ScienceShot: Two-Dimensional Glass - ScienceNOW

ScienceShot: Two-Dimensional Glass - ScienceNOW: The glass, made of silicon and oxygen, formed accidentally when the scientists were making graphene, an atom-thick sheet of carbon, on copper-covered quartz. They believe an air leak caused the copper to react with the quartz, which is also made of silicon and oxygen, producing a glass layer with the graphene. The glass is a mere three atoms thick—the minimum thickness of silica glass—which makes it two-dimensional

Telepathy machine reconstructs speech from brainwaves - New Scientist - New Scientist

Telepathy machine reconstructs speech from brainwaves: The team presented spoken words and sentences to 15 people having surgery for epilepsy or a brain tumour. Electrodes recorded neural activity from the surface of the superior and middle temporal gyri – an area of the brain near the ear that is involved in processing sound. From these recordings, Pasley's team set about decoding which aspects of speech were related to what kind of brain activity.

First quantum jiggles detected in solid object

First quantum jiggles detected in solid object: The new experiment uses a silicon bar about 12 micrometres long and less than a micrometre across. Oskar Painter at the California Institute of Technology in Pasadena and colleagues cooled the bar to within half a degree of absolute zero and then used a laser to detect its motion.

Some photons from this laser got a shift in energy when they hit the vibrating bar. Ordinary thermal vibrations can either boost or reduce photon energy, but the zero-point quantum vibration is different. Because it is the lowest energy state possible, it can only absorb energy. Painter's group detected this bias towards lower-energy scattered light, a clear signature of a quantum twang...

T-rays technology could help develop Star Trek-style hand-held medical scanners

T-rays technology could help develop Star Trek-style hand-held medical scanners: This new design creates a T-ray beam at low temperatures, essentially by mixing and amplifying beams of light at different wavelengths. It uses a pair of electrodes situated just 100 nanometers apart on a semiconductor substrate. Light in two different wavelengths shines on the electrodes and is funneled through the 100-nm gap. A strong current between the electrodes acts as an antenna and amplifies the light to the THz range. The T-rays can even be tuned to create a constant beam, which would be required for a T-ray scanner. The setup is two orders of magnitude stronger than existing THz systems, the researchers say in their paper, which was published this month in Nature Photonics.
Along with their efficacy at low temperatures, the best thing about this T-ray beam is its small size — it’s tiny enough to be integrated into existing silicon chips.

Blog - Demonstration of Actuation-at-a-Distance Effect for Labs on a Chip

Blog - Demonstration of Actuation-at-a-Distance Effect for Labs on a Chip: Today, he and his pal Matthieu Gaude put the photoelectrowetting effect into action. These guys have made a cantilever sitting above an insulated conductor and placed a droplet of water between them so that it fills the gap by capillary action (see above).

Zapping this system with light changes the wetting angle the droplet makes with the cantilever and the electrode below. This makes the droplet thinner, pulling the cantilever down.

The ability to actuate at a distance using light alone could have many applications because it eliminates the need for the complex circuitry and pumps now used to transport droplets. It could also allow optical addressing of autonomous, wireless sensors.

Watching a gas turn superfluid - MIT News Office

Watching a gas turn superfluid - MIT News Office: Think of the trap as a valley filled with fog: In the upper regions, one would encounter less dense regions of fog, while down in the valley the fog gets denser. By measuring three quantities — the gas density at a given height line, its change from one line to the next and the total amount of gas encountered on the way down to that height — the researchers could determine the equation of state of their gas of fermions.

The atoms in these gases interact very strongly, not unlike the electrons in high-temperature superconductors. The exact mechanism for superconductivity is not yet understood, and so far, physicists have not been able to predict materials that would become superconducting at room temperature. The MIT team has now measured the critical temperature for superfluidity in their atomic Fermi gas and shown that scaled to the density of electrons in a metal, superfluidity would occur far above room temperature.

Superstuff: When quantum goes big

Superstuff: When quantum goes big: Imagine you have two identical particles, and you swap their positions. The physical system looks exactly the same, and responds to an experiment exactly as before. However, quantum theory records the swap by multiplying their quantum state by a "phase factor". Switching the particles again brings in the phase factor a second time, but the particles are in their original position and so everything returns to its original state. "Since switching the particles twice brings you back to where you were, multiplying by this phase twice must do nothing at all," says John Baez at the Centre for Quantum Technologies in Singapore. This means that squaring the phase must give 1, which in turn means that the phase itself can be equal to 1 or -1.

String theorists squeeze nine dimensions into three

String theorists squeeze nine dimensions into three: In the simulation, the universe starts off as a tiny blob of strings that is symmetric in nine different dimensions. As the strings interact, a random energy fluctuation — provided by the quantum laws that govern these small scales — breaks the symmetry. Three dimensions balloon outward, leaving the other six stunted at a billionth of a trillionth of a trillionth of a centimeter, far too small to be detected.

Superconducting current limiter guarantees electricity supply of the Boxberg power plant

Superconducting current limiter guarantees electricity supply of the Boxberg power plant: Below a temperature of 90° Kelvin or minus 183° Celsius, the material becomes superconductive. However, superconductivity collapses abruptly when the current in the conductor exceeds the design limits. This effect is used by the current limiter. In case of current peaks in the grid, the superconductor loses its conductivity within fractions of a second and the current will flow through the stainless steel strip only, which has a much higher resistance and, thus, limits the current. The heat arising is removed by the cooling system of the superconductor. A few seconds after the short circuit, it is returned to normal operation in the superconducting state. YBCO superconducting layers on stainless steel strips are more stable and operation-friendly than first-generation superconductors based on BSCCO ceramics.

Naked black-hole hearts live in the fifth dimension

Naked black-hole hearts live in the fifth dimension: Lehner has now proposed another situation where naked singularities might exist: in the extra dimensions proposed by string theory. The rub is that this time, they aren't unusual.

To understand why, think of black holes as points in the four dimensions we experience - three of space and one of time. These become "black strings" when extended into a fifth dimension of space (see diagram).

Black strings are unstable and break up into smaller black holes like a stream of water splitting into droplets. Lehner showed that at the point where a smaller black hole pinches off from the stream, the black hole's radius is zero, which means its density is infinite. In other words, it is a naked singularity. Lehner showed this will happen any time you have a black string.

How a time cloak could change the past

How a time cloak could change the past: The demo shows how manipulating the laser beam creates an opportune time gap. Laser pulses, shown in red, break the signal beam, denoted in green, into a rainbow of different wavelengths that travel at different speeds. This change creates an opening in the beam where the ball can pass. The effect is then reversed with another pulse of light to make the change undetectable.

Largest dark matter map holds clues to dark energy

Largest dark matter map holds clues to dark energy: Heymans's team used the Canada-France-Hawaii Telescope to observe 10 million galaxies, each about 6 billion light years away. The researchers analysed the images to build a map of dark matter spanning 10 billion light years, the first direct glimpse of dark matter on such a large scale.
The map shows a great cosmic web, with scattered clumps of dark matter linked by wispy filaments...
The map also reaffirms the need for dark energy to account for the accelerating expansion of the universe. Some proposed alternatives say that, instead of invoking a whole new entity, physicists might simply need to tweak Einstein's theory of general relativity on very large scales. But the new map, which spans very large scales yet is consistent with general relativity, lets the air out of those theories. "So far," says Miller, "there is no observational evidence for any departure from Einstein's theory."

Finding the star in this supernova could unlock the secrets of the universe

Finding the star in this supernova could unlock the secrets of the universe: At the center of this supernova remnant should be the companion star to the star that blew up. Identifying this star is important for understanding just how Type Ia supernova detonate, which in turn could lead to a better understanding of why the brightness of such explosions are so predictable, which in turn is key to calibrating the entire nature of our universe. The trouble is that even a careful inspection of the center of SNR 0509-67.5 has not found any star at all.

Fusion plasma research helps neurologists to hear above the noise

Fusion plasma research helps neurologists to hear above the noise:  MEG has great potential as a useful diagnostic tool - it is non-invasive and much more comfortable for the subject than other techniques - but the neuromagnetic signal varies fast, the signal to noise ratio is low meaning that such data are challenging to understand.

These challenges - extracting signal from noise in observations that can only be made from external sensors - are also often faced in magnetically confined plasmas for fusion. Fusion plasma researchers at the University of Warwick have developed methods to deal with data analysis problems similar to those faced by the neuroscientists. The Warwick researchers have now shared these methods and analytical techniques with their neuroscientific colleagues in Cambridge and Birkbeck. Together they have been able to carry out new studies that are already beginning to provide new insights into the brain's network - they have made the first map of the dynamically changing network of the brain as it deals with the 'surprise' of the different sounds.

Seeing quantum mechanics with the naked eye

Seeing quantum mechanics with the naked eye: They built microscopic cavities that tightly trap light in the vicinity of electrons within the chip, producing new particles called “polaritons” that weigh very little, encouraging them to move freely...

Injecting them in two laser spots, they found that the resulting quantum fluid spontaneously started oscillating backwards and forwards, in the process forming characteristic quantum pendulum states known to scientists, but at THz frequencies.

The resulting quantum liquid has some peculiar properties, including trying to repel itself. It can also only swirl around in fixed amounts, producing vortices laid out in regular lines. Increasing the number of laser beams creates even more complicated quantum states.

Alexander's Horned Sphere fractal changes how we define inside and outside

Alexander's Horned Sphere fractal changes how we define inside and outside: Other fractals occupy decimal dimensions or are seemingly solid shapes that are actually all surface area - this fractal can divide the world into one single spherical 'inside' but more than one 'outside.'

Getting just a little crazier, this is only even conceptually possible in a three dimensional universe. The Jordan Curve Theorem, showed that there is no single, enclosed curve that cannot carve a two-dimensional plane into an inside and an outside that mirror each other. It's only in the universe that we perceive that things can get more complicated than that. It's only in our reality that one spherical inside creating more than one outsides is possible.

Blog - Encrypting Pictures Using Chaotic Cellular Automata

Blog - Encrypting Pictures Using Chaotic Cellular Automata: Start by entering the password to produce a starting pattern of cells in the cellular automaton. Then run through 20 million iterations to generate a pseudorandom output. Superimpose this on the picture you want to encrypt and then send it.

Physicists propose test for loop quantum gravity

Physicists propose test for loop quantum gravity: Now in a new study, scientists have found that, when black holes evaporate, the radiation they emit could potentially reveal “footprints” of loop quantum gravity, distinct from the usual Hawking radiation that black holes are expected to emit....
In their study, the scientists have used algorithms to show that primordial black holes are expected to reveal two distinct loop quantum gravity signatures, while larger black holes are expected to reveal one distinct signature. These signatures refer to features in the black hole’s energy spectrum, such as broad peaks at certain energy levels.
Using Monte Carlo simulations, the scientists estimated the circumstances under which they could discriminate the predicted signatures of loop quantum gravity and those of the Hawking radiation that black holes are expected to emit with or without loop quantum gravity. They found that a discrimination is possible as long as there are enough black holes or a relatively small error on the energy reconstruction.

Blog - Amazon Democratizes Supercomputing

Blog - Amazon Democratizes Supercomputing: Though Amazon's offering pales in comparison to some of those 41 faster supercomputers--Amazon can run at 240 teraflops, handling 240 trillion calculations a second; Fujitsu's K Computer runs at 10.51 petaflops, or 10 quadrillion per second--EC2 represents a real potential disruption in the supercomputing market. Recently, a "Top 5 Pharma" customer (Amazon won't specify who; indeed it seems to be avoiding much public comment about the supercomputer) ran the cluster for seven hours at a peak cost of $1,279, per Ars Technica.

More than glue: Glia cells found to regulate synapses

More than glue: Glia cells found to regulate synapses: The brain is like a social network, says Prof. Ben-Jacob. Messages may originate with the neurons, which use the synapses as their delivery system, but the glia serve as an overall moderator, regulating which messages are sent on and when. These cells can either prompt the transfer of information, or slow activity if the synapses are becoming overactive. This makes the glia cells the guardians of our learning and memory processes, he notes, orchestrating the transmission of information for optimal brain function.

UCSD reveals surprise about rainbows | UTSanDiego.com

UCSD reveals surprise about rainbows | UTSanDiego.com: “Raindrops differ in size, and the larger ones are more affected by air pressure as they fall,” said Jensen. “The bottom of the drops flatten out some. They take on a shape that’s more like a hamburger than a drop.”

These “burgeroids,” as they came to be known, bend and redirect light a bit differently than circular raindrops. Jensen and Sadeghi tweaked their computer models to reflect this insight, and produced the first accurate simulation of twinned rainbows....

“We thought everything about rainbows was understood. But it’s not. It turns out they’re more complicated than people thought.”

Holographic 3-D looks tantalizingly closer in 2012

Holographic 3-D looks tantalizingly closer in 2012: In their nanoscale system, they work with chips made by growing a layer of silicon oxide on to silicon wafer. They etch square patches of the silicon oxide. The result is a checkerboard-like pattern where etched-away pixels are nanometers lower than their neighbors. A reflective aluminum coating tops the chip. When laser light shines on the chip, it bounces off of the boundary between adjacent pixels at an angle. Diffracted light interferes constructively and destructively to create a 3-D picture where small mirrored platforms are moving up and down, many times a second, to create a moving projection. The process can also be described as the pixels closer to the light interfering with it one way and those further off, in another. The small distances between them generate the image that the eye sees.

Scientists learn the secret of a famous anti-superconductor

Scientists learn the secret of a famous anti-superconductor: The flip from conductor to insulator, at minus 150 degrees Celsius, discovered by Evert Verwey in 1939, has puzzled scientists ever since. Recently, though, a team from the University of Edinburgh was able to peer inside a crystal of magnetite by aiming an X-ray beam at it. The crystal was half the diameter of a human hair. The team dropped the temperature of the crystal, and saw that the entire structure rearranged itself when brought down to negative 150 degrees. The iron atoms, until then happy to let the electrons proceed, suddenly shifted into organized groups of three, pinning the electron between them. The electrons were trapped, and unable to flow, stopping all current through the magnetite.

BBC News - Ultracold science finds new method to get even colder

BBC News - Ultracold science finds new method to get even colder: The team carefully adjusted the intensity of the crossed light beams. The trick was to do so in such a way that only the most energetic atoms in each lattice site absorbed energy from the light fields, becoming more energetic again.

By adjusting how frequently the light beam intensities were changed, the team was able to remove these "hottest" atoms from the system, leaving only the "coolest" ones behind.

Terahertz pulse increases electron density 1,000-fold

Terahertz pulse increases electron density 1,000-fold: Working with standard semiconductor material (gallium arsenide, GaAs), the team observed that exposing the sample to a terahertz (1,000 gigahertz) range electric field pulse caused an avalanche of electron-hole pairs (excitons) to burst forth. This single-cycle pulse, lasting merely a picosecond (10-12 s), resulted in a 1,000-fold increase in exciton density compared with the initial state of the sample...
"Since terahertz waves are sensitive to water, our goal is to create a microscope that will allow us to look inside living cells in real time," says Prof. Tanaka.

Astrophile: Stopped clocks deepen pulsar enigmas

Astrophile: Stopped clocks deepen pulsar enigmas:  In the 1970s, some regular pulsars were spotted switching off for a few seconds to a few minutes, a phenomenon known as "nulling". And in the past decade, a new class of pulsars has been found , in which the silences can range from minutes to a few hours. They were dubbed rotating radio transients, or RRATs. Around the same time, a pulsar was found that pulsed for about a week and then switched off for about a month before repeating the cycle.

With an "off" period of 580 days, Camilo's pulsar has taken by far the longest break seen so far. Having switched back on only in August this year, it is too early to tell whether the year on/year-and-a-half off cycle is a regular thing, but Camilo says it makes him wonder what other pulsars are hiding.

Nano-Engineered Bioconstructs Perform Photosynthesis Faster Than Nature Does | Popular Science

Nano-Engineered Bioconstructs Perform Photosynthesis Faster Than Nature Does | Popular Science: Researchers led by Carolyn Lubner at Penn State worked with a cyanobacterium called Synechococcus and another bacterium, Clostridium acetobutylicum. In nature, photosynthetic organisms use light-capturing enzymes nicknamed Photosystem I and II, which absorb light and excite electrons to a higher energy state. Another enzyme called FNR then uses these electrons to produce an energy-storage molecule. This molecule is used to make sugars to keep the organism alive, and that's your basic photosynthesis process.
Lubner et al replaced the FNR enzyme with a hydrogenase enzyme, which combines electrons with hydrogen ions to make molecular hydrogen (instead of a sugar-producing system). Then they used this enzyme to stitch together iron-based terminals of a Photosystem I enzyme from each of the bacteria. This stitch served as a molecular wire, easily and quickly transferring electrons. The researchers doped it with vitamin C, which served as the electron feedstock.
The result was a high-throughput hydrogen-producing system — electron flow was more than twice as high as the bacteria’s individual rates, the authors say.

Magnetic breakthrough may have significant pull

Magnetic breakthrough may have significant pull: ...the compound manganese gallium can be synthesized on the nanoscale to produce a coercive field that rivals materials containing rare-earth elements, which are considerably more expensive to process and mine.

Blog - Quantum Computing With Holograms

Blog - Quantum Computing With Holograms: In recent years, however, physicists have worked out how to make photons interact using interferometers and to carry out quantum computations using the output of one interferometer as the input for another...

The researchers then plan to stack the interferometers to perform simple quantum computations. "The approach here will "lock" these interferometers within a tempered piece of glass that is resistant to environmental factors," they say.
MacDonald and co suggest using a commercial holographic material called OptiGrate to store these holograms and show how these devices could carry out simple tasks such as quantum teleportation and CNOT logic.

Blog - Bio-Assembling in 3D with Magnetic Levitation

Blog - Bio-Assembling in 3D with Magnetic Levitation: The secret ingredient is a proprietary mix of nanoparticles the company calls Nanoshuttle. The addition of these particles to a dish of living cells allows them to move in response to magnetic fields that can be varied in three dimensions and across time.

According to an abstract on the work from the just-concluded meeting of the Tissue Engineering International & Regenerative Medicine Society, they've managed to tune this effect until it can create a "BioAssembler" that "leads to rapid formation of levitated 3D cell cultures."

Blog - Quantum PageRank Algorithm Outperforms Classical Version

Blog - Quantum PageRank Algorithm Outperforms Classical Version: The way they think about this is to imagine a quantum page crawler wandering around the network along paths that connect one quantum node to the next. While the quantum paths remain in a quantum superposition, the importance of a page is the probability of finding the crawler on that page at any instant.

Paparo and Martín-Delgado then outline a quantum algorithm that will produce a ranking of pages at any given instant using these quantum probabilities. They go on to simulate its performance on two relatively small networks: a tree-like network and a directed graph network with no specific structure.

Download Knowledge Directly to Your Brain, Matrix-Style

Download Knowledge Directly to Your Brain, Matrix-Style: Led by BU neuroscientist Takeo Watanabe, researchers used a method called decoded fMRI neurofeedback to stimulate the visual cortex. First they showed participants circles at different orientations. Then they used fMRI to watch the participants’ brain activity. The researchers were then able to train the participants to recreate this visual cortex activity.

The volunteers were again placed in MRI machines and asked to visualize shapes of certain colors. The participants were asked to “somehow regulate activity in the posterior part of the brain” to make a solid green disc as large as they could. They were told they would get a paid bonus proportional to the size of this disc, but they weren’t told anything about what the disc meant. The researchers watched the participants’ brain activity and monitored the activation patterns in their visual cortices.

Blog - Largest-Ever Simulation of the Universe Revealed

Blog - Largest-Ever Simulation of the Universe Revealed: ...These guys have carried out the largest simulation of the universe ever undertaken, consisting of 374 billion particles in a box some 10 gigaparsecs across. That's roughly equivalent to about two thirds the size of the observable universe...


The purpose of the simulation is to reproduce the entire evolution of a universe made largely of cold dark matter to see whether it produces same structures that we see in ours--from the galactic structures to galactic clusters, galactic superclusters and beyond.

The most recent theories predict that our universe ought to have structures on the very largest scales called acoustic baryon oscillations. These are essentially the leftovers of waves in the plasma that existed in the very early universe which became frozen in place as they cooled.

Scientists still puzzled by a fractal discovered 500 years ago

Scientists still puzzled by a fractal discovered 500 years ago: Strip the leaves off of the average tree, soak the whole thing in water until it gets mushy, bundle the branches up together, and you'll get what looks like one long trunk. That's what Leonardo Da Vinci said in the fifteen hundreds. If a tree trunk splits off into three main branches, each of the branches will be one third the size of the trunk. When each of those branches splits into three again, making nine branches on the second 'tier' of the tree, each of these second tier branches will be one ninth the side of the trunk. As the branches grow and split, they will always be a particular fraction of the size of the trunk, and adding together all the fractional bits of each 'tier' of branches will always add up to 'one trunk.'

Could a planet have only one pole?

Could a planet have only one pole?: You are on Boy's Surface, discovered by Werner Boy in 1901, and represented as a strange planet by John Pierre Petit in his book, Le Topologicon, in 1902. Each of the 'wings' can be traced by a Mobius Strip. The planet is a four dimensional object that penetrates itself without causing any holes or edges.

What if there is no Higgs boson?

What if there is no Higgs boson?:  Physicists are only looking for the Higgs particle because it is the easiest way to access the field. If they don't see it, then it suggests the field is different from the one predicted by the standard model. Normally, particles in fields are like ripples in ponds – photons are ripples in the electromagnetic field, for example. But if the field is more like molasses than water, then the ripples die away too quickly for us to detect.

That means matter might get its mass from a thick Higgs-like field that has no associated particle. To get such a goopy field, theorists need to add in more exotic possibilities – such as new particles or forces of nature...

The existence of a new force, called technicolour, could also give particles mass without the need for a Higgs boson. Technicolour would act like a heavy-duty version of the strong nuclear force, which binds quarks together in the nuclei of atoms. The technicolour force would fill space with pairs of still more new particles, which would form a soup through which other particles would travel, gaining mass in the process....

The existence of a fourth dimension of space, beyond the three we experience, could explain why particles have different masses – a fact that is usually attributed to the Higgs boson.

Bee swarms behave just like neurons in the human brain

Bee swarms behave just like neurons in the human brain: "It appears that the stop signals in bee swarms serve the same purpose as the inhibitory connections in the brains of monkeys deciding how to move their eyes in response to visual input. In one case we have bees and in the other we have neurons that suppress the activity levels of units – dancing bees or nerve centers – that are representing different alternatives. Bee behavior can shed some light on general issues of decision making..."

This phenomenon, known as cross inhibition, serves precisely the same function with bees that it does in nervous systems. It's a way of avoiding decision-making deadlock when presented with a set of equally viable alternatives.

Blog - Elastic Electrical Cables for Robotic Skin

Blog - Elastic Electrical Cables for Robotic Skin: Typically, for robots to be able to articulate their rigid joints, roboticists have to include extra, slack wiring to accommodate the movement. A stretchy cable is more forgiving, eliminating the need for some of that slack. Asahi Kasei is also one of the world's major manufacturers of spandex (though under the brands ROICA and Dorlastan), so the company is very much at home in the world of the stretchy. "We thought, if we can make a cable that stretches by a factor of 1.5, it could be used for wearable electronics, or for wiring the skin of humanoid robots..."

Graphene Spun into Meter-Long Fibers

Graphene Spun into Meter-Long Fibers: They have used an industrial process called wet spinning to turn an aqueous solution of graphene oxide--a modified form of graphene that is easier to dissolve--into fibres that are tens of metres long. A final chemical reduction treatment turns the long strings of graphene oxide back into grapheme...


The team's trick for fibre formation is to start with a solution of graphene oxide so pure and so concentrated that it forms liquid crystals. This half-liquid, half-solid state will flow like a viscous fluid, but the graphene oxide molecules within it are assembled into neat rows. Because of this internal order, liquid crystals are a good starting material for spinning fibres, says Gao, noting that Kevlar is also made from liquid crystals.

More evidence found for quantum physics in photosynthesis

More evidence found for quantum physics in photosynthesis: In an experiment published Dec. 6 in Proceedings of the National Academy of Sciences, a connection between coherence—far-flung molecules interacting as one, separated by space but not time—and energy flow is established.

..."Here we can watch the relationship between coherence and energy transfer. This is the first paper showing that coherence affects the probability of transport. It really does change the chemical dynamics."

...Energy from incoming photons could simultaneously explore every possible chlorophyll route from a protein's surface to the reaction center at its core, then settle on the shortest path.


...a team... analyzed the fluctuation of lasers as they passed through antenna proteins. Depending on how they shifted, the researchers could track what happened inside.

They found a clear mathematical link between energy flows and fluctuations in chlorophyll coherence. The link was so clear it could be described in derivative sines and cosines, mathematical concepts taught in college trigonometry.

New Theory Explains How Objective Reality Emerges from the Strange Underlying Quantum World | Guest Blog, Scientific American Blog Network

New Theory Explains How Objective Reality Emerges from the Strange Underlying Quantum World | Guest Blog, Scientific American Blog Network:  We consider how measurements work in the macroworld, finding that some quantum features are simply unobservable. Most remarkably, this approach shows that something called quantum nonlocality disappears for objects big enough to contain roughly the Avogadro number of atoms...
Our result derives from this concept of macroscopic observables being a kind of average. There is a limit to the number of quantum correlations each particle can have with another, which is referred to as the “monogamy” of quantum correlations. The concept is simple: if particles A and B exhibit correlations of the kind predicted in the EPR experiment then A and B can only have local and realistic correlations with other particles...
This monogamous behaviour extends to correlations between larger groups of quantum particles, which is the main idea behind our result. Imagine you are making a macroscopic measurement between two regions in space, A, containing quantum particles A1, A2, A3, etc., and B, containing B1, B2, B3, etc. The measurement samples all possible pairs. Due to monogamy, as you increase the number of particles, the overall strength of the correlations measured dilutes. For instance, AiBj may be strongly correlated but then Ai and any other B-particle exhibit only local realistic correlations (see figure). Analysing the statistics, we find that local realism emerges for macroscopic correlations without us needing to invoke any other mechanism.

Blog - Giant Casimir Effect Predicted Inside Metamaterials

Blog - Giant Casimir Effect Predicted Inside Metamaterials:  They say that in a particular kind of electromagnetic space called a Rindler space, the Casimir effect is huge. The essential idea here is that the space can be designed to allow only certain wavelengths to operate. If the electromagnetic properties of the Rindler space are matched to the ambient temperature, then these kinds of thermal waves can be made to dominate the Casimir energy.

That makes the Casimir energy huge. Zhao and Miao calculate that in a lab at 300K (room temperature), the Casimir energy would be some 10^11 times bigger than the free space value...

Zhao and Miao also say that this kind of material ought to be relatively straightforward to build, layer by layer.

Neurons illuminate as they fire, may open new ways to trace brain signals

Neurons illuminate as they fire, may open new ways to trace brain signals: Cohen and his team infected brain cells that had been cultured in the lab with a genetically altered virus that contained the protein-producing gene. Once infected, the cells began manufacturing the protein, allowing them to light up.

When a neuron fires, its voltage reverses for a very short time, about a thousandth of a second, he explained. “This brief spike in voltage travels down the neuron and then activates other neurons downstream. Our protein is sitting in the [outside] membrane of the neurons, so as that pulse washes over the proteins, they light up, giving us an image of the neurons as they fire.”

We can now see how these signals spread through the neuronal network, said Cohen.

Nano Paint Could Make Airplanes Invisible to Radar

Nano Paint Could Make Airplanes Invisible to Radar: This effect works, Guo says, because the nanotubes are perfectly absorbing, and because when they are grown with some space between them, as in his experiments, their index of refraction is nearly identical to that of the surrounding air. This means that light won't scatter out of the nanotubes without being absorbed.

Astronomy Without A Telescope – Could Dark Matter Not Matter?

Astronomy Without A Telescope – Could Dark Matter Not Matter?  ...Carati has come along with a seemingly implausible idea that the rotational curves of spiral galaxies could be explained by the gravitational influence of faraway matter, without needing to appeal to dark matter at all.


Conceptually the idea makes little sense. Positioning gravitationally significant mass outside of the orbit of stars might draw them out into wider orbits, but it’s difficult to see why this would add to their orbital velocity. Drawing an object into a wider orbit should result in it taking longer to orbit the galaxy since it will have more circumference to cover. What we generally see in spiral galaxies is that the outer stars orbit the galaxy within much the same time period as more inward stars.

But although the proposed mechanism seems a little implausible, what is remarkable about Carati’s claim is that the math apparently deliver galactic rotation curves that closely fit the observed values of at least four known galaxies. Indeed, the math delivers an extraordinarily close fit.

Soot coating creates self-cleaning surface

Soot coating creates self-cleaning surface: A candle flame will coat a glass slide with black soot. The soot looks uniform, but a scanning electron microscope reveals a fractal-like network of carbon particles that makes it superhydrophobic, or incredibly water-repellent...
Now, researchers at the Max Planck Institute for Polymer Research in Mainz, Germany, and the Technical University Darmstadt, also in Germany, have realised that coating the soot particles in a thin layer of silica replicates their water-repelling structure. They then heat the surface to 600 °C for 2 hours to destroy the soot particles, leaving behind the see-through silica.

Entangled diamonds blur quantum-classical divide

Entangled diamonds blur quantum-classical divide: "It turns out all you need to do is look on a very short timescale, before all that jostling and mugging around has a chance to destroy the coherence."

The team placed two diamonds in front of an ultrafast laser, which zapped them with a pulse of light that lasted 100 femtoseconds (or 10-13 seconds)...

If the system were classical, the second photon should pick up extra energy only half the time – only if it happened to hit the diamond where the energy was deposited in the first place. But in 200 trillion trials, the team found that the second photon picked up extra energy every time.

Blog - Human Brain Is Limiting Global Data Growth, Say Computer Scientists

Blog - Human Brain Is Limiting Global Data Growth, Say Computer Scientists: When two parameters are involved, the relationship between the stimuli and perception is the square of the logarithm. An example would be video in which images change with time...
These guys measured the type and size of files pointed to by every outward link from Wikipedia and the open directory project, dmoz.org...
Sure enough, they discovered that the audio and video file distribution followed a log-normal curve, which is compatible with a logarithmic squared-type relationship. By contrast, image files follow a power law distribution, which is compatible with a logarithmic relationship...

...it'll be interesting to see how machine intelligence might change this equation. It may be that machines can be designed to distort our relationship with information.
If so, then a careful measure of file size distribution could reveal the first signs that intelligent machines are among us!

Blog - Printing Bones in 3-D

Blog - Printing Bones in 3-D: Researchers at Washington State University tweaked a commercial 3-D printer to create three-dimensional structures made from a bone-like material. When incubated in the lab with immature bone cells, the printed bone helped support growth of a new network of bone cells.

Laser's Quantum Fluctuations Provide a Better, Faster Source of Random Numbers

Laser's Quantum Fluctuations Provide a Better, Faster Source of Random Numbers: Ben Sussman at the National Research Council in Ottawa works with a laser pulse lasting a few trillionths of a second, and shines it at a 3-mm piece of diamond crystal. The interactions with vacuum fluctuations changes the incoming photons, whose signals are amplified and converted into binary to generate random bit sequences...
Other researchers have tapped quantum uncertainty to build truly random sequences, including a Chinese team that used quantum noise last year to introduce small frequency changes in laser light. Their method achieved 300 megabits per second of random data, pretty fast but still not great compared to modern bit-rate requirements. Sussman says his method is much faster, capable of producing gigabit-per-second random data.