Turning Off the Fog of War in Real Warfare

It can be really annoying to miss an opponent in an FPS because a cloud of dust came up between you and them. In some video games there are ways to get through this though with fancy goggles and vision augments. In real life though, this technology is either not common, or non-existent, but the Air Force Office of Scientific Research (AFOSR) has found a way to change that.

When light passes through a fog it becomes polarized. The polarization of light is just the direction its energy vibrates in, and it can provide a great deal of information. Polarized optics have been in use for a long time now; triple-polarized goggles were developed for the flight crews that dropped the atomic bombs at the end of WWII. More modern uses include glasses for watching 3D content. Quite often though, these rely on linear polarization, because circular polarizes are hard to create. The AFOSR has found a way to more easily produce these polarizers by creating a device which measures the circularly polarized light.

This device can actually be integrated into cameras to capture the polarization information while still collecting color information. With this polarization information, clouds and dust can be more easily seen through because these optical obstacles will polarize light in one direction. Removing the light polarized in that one direction will leave the light from behind the fog. Of course, fog is not the only thing with a special polarization compared to its environment. Biological materials, including DNA, can be identified via polarization. This may lead to ways of finding cancer cells, where the DNA is improperly encoded, more easily.

Innovation-Enhancing Toolkit Developed

What do you get when you combine philosophy, computer science, and cognitive psychology? Apparently a researcher at the University of Massachusetts at Amherst, and he has used his background to study mental obstacles to innovation. Many times an innovative idea is a solution built around an obscure feature. The origin of Velcro is an example of this as the mechanics of the material are based on burrs attaching to clothing. Most people would just notice something on their sweater and try to remove it, but then someone realized it was two different materials lightly-attached together. Everyone knew that, but only one actually considered it.

The general parts technique (GPT) involves examining the different parts and features of something without considering their functions. The researcher taught GPT to 14 students before giving them a test, along with 14 untrained students. The GPT students ended up solving 67.4% more problems than the untrained control group, which is a statistically significant amount. As part of a follow-up study, the students were asked to list features of the objects used in the original questions. The GPT trained students listed the required obscure features 75% of the time, while the untrained students only listed them 27% of the time. Obviously the GPT training is having an effect.

The researcher has won an NSF grant to create software based on his Obscure Features Hypothesis, to improve more people’s innovative skills. Additional mental blocks are also going to be looked at, to hopefully develop more techniques to overcome them.

How to See Through Iron

Most people would not think iron could ever be made transparent in any way, but then most people do not work with the Helmholtz Association of German Research Centers. Researchers there have successfully duplicated an effect observed in laser physics with iron and X-rays. Electromagnetically induced transparency (EIT) occurs through a complex interaction of light with an atom’s electron orbitals. The result is the atom becomes transparent to light of a certain wavelength. Though not an exact duplication of the EIT phenomenon, the researchers have made iron transparent to X-rays. This was accomplished in an optical cavity, where the X-rays bounced off of two platinum mirrors and passed through iron sheets multiple times. When the iron planes were positioned at the peak and trough of the X-ray signal, they no longer blocked the radiation. Movement from those positions though causes the X-rays to be immediately blocked.

This could have several implications for quantum computers, where the control of X-rays, whose wavelengths can reach down to the size of an atom, is useful. Another observation is the radiation was greatly slowed. Normally X-rays travel at or near 299,792,458 m/s, the speed of light in a vacuum. In this situation though, the photons were covering only a few meters per second. This could also be an important finding for quantum computers, which may require information be stored as slow or stopped light waves.

Quantum Dots that Turn You On, Literally

There are a great many mysteries about the brain, and one way to study them is to stimulate specific parts of the brain, to see what happens. Electrical probes are already used in medical procedures as well as research but suffer from their large surface area. It is not possible for them to stimulate a single neuron, but a whole area of them.

As reported by the Optical Society of America, researchers have found quantum dots can be used to activate specific nerve cells, without disturbing those around it. Quantum dots are semiconducting crystals occasionally called design molecules as they can be made to emit whatever frequency of light a researcher wants. When producing light, an electric field is also created by the quantum dots, which will then trigger a cell. Such control could allow for treatments of Parkinson’s disease, Alzheimer, psychiatric disorders, and more.

There is still a great deal of work to be done though. The only tests performed thus far have been outside of the body, with cells actually grown on the quantum dots to ensure an effect. Also the quantum dots used are toxic to living cells, so others made of silicon will have to be tested. This is a promising proof-of-concept though.

Using Nature for Cheap Solar Cells

Nature is old and humanity is not, so there is a good chance that a lot of the stuff we try to do, Nature has already figured out, to some degree. An example of this is solar power. The majority of life on the planet is plant life and it uses solar radiation along with some chemistry to survive. Now researchers at MIT and the University of Tennessee have figured out a way to use photosystem-I (PS-I) in photoelectric systems.

When the chemical was first collected from plants and then stabilized for use, it was not producing a strong enough current to be useful. The chemical process to stabilize it was also quite complicated. The scientists have since simplified the chemistry to the point that a high school lab could do it, while also increasing the efficiency of the photoelectric system to 0.1%; a full 10,000 times better than it was before. This is not enough to be useful, but it is a major step towards achieving 1-2% efficiency.

The beauty of this research is not just the use of a natural compound, but also the ease of creation and use. Only needing chemistry supplies found in a high school class will allow PS-I to be produced almost anywhere very cheaply. It can then be sold to someone in a bag, who will spread it out on a substrate, such as a house roof. The power produced may only be enough to power a lamp or charge a cell phone, but in the developing world where kerosene lamps are still used, this would be truly useful.

Graphene to Enable Molecular Electronics

Researchers at the University of Copenhagen have realized a way to use graphene that will allow molecular electronics to be work. Molecular electronics have the potential to replace modern components with single molecules, but when tested will short circuit between the electrodes. Graphene, a single-atom thick sheet of carbon, has extraordinary conductive properties and by placing a piece on top of the molecules, the short circuits can be averted.

Also important to the discovery is the recent development of processes to create graphene flakes large enough for this use. While molecular electronics can obviously advance computer circuitry, they also have potential in ultra-thin displays and solar cells.

Shrinking Superconducting Crystal

There is always a way to surprise someone. Researchers at NIST and the University of Maryland were quite surprised when working with an iron superconductor. Many high-temperature superconductors use copper, but some use iron instead, with some advantages and disadvantages. The iron superconductors can be manipulated to express certain properties, by changing the atoms in the crystal structure of the material. However, they do not have as high a limit of superconductivity. The researchers did manage to achieve a new record though, by reaching 47 K before superconductivity was lost.

The surprise involves how they reached this new temperature. The iron superconductor is of the 1:2:2 class, which refers to its crystal having one calcium atom at the center, with two iron and two arsenic atoms connected to it. The researchers removed the calcium atom to replace it with a smaller atom; this lead to the higher temperature. It also caused the crystal to collapse by 10%. That is a very dramatic size change and quite noticeable on scans. The researchers have found a way to prevent this collapse from happening, without sacrificing superconducting, which is important as a manufacturer could not use something that suddenly shrinks when being used.

New Nano-lasers Developed

Lasers are cool. What is cooler than a laser? How about a laser smaller than the period at the end of this sentence? Researchers at the University of California, San Diego have developed some new nano-lasers that measure half a micron (500 nm) across. No other laser capable of operating at room temperature has been made that small before, and never has there been a thresholdless laser.

Lasers require so much power be put into them before the material actually starts lasing. This energy requirement is called the threshold and the design the researchers have developed does not have one. This is greatly important as no power is wasted with a thresholdless laser.

The laser is coaxial in design, similar to a coaxial cable, with a metal rod surrounded by a metal-coated ring. The ring is designed to cause quantum electrodynamic effects which are what remove the lasing threshold. This design also appears to be scalable, so the researchers may be able to make an even smaller laser.

Such small lasers could be integrated into computer chips, biochemical sensors, and high-resolution displays. With a little math that’s 16933 pixels to an inch, assuming each pixel is three lasers wide and the lasers could be placed directly next to each other. Lasers are cool.

Wirelessly Powering Cars on the Highway

There seems to be a general push in consumer electronics to a wire-free society. From networks to headphones, the cords are being cut. Now researchers at Stanford University are working to pull the plug on electric cars.

Two of the biggest issues with electric vehicles are their short range and long recharge times. Needing several hours for a single charge that only gets you 100 miles does not look as good as a tank of gas getting you 250+ miles. To address this, the researchers devised a way to wirelessly provide power to an electric vehicle while it is on a highway. The solution involves electromagnets buried beneath the road and within the car. The copper coils underground resonate at a specific frequency, which the magnets in the car also react to. When the car drives over them, the onboard copper coils are affected by the magnetic field of the other electromagnet, and start to resonate as well. This transfers energy that is then used to power the vehicle.

A major concern for this system is how the magnetic field will affect people, animals, and other pieces of technology. While only something with the same resonance as the electromagnet will feel the full power of the magnetic field, there is still 10 KW of power in the magnetic field. More research has to be done, but the initial simulations are quite promising.

Electron-Photon Interactions in Graphene

Graphene, like many other materials, responds to light by creating an electric current, and researchers want to know just how fast this happens. This information will be crucial for ultra-fast photodetectors based on the atom-thick plane of carbon. Making such a measurement though has been difficult for researchers, as it occurs on the order of picoseconds (10^-12 seconds), but those at Technische Universitaet Muenchen figured out a way to do it.

The measurement was done using the pump-probe technique. This involves shining a laser pulse onto a material to excite its electrons then firing a second pulse at the material to see what the electrons do. Think of it like trying to take a picture of insects scattering from a camera flash. You first use the camera flash to cause the insects to scatter, then a second flash to take a picture of them actually scattering.

Incidentally, the researchers found an interesting reaction of graphene to the optical laser. The light emitted by the graphene, after the optical lasers stimulated the electrons, was in the terahertz band. Radiation in this range of frequencies has a myriad of uses as it can pass through many materials, but illuminates organic compounds without damaging them. The ability to produce these photons from optical photons could prove useful in the future.

Putting Electronics into Fiber Optics

Fiber-optic cables are a key part of modern information technology. The high speed and bandwidth they provide is necessary for the Internet to exist in its current form. Using them however is not very simple though as optics use photons and electronics use electrons. At the ends of every fiber-optic cable there has to be technology to convert electronic and optical signals, and something to allow a round cable to interface with a flat chip.

Researchers at Penn State and the University of Southampton have developed a new optical cable to simplify the optical-electronic connection. Instead of having all of the conversion technology on the computer chip, the researchers have moved some of it into the optical cable itself. This means the necessary computer chips do not need to have fiber-optics integrated anymore. Creating such chips requires extremely expensive clean rooms but this new fiber-optic cable can be made with much simpler and cheaper equipment.

Blazing Fast Hard Drives Developed

In physics the Curie Point is the temperature at which a magnet will lose its strength. Materials are magnetized when the atoms align themselves so their individual magnetic fields add together. As heat causes atoms and molecules to move around, it is not too surprising that a high temperature can destroy magnetic properties. Now researchers at the University of York have found heat can make a material a magnet, which has implications in magnetic storage.

All traditional hard drives use magnetic ‘hard disk’ platters to magnetic store information, an electromagnetic headers to flip the bits on the platters from 0 to 1, and vice versa. Magnetically flipping a bit is not easy though, so researchers have already tried heating the bit to enable faster flipping. Though the writing is easier, it still takes around 1 ns to happen, thereby limiting the maximum write speed of the drive. By just using heat though the researchers have found the process can be accelerated to just a couple thousands of a nanosecond; roughly 500 times faster. In terms of an actual transfer speed, we are talking about terabytes of data being written every second. All of this is also accomplished with much less energy than the electromagnets found in a modern HDD too.

This technology may not enter a consumer product anytime soon though, and maybe not ever. Other techniques of quickly and efficiently writing information to a hard disk have been in development for a while and will likely reach the market before this can catch on; especially as the lasers needed for this are about a meter long at the moment. However, in areas where speed is needed more than a compact size, or use optical signals already, this could still prove useful.

Enhancing Fused Processors by 21.4%

Both AMD and Intel have been developing and selling CPUs with GPUs built in. This integration allows for cheaper and more efficient systems, as a dedicated GPU is not needed, but their designs are not perfected yet, at least according to North Carolina State University researchers.

The purpose and potential of CPUs and GPUs are quite different, with GPUs better at performing simple calculations and CPUs better at more complex problems. For some math, such as linear algebra, the GPU is far superior to the CPU, but for operations that require flexible data retrieval and decisions, the CPU is the best choice.

Despite the cores’ proximity on the new chips, they are not utilized as though they were on the same silicon. What the researchers propose, and have tested, is having the CPU aid the GPU by loading data the GPU will need into the shared L3 cache. This allows the data to be accessed much faster than if the GPU had to call it from off-chip memory. The average speed increase was 21.4% in the testing, but it reached as high as 113%.

No word on when this might be incorporated into processors, but one of the co-authors of the study is from AMD, and it was funded in part by AMD as well. The paper is to be presented on February 27 at the International Symposium on High Performance Computer Architecture.

From High Heat to Power

Wouldn't it be nice if some of that energy lost as heat from your computer, phone, or anything else really, be recaptured and used? Researchers at MIT have something that may lead to just that, but not only for our electronics, but also solar panels and space missions.

The researchers have created a photonic crystal that can withstand temperatures as high as 1200 C. Such a high tolerance makes the material potentially suited for a wide range of applications: solar-thermal conversion or solar-chemical conversion; radioisotope-powered devices; hydrocarbon-powered generators; and more. If coupled with a chemical microreactor to generate the heat, the technology could allow a device to run 10 times longer than with a modern battery, of the same size.

Currently the material is just a material and further work will have to be done for it to be used in any commercial product. Luckily though, modern techniques for making computer chips can be used to create the photonic crystal, so when products are designed, they can be produced.

Terahertz Polarizer Tested

Terahertz radiation exists at the edge of the far infrared part of the spectrum, near microwaves. This range of frequencies is of great interest to researchers the world over because only water and metal blocks it. This property makes terahertz incredibly useful for communication and sensing devises as the radiation does not adversely affect the human body. From medicine to security and communication, terahertz technology would have a great impact. Before that can happen though, researchers have to be able to control the waves.

Rice University researchers have recently devised a terahertz polarizer that operates on frequencies from 0.5 to 2.2 THz. This is huge compared to other polarizers. The new design utilizes nanotubes that will other block or allow transmission of the radiation based on an external electric field. A nanotube polarizer had been tried before, but was only able to block 30-50%, which isn’t enough. To fix this the researchers made it thicker. The result is a polarizer that can switch from allowing 100% of a terahertz signal through, to blocking 99.9%.

Further improvements to the polarizer can be made, but they will require overcoming an issue all nanotube researchers are having. When nanotubes are grown the sample includes both semiconducting and metallic nanotubes. Only the semiconducting are useful in the polarize, but there is currently no efficient way to either sort out the types of nanotubes, or simply produce one kind instead of both.

Prototype Naval Railgun Testing Begins Soon

An advantage to large naval ships is the ability to house large and powerful weapons, from missiles to cannons. The Navy has been working on an advanced type of weapon called a railgun. Unlike most guns which rely on a chemical fuel (such as gunpowder), railguns use electricity to create powerful magnetic fields. With the proper setup, these fields can accelerate objects to incredible velocities; in this case the projectiles can reach 4500 mph to 5600 mph.

Much of the research and development had been done by the Office of Naval Research in their own laboratories, but soon they will be testing the first industry railgun prototype launcher built by BAE systems. This device uses 32 megajoules of energy, while Navy’s device was only firing at 1.5 Mj. (A one ton car travelling at 100 mph is roughly one megajoule.) At first the testers are aiming for a range of just 50-100 nautical miles (57-115 miles) but intend on expanding this to 220 nautical miles (253 miles) in the future.

More work will have to be done before these weapons will be found on ships though, as automated reloading and cooling systems have to be developed. The Office of Naval Research though has recently award $10 million contracts to Raytheon Corp, BAE Systems and General Atomics to create pulsed power systems that should allow a for a firing rate of 6-10 shots per minute.

Self-limiting Optical Welding of Nanowires

When trying to weld together pieces of metal, most people look to a torch or electric-arc welder, and some look to a friction welder (NASA used this for welding together sections of a capsule because it does not add weight but still creates a high quality weld). None of these methods work when dealing with nanowires though. Heating them risks destroying the sample, and pressure can also ruin the delicate structures. Fortunately, at such a small scale there are certain phenomena that can be used.

Researchers have been looking to plasmons for a variety of reasons. These quasi-particles, which are a photon and electron coupled together, have some interesting properties and can be directed along the metals they are formed. Researchers at the Stanford School of Engineering have realized that shining light onto nanowires will cause hotspots where two wires cross because of plasmonic effects.

The top wire collects plasmons, like an antenna, and focuses them at the junction between the two wires. This creates a hotspot as the energy transfers from one wire to the other, and the heat is enough to fuse them together. Once the weld is made though, the effect stops, because it is the transfer from one wire to the other that generates the heat.

To test the potential and quality of this welding technique, the researchers sprayed silver nanowires onto a piece of Saran wrap, which has a considerably lower melting point than the metal. An advantage to testing with Saran wrap is the nanowire mesh should be transparent, like the plastic. The plastic was completely unharmed by the welding process, unlike if this were done on a hot plate. The researchers then balled up the plastic and nanowire mesh, to check if the welds would withstand such treatment, and they did. This means nanowire meshes, which could be used in solar panels, LEDs, touch and non-touch screen displays, could be sprayed onto most any surface, and welded on the spot. In the future this could allow a ‘solar panel’ to be sprayed onto you window.

New Graphene Transistor Design

Graphene is fairly often described as a potential replacement of silicon, but for one issue; the lack of a band gap. It turns out though that there are other issues preventing 300 GHz graphene transistors from being used. If such transistors were packed as densely as modern CPU transistors, the current leak would melt the chips in a fraction of a second. (No, the NH-D14 wouldn’t help with that.) Researchers at the University of Manchester have an idea for a solution though; build up instead of out.

The previous graphene transistors were built in a plane, which makes some sense since graphene is as close as one can get to an actual two dimensional object. The new design from Manchester has vertical graphene sheets and uses the material’s quantum mechanical properties. By placing the graphene on one side of a dielectric (resistant material) and a metal on the other, electrons can be made to tunnel through the dielectric. This will greatly reduce the energy and current needed for operation. Not only will the graphene encourage the electrons to tunnel, but it has the peculiar effect of allowing an external voltage to change the energy of the tunneling electrons.

Putting this all together makes the design the first vertical field-effect tunneling transistor. With further work, the researchers believe the transistor can be improved and scaled down in size to just nanometers. Ironically though, the transistor design itself may not be the most important aspect of this research. Instead it is how the researchers built the transistor one atomic layer at a time. Such control will allow for even more amazing structures to be made.

Making an Atomic Antenna

Even though graphene may one day replace silicon in electronics, when they work together interesting things can happen. From Oak Ridge National Laboratory (ORNL) comes a proof-of-concept experiment that has made an atomic antenna. This device has the ability to receive an optical signal, convert it to an electrical signal for transmission, and then back to an optical signal.

The researchers took a piece of graphene and made point defects in it; single carbon atoms were replaced with single silicon atoms. These impurities cause a plasmonic reaction that converts optical and electronic signals.

This experiment is only a proof-of-concept test though, but it still shows promise for the future of optoelectronics. After all, a compact and reliable means to use combine optics and electronics could greatly speed up computers while also reducing energy requirements.

Distraction Dodger: The Game

Distracted driving is a big issue as it causes a very large number of accidents, and fatalities, every year. The problem is especially evident in teenage drivers who have been exposed to cellphones for a large portion of their life, compared to older divers.

Researchers at the University of Minnesota have created a game to educate teenage drivers to the dangers of distracted driving. The belief is some people simply do not understand how important it is to maintain focus while driving, which then makes using a cellphone, changing the radio station, eating, putting on makeup, reading, and any other activity seem less of an issue.

The game, named Distraction Dodger, has the player drive a pizza delivery truck. At first there are almost no distractions or congestion, but as the player advances, the difficulty increases as well. While driving to the next customer you have to watch out for other cars, road construction, jay-walkers, stop signs, etc. Every time you make a mistake, it is recorded and displayed to you in a graph at the end of the level. The graphics and plot may not be even close to Skyrim, but it may still be worth seeing how well you do.

Internet Media Constrained by Brain, not Economy

Researchers have found it is not economic influences that limit the growth of digitally stored information on the Internet, but the human brain. Reported by Springer is the study (pdf) which considered some 633 million files, constituting 675 TB of data. This represents every file there is an outgoing link to from Wikipedia and dmoz. The file types include applications, text, images, audio and video.

The researchers looked at specific characteristics of the files, such as the bit rate, resolution, and length. These data were then plotted by how often they occur for each data type. The graph shows a decline as the axes increase, but is without an exponential tail at the end. If economic factors, such as the cost of hard drives, limited how large or how high of quality a file was, there would be such a tail. Further examination of the graph showed patterns which match the Weber-Fechner law. Basically what this law says is the noticeability of a change is follows a logarithmic curve. For example, increasing the resolution of a low resolution image is more noticeable than increasing the resolution of an already high resolution image.

What this implies is the information on the Internet cannot grow faster than what our brains can handle.

Smart Stereo Earphones

While some people may not care, for others it is a habit to make sure the left ear phone is in the left ear and right earphone in the right ear. For some audio sources, it won’t matter much, but others, like movies and video games, require the proper channels are going to the proper ear. (You don’t want to turn the wrong direction when an alien, orc, or other enemy is firing at you.)

To solve this problem, researchers at the Igarashi Design Interfaces Project have added electrodes to the front of ear buds. When the buds are put in the correct ears, the electrodes will be against the outer ear, which will form a connection. If the ear buds are reversed though, the electrodes are out in the air and not making a connection. This then triggers a chip to switch the channels, thereby ensuring the proper audio is going to its proper place.

The researchers went a step further with this though, as they also added a way for the earphones to know when they are being shared by two people. When worn by one person, there will be a weak electric current between the ear buds, but when two people wear them, the circuit is broken. This causes the chip to combine the stereo channels into a mono channel, which is sent to both ear pieces. This way both listeners get all of the audio.

Stereotype Threat Threatened

A classic stereotype is that men are better at math than women, but there has been little if any solid evidence to explain this, even though women are not often found in high positions that require math. (Having worked with and been taught by female mathematicians, I know ability is not dependent on sex.) Basically the stereotype exists and the population seems to display it, but the explanation for why this could be true has not been found. One promising theory is called stereotype threat and it explains that if a woman believes the stereotype she will perform worse than what she is capable of.

Researchers at the University of Missouri-Columbia have reexamined the studies supporting stereotype threat and have found several issues with them. For example, there is a lack of male control groups and the improper application of statistical techniques in some of these studies. The researcher did what they could to correct the problems and when they did the significance of the results disappeared, showing the studies’ conclusions were wrong.

This is a major issue because of the amount of focus given to the theory. If it were to turn out stereotype threat is incorrect then school policies and funding have been wasted trying to fix a problem in the wrong place.

Impurities Held Back Quantum Dot Production Method

Quantum dots are nanoscale semiconducting crystals sometimes also referred to as designer molecules. All semiconductors will have electrons excited by certain frequencies of light, and also give off certain frequencies of light if there is enough energy available. This is key to both LEDs and photovoltaics. What the frequencies of light are though will differ from material to material. Quantum dots on the other hand can be made to respond to whatever frequency someone wants; only production techniques stand in the way.

This makes them very interesting to every field that deals with both electronics and optics. Unfortunately creating them is not always very easy, and one method that, on paper, looked promising was not performing as people wanted. Now researchers at Berkeley Lab have figured out why, by accident.

While cleaning out the lab, a researcher checked the luminescence of a sample of quantum dots that was ix months hold. To his surprise it was responding seven times stronger than when it was freshly made. Already that is a large improvement, but why? To figure it out the researcher heated the sample to 100 C, to accelerate whatever happened during those six months. The result was a 400-fold increase in just 30 hours and an explanation.

The production method used is solution-based as opposed to the traditional colloid-based technique. This was leaving behind cations though which were blocking the movement of charge carriers. Heat causes the impurities to leave the sample, and thus boost the luminescence. Perhaps we will be seeing quantum dot displays and solar panels sooner than we thought.

Estimation without Counting Observed in Artificial Neural Network

Researchers have been wondering for a long time how humans learn. After all, no one is born with an understanding of math or language, yet both of these develop throughout early life. In the case of math at least, many forms of life, including humans, have demonstrated an ability to understand when one set is larger than another, without counting the items. Now a virtual neural network has done the same.

This neural network was designed only to mimic the retina of an eye and then generate false images, similar to what it originally saw. How the neurons fire as the original image is viewed and the false ones made is recorded. The researchers found the lowest level of neurons, those furthest from the virtual retina, were firing based on the number of objects in the original image, despite the fact that there is no understanding of numbers in the program. This information was then given to a second program which was able to estimate whether the image had more or fewer objects than some reference number the researchers also gave it.

This finding could be very important for understanding not only how humans learn numbers, but also dyscalculia and robotic vision. Dyscalculia is a condition which makes it almost impossible for a person to acquire even basic math skills.

Listening to the Brain

Some months ago researchers demonstrated an ability to reconstruct a silent video a person watches, just by measuring signals from the brain. Soon we may be getting a talkie from brain. Researchers at the University of California, Berkeley have successfully converted brainwaves into sounds close enough to the original word for it to be guessed accurately 80-90% of the time.

This technology required the use of electrodes placed on the brain (the volunteers were already going to receive such implants for a normal medical procedure) and the signal was recorded as single words were spoken to the subject. Using computational models the brain waves were translated into audible sounds which were close enough for the original word to be guessed. With hours of repetition it should be possible to perfect the sound, so a guess is not needed, but the researchers recognize this isn’t very helpful. In real life a conversation cannot be repeated over and over again; the conversion has to work on the first try.

This could be a huge advance for people who have lost the ability to speak due to disease or stroke. If neuroscientists can find where imaginary conversation occur within the brain (where one talks to him or herself), then it may be possible to return to these people the ability to talk. That may still be a ways off, but this is an impressive step towards that end. You can listen to the audio of the original words and the converted brainwaves at the source link.

Survey Shows One Quarter of Tweets are Not Worth Reading

Researchers at Carnegie Mellon University have conducted a survey on Tweets and will be presenting their full study February 13. The goal of this research was to find what characterizes a ‘good’ and ‘bad’ Tweet. For example, no one enjoys Tweets about what you are eating right then and other personal details. However, Tweets with questions, information, and even self-promotion were well received. Overall though, only 36% of the 43738 were liked by the 1443 participants in the student, with 25% not worth reading, and the remaining 39% not provoking a strong opinion either way. What that means is only about a third of Tweets are interesting and something people want to read.

The information was collected using the site Who Gives a Tweet. There participants were able to anonymously rate the Tweets of those they already follow. Putting together the ratings and reviews has allowed the researchers to devise nine lessons for improving content (more details at source link):

• Old news is no news
• Contribute to the story
• Keep it short
• Limit Twitter-specific syntax
• Keep it to yourself
• Provide context
• Don't whine
• Be a tease and don’t give away everything; encourage followers to visit the link
• For public figures don’t share personal gossip or everyday details

Brighter is Better for Nanotubes

Carbon nanotubes, like their cousin graphene, have the potential to greatly enhance modern technology thanks to their small size, incredible strength, and good conduction. For mass production and use though there has to be some way to identify the highest quality samples and filter out those with imperfections. Researchers at Rice University appear to have found a characteristic of impurities which may aid in this way.

After painstakingly analyzing individual nanotubes, the researchers are confident in their conclusion that the fluorescence of nanotubes is directly linked to both their length and purity. The brightness seems to be limited by the length of the nanotubes, with longer samples shining brightest, but when length was held constant the brightness still varied. When a nanotube is damaged or defective, there can be other atoms attached to its surface which can disrupt the emission of light.

Fortunately the researchers have worked out an automated way to continue this research, shortening the time needed from months to just weeks. With this tool the researchers want to determine if specific production methods are causing damage to the nanotubes as they are grown.

Possibly Perfect Light Absorber

As reported by the Institute of Physics, researchers believe they have found a perfect absorber of light, in the infrared range of the spectrum. This could be very useful for light sensors that operate in this part of the spectrum. The material is one we’ve already come to know and love; graphene. That’s right; our atom-thick friend is at it again, being a miracle material.

The researchers found this form of carbon can absorb light by being carefully arranged in nanodiscs. Provided there is a voltage across the disks, incoming light will be absorbed as it becomes trapped in areas hundreds of times smaller than the wavelength. Key to this are plasmons; quasi-particles that actually represent the interaction between an electron and a photon. Controlling the charge on the disks affects what wavelengths are absorbed, as the charge is directly related to the electrons on the graphene disks.

The researchers wish to examine other materials and explore other frequency ranges. There is a need for good infrared light absorbers, as the current absorbers are not all that great. Potentially new and advanced infrared cameras and sensors, or even solar cells could be developed based on this work.

Superfluorescence Observed in Solid-State Material

For the first time ever, superfluorescence has been observed in a solid-state material. Previously this phenomenon had only been seen in molecular and atomic gases. As the name suggests, superfluorescence has to do with an extraordinary emission of light. Given the proper circumstances, a material’s electrons can be excited and collectively fall back to lower energies, releasing photons in a single, great pulse. Researchers at Rice University have successfully gotten this to occur in a material with 15 quantum wells stacked on top of each other, with gallium arsenide (GaAs) layers in between. Gallium arsenide is a semiconductor which will transfer the energy of an incoming photon to an electron.

With a sufficiently powerful, and fast, laser pulse, the electrons of the GaAs were excited. When electrons are excited into the conduction band, they leave bind holes where they had been. There were enough electron-hole pairs to form a magneto-plasma, and initially there was no pattern to the plasma. Before long though, the pairs lined up and started falling into the quantum wells where the pairs would recombine and release a photon. The photons then travel through the stack causing a macroscopic coherence of all photon emissions. Essentially, the laser pulse that energizes the system is like a potential energizing a capacitor. Eventually the energy in the capacitor is released all at once.

There are several mysteries surrounding this experiment though. For example, the frequency of the emitted light is related to the time it is released. Also, there were distinct peaks in time for the superfluorescent emission. Of course, what’s the fun of answering one question without thinking of a few more to ask?