Submeta Notebook

First quantum jiggles detected in solid object

2012-01-28T17:22:00.000-08:00

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

2012-01-23T17:28:00.000-08:00

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

2012-01-18T17:19:00.000-08:00

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

2012-01-18T17:15:00.000-08:00

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

2012-01-16T16:45:00.000-08:00

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

2012-01-13T14:56:00.000-08:00

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

2012-01-13T14:34:00.000-08:00

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

2012-01-13T13:56:00.000-08:00

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

2012-01-12T15:08:00.000-08:00

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

2012-01-12T15:05:00.000-08:00

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

2012-01-12T15:02:00.000-08:00

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

2012-01-10T13:41:00.000-08:00

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

2012-01-10T13:19:00.000-08:00

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

2012-01-05T13:50:00.000-08:00

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

2012-01-04T13:53:00.000-08:00

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

2012-01-03T14:54:00.000-08:00

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

2011-12-30T09:48:00.000-08:00

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

2011-12-30T09:47:00.000-08:00

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

2011-12-29T14:58:00.000-08:00

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

2011-12-28T13:48:00.000-08:00

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

2011-12-23T13:32:00.001-08:00

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

2011-12-22T13:32:00.000-08:00

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

2011-12-20T13:34:00.002-08:00

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

2011-12-20T13:34:00.001-08:00

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

2011-12-20T13:34:00.000-08:00

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

2011-12-20T13:33:00.000-08:00

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

2011-12-19T13:33:00.000-08:00

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

2011-12-14T20:48:00.000-08:00

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

2011-12-13T20:54:00.000-08:00

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

2011-12-12T20:56:00.000-08:00

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

2011-12-12T20:54:00.000-08:00

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

2011-12-11T10:30:00.002-08:00

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?

2011-12-09T10:30:00.001-08:00

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?

2011-12-09T10:30:00.000-08:00

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

2011-12-08T10:33:00.000-08:00

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

2011-12-06T10:37:00.000-08:00

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

2011-12-06T10:35:00.000-08:00

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

2011-12-06T10:34:00.000-08:00

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

2011-12-05T18:45:00.000-08:00

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

2011-12-05T10:39:00.001-08:00

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

2011-12-05T10:39:00.000-08:00

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

2011-12-05T10:37:00.000-08:00

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?

2011-12-03T10:38:00.000-08:00

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

2011-12-01T16:19:00.000-08:00

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

2011-12-01T16:18:00.000-08:00

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

2011-12-01T16:17:00.001-08:00

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

2011-12-01T16:17:00.000-08:00

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

2011-11-30T16:16:00.000-08:00

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.

Walk-Through-Wall Effect Might Be Possible With Humanmade Object, Physicists Predict

2011-11-29T16:16:00.000-08:00

Walk-Through-Wall Effect Might Be Possible With Humanmade Object, Physicists Predict: ...Researchers would fashion the micrometer-wide trampoline out of graphene, a superstrong, superflexible sheet of carbon only one atom thick. They would suspend the membrane—small but much larger than the atoms and molecules that are the usual domain of quantum physics—over a metal plate. When experimenters applied an electrical voltage, the membrane would have two stable positions: one in which it bows slightly in the middle and one in which it bends enough to contact the plate below. In the Finnish team's design, the electrical and mechanical forces on the membrane create an energy barrier between these two positions. If researchers could lower the membrane's energy by cooling it to a temperature of less than a thousandth of a degree above absolute zero, then the only way it could get between the two positions is quantum tunneling. The experimenters could then observe the membrane's change of configuration by looking for a change in the system's capacitance, a measure of how well it can store electrical charge...

Fire Burns Differently in Space, Space Station Experiment Shows | NASA & International Space Station Science | Fire & Microgravity Research | Space.com

2011-11-29T09:53:00.000-08:00

Fire Burns Differently in Space, Space Station Experiment Shows: To study fires in space, FLEX researchers ignite a small drop of heptane or methanol fuel in a special experiment rack aboard the space station. As the droplet burns, a spherical flame engulfs it, and cameras record the whole process.

So far, researchers have observed some unexpected phenomena.

"Thus far, the most surprising thing we've observed is continued apparent burning of heptane droplets after flame extinction under certain conditions," Williams said. "Currently, this is entirely unexplained."

Tiny Kilobots to go on sale

2011-11-23T18:44:00.000-08:00

Tiny Kilobots to go on sale: Along with its lithium-ion battery and rigid legs, each Kilobot incorporates an LED bulb, two motors (which vibrate the legs), a wide-angle infrared transceiver, and a microcontroller. An unlimited number of the little guys can be programmed via a computer-linked overhead infrared controller in under 40 seconds, and each have the ability to act autonomously, based on the parameters of that programming.

Perfect black coating can render a 3D object flat, raises intriguing dark veil possibility in astronomy

2011-11-22T14:55:00.000-08:00

Perfect black coating can render a 3D object flat, raises intriguing dark veil possibility in astronomy: To demonstrate this concept, the researchers made a raised, microscopic tank shape on a piece of silicon. They then grew the carbon nanotube carpet on top of the entire silicon chip. In photos taken through an optical microscope, they show that the tank is imperceptible. As a control, they did this again, carving out a rectangle that was not coated with carbon nanotubes. The rectangle is visible on this chip, but the tank remains hidden.

Blog - Pulsars Are Giant Permanent Magnets, Say Physicists

2011-11-21T14:56:00.000-08:00

Blog - Pulsars Are Giant Permanent Magnets, Say Physicists: Another problem is how pulsars end up with magnetic fields that are so strong. The conventional view is that the process of collapse during a supernova somehow concentrates the original star's field. However, a star loses much of its material when it explodes as a supernova and this presumably carries away much of its magnetic field too. But some pulsars have fields as high as 10^12 Tesla, far more than can be explained by this process.

Today, Johan Hansson and Anna Ponga at Lulea University of Technology in Sweden suggest a clever way out of this conundrum. They point out that there is another way for magnetic fields to form, other than the movement of charged particles. This other process is by the alignment of the magnetic fields of the body's components, which is how ferromagnets form.

Their suggestion is that when a neutron star forms, the neutron magnetic moments become aligned because this is the lowest energy configuration of the nuclear forces between them. When this alignment takes place, a powerful magnetic field effectively becomes frozen in place.

Quantum Theory's 'Wavefunction' Found to Be Real Physical Entity

2011-11-17T14:58:00.000-08:00

Quantum Theory's 'Wavefunction' Found to Be Real Physical Entity: Action at a distance occurs when pairs of quantum particles interact in such a way that they become entangled. But the new paper, by a trio of physicists led by Matthew Pusey at Imperial College London, presents a theorem showing that if a quantum wavefunction were purely a statistical tool, then even quantum states that are unconnected across space and time would be able to communicate with each other. As that seems very unlikely to be true, the researchers conclude that the wavefunction must be physically real after all.

Atoms find quantum solace in the deep chill of space

2011-11-17T14:32:00.001-08:00

Atoms find quantum solace in the deep chill of space: But at ultracold temperatures, the particles are more sluggish, allowing the electron to, in effect, have one foot on its own calcium atom and another on the ytterbium ion. As quantum objects, the particles behave like waves, and they remain close to each other long enough for their wavelengths to overlap. This is essentially equivalent to being a single molecule in an excited, or less stable, energy state. If the quasi-joined particles then emit a photon, they can relax into a lower energy state, becoming a bona fide molecule in a process known as radiative association. "These radiative processes are much more likely at low temperature," Hudson says. "It's because of them that we see this enormous reaction rate."

That's exciting to astrochemists like Jean Turner, also of UCLA. "Radiative association is a key starting point of interstellar chemistry," she says.

World's lightest material developed

2011-11-17T14:30:00.001-08:00

World's lightest material developed: "The trick is to fabricate a lattice of interconnected hollow tubes with a wall thickness 1,000 times thinner than a human hair," said lead author Dr. Tobias Schaedler of HRL.
The material's architecture allows unprecedented mechanical behavior for a metal, including complete recovery from compression exceeding 50 percent strain and extraordinarily high energy absorption.
"Materials actually get stronger as the dimensions are reduced to the nanoscale..."

Scientists create light from vacuum

2011-11-17T14:30:00.000-08:00

Scientists create light from vacuum: The “mirror” consists of a quantum electronic component referred to as a SQUID (Superconducting quantum interference device), which is extremely sensitive to magnetic fields. By changing the direction of the magnetic field several billions of times a second the scientists were able to make the “mirror” vibrate at a speed of up to 25 percent of the speed of light.
“The result was that photons appeared in pairs from the vacuum, which we were able to measure in the form of microwave radiation,” says Per Delsing. “We were also able to establish that the radiation had precisely the same properties that quantum theory says it should have when photons appear in pairs in this way.”
What happens during the experiment is that the “mirror” transfers some of its kinetic energy to virtual photons, which helps them to materialise.

Squishybots: Soft, bendy and smarter than ever

2011-11-16T14:33:00.000-08:00

Squishybots: Soft, bendy and smarter than ever: They were born thanks to a rethink of how we should design intelligent machines - an approach called "morphological computing". Its proponents argue that it is not only a robot's brain that can compute, but its body too. The way a limb, torso, or whisker interacts with its surroundings can be optimised to enhance its computational abilities - and therefore how smart the robot is...

Out of the water, the arm is floppy and helpless. But place it in its tank and something extraordinary happens. Its movement suddenly bears an uncanny resemblance to the reaching motion of an octopus. In fact, it almost looks alive.
And that's the trick. With morphological computing, it's not just the shape and substance of a body that's important, it's also the interaction with its environment that is crucial. It has the dexterity and grip to grab hold of all sorts of different objects placed into its tank. It can also push against the bed in the same way that octopuses use to "walk". And all with relatively little programming.

Liquid could power and cool mobile supercomputers

2011-11-16T14:32:00.000-08:00

Liquid could power and cool mobile supercomputers: Michel and his team's idea is to stack hundreds of silicon wafers on top of each other to create three-dimensional processors. Between each layer is a pair of fluidic networks. One of these carries in charged fluid to power the chip, while the second carries away the same fluid after it has picked up heat from the active transistors - effectively creating a microscopic flow battery...
"The use of liquid to cool 3D chips is not new," says Bob Patti, chief technology officer of Tezzaron. "However, using the liquid as a power source as well as for cooling is a concept I haven't seen before."

Pair claim they have turned hydrogen to metal

2011-11-15T23:11:00.000-08:00

Pair claim they have turned hydrogen to metal: when they put a sample of hydrogen in a alumina-epoxy gasket that they put inside of a diamond anvil cell, an arrangement that allowed them to test the opacity via laser and the electrical resistance using electrodes, they found that without heating or cooling and at a pressure of 220GPa, the sample clouded to the point of becoming opaque and began to demonstrate an ability to conduct electricity...
...the procedure clearly can make hydrogen conductive at room temperature, which means it could conceivably turn out to be that elusive superconductor that scientists the world over have been searching for.

Mimicking the brain, in silicon - MIT News Office

2011-11-15T19:06:00.000-08:00

Mimicking the brain, in silicon - MIT News Office: With about 400 transistors, the silicon chip can simulate the activity of a single brain synapse...
The MIT researchers designed their computer chip so that the transistors could mimic the activity of different ion channels...

Previously, researchers had built circuits that could simulate the firing of an action potential, but not all of the circumstances that produce the potentials. “If you really want to mimic brain function realistically, you have to do more than just spiking. You have to capture the intracellular processes that are ion channel-based,” Poon says.

Blog - How Superconductors Can Detect Gravitational Waves

2011-11-15T14:48:00.000-08:00

Blog - How Superconductors Can Detect Gravitational Waves: They imagine a bar of superconducting metal being hit by a gravitational wave. The waves act on all masses within the bar but the resulting movement of the metallic lattice, which is bound in place, will be very different from the movement of superconducting electrons, which are entirely unbound and free to move...
Next, they place another superconducting bar at the end of the first but at right angles to it. While the first bar is squeezed by a gravitational wave, the second will be stretched. So the electrons in this bar will oscillate too, albeit shifted by half a period relative to the first.
Finally, if these bars are connected by a superconducting wire, an oscillating current should flow through it.

3-D Projection Tech Makes Images Hover in Mid-Air, No Screen Necessary

2011-11-15T14:31:00.000-08:00

3-D Projection Tech Makes Images Hover in Mid-Air, No Screen Necessary: Rather than using a screen to generate the illusion of three dimensions, Aerial 3D is a laser system that uses beams of light projected from below to generate plasma excitation in atoms of oxygen and nitrogen in the air. It currently can create 50,000 points of light per second, giving it a somewhat choppy frame rate of 10-15 fps. Burton is working to improve that to 24-30 fps, comparable to that of basic video.

Carbon nanotube sheets create invisibility

2011-11-14T14:48:00.000-08:00

Carbon nanotube sheets create invisibility: This invisibility for light oblique to the nanotube sheets is caused by the mirage effect (photothermal deflection), in which a thermally generated refractive index gradient bends light array from a hidden object.

“The remarkable performance of nanotube sheets suggests possible applications as photo-deflectors and for switchable invisibility cloaks, and provides useful insights into their use as thermoacoustic projectors and sonar,” the authors say.

Proof Found for Unifying Quantum Principle

2011-11-14T14:47:00.001-08:00

Proof Found for Unifying Quantum Principle: His conjecture is called the a-theorem. It says that the number of ways in which quantum fields can be energetically excited (a) is always greater at high energies than at low energies...

Although lots of work has gone into relating short- and long-distance scales for particular quantum field theories, there are relatively few general principles that do this for all theories that can exist...
But Cardy's a-theorem could be one such principle. A version of it had already been proven in two dimensions, but Cardy proposed that it might hold in four dimensions--such as the three dimensions of space and one of time that exist in the space in which we live.

Not Pulling Your Leg: Tractor Beams May Be Possible

2011-11-14T14:47:00.000-08:00

Not Pulling Your Leg: Tractor Beams May Be Possible: The tractor beam would work in a new way. In this case, the light would pull an object toward the source of the beam even though the beam has the same intensity all along its length. The trick is to use a special type of laser beam. In an ordinary beam, each photon moves in the direction of the beam, so when a photon bounces directly back from an object, it imparts the largest possible push. However, physicists can generate a beam by overlapping light waves that make an angle relative to the desired direction (see figure). The overlapping waves produce a forward-moving beam known as a Bessel beam whose intensity remains constant along its length. But each photon is now moving at an angle relative to the beam. So when one bounces off an object, it exerts a smaller forward push.

Nevertheless, the beam is still pushing, and to overcome that push, physicists need to rely on another bit of physics. Again, the light will polarize the material in the object electrically and magnetically. The polarized object will then radiate and redirect the light. By adjusting the material properties of the object and the polarizations and synchronization of the individual light waves in the beam, physicists can make the object radiate more light forward along the beam than backward toward its source. The radiated light then acts like a reverse thruster, overcoming the already-reduced forward push of the beam and driving the object back toward its source.

Superconductor May Hide Long-sought Secret - Science News

2011-11-14T10:13:00.000-08:00

Superconductor May Hide Long-sought Secret - Science News: To probe the material, Yoichi Ando of Osaka University and colleagues in Japan injected current into it using a gold wire. This excited electrons at the surface, creating ripples of energy. Conventional superconductors have a dead spot in their surfaces that prevents low-energy, slow-wobbling ripples from forming. But a close look at this material revealed a sea of waves bouncing up and down both quickly and slowly.

Ando says that this pattern of ripples is “unambiguous evidence” of a type of superconductivity never seen before: topological superconductivity, in which electrons become waves molded into a complex shape that resembles the outside of a doughnut. These waves, says Ando, seem to be behaving like exotic two-dimensional particles at the surface of the material — specifically, Majorana fermions.

“This is the best evidence so far for Majorana fermions in a solid material,” says Taylor Hughes, a theoretical physicist at the University of Illinois at Urbana-Champaign.

HRP-4C female robot has a new walk (w/ video)

2011-11-13T14:50:00.000-08:00

HRP-4C female robot has a new walk (w/ video): The AIST researchers focused on a few key areas of the robot to improve results. The robot’s toes now support the legs better during each stride, and the legs straighten out more...
The authors explain that in working up a model of a walking pattern imitating human motion their focus was placed on three characteristics of walking: single toe support, knee stretching, and swing leg motion.

Planets Could Orbit Singularities Inside Black Holes - Technology Review

2011-11-11T18:39:00.001-08:00

Planets Could Orbit Singularities Inside Black Holes - Technology Review: It's well known that a traveller passing through a black hole's event horizon arrives in a region in which the radial dimension becomes time-like, rather than space-like. Conventional orbits are clearly impossible here.

But travel further in and there is another horizon where the dimensions switch back again (at least, inside charged and rotating black holes). This is the inner Cauchy horizon and it's beyond here that Dokuchaev says the interesting orbits for massive planets exist.

He calculates that the stable orbits are nonequatorial and have a rich structure...

Pulse of light creates instant origami

2011-11-11T18:38:00.002-08:00

Pulse of light creates instant origami: Watch a self-folding material produce a range of 3D shapes when subjected to heat.

ScienceShot: The Fastest Spinning Normal Star

2011-11-11T18:36:00.001-08:00

ScienceShot: The Fastest Spinning Normal Star: How fast can a star spin? Our sun rotates at a leisurely 2 kilometers per second, but now astronomers have discovered that a star in another galaxy spins 300 times faster—with a record-breaking speed of 600 kilometers per second. At that velocity, an airplane could circle Earth in little more than a minute... If the star spun just 20% faster, the centrifugal force would fling it apart.

Magnetic Cows Finding Disputed by Researchers

2011-11-11T14:50:00.000-08:00

Magnetic Cows Finding Disputed by Researchers: Burda says that half of the Jelinek team's data should be excluded because some of the pastures are on slopes or near high-voltage power lines, for example, or because the images are too poor to make out cattle, or appear to contain hay bales or sheep instead. "One half of their data is just noise," says Burda.

In addition, Burda's group looked at herds as a whole, whereas Jelinek's team analyzed individual cows. "Of the data that were useable, they looked only at 50 percent of the cows. It's very subjective," Burda adds. His team's reanalysis of the Jelinek data actually does support the theory that cattle can magneto-sense, says Burda.

A revolution in knot theory

2011-11-10T18:39:00.000-08:00

A revolution in knot theory: In the mid-1990s, mathematicians discovered something strange. There are Gauss codes for which it is impossible to draw planar knot diagrams but which nevertheless behave like knots in certain ways. In particular, those codes, which Nelson calls *nonplanar Gauss codes*, work perfectly well in certain formulas that are used to investigate properties of knots. Nelson writes: "A planar Gauss code always describes a [knot] in three-space; what kind of thing could a nonplanar Gauss code be describing?" As it turns out, there are "virtual knots" that have legitimate Gauss codes but do not correspond to knots in three-dimensional space. These virtual knots can be investigated by applying combinatorial techniques to knot diagrams.

Taut-Tech: Smaller, Softer Artificial Muscles to Help Bring Power to Toys and Cell Phones

2011-11-09T16:27:00.000-08:00

Taut-Tech: Smaller, Softer Artificial Muscles to Help Bring Power to Toys and Cell Phones: Scientists at the University of Auckland's Bioengineering Institute in New Zealand are developing an advanced artificial muscle that essentially does the same thing without the need for external conductors. The researchers start by applying grease infused with carbon particles—known as carbon grease—onto a polymer. "By carefully laying down soft electrodes on the membrane's surface, we can control the charge in a clever way, and create something that is smaller, lighter and more portable than previously possible..."

A Super-Absorbent Solar Material

2011-11-09T16:18:00.000-08:00

A Super-Absorbent Solar Material: Atwater worked with Koray Aydin, now an assistant professor of electrical engineering and computer science at Northwestern University, to develop the super-absorber design, which takes advantage of a phenomenon called optical resonance. Just as a radio antenna will resonate with and absorb certain radio waves, nanostructured optical antennas can resonate with and absorb visible and infrared light. The length of a structure determines what wavelength of light it will resonate with. So Atwater and Aydin designed structures that effectively have many different lengths: wedge shapes with pointy tips and wide bases. The thin, nanoscale wedges strongly absorb blue light at the tip and red light at the base.

Atwater and Aydin demonstrated this broadband effect in a 260-nanometer-thick film made of a layer of silver topped with a thin layer of silicon dioxide and finished with another thin layer of silver carved with arrays of wedges that are 40 nanometers at their tips.

Black Holes, Safety, and the LHC Upgrade - Technology Review

2011-11-09T15:54:00.000-08:00

Black Holes, Safety, and the LHC Upgrade - Technology Review: These guys assume that after microscopic black holes form, they would go through four phases. First there is the balding phase in which the newly formed back hole evolves from a highly asymmetric object to a more symmetric one, shedding its asymmetry through gravitational radiation.

In the second phase, called the spin-down phase, the black hole loses mass and angular momentum by emitting Hawking radiation. The third, the Schwarzschild phase, the black hole becomes spherical and the rate of mass loss slows down. And in the final Planck phase, the black hole winks out of existence.

Weird world of water gets a little weirder with a new anomaly

2011-11-09T15:36:00.000-08:00

Weird world of water gets a little weirder with a new anomaly: They found that when they chilled liquid water in their simulation, its propensity to conduct heat decreases, as expected for an ordinary liquid. But, when they lowered the temperature to about 54 degrees below zero Fahrenheit, the liquid water started to conduct heat even better in the simulation. Their studies suggest that below this temperature, liquid water undergoes sharp but continuous structural changes whereas the local structure of liquid becomes extremely ordered -- very much like ice. These structural changes in liquid water lead to increase of heat conduction at lower temperatures. The researchers say that this surprising result supports the idea that water has a liquid-liquid phase transition.

The acousto-optical effect that uses lasers to see sound

2011-11-08T18:40:00.000-08:00

The acousto-optical effect that uses lasers to see sound: As pressure waves move through the air, they change the air density. That shift in density changes the air's refractive index. When light hits a high-density section, it will be slowed down. When it hits a low-density section, it will shoot ahead. These regular high-density and low-density sections can also act as a diffraction grating, causing the light to splay out and cause interference. By bouncing laser light off a reflective sheet on the far side of the speaker, light makes two trips through the acoustic waves. It's then taken up by a detector. The acoustic waves will have caused the light to move at different angles and different speeds, causing phase shift.

New Scientist TV: Seeing Relativity: Mind-bending tour of the solar system

2011-11-08T15:56:00.000-08:00

New Scientist TV: Seeing Relativity: Mind-bending tour of the solar system: The tour starts in an orbit high above the surface of the Earth. As you move further away, oceans turn green and continents look red due to the Doppler effect. Passing by Mars, its surface changes colour dramatically. Then, as you speed up, Jupiter appears smaller than it actually is due to time dilation, since you're seeing what it looked like in the past, when it was further away. A small window in the lower right of the video shows the planet's actual appearance for comparison.

Flying towards Saturn, its rings look distorted and, as you reach light speed, everything around you is compressed to a single spot.

Christmas Ornaments, Packed Like Sardines - ScienceNOW

2011-11-08T09:25:00.001-08:00

Christmas Ornaments, Packed Like Sardines - ScienceNOW: Chan realized he could solve the problem by imagining his cylinder full of ball bearings as a stack of disks, with a single layer of ball bearings on each disk. He then wrote a computer simulation to model it that way. The computer would lay spheres in a disk, and when it ran out of room, it would move up until it found enough space to fit another sphere. It would then rotate around fitting spheres on that level until there was no more room, moving up again, and repeating. Not all the spheres on a certain disk needed to be level; if a sphere could nestle down a little into a space created by two spheres on the disk below to get the tightest fit, it would. If the spheres below pushed it up a little higher than the other spheres on its disk, that was okay, too.

Chan was pleased to see that the program, running just 15 minutes on a laptop, produced results very close to those of weeklong computer simulations run by his colleagues...

Nuclear clock could steal atomic clock's crown - New Scientist - New Scientist

2011-11-07T16:14:00.000-08:00

Nuclear clock could steal atomic clock's crown: A nuclear clock has not yet been made but the idea would be to use the atomic nucleus like a tuning fork. A nucleus will jump to a higher energy state, then fall back down, and jump up again, only if it is hit with a very specific frequency of light. Tuning a laser so that it prompts these jumps is a way to set its frequency with a phenomenal level of precision. The frequency can then be used like a clock's tick to keep time.

A similar method is used in atomic clocks, except it is the electrons orbiting the nucleus that make the energy jump...

A thorium clock controlled in this way would drift by just 1 second in 200 billion years...

New Scientist TV: Spiny ferrofluid performs magnetic ballet

2011-11-07T16:08:00.000-08:00

New Scientist TV: Spiny ferrofluid performs magnetic ballet: In this video, ferrofluid spikes take to the floor and perform a magnetised dance. Created by engineer Tatyana Arefyeva at the Ivanovo State Power University in Russia, the spiny ballet exploits the magnetic fields of a ferrofluid. Using a computer program to manipulate these fields, Arefyeva made the substance change shape. The particles align themselves along field lines moving with the magnetic force. When the field is turned off, they return to a random alignment.

Bell Labs builds telepresence 'robots' - News - iTnews Mobile Edition

2011-11-07T15:50:00.000-08:00

Bell Labs builds telepresence 'robots' - News - iTnews Mobile Edition: Researchers are working on a low-cost camera and screen that swivels on a set of robotic shoulders, and sits at a meeting table with physical attendees...

Bouwen highlighted the value of a “turn-taking mechanism” that determines who should be next to speak.
In person, two people who begin to speak to a group at the same time tend to take their cues from the direction in which most group members are looking...
“Someone showing clear agreement or clear disagreement is [also] important. If you’re trying to explain something, knowing who is confused and not following is important.”

Fundamental Constant May Depend on Where in the Universe You Are - ScienceNOW

2011-11-04T15:43:00.000-07:00

Fundamental Constant May Depend on Where in the Universe You Are - ScienceNOW: Light from the quasars must pass through clouds of gas on its several-billion-year journey to Earth, and the atoms in the gas absorb light of specific wavelengths. So the spectrum of the light reaching Earth is missing these wavelengths and looks a bit like a bar code. The overall shift of the lines tells researchers how far away a gas cloud is and, hence, how long ago the light passed through it. The relative spacing of the lines lets them estimate the fine-structure constant at that time. Analyzing such data, Webb and colleagues argued that the fine-structure constant was about 1 part in 100,000 smaller 12 billion years ago than it is today...
Now Webb and his colleagues have scoured the southern sky themselves using the VLT. Their 153 clouds suggested a difference of 1 part in 100,000 in the fine-structure constant 12 billion years ago. Except in the southern sky, the constant seems to be larger. Connecting the two extremes with a line, the team found that absorption patterns in the clouds along that line are consistent with the fine-structure constant changing slowly through space—smaller in the distant northern sky and larger on the southern side.

MAKE | How-To: Homemade Memristor

2011-11-03T16:05:00.000-07:00

MAKE | How-To: Homemade Memristor: Fascinating video from Nyle Steiner, who reports on his experiments with simple homemade memristors made from what are, probably, Al-CuxSy-Cu and Al-PbS-Pb junctions. He describes the observations that led him to experiment with these systems and the results of his experiments, and then wraps up by drawing out a simple memristor demonstration circuit and showing its operation on-camera.

One weird theory could make anti-gravity and faster-than-light travel possible

2011-11-03T10:29:00.000-07:00

One weird theory could make anti-gravity and faster-than-light travel possible: Heim Theory was originated by Burkhard Heim, a German physicist, in the mid-twentieth century. It was attempted as a way to reconcile the two pillars of physics, quantum theory and general relativity. It takes what's currently the only way out, between the two theories - extra dimensions...
Heim's goal was to find ways to convert between all kinds of energy, and in adding two dimensions to his calculations he was able to equate, at least in theory, gravitational energy and electromagnetism.

Fully-Immersive 3D Volumetric Projection - YouTube

2011-11-01T14:55:00.000-07:00

Fully-Immersive 3D Volumetric Projection - YouTube: Using multiple projectors to build images in "thick air".

Role of fractal dimension in random walks on scale-free networks

2011-10-31T19:19:00.000-07:00

Role of fractal dimension in random walks on scale-free networks: Fractal dimension is central to understanding dynamical processes occurring on networks; however, the relation between fractal dimension and random walks on fractal scale-free networks has been rarely addressed, despite the fact that such networks are ubiquitous in real-life world. In this paper, we study the trapping problem on two families of networks.

Invisibility Tiles Can Cloak Any Shape - Technology Review

2011-10-27T19:17:00.000-07:00

Invisibility Tiles Can Cloak Any Shape - Technology Review: Creating a cloak that exactly follows the shape of the object it is intended to hide is hard because curve cloaks are hard to make.

Instead, Paul and co approximate the shape using flat facets. These 'invisibility tiles' fit together in the same way as the triangular facets in a computer animation. And since each flat tile is relatively simple and easy to make, it becomes much cheaper and easier to build complex cloaks.

Artificial Skin Feels With Nerves Made of Clear Nanotube Springs | Popular Science

2011-10-25T19:13:00.000-07:00

Artificial Skin Feels With Nerves Made of Clear Nanotube Springs | Popular Science: Lipomi and colleagues in Zhenan Bao’s skin lab used nanotubes suspended in liquid, spraying them onto a silicone surface and then stretching the silicone...
The sensors are made from two nanotube-coated silicone pieces, sandwiching a third layer of deformable silicone that stores an electrical charge. When pressure is applied, the device’s capacitance increases, and this can be used to calculate the amount of pressure. It’s not quite as sensitive as another super-sensitive skin developed in the same lab last year, because the researchers were focused on making this one transparent.

New Scientist TV: Time-lapse Tuesday: Shaking nails mimic melting crystals

2011-10-25T19:06:00.000-07:00

New Scientist TV: Time-lapse Tuesday: Shaking nails mimic melting crystals: According to Morris, the parallels are surprising because the shaking only roughly equates to an increase in temperature and the different stages are not equilibrium states.

"Since the nails lose energy on collisions, we must continuously feed energy in via the shaking," Morris said. "So this is a very non-thermodynamic situation, yet we observe more or less the same phases as in liquid crystals."

New Scientist TV: Superconducting disc locked in upside-down levitation

2011-10-20T16:35:00.000-07:00

New Scientist TV: Superconducting disc locked in upside-down levitation: Almog's disc can be locked in place thanks to tiny gaps in the ultra-thin superconducting coating that allow some of the magnetic fields to seep in. Since the superconductor hates magnetic fields, it traps them in weak areas. So the tiny spaces act as pins, holding up the disc in space.

"We have achieved what was thought to be impossible up until today: growing high quality superconducting layers on sapphire wafers," says Almog. "Since the superconductor is of the highest quality, it allows a micron thick layer to be locked in space with enough power."

Robot builds its own body from sprayable foam - tech - 19 October 2011 - New Scientist

2011-10-19T19:03:00.000-07:00

Robot builds its own body from sprayable foam: Created by Shai Revzen and colleagues at the University of Pennsylvania Foambot consists of a wheeled "mothership" platform along with several simple joint modules capable of powered bending and flexing. The platform has an on-board supply of chemical reagents and a spray nozzle; when mixed, the reagents expand into hard urethane foam. First the remote-controlled platform arranges the modules on the floor and then it sprays the foam to connect them into the required form.

One clock with two times: When quantum mechanics meets general relativity

2011-10-19T18:50:00.000-07:00

One clock with two times: When quantum mechanics meets general relativity: The team at the University of Vienna considers a single clock (any particle with evolving internal degrees of freedom such as spin) which is brought in a superposition of two locations – one closer and one further away from the surface of the Earth. According to general relativity, the clock ticks at different rates in the two locations, in the same way as the two twins would age differently. But since the time measured by the clock reveals the information on where the clock was located, the interference and the wave-nature of the clock is lost. "It is the twin paradox for a quantum 'only child', and it requires general relativity as well as quantum mechanics. Such an interplay between the two theories has never been probed in experiments yet..."

MAKE | Raytheon-Sarcos Prototype Power Loader

2011-10-18T16:39:00.000-07:00

MAKE | Raytheon-Sarcos Prototype Power Loader

Seeing through walls - MIT News Office

2011-10-18T16:37:00.000-07:00

Seeing through walls - MIT News Office: Even when the signal-strength problem is addressed with amplifiers, the wall — whether it’s concrete, adobe or any other solid substance — will always show up as the brightest spot by far. To get around this problem, the researchers use an analog crystal filter, which exploits frequency differences between the modulated waves bouncing off the wall and those coming from the target. “So if the wall is 20 feet away, let’s say, it shows up as a 20-kilohertz sine wave. If you, behind the wall, are 30 feet away, maybe you’ll show up as a 30-kilohertz sine wave,” Charvat says. The filter can be set to allow only waves in the range of 30 kilohertz to pass through to the receivers, effectively deleting the wall from the image so that it doesn’t overpower the receiver.

The mechanism that gives shape to life | KurzweilAI

2011-10-17T21:37:00.000-07:00

The mechanism that gives shape to life | KurzweilAI: In the embryo’s first moments, the Hox genes are dormant, packaged like a spool of wound yarn on the DNA. When the time is right, the strand begins to unwind. When the embryo begins to form the upper levels, the genes encoding the formation of cervical vertebrae come off the spool and become activated. Then it is the thoracic vertebrae’s turn, and so on down to the tailbone. The DNA strand acts a bit like an old-fashioned computer punchcard, delivering specific instructions as it progressively goes through the machine.

“A new gene comes out of the spool every 90 minutes, which corresponds to the time needed for a new layer of the embryo to be built,” explains Duboule. “It takes two days for the strand to completely unwind; this is the same time that’s needed for all the layers of the embryo to be completed.”

Original spin: Was the universe born whirling? - space - 17 October 2011 - New Scientist

2011-10-17T21:31:00.000-07:00

Original spin: Was the universe born whirling?: All other things being equal, you would have expected these galaxies generally to be spinning in random directions, according to local conditions when they formed. And that indeed was the case. In most sectors of the northern sky, equal numbers of galaxies were rotating to the right, or clockwise, and to the left, anticlockwise. But along one direction, at about 10 degrees to our own galaxy's spin axis, there were more left-handed spirals than right-handed ones...
"If this asymmetry is real, it means the universe has a net angular momentum..."
It is too early for him to have incorporated the details of the galaxy asymmetry into his work explicitly, but he sees a suggestive thread: an initially spinning universe brought on a parity-violating asymmetry in gravity that allowed matter to triumph over its antimatter rival. And that process left two marks behind: the axis of evil in the cosmic background radiation, and the inconspicuous alignment of galaxies that Longo has spotted.

Robot biologist solves complex problem from scratch | KurzweilAI

2011-10-17T18:44:00.000-07:00

Robot biologist solves complex problem from scratch | KurzweilAI: The biological system that the researchers used to test ABE is glycolysis, the primary process that produces energy in a living cell. They focused on how yeast cells control glycolytic oscillations because it is one of the most extensively studied biological control systems. ABE derived the equations a priori. The only thing the software knew in advance was addition, subtraction, multiplication and division...

Lipson used genetic programming for the breeding process... However, this process also proved to be too slow.
So Lipson combined the breeding and the debugging processes in an approach he calls co-evolution.

Extremely strong coupling superconductivity of heavy-electrons in two-dimensions

2011-10-17T15:39:00.000-07:00

Extremely strong coupling superconductivity of heavy-electrons in two-dimensions: Most remarkably, the superconductivity in superlattices persists under significantly higher reduced magnetic fields than in the bulk, implying that the force ("glue") holding together the superconducting electron pairs takes on an extremely strong coupled nature as a result of two-dimensionalization (Fig. 2) -- a situation reminiscent of the high-Tc cuprates.