks that emulate biological circulatory systems.
"In the same manner that a cut in the skin triggers blood flow to promote healing, a crack in these new materials will trigger the flow of healing agent to repair the damage," said Nancy Sottos, a Willett Professor of materials science and engineering, and the corresponding author of a paper accepted for publication in the journal Nature Materials, and posted on its Web site.

"The vascular nature of this new supply system means minor damage to the same location can be healed repeatedly," said Sottos, who also is a researcher at the university's Beckman Institute.

In the researchers' original approach, self-healing materials consisted of a microencapsulated healing agent and a catalyst distributed throughout a composite matrix. When the material cracked, microcapsules would rupture and release healing agent. The healing agent then reacted with the embedded catalyst to repair the damage.

"With repeated damage in the same location, however, the supply of healing agent would become exhausted," said Scott White, a Willett Professor of aerospace engineering and a researcher at the Beckman Institute. "In our new circulation-based approach, there is a continuous supply of healing agent, so the material could heal itself indefinitely."

To create their self-healing materials, the researchers begin by building a scaffold using a robotic deposition process called direct-write assembly. The process employs a concentrated polymeric ink, dispensed as a continuous filament, to fabricate a three-dimensional structure, layer by layer.

Once the scaffold has been produced, it is surrounded with an epoxy resin. After curing, the resin is heated and the ink - which liquefies - is extracted, leaving behind a substrate with a network of interlocking microchannels.

In the final steps, the researchers deposit a brittle epoxy coating on top of the substrate, and fill the network with a liquid healing agent.

In the researchers' tests, the coating and substrate are bent until a crack forms in the coating. The crack propagates through the coating until it encounters one of the fluid-filled "capillaries" at the interface of the coating and substrate. Healing agent moves from the capillary into the crack, where it interacts with catalyst particles. If the crack reopens under additional stress, the healing cycle is repeated.

"Ultimately, the ability to achieve further healing events is controlled by the availability of active catalyst," said Kathleen S. Toohey, a U. of I. graduate student and lead author of the paper. "While we can pump more healing agent into the network, 'scar tissue' builds up in the coating and prevents the healing agent from reaching the catalyst."

In the current system, the healing process stops after seven healing cycles. This limitation might be overcome by implementing a new microvascular design based on dual networks, the researchers suggest. The improved design would allow new healing chemistries - such as two-part epoxies - to be exploited, which could ultimately lead to unlimited healing capability.

"Currently, the material can heal cracks in the epoxy coating - analogous to small cuts in skin," Sottos said. "The next step is to extend the design to where the network can heal 'lacerations' that extend into the material's substrate."

With Sottos, Toohey and White, the paper's other co-authors are Jennifer Lewis, the Thurnauer Professor of Materials Science and Engineering and interim director of the Frederick Seitz Materials Research Laboratory, and Jeffrey Moore, a William H. and Janet Lycan Professor of Chemistry and a researcher at the Frederick Seitz Materials Research Laboratory and Beckman Institute. White, Sottos and Moore co-invented self-healing plastic; Lewis and White pioneered direct ink writing of three-dimensional microvascular networks. The work was funded by the U.S. Air Force Office of Scientific Research and the Beckman Institute.

http://www.terradaily.com/reports/Self_Hea..._Again_999.html