Two independent groups of physicists have built invisibility cloaks that can shield large objects lying on a plane. These "carpet cloaks" are far closer to the intuitive idea of an invisibility cloak than devices previously built, they argue, because they hide objects that can be seen with the naked eye and do so at visible wavelengths. The cloaks are also relatively cheap and easy to make, being constructed from the natural material calcite.
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Acasa - Media - 1 views
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Acasa was born out of Singularity University, a unique, world-changing institution founded in 2008 by Ray Kurzweil and Peter Diamandis. After nine weeks at NASA Ames, the home of Singularity University, four teams emerged with projects focused on one common goal-to positively affect the lives of one billion people over ten years. Our team has designed a business plan to leverage advances in rapid 3D additive manufacturing technologies in order to construct affordable, customizable housing for the developing world. This environmentally sustainable solution has the potential to create a powerful new paradigm for improving housing construction using local resources.
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cool video, i'd like to see that in reality... Though i'm not sure it would be less expansive than the very cheap workers you can get on site ! You need to build the robot, to bring it on-site, highly specialised enginneers to supervize the project, etc... -
yeah I am not sure about that either but the idea seems nice though
Invisibility cloaks shield the large and visible - physicsworld.com - 1 views
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The team used a technique known as transformation optics to design their cloak.
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Tomas Tyc of Masaryk University in the Czech Republic, who was not a member of either group, thinks that the papers "describe important achievements in the area of experimental cloaking." But he maintains that a carpet cloak is quite different to a fully fledged Harry Potter-style invisibility cloak. He points out that a carpet cloak only really works when viewing an object – be it a rucksack or a sword on someone's back, for example – side on. Otherwise the object will appear flat but still be visible.
101 uses for guar gum - 0 views
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Guar gum, a polysaccharide, is a cheap and environmentally friendly material produced naturally by a leguminous shrub.
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The film has a high tensile strength and Kadokawa says it can conduct electricity as efficiently as semi-conductors. Uniquely, the film hardens upon heating but becomes soft again as it cools. These properties mean that it could be used to produce temperature sensors.
Access : Coherent emission of light by thermal sources : Nature - 0 views
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how "large" could these distances be? - ready for SPS?
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I don't think that the distance is the important criteria... It seems that the directivity is of the order of a laser one, so the divergence will be equivalent. Perhaps the important criteria is that the cost of these type of light sources could be cheaper...? and also perhaps what power transmission is achievable? It seems also that now that this concept could be used for to focus cheap lasers, instead of using complex optics in cd-rom players, etc... see http://news.softpedia.com/news/Highly-Directional-Semiconductor-Laser-Created-at-Harvard-90839.shtml
Technology Review: Stretchable Displays - 0 views
Cheap ways to cut temperatures - 0 views
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looks too simple to be true .... but? ...
NASA Builds a Cheap Standardized Space Probe - 0 views
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Meet the Spacecraft That Could Save NASA a Fortune. Somehow related with Leopold's cubesats. To my eyes, this kind of spacecraft can open the door to "cubepayload"
Blue Energy - 0 views
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Something for Oisin?
AlGaN LED´s: LED lighting as cheap as CFLs - 0 views
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GaN in the future of lighting
hydrogen storage using chicken feathers - 1 views
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apparently competitive with CNT and others in performance, while as you would expect very cheap. anyone know what happens to chicken feathers in a vacuum?
Water-Powered Spaceship Could Make Spaceflight Cheaper | Space Travel and Exploration |... - 1 views
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what to think about that? spoiling important ressources, smart idea?, and is it really cheap?
Cheap materials could make grid battery storage feasible @techreview @nature - 0 views
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The new battery, which is described in the journal Nature, is based on an organic molecule-called a quinone-that's found in plants such as rhubarb and can be cheaply synthesized from crude oil.
The Nanodevice Aiming to Replace the Field Effect Transistor - 2 views
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very nice! "For a start, the wires operate well as switches that by some measures compare well to field effect transistors. For example they allow a million times more current to flow when they are on compared with off when operating at a voltage of about 1.5 V. "[A light effect transistor] can replicate the basic switching function of the modern field effect transistor with competitive (and potentially improved) characteristics," say Marmon and co. But they wires also have entirely new capabilities. The device works as an optical amplifier and can also perform basic logic operations by using two or more laser beams rather than one. That's something a single field effect transistor cannot do."
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any idea how the shine the light selectively to such small surfaces?
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"Illumination sources consisted of halogen light, 532.016, 441.6, and 325 nm lasers ported through a Horiba LabRAM HR800 confocal Raman system with an internal 632.8 nm laser. Due to limited probe spacing for electrical measurements, all illumination sources were focused through a 50x long working distance (LWD) objective lens (N.A. = 0.50), except 325 nm, which went through a 10x MPLAN objective lens (N.A. = 0.25)." Laser spot size calculated from optical diffraction formula 1.22*lambda/NA
Small, cheap gravity gadget to peer underground - BBC News - 2 views
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According to their Nature article, they can detect "a tunnel less than 1m across, buried 2m underground" just from its gravitational difference. Using a device that they predict could cost ~100 € in mass production. UK researchers have built a small device that measures tiny fluctuations in gravity, and could be used to monitor volcanoes or search for oil. Such gravimeters already exist but compared to this postage stamp-sized gadget, they are bulky and pricy.
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