Chronic Pain Isn't All in the Brain

One in five of us has been experiencing chronic pain over the past three months, or longer. Chronic pain won’t kill us; it just makes our lives miserable. More miserable, research suggests, than for example having asthma or diabetes. So if chronic pain is a common, dismal health state, why don’t we talk more about it? Perhaps because in many cases we don’t know why we get it.

As we often don’t find a reason for this invisible conundrum, we may tend to believe that it must be all in our brains, maybe even our personality. And if you have pain you may become desperate to find a way to get your brain to drop this unnecessary folly.

So here we are, in the 21st century and every fifth person is suffering from this health problem, which we don’t understand. A health problem, which can be so debilitating that those experiencing it often stop working, stop socialising and stop doing things they like doing, or should be doing.

The vulnerable brain

For clarity, pain is not all in the bones – experts have known this for at least a decade. Unless you have a tissue-threatening problem, there is no association between how your bones and disks look like on x-ray or MRI (for example, bulging, crumbled, degenerate or old), and your pain. None at all. So what about the brain?

Science has almost adopted the idea that pain ought to be all in the brain. There is sophisticated research showing that some brain areas light up more when we are in pain. When we recover, these areas stop lighting up. There are even therapies directed at “retraining” the brain, which can sometimes reduce, or even occasionally cure chronic pain.

So scientists have developed the following concept: after injury or operation our tissues will heal, and normally all goes well - unless we are “vulnerable”. There is some evidence suggesting that when we are poor, smoke, are depressed, stressed, or have had chronic pain in the past, we may be more likely to develop chronic pain.

The idea is that the vulnerable brain retains memory of the trauma with its associated pain: it develops “abnormal neuroplasticity”. A good example is phantom limb pain. Following amputation many people develop pain the non-existing limb; they are more likely to do so if they had experienced a lot of pain before the amputation, so clearly the brain must be involved.

New clues

But the “neuroplasticity” concept cannot explain everything. For starters most people get chronic pain without ever having experienced major trauma. And in cases where there has been trauma, the known vulnerabilities explain only small bits of pain variability (that is, these vulnerability factors are poor predictors for who develops pain after trauma). In many pain-types scientists have never been able to identify any such vulnerability.

Finally, and most unfortunately, “brain training” methods generally don’t work. Phantom limb pain is something of an exemption (and even here a cure through brain training is very rare indeed).

But exciting new clues have now emerged which may change the way we think about chronic pain. Peculiar peripheral factors may contribute. In phantom limb pain, if you block the cell-bodies of peripheral nerves using local anaesthetic, the phantom sensation and pain can diminish. This suggests that abnormal input produced in these cell bodies may be needed to sustain the abnormal brain response: so brain and peripheral nerves jointly cause this condition.

Complex Regional Pain Syndrome (CRPS), one of the most severe body pains, can occur after injury to a limb. The injury preceding the condition may be small, sometimes a bee sting. Large parts of the limb become excruciatingly painful and virtually untouchable – even a draft of air may be difficult to bear.

As with other chronic pains, many of us experts have been assuming the main problem for these patients is in the brain. But it recently emerged that the blood of patients with this condition carries specific immune substances, termed “autoantibodies”. These substances can probably cause pain by binding to peripheral tissues, prompting sensory nerves to misfire – although the exact pathway is not understood. Misfiring of sensory nerves results in a state where the central nervous system, including the brain, has become “wound up”.

In CRPS, peripheral nerves may thus play a role comparable to electronic transistors: with very low abnormal peripheral input generated by the autoantibodies, the nerves steer a massive central abnormality. Without trauma these newly discovered antibodies are probable harmless; the trauma-induced inflammation is required to render them harmful.

In fact, these antibodies may only be present for a limited time, during a “window of vulnerability”, in sufficiently high concentration to cause harm after trauma; the same trauma sustained either earlier or later may not trigger CRPS. The good news is that there are treatment methods, originally established for the treatment of other diseases designed to reduce or remove auto-antibodies, which can now been tried.

So chronic pain is not all in the brain. Abnormal peripheral nerve activity (phantom limb pain), or peripheral immune activation (CRPS) are probably the main culprits for causing some chronic pain conditions, and this should become treatable.

How to Cool Buildings Without Electricity? Beam Heat into Space

A new superthin material can cool buildings without requiring electricity, by beaming heat directly into outer space, researchers say.

In addition to cooling areas that don't have access to electrical power, the material could help reduce demand for electricity, since air conditioning accounts for nearly 15 percent of the electricity consumed by buildings in the United States.

The heart of the new cooler is a multilayered material measuring just 1.8 microns thick, which is thinner than the thinnest sheet of aluminum foil. In comparison, the average human hair is about 100 microns wide.

This material is made of seven layers of silicon dioxide and hafnium dioxide on top of a thin layer of silver. The way each layer varies in thickness makes the material bend visible and invisible forms of light in ways that grant it cooling properties.

Invisible light in the form of infrared radiation is one key way all objects shed heat. "If you use an infrared camera, you can see we all glow in infrared light," said study co-author Shanhui Fan, an electrical engineer at Stanford University in California.

One way this material helps keep things cool is by serving as a highly effective mirror. By reflecting 97 percent of sunlight away, it helps keep anything it covers from heating up.

In addition, when this material does absorb heat, its composition and structure ensure that it only emits very specific wavelengths of infrared radiation, ones that air does not absorb, the researchers said. Instead, this infrared radiation is free to leave the atmosphere and head out into space.

"The coldness of the universe is a vast resource that we can benefit from," Fan told Live Science.

The scientists tested a prototype of their cooler on a clear winter day in Stanford, California, and found it could cool to nearly 9 degrees Fahrenheit (5 degrees Celsius) cooler than the surrounding air, even in the sunlight.

"This is very novel and an extraordinarily simple idea," Eli Yablonovitch, a photonics crystal expert at the University of California, Berkeley, who did not take part in this research, said in a statement.

The researchers suggested that their material's cost and performance compare favorably to those of other rooftop air-conditioning systems, such as those driven by electricity derived from solar cells. The new device could also work alongside these other technologies, the researchers said.

However, the scientists cautioned that their prototype measures only about 8 inches (20 centimeters) across, or about the size of a personal pizza. "We are now scaling production up to make larger samples," Fan said. "To cool buildings, you really need to cover large areas."

New 'Super-Repellent' Material Could Protect Medical Implants

cientists have created the most non-stick surfaces yet, using microscopic liquid-repellent structures instead of plastic coatings such as Teflon.

These new surfaces could help protect medical implants from gunk that can build up on and ruin the devices, endangering patients, researchers say.

Natural materials such as insect wings and duck feathers are often water-repellent, or hydrophobic. Many other substances are oleophobic, which means they repel oil.

Most liquid-repellent surfaces use plastic coatings. However, these degrade at high temperatures, which limits their use.

Now, scientists have developed a way to render many different materials super-repellent to both water and oil without using coatings. Instead, the roughness of the materials' surface is simply altered to make them "superomniphobic."

Surface tension is the property that makes drops of liquid want to bead up. But, the surface that a liquid rests on can exert attractive forces that cause the liquid to wet or spread across that surface.

In the past 20 years or so, scientists have discovered that super-hydrophobic objects, such as lotus leaves, are often covered in microscopic bumps so that droplets float on top. The first water-resistant materials, developed in the 1960s, similarly took into account surface roughness.

"Usually artificial surfaces repel water because of the chemical composition of the material, but in our case, the repulsion is almost completely by mechanical means," said study co-author Chang-Jin Kim, a mechanical engineer at the University of California, Los Angeles.

The researchers started with silica and etched a "bed of nails" structure onto it, with each nail head measuring 20 microns wide, or about one-fifth the average width of a human hair. They next undercut their nail heads to create overhangs resembling the fringes of beach umbrellas that were 1.5 microns long and three-tenths of a micron thick. Kim first imagined a shape similar to these structure more than 25 years ago, and had been waiting since for micro-machining techniques advanced enough to actually fabricate them.

The scientists found that these newly developed surfaces repelled not just oil and water, but also fluorinated solvents, which are liquids with the lowest surface tension known. These solvents completely wet all other known surfaces, including Teflon. Without a plastic coating, the super-repellent silica could withstand temperatures more than 1,830 degrees Fahrenheit (1,000 degrees Celsius).

The researchers found similar results when they etched these structures onto a metal, tungsten, and a plastic, parylene. "It doesn't matter what kind of material we use — they repel liquids exactly the same way because the repulsion is mechanical in nature, not chemical," Kim told Live Science.

The researchers expect these super-repellent materials to last longer in outdoor environments and industrial settings than traditional super-repellent materials. "This could also have biomedical applications — you won't have unwanted substances building up on surfaces anymore in the body," Kim said.

Although the fabrication methods the researchers used to create these structures for their experiments are quite expensive, Kim said the structures can be mass-produced using simpler and cheaper processes.

How Blu-ray Discs Can Improve Solar Panels

Blu-ray discs could help make the solar cells used in solar panels more efficient, researchers say. 

Solar cells rely on materials that convert photons of light into electricity. Prior research had revealed that if microscopic structures that are only nanometers (billionths of a meter) high are placed on the surface of solar cells, they can scatter light in ways that increase the cells' efficiency.

The best patterns of nanostructures to place on solar cells are quasi-random ones — patterns that are neither too orderly nor too random. Patterns that are too orderly only help concentrate single wavelengths of light, while patterns that are completely random concentrate the wavelengths seen in sunlight and inefficiently concentrate relatively useless wavelengths.

"For solar cell applications, we want to enhance light absorption over the entire solar spectrum — wavelengths from about 350 nanometers to 2,300 nanometers," said study co-author Jiaxing Huang, a materials scientist at Northwestern University in Evanston, Illinois.

Very expensive fabrication techniques are usually needed to create quasi-random patterns suitable for solar cells, thus limiting their widespread application. Now, Huang and his colleagues have found that Blu-ray discs may help create such patterns far more inexpensively.

Blu-ray discs can hold more data than CDs or DVDs can. They encode data using microscopic pits only 25 to 30 nanometers deep and 75 nanometers long. These pits, and the islands between them, together represent the 0s and 1s of binary code that computers use to symbolize information.

The researchers used a Blu-ray of "Police Story 3: Supercop," starring Jackie Chan, to create a mold for a quasi-random surface texture that they placed on a solar cell. They found that this pattern boosted light absorption significantly — by 21.8 percent over the entire solar spectrum, more so than either a random pattern or no pattern.

"The big surprise is that the pattern worked so well," Huang told Live Science.

In tests of a wide range of movies and television shows, the researchers found that it didn't matter which video content was on the Blu-ray discs; they all worked equally well to enhance the light absorption in the solar cells. Instead, the secret lies in the algorithms used to encode data on Blu-rays, which turn data into quasi-random patterns that are "surprisingly well-suited for light-trapping over the solar spectrum," Huang said.

Because Blu-ray manufacturing is already suitable for mass production, this finding may provide a cost-effective way to improve solar cells, the researchers said. Although the researchers conducted their experiments on polymer solar cells, they said their calculations suggest that Blu-ray patterns also could work with other common types of solar cells.

What Is the Future of High Resolution?

Today's viewers watch a variety of video content on a number of devices. With the proliferation of mobile technologies, consumers continue to push the boundaries for that content, specifically for video quality. The recent introduction of 4K tablet computers and an iMac computer with a 5K Retina display is an indication of the interest in high-resolution images, even in smaller screen environments. With the introduction of these higher-resolution formats for a variety of devices, will displays arrive at a resolution where our vision deems all the extra pixels unnecessary?  

Picture perfect: the case for pixels

All of the heavy-hitting technology companies have one thing in common when releasing new devices: resolution is a focal point as one of the selling features. And why shouldn't it be? One of the main attractions of laptops and mobile devices is for entertainment purposes, such as watching shows or movies on Netflix.

As a result, video streaming has become a standard activity for consumers. For example, within the last few years, the concept of "TV everywhere" has exploded. This has caused service providers to upgrade network capabilities to offer the best possible viewing experience for their customers. High-definition viewing is no longer a benefit, but a standard for consumers.

Higher resolution content lets users see smaller features, and can lead to new games and other entertainment experiences where small features may be important. That capability is also valuable for amateur and professional video and still-image editors who may need to make edits at close to the pixel level.

4K and 8K: pixel overload?

4K technology is steadily making its way into entertainment channels, but it is not the limit for high-resolution video. Currently, NHK in Japan is leading development of the infrastructure for 8K by 4K video. The 8K video platform will have about four times as many pixels as 4K video, since the pixel dimensions are roughly doubled in each dimension. In addition, as the resolution increases, the frame rate of the captured (and displayed video) will likely go up to prevent certain video artifacts. Thus the total size of an 8K video movie could be 100-times larger than today's HD (about 2,000 by 1,000 pixels). As a result, this will impact the storage capacity sizes of future consumer devices. This is already becoming evident with the launch of the iPhone 6 and iPhone 6 Plus, which offers up to 128 gigabytes of storage. We will see this in other products as the demand for space continues to rise.

8K video demonstrations with large-screen displays at trade shows provide amazing details that are lost or blurred in lower-resolution technologies. Today 8K video is experimental and very expensive, but there are several 8K video projects in development, with 8K TV broadcasts beginning in Japan by the start of the next decade. In another 4 to 5 years, 8K by 4K displays may be the next big thing, like 4K displays are today.

Putting it together: What the future holds

But what is the limit of video resolution that a user could want? Well, what this higher resolution is all about is creating a more immersive user experience. Ultimately we want an all-encompassing display that is hard to distinguish from reality itself — what we want is a holodeck (for you "Star Trek" fans). A totally immersive artificial reality will require at least 8K video content, and possibly 16K by 8K video resolution. This video content would be projected in an area rather than a surface. Essentially the viewer will be surrounded by the images, creating an immersive sense of "being there."

This immersive content would be captured by multiple, synchronized cameras surrounding a field of view or generated by 3D rendering equipment that then must be projected in a free-floating format. The technology required to make such immersive experiences is likely more than 10 years away, and when it is ready, consumers will want to have it. As a result of these continuous technological advancements and video format qualities, I don't believe the current concept of TV and the use of single displays for experiencing content will remain for long. A single fixed display can only hold so much resolution. Therefore, new and innovative devices will need to be created until we reach the point of commercializing free-floating holographic display technology.

Welcoming the Era of In-Space Manufacturing

Human spaceflight reached an important milestone this week. An additive manufacturing device, or 3D printer, was turned on, and initiated the first official 3D print on the International Space Station (ISS). 

The print took slightly more than an hour, and once it finished, the world changed. At the Made In Space Operations Center in Moffett Field, California, the rest of the team and I had the ability to command the printer and see inside it as the machine received and executed our commands. For the first time, humans demonstrated the ability to manufacture while in space. At this moment, if the space station absolutely needs a part that the 3D printer can build, I can start producing the part onboard the ISS within minutes — from my chair in California.

The ability to deliver components on demand without the need of a launch vehicle can redefine how space-mission strategies work. Before last week, every object that humans have ever put in space was launched there and not made in space. Of course, many experiments and efforts have been able to form items such as crystalline structures and latex spheres, as well as assembly-type construction. 3D printing is completely different. This capability does more than just build predetermined articles that were designed months or years before launch. The 3D printer can build files that are created after launch and sent to orbit when needed.

Our printer is part of the NASA-funded 3D Printing in Zero-G Technology Demonstration, which is setting out to characterize the performance and demonstrate the functions of additive manufacturing in orbit. The experiment will also help troubleshoot potential problems for future facilities now under development, mainly the Additive Manufacturing Facility (AMF), which launches next year and offers commercial services. While the AMF will be a more advanced and a longer-term device, the 3D printer that currently resides on the space station is a great stepping stone to the future.

The space station's printer will use common consumer plastics, which limits its applications. But the printer's arrival still means that a set of components will never have to be launched again. The AMF will increase the number of such components, and future facilities will keep increasing the capabilities, to a point where the only items necessary to be launched into space are the astronauts themselves.

This future of space manufacturing may be distant, and will undoubtedly take an extremely large amount of effort and work to accomplish, but it is achievable.

It is often difficult to see the importance of the first steps to something that eventually solves larger problems. A groundbreaking endeavor requires an extreme amount of understanding and trust at the outset. Even just 30 years ago, one would be hard-pressed to find anyone who believed that a device that can fit inside your pants' pocket could contain a phone, messaging service, calendar, computer and GPS receiver. However, there were people whose actions and drive made that a reality.

Similarly, it will be hard to convince everyone that a machine the size of a microwave has the ability to produce most of the parts of a spacecraft in the future. Some of the technologies that such a machine will need have not been invented yet, and others are at low-maturity level. This idea tends to be difficult for me to digest myself; however, the benefit of such a device would revolutionize how future exploration missions are realized.

Space-based manufacturing will also provide innumerable advances to the logistics and manufacturing of products on Earth. It is impossible to determine all of the benefits to Earth that a future digital manufacturing device may hold. Products will be available at your fingertips, similar to how Internet stores function now. The key difference is that shipping will not be needed; the product will just materialize using raw materials and a manufacturing system. This will reduce the amount of transportation associated with the supply chain, reducing the cost of products and eliminating the pollution generated by ships, trucks, and trains.

These are just two examples of the benefits that can come from 3D-printing technologies. There could be many more that are even more beneficial. Henry Ford's obvious goal when he started mass-producing automobiles was to lower the price to create high demand. Any history book will tell you he was highly successful. An omission in that story is how his efforts also made urban environments more sanitary. The automobile replaced the horse, whose presence required stables, which had to manage the urine and fecal waste from the horses. When the animals were largely eliminated from transportation use, that requirement faded away.

Clearly automobiles exchanged one environmental concern with another, but automobile waste does not tend to facilitate biological agents that cause disease and sickness to be passed and multiply. You can never truly know how a technology will affect its surroundings in totality, which is the most exciting part of working with any newly developing technology. Even the current 3D printer on ISS will most likely surprise people, as I believe the most advantageous uses have yet to be conceived.  

The future is going to be very exciting for manufacturing in space, with significant developments coming as soon as next year. New technologies are currently being developed in order to alleviate the need to launch the feedstock, for example. Progress develops along interesting paths, many of them unintentional. The availability of an in-space manufacturing platform will provide a multitude of new possibilities, and I cannot wait to see what results.

Vest for the Deaf Translates Speech Into Vibrations

WASHINGTON — A new wearable device that translates spoken words into vibrations could help deaf people perceive speech in a completely new way.

There are about 2 million functionally deaf people in the United States and 53 million worldwide. Cochlear implants can effectively restore hearing in some individuals, but they are costly, require invasive surgery, and don't work as well for deaf people over  age 12.

Scott Novich and David Eagleman, neuroscientists at Baylor College of Medicine in Houston, Texas, are developing a device that relies on sensory substitution, which involves feeding information from one sense into another.  For example, a New York-based company called Tactile Navigation Tools is creating a vest that can transform spatial information into vibrations to aid blind people.

"At the end of the day, your sensory receptors are all sending electrical signals to the brain," Novich told Live Science. "Your receptors are tuned for a specific kind of information, but there's nothing saying you actually have to send that type of information."

The new device, known as the VEST (short for versatile extra-sensory transducer), can be worn on top of clothing or underneath. A microphone on the vest captures sounds from the environment and feeds them into an Android tablet or smartphone, which extracts the audio relevant to speech and converts it into unique patterns of vibration in about two dozen tiny buzzers (similar to the ones found in a cellphone).

Novich and Eagleman tested their device on a handful of deaf and hearing volunteers. In each trial, the vest would vibrate in a pattern corresponding to a randomly chosen word, and the wearer had to guess the correct word from a set of four choices.

They compared two different algorithms for translating words into vibration. The participants performed between 300 and 600 trials once per day, either until they got more than 75 percent of the words correct, or for a 12-day period, depending on the experiment.

The researchers are still collecting data, but preliminary results suggest that both the deaf and hearing participants can learn to interpret spoken words as patterns of vibration on the skin.

After about two weeks of wearing the device, Eagleman said he expects it will become a direct sensory experience for users, in which feeling a pattern of vibration will be recognized as "hearing" a word. In the next phase of testing, people will use the device for as long as six consecutive weeks, he added.

The team has already raised more than $47,000 for the research through a Kickstarter campaign. Novich and Eagleman estimate their device, when available, will cost less than $2,000.

Robot Sub Finds Surprisingly Thick Antarctic Sea Ice

Antarctica's ice paradox has yet another puzzling layer. Not only is the amount of sea ice increasing each year, but an underwater robot now shows the ice is also much thicker than was previously thought, a new study reports.

The discovery adds to the ongoing mystery of Antarctica's expanding sea ice. According to climate models, the region's sea ice should be shrinking each year because of global warming. Instead, satellite observations show the ice is expanding, and the continent's sea ice has set new records for the past three winters. At the same time, Antarctica's ice sheet (the glacial ice on land) is melting and retreating.

Measuring sea ice thickness is a crucial step in understanding what's driving the growth of sea ice, said study co-author Ted Maksym, an oceanographer at the Woods Hole Oceanographic Institution in Massachusetts. Climate scientists need to know if the sea ice expansion also includes underwater thickening.

"If we don't know how much ice is there is, we can't validate the models we use to understand the global climate," Maksym told Live Science. "It looks like there are significant areas of thick ice that are probably not accounted for."

The findings were published in the journal Nature Geoscience.

Like icebergs, much of Antarctica's floating sea ice is underwater, hidden from satellites that track seasonal sea ice. And it's difficult to take direct measurements from ships or drilling, because the thickest ice is also the hardest to reach, Maksym said.

The researchers were stuck aboard an icebreaker in 20-foot-thick (6 meters) pack ice for more than a week after taking advantage of a lead, or open water, that accessed thick ice, he said. "Obviously that carried some risk, and we were stuck until the wind changed direction again," he said.

Pinging the ice

Over the last four years, the international group of researchers has mapped the bottom of sea ice with an underwater robot, or autonomous underwater vehicle (AUV), during two research cruises offshore Antarctica. The AUV can swim to a depth of about 100 feet (30 m) and has upward-looking sonar to survey the bottom of the sea ice.

"With the AUV, you can get under ice that is either difficult to access or difficult to drill, and in each region, we found some really thick ice, thicker than had been measured anywhere else," Maksym said.

Almost all of the sea ice that forms during the Antarctic winter melts during the summer, so scientists had assumed most of the ice never grew very thick. Previous studies suggested the ice was usually 3 to 6 feet (1 to 2 m) thick, with a few rare spots reaching up to 16 feet (5 m) in thickness. For comparison, most of the Arctic sea ice is twice as thick (6 to 9 feet, or 2 to 3 m), with some regions covered with 12 to 15 feet (4 to 5 m) of ice.

The robot sub surveys, which were spot-checked by drilling and shipboard tests, suggest Antarctica's average ice thickness is considerably higher than previous estimates. On average, the thickness of the ice was 4.6 to 18 feet (1.4 to 5.5 m). In the three regions it surveyed, the robot sub found that deformed, thickened ice accounted for at least half of and as much as 76 percent of the total ice volume, the researchers report.

"Our study shows that we're probably missing some of this thick ice, and we need to try to account for that when we try to compare what we see in models and satellites to what we see in the field," Maksym said.

The thickest ice measured during the survey was about 65 feet (20 m) thick, in the Bellingshausen Sea, Maksym told Live Science. In the Weddell Sea, the maximum ice thickness hit more than 45 feet (14 m), and offshore of Wilkes Land, the ice was about 53 feet (16 m) thick.

Next steps

These thick, craggy floes likely wouldn't exist without the fierce winds that circle Antarctica from west to east, the researchers said. Winter storms bash up the ice, freezing and reforming the rubble into new, thicker ice. "It must have been crunched up a tremendous amount and [the floes] piled up on top of each other," Maksym said. "The ice can generate enormous amounts of force if you have these strong winds. [The wind] is like an accordion, stretching it out and squishing it back together again."

The researchers' next step is to measure how much of Antarctica's total sea ice this thick ice represents. Maksym said it could be a "reasonably significant area of the pack."

The sea ice growth around Antarctica has averaged about 1.2 percent to 1.8 percent per decade between 1979 and 2012, according to the 2013 Intergovernmental Panel on Climate Change's Fifth Assessment Report. The increases are concentrated primarily in the Ross Sea in western Antarctica. Sea ice in the nearby Bellingshausen and Amundsen seas has significantly decreased. Researchers suspect these regional differences could result from stronger winds or increased meltwater from the Antarctic ice sheet, or a combination of both factors.

'Interstellar' Science: Is Wormhole Travel Possible?

Sci-fi fans who hope humanity can one day zoom to distant corners of the universe via wormholes, as astronauts do in the recent film "Interstellar," shouldn't hold their breath.

Wormholes are theoretical tunnels through the fabric of space-time that could potentially allow rapid travel between widely separated points — from one galaxy to another, for example, as depicted in Christopher Nolan's "Interstellar," which opened in theaters around the world earlier this month.

While wormholes are possible according to Einstein's theory of general relativity, such exotic voyages will likely remain in the realm of science fiction, said renowned astrophysicist Kip Thorne of the California Institute of Technology in Pasadena, who served as an adviser and executive producer on "Interstellar."

"The jury is not in, so we just don't know," Thorne, one of the world's leading authorities on relativity, black holes and wormholes, told Space.com. "But there are very strong indications that wormholes that a human could travel through are forbidden by the laws of physics. That's sad, that's unfortunate, but that's the direction in which things are pointing."

The major barrier has to do with a wormhole's instability, he said.

"Wormholes — if you don't have something threading through them to hold them open — the walls will basically collapse so fast that nothing can go through them," Thorne said.

Holding wormholes open would require the insertion of something that anti-gravitates — namely, negative energy. Negative energy has been created in the lab via quantum effects, Thorne said: One region of space borrows energy from another region that didn't have any to begin with, creating a deficit.

"So it does happen in physics," he said. "But we have very strong, but not firm, indications that you can never get enough negative energy that repels and keeps the wormhole's walls open; you can never get enough to do that."

Furthermore, traversable wormholes — if they can exist at all — almost certainly cannot occur naturally, Thorne added. That is, they must be created by an advanced civilization.

And that's exactly what happens in "Interstellar": Mysterious beings construct a wormhole near Saturn, allowing a small band of pioneers, led by a former farmer named Cooper (played by Matthew McConaughey) to journey far afield in search of a new home for humanity, whose existence on Earth is threatened by global crop failures.

Anyone interested in learning more about the science of "Interstellar" — which also features gravitational time dilation and depictions of several alien planets orbiting close to a supermassive black hole — can check out Thorne's new book, which is called, appropriately enough, "The Science of 'Interstellar.'"

Further, the California-based Kavli Foundation will host a webcast Wednesday (Nov. 26) in which physicists discuss the movie's science

.

Wormholes have been a staple of science fiction for decades. Interestingly, Thorne said that one of the genre's most famous titles helped inspire scientists to try to better understand the hypothetical structures.

"The modern research on the physics of wormholes largely stems from the movie 'Contact,' from conversations I had with [renowned late scientist] Carl Sagan — actually, when he was writing his novel 'Contact,'" Thorne said.

"Contact" features traversable wormholes. The novel came out in 1985, while the movie (which also stars Matthew McConaughey, apparently a wormhole connoisseur) was released in 1997.

Gecko Tech: Sticky Invention Lets People Scale Walls

Like Spider-Man scaling skyscrapers, people may someday climb glass walls with the help of a gecko-inspired invention, researchers say.

In addition to futuristic gear used by soldiers and spies to climb walls, the researchers suggest their new invention could lead to boots that help astronauts conducting spacewalks and to mechanical grippers that snag debris in orbit.

The invention was inspired by gecko feet. These reptiles can scale vertical walls and even hang upside down because their plump toes are covered in hundreds of microscopic bristles called setae, which generate a kind of electric force known as van der Waals force, strong enough to keep geckos stuck onto surfaces.

Science of stickiness

Scientists discovered how gecko stickiness works more than a decade ago, and since then, researchers have developed many synthetic adhesives with geckolike properties, such as reusability. Advances based on such technology include medical adhesives that can seal wounds.

But one problem that both real geckos and synthetic materials face is that they cannot support as much weight as one would predict from the total area of adhesive surface they possess. For instance, a machine known as Stickybot, created by researchers at Stanford University, had enough geckolike adhesive to support an 11-pound (5 kilograms) load, but in practice, the machine could support only a tenth of that weight.

"We noticed our device wasn't performing to its highest potential, and engineers hate inefficient things," said lead study author Elliot Hawkes, a mechanical engineer at Stanford.

Now Hawkes and his colleagues have outdone nature with new gecko-inspired devices that they have used to climb glass walls. The devices are about the size of a human hand but are nevertheless strong enough to support the weight of a person.

In contrast, if one were to somehow try climbing walls with real gecko feet, a climber weighing about 155 lbs. (70 kg) would require a sticky surface at least 186 square inches (1,200 square centimeters) large. In comparison, a modern tennis racket has an area of about 105 square inches (675 sq. cm).

How it works

The device consists of two plates that a climber holds. Each plate is covered with 24 tiles, each about 1 square inch (6.4 sq. cm) in size, or about as large as a postage stamp. Each tile is covered with tiny silicon rubber hairs about 100 microns high, or as tall as an average human hair is wide.

Each tile is connected to the rest of the device by a tendonlike string that ends in a spring made of an alloy known as nitinol. Unlike most springs, which get stiffer when they stretch out, nitinol springs become less stiff the more they stretch.

By cleverly arranging the tendons, the researchers ensured that a climber's weight gets spread evenly across each tile.

"I was the climber in the tests," Hawkes said. "That was extremely exciting. To be able to climb glass felt a little bit magical — it feels like you're hooking this device onto a perfectly flat smooth surface, and it doesn't feel possible."

Real geckos and previous synthetic geckolike devices distribute weight in such a way that some patches of adhesive support more weight than their neighbors. "Then, when one tile gets overloaded with weight, it will fail, and then its neighbors will fail, and such failure will propagate like an avalanche," said study co-author Mark Cutkosky, a mechanical engineer at Stanford.

The new devices support what are essentially pedals that a climber places his or her feet in. This way the climber's weight is pulling on the adhesive tiles and not on the climber's arms. "It feels like a movable ladder, like I'm placing a new rung with each step," Hawkes said.

"To stick the adhesive onto a surface, you just step on the surface, and to lift it off, you just take your weight off the surface," said study co-author Eric Eason, an applied physicist at Stanford.

Hawkes neither climbs as a hobby nor professionally. "I wanted to design a system that an everyday person could use," he said.

Gecko-inspired tech

In June, researchers at the U.S. Department of Defense had reported developing a set of gecko-inspired handheld paddles that could support a 218-lb. (99 kilograms) man carrying a 50-lb. (23 kg) pack while he scaled a 25-foot-high (7.6 meters) glass wall. However, these paddles are much larger than the new devices that Hawkes and his colleagues have developed.

The scientists are now looking to use their adhesive to snag garbage in space. Orbital debris can cause a lot of damage by slamming into spacecraft, astronauts and satellites at speeds much faster than bullets. Magnets would not do well at capturing space junk because many structures in space are made of materials that are, at best, weakly attracted by magnetic fields. Suction cups are similarly not a viable solution, since they only work in air, not in the vacuum of space, and many other adhesives would freeze and crack in the cold of space.

"We're working on a project to build a 'garbage truck' satellite that can grab space junk and remove it either to a graveyard orbit or to the atmosphere where it can burn up," Hawkes said.

Applications closer to Earth may include manufacturing robots to grasp panes of glass, solar panels and video screens. The technology could also be used to develop climbing robots "to inspect or clean windows," Eason said. Sticky pads could also help flying robot drones cling onto windows, Hawkes said.

Next Fitness Trackers Will Be Printed on Clothes

SANTA CLARA, CALIFORNIA — Hitting the track with a bulky fitness tracker on your wrist or hip may soon be a thing of the past. Tiny sensors that can be embedded into a shirt, sports bra or even a pair of glasses are now able to continuously track your heart rate, log miles walked and calculate calories burned.

These sensors are possible because scientists have developed new technologies that allow tiny, stretchable electrical circuits to be printed onto fabric. These new technologies — from printable ink to yarn that can conduct an electrical impulse — are being paired with rugged sensors, to create new types of wearable fitness trackers.

And unlike other trackers, these can simply be tossed in the wash after a sweaty workout.

Embedded circuits

Traditional electronic devices can contain a labyrinthine electrical circuit made of metal wire and silicon chips. But typical electronic components aren't stretchy or waterproof, and so they must be placed on a rigid backing, like a computer motherboard.

For several years, researchers have been trying to develop stretchy, conductive materials that could be used to power the next generation of sci-fi devices, from stretchy batteries for bionic eyes to electronic skins. Some technologies have even worked fairly well, but they couldn't be scaled up to the existing manufacturing processes for textiles. But in the last few years, technologies for stretchy conductive materials have taken off.

One way of making such devices uses stretchable ink that serves as the wires between different sensors, such as global positioning systems(GPS), accelerometers, heart rate monitors or temperature sensors. The ink is made of conductive-silver nanoparticles that are embedded in a stretchy polymer resin, said Michael Burrows, the segment manager at DuPont Microcircuit Materials, which developed the ink. 

Unlike past efforts, newer conductive inks can be screen-printed or laminated onto a shirt or a bra using technology that's available in almost any textile factory, from Bangladesh to the United States, said Steven Willoughby, the marketing manager for DuPont Microcircuit Materials. 

"The backbone to the entire system will be this stretchy ink system that allows the entire technology to be worn on a shirt, on a sleeve, on a watch or even on glasses," Burrows told Live Science.

And while an accidental trip through the washing machine spells doom for the average smart phone, the new ink can withstand at least 100 wash cycles, Burrows said.

Another technology already in use is a type of conductive yarn, made of metal strung through the fibers of the clothing. Conductive yarns tend to be stretchier and more comfortable than printable inks, whereas the inks provide a more ready-made platform for inserting silicon-based processors into clothing, said Akseli Reho, the CEO of Clothing+, a company that designs wearable technology.

New clothes

Despite changing fashion trends, clothing is a very old technology whose main functions — keeping people cool or warm, covering the body, and helping people to look attractive — haven't changed much since early humans draped fur pelts over their bodies.

"I would claim that the pocket is the last big invention in clothing," Reho told Live Science.

But that is set to change, with several smart shirts, bras, bicycle pants and socks on or about to hit the market. These smart clothes are only a little more expensive than their "dumb" counterparts.

And new smart sensing technology could bring a whole new set of uses to clothing, such as highly accurate, continuous heart-rate monitoring — which could be key for getting real measures of calories burnt, recovery time and workout impact for a wearer, Reho said.

Clothing could also one day be used in clinical applications to monitor patients' health more closely and could even predict or avert health crises, he added.

And unlike existing fitness trackers, the new electronics could be embedded into something the person would wear anyway, Burrows said.

Electric Vehicle Fleet Gives California Green Energy Boost

The crowded highways of Los Angeles just got a little greener, thanks to a new electric-vehicle program sponsored by the U.S. Air Force.

The fleet of 42 electrically powered sedans, trucks and vans was recently unveiled at Los Angeles Air Force Base in California. Based on technology known as V2G, or vehicle-to-grid, the vehicles are plugged in to charge when not in use, but they can also be used as generators — producing electricity that is directed back into the local power grid.

Collectively, the fleet is capable of providing more than 700 kilowatts of power to the grid, which is enough electricity to power 140 homes, Air Force officials said in a statement.

Electric lexicon

The new vehicles will replace Los Angeles Air Force Base's general-purpose vehicle fleet — presumably, the cars and trucks that military personnel use to drive around the city. Many of the vehicles are plug-in electric vehicles, or PEVs.

Unlike hybrid electric vehicles — which rely on gasoline-powered engines to stay charged — plug-in electric vehicles are charged the same way cellphones and other electric devices are charged. You simply plug them into a wall socket to recharge their batteries. There are also plug-in hybrid electric vehicles that still have a gas engine but can also be plugged in to recharge the car's battery packs.

Only some of the military's new electric cars and trucks have gas engines. Others run only on battery power and differ from many other electric cars because of their ability to transfer electricity back to the grid, in a process known as bi-directional charging. In other words, when these cars are plugged into an electric socket, drivers can either charge the vehicle's batteries, or remove the energy stored in the car's batteries and pump it back into the grid.

Powerful stuff

The idea of integrating electric cars into America's power grid has been around since at least 1997, when Willet Kempton, a professor in the College of Earth, Ocean and Environment at the University of Delaware, published his first paper on vehicle-to-grid technology in the peer-reviewed journal Transportation Research.

Kempton's more recent work has focused on how whole fleets of V2G-enabled electric vehicles could be used to support existing power systems, as well as future power systems that rely more on solar and wind energy.

Currently in the U.S., the power grid handles fluctuations in demand for electricity by storing power in large generators. These generators kick on during peak hours of energy usage (e.g., when everyone gets home from work) and they turn off again when demand for power goes down (e.g., in the middle of the night), Kempton told colleagues at a recent lecture at the University of Delaware.

"At times, there really isn't enough electricity on the system, and this is when operators would like to take electricity out of storage devices and put it back on the electric grid," Kempton said. "There is a lot of inherent storage available in electric vehicles, and batteries are the cheapest and most versatile way to store electricity."

Cars are an especially good energy-storage optionbecause, most of the time, they're not in use, Kempton said.

"If a person buys an electric vehicle, they usually drive it about an hour each day. The vehicle is idle for the remaining 23 hours," Kempton said. "We are going to use this electric storage device for the other 23 hours."

Electric cars are also a cleaner storage option than generators, many of which still use coal, oil or natural gas to generate electricity. However, some of today's generators do use hydroelectric dams or nuclear reactors — not fossil fuels.

Test pilot

The Air Force's new fleet of V2G, plug-in electric vehiclesis one of the first full-scale tests of this technology in the United States. The project received support from the California Energy Commission, which invested $3 million. Federal, state and private energy organizations also contributed to the project, according to Air Force officials.

In the near future, the Air Force hopes to expand its V2G program to other bases around the country, including Joint Base Andrews in Maryland and Joint Base McGuire-Dix in New Jersey.

"The forward thinking of the Air Force promises to be an important signal to the market to move this technology into the mainstream," Kempton said. "By requesting V2G-capable trucks and cars from several vehicle manufacturers, placed in bases in several states, the Air Force has helped to stimulate demand from both automotive suppliers and the electric industry in these states."