Archive
‘Nanofishnet’ Could Be the First Metamaterial to Impossibly Bend Light in the Visible Spectrum
By Clay DillowPosted 04.30.2012 at 2:09 pm
Metamaterials hold the elusive promise of the true invisibility cloak, one that bends light right around objects to make them invisible to viewers. But most metamaterials with any kind of potential can only be fabricated in very small sizes, and even the ones that work well–and there are a few–generally don’t work in the visible spectrum. But researchers from Spain and the UK have reported that they have constructed what may be the first practical metamaterial that works in the visible range.
The material was designed with optical switching in mind–sub-picosecond pulsing of light in fiber optics networks or in highly tuned pulsing lasers–but the researchers themselves are convinced that its layered structure could be scaled up into usable, practically-sized objects. Everyone in the materials science community isn’t so optimistic, but the fact that it works at all in the visible range marks something of a breakthrough in the field.
Visible light has been a particularly tough nut to crack when it comes to metamaterials, which essentially bend light unnaturally to achieve a desired effect. Light waves in the visible spectrum tend to degrade to nothing after passing through materials just a fraction of a wavelength thick, so it’s tough to make a metamaterial that can bend light in a predetermined way without also losing the visible light wave altogether.
The UK/Spanish team (from King’s College London and the Valencia Nanophotonics Technology Center, respectively) overcame this through a novel layered construction of silver and hydrogen silsesquioxane (a type of glass). Using a focused ion beam, they punched tiny holes through the layers to create a structure they refer to as a “nanofishnet.” This combination of materials, layering, and nanofishnet structure allows the material to create the necessary negative magnetic permeability (a necessary ingredient for metamaterials that you can learn more abouthere) in the red and near-infrared parts of the spectrum.
By varying the size of the holes in the nanofishnet the team was able to adjust the materials index of refraction, giving them some degree of freedom when it comes to “programming” the material for different kinds of light. So while the team hasn’t created the wundermaterial that will enable our invisibility-cloaked future, they have created a metamaterial that works in one sliver of the spectrum and that could perhaps be cajoled into working in other slivers as well. Click through toIEEE Spectrum for a much more detailed explanation of this.
Water drop at 10.000 fps
NASA Invests In Satellites That Beam Power Down to Earth
By Rebecca Boyle Posted 04.11.2012 at 4:05 pm
As spaceborne energy-harvesting schemes go, this one seems faintly possible — an array of curved mirrors directing sunlight toward solar cells, their energy production microwaved down to Earth. It’s so realistic, actually, that NASA is providing funding for a proof-of-concept study.
A former NASA engineer named John Mankins, now with a company called Artemis Innovation Management Solutions, detailed his plans at a NASA innovation conference recently. The concept is called called Solar Power Satellite via Arbitrarily Large PHased Array (SPS-ALPHA), and it would harvest solar energy from a perch in high Earth orbit.
It would consist of a modular array of movable thin-film mirrors, which could be taken into space using current cargo ships and assembled piece by piece. This would be less expensive than building a gigantic array and launching it. These curved mirrors would redirect sunlight toward an internal collection of photovoltaic panels, and the solar energy would be converted into microwaves. Then the Earth-facing portion, or the bottom of the margarita glass in the image at top, would transmit low-frequency, low-intensity waves toward Earth. At the receiving end, power plants would convert the microwave energy into electricity, adding it to the power grid.
It’s not as comprehensive — nor potentially destructive — as building a Dyson sphere around the Earth, but it’s sort of along the same lines, building a space-based system that can harness solar radiation and somehow beam it back to the planet. Mankins’ design is inspired by nature, according to an account of his presentation over at Space.com. It does sort of look like a flower.
His project, first announced last fall, is part of NASA’s NASA Innovative Advanced Concepts project, under the Office of the Chief Technologist. A one-year study is ongoing.
[via PhysOrg]
NASA’s Building of the Future: a Model for Tomorrow’s Moonbases
by:Charlie Jane Anders at http://io9.com/5904872/nasas-building-of-the-future-a-model-for-tomorrows-moonbases?tag=space
Check out this gorgeous cutting-edge building, which NASA just opened in Moffett Field, CA and won the coveted Platinum LEED certification.
Ames Research Center director Pete Worden described the Sustainability Center as “the first Moon building on the planet Earth,” because of all the insane technology that’s been deployed here. A water recycling system, similar to what’s on the Space Station, will cut water use by 90 percent. The building uses geothermal wells for heating and cooling, and opening and closing windows to adapt to changing weather conditions. And solar panels and fuel cells power the building and other buildings at Ames. [Mountain View Voice]
Why Mining an Asteroid for Water and Precious Metals Isn’t as Crazy as it Sounds
Billionaire-backed space startup Planetary Resources has officially unveiled its business plan to much fanfare and with few surprises. The company’s principals–which include X-Prize Foundation founder Peter Diamandis, Space Adventures co-founder Eric Anderson, and former NASA Flight Director Chris Lewicki–today pledged that Planetary Resources would make the abundant resources of space available here on Earth, and introduced a couple of the company’s own spacecraft that will make such space prospecting possible. The rush for space resources is officially on.
In New Quantum Experiment, Effect Happens Before Cause
A real-world demonstration of a thought experiment conducted at the University of Vienna, has produced a result that is somewhat befuddling to people with what the lead researcher calls a “naïve classical world view.” Two pairs of particles are either quantum-entangled or not. One person makes the decision as to whether to entangle them or not, and another pair of people measure the particles to see whether they’re entangled or not.
The head-scratcher is: the measurement is made before the decision is made, and it is accurate. “Classical correlations can be decided after they are measured,” says Xiao-song Ma, the writer of the study. Entanglement can be created “after the entangled particles have been measured and may no longer exist.”
The finding can be integrated into potential quantum computers, one hopes. Causality, clearly, is a quaint, irrelevant concept.
[Nature]
France Will Soon Host Thermonuclear Star-Making Technology
Friday, 20 April 2012 08:29
‘An artificially excavated limestone pit in the south of France will soon host star-making technology, New Scientist reports. “If all goes well,” the magazine explains, in a few year’s time the pit will “rage with humanity’s first self-sustaining fusion reaction, an artificial sun ten times hotter than the one that gives our planet life.”
Reaching that point, however, requires an ambitious reformatting of the entire site, seemingly the very limit of landscape architecture: a kind of concrete garden that produces stars.’
Read more: France Will Soon Host Thermonuclear Star-Making Technology
Canada Launches Its Own Virtual Cash, Called MintChip
By Rebecca Boyle Posted 04.12.2012 at 11:02 am
Next time you visit Canada, you might use digital currency to purchase your poutine, using something called MintChip backed by the Canadian government. The Royal Canadian Mint announced it’s getting rid of the penny and starting a new e-currency instead, and it wants the software community to help develop it.
The government just launched the MintChip Challenge— which was apparently so popular it’s already fully registered — to seek new digital payment apps for this new virtual currency. The idea is sort of a hybrid, combining the convenience of electronic transactions and the anonymity of cash. It will work via SD cards, but it will have no personal information or bank account data associated with it. It’s sort of like BitCoin but with actual, government-backed value.
The four-month contest includes 500 developers who will build apps that can demonstrate MintChip’s value. They’ll have to work on a variety of smartphone and desktop browsers. The prize: Solid gold wafers and coins worth about $50,000.
Its anonymity is a pretty unique idea. Other electronic payment systems — PayPal, Square, NFC-enabled phones, etc. — all connect to a person’s credit card or bank account. But cash is a great equalizer; you don’t need to have good credit to use it. MintChip would enable the same type of low-cost transactions for which you’d normally use cash. A Canadian banking group called Interac estimates that small-value transactions under $20 are worth $90 billion to the Canadian economy, the Toronto Star reported.
MintChip still has some kinks to be ironed out, including privacy, security of the currency and other questions. But it’s certainly an interesting concept.
[via Slashdot]
Nanoparticle Coating Makes Paper Magnetic, Waterproof, and Antibacterial
By Rebecca Boyle Posted 04.18.2012 at 4:28 pm
Scientists at the Istituto Italiano di Tecnologia in Genoa, Italy, developed a process to cover any cellulose fiber, like paper or fabric, with a reactive coating. It involves combining the fiber molecules with a nanoparticle solution, creating a polymer matrix.
Electrogravitics – A Simplified Description
Monday, 02 April 2012 
‘Electrogravitics. This technology was being developed and tested in all major aerospace companies in the 1950s. Martin, Convair, Lear, Sperry, Raytheon, and many others all were eagerly studying electrogravitics. But in 1959 or early 1960, the technology became highly classified and the path to energy abundance was stymied. Here is a basic description of electrogravitics.’
Believe nothing 