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Kevin de Groote

WordItOut - Transform your text into word clouds! - 4 views

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    Transform your text into word clouds! Word clouds are a fun way to show words, where the most important ones are bigger than the others. Make and share word clouds from any text with WordItOut!
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    WOW!!!!
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    Impressive. Really nice work!!!
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Luzi Bergamin

[1107.0167] Nonlinear transformation optics and engineering of the Kerr effect - 9 views

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    The best paper on transformation optics written ever :-)
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    Finally something worth to read in the MM field!. The idea is excellent, congratullations. However, I think there is a typo or mistake in the definition of l=3x10-13 m, the "waist" of the laser beam. Seems clear that 0.3 pm is too small for being a waist of any laser beam.
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    Thanks for your commendation. Of course, the problem with nonlinear transformation optics is the same as with linear: it's very easy to come up with theoretical descriptions of devices that have the most absurd properties, but it will be extremely hard to fabricate them. But if you have any good suggestion, please shoot! About the laser beam: Pekka made the simulations, since I am not a "Comsolist", but still I think the numbers are correct. You are right that we should not call this a laser beam. Our problem was the following: we need to have a very simple model that can be simulated exactly (full Maxwell equations) but naturally exhibits self focusing. The Gaussian beam was the simplest solution. Since our model is purely classical and moreover we do not take into account diffraction effects, the parameter "l" is of minor importance. Taking "l" much larger gives almost the same picture but requires much more computer power to simulate. I guess that's why Pekka chose an unnaturally small number.
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    Concerning the fabrication... as usual, no idea. I agree that this is the main drawback of MM, and certainly difficult to overcome. I would double check that number, because its value is related with the beam shape of Fig. 1 A. I believe that the simulations are correct, it's just a detail.
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    wow ... still publishing despite babysitting and new job!!
Alexander Wittig

Wearable Robot Transforms Musicians into Three-Armed Drummers - 2 views

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    Now this would be really cool if it had a brain computer interface and could be controlled by a trained drummer's mind! Science and Technology Society and Culture Georgia Institute of Technology researchers have built a wearable robotic limb that allows drummers to play with three arms. The two-foot long "smart arm" can be attached to a musician's shoulder. It responds to human gestures and the music it hears.
Guido de Croon

sFFT: Sparse Fast Fourier Transform - 1 views

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    Much faster than the Fast Fourier Transform if the signal's frequency content is sparse, which is commonly the case for many real signals.
santecarloni

Occupy Federal Science: "Transformative" Research Can't Come From Milquetoast | The Cru... - 4 views

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    I like this one "The kind of idle pastime that might amuse physicists is to imagine drafting Einstein's grant applications in 1905. "I propose to investigate the idea that light travels in little bits," one might say. "I will explore the possibility that time slows down as things speed up," goes another. Imagine what comments these would have elicited from reviewers for the German Science Funding Agency, had such a thing existed. Instead, Einstein just did the work anyway while drawing his wages as a technical expert third-class at the Bern patent office. And that is how he invented quantum physics and relativity." There is an even more pointer example of the Prussian academy of sciences reviewing the Dr. application of Hertz ...
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    Shocking. What is federal research funding for? No, wrong question. Instead maybe: What is federally funded review for?
johannessimon81

Transformer drone! (Haha) - 6 views

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    At least we don't come up with this kind of crap!
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    OMG ... its coming ... the future we all have dreaded where in perfectly flat caribbean beaches underwater mines are growing like flowers
johannessimon81

Astronomers Uncover a 'Transformer' Pulsar: switching between X-ray and Radio - 0 views

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    In a feat never before observed, a newly discovered pulsar shifts back and forth between emitting X-rays and radio waves. The discovery represents a long-sought "middle" phase in the life of these powerful objects.
santecarloni

Space-time cloak could hide events : Nature News - 3 views

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    I think they are taking it a bit too far....
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    I'm a little bit surprised as well about the crude story of the burglar, pure nonsense, of course! But the paper is deadly serious, Alberto and Paul are my best collaborators in metamaterials and optics, they are not this type of TV-show scientists as Leonhardt etc. But as Alberto told me: just put the name "cloak" in the title and you're in all the news. It's not science, it's kindergarden :-(.
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    is my memory wrong or isn't this what you have already mentioned as theoretically possible a few years back when discussing this, Luzi?
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    Very well possible that I mentioned this. In fact I was one of the first who took spacetime transformations in transformation optics seriously. But first, my name is not Leonhardt and I don't work at Imperial, that's why nobody cites me and second I most probably found the idea too stupid to be published. You see the two reasons why I'm not successful in science...
Luzi Bergamin

Power scattering and absorption mediated by cloak/anti-cloak interactions: A transforma... - 1 views

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    To keep you updated in the field of metamaterials. "Invisible sensors" are a hot topic at the moment. Of course, mainly due to military applications. Might be interesting to sense something while minimizing the perturbations due to the sensor.
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    And all seems to be allowed by transformation optics ..... mah
pacome delva

3D invisibility cloak unveiled - physicsworld.com - 1 views

  • For Wegener the aim of the work is not about focusing all efforts on creating invisibility cloaks, but is about exploring a range of applications in transformation optics. This involves calculating what kind of material is needed to bend light in a certain way, by considering light trajectories as the result of the warping of space. Wegener says that transformation optics should lead, for example, to the design of better antennas or smaller optical resonators.
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    We don't have Science Express subscription here, so I have to wait till the normal paper is out. From what I heard about it, I doubt that this would have made it to Science without the names Pendry and Wegener in the autor list! Certainly, they are two of the smartest guys in Metamaterials, but they are also two of the absolut class A sellers. Pendry by definition is the first in whatever (at least in HIS talks...) but apart from this he's a very nice guy. Better let's not try to characterize Wegener...
LeopoldS

Three-Dimensional Invisibility Cloak at Optical Wavelengths - 4 views

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    more transformation optics ... 
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    I still believe that it is worth to check the thermal, mechanical and chemical properties of the developed metamaterials. For hyperbolic re-entries the radiation is still the dominating heat load source and a dominating bandwith may be indentified. A resistive metamaterial should be placed on the nose cap of the entry body in order to reduce local radiation heat load.
LeopoldS

[0812.2633] Ghost imaging with a single detector - 2 views

shared by LeopoldS on 20 Sep 11 - No Cached
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    anything happening on this since 3 years?
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    yes it seems like. most of it seems however directed toward understanding this effect, and not toward applications. But i'm still convinced that we could find many very interesting applications !!! a few references from ADS: 1 2011PhRvA..83f3807B 1.000 06/2011 A E X R C U Brida, G.; Chekhova, M. V.; Fornaro, G. A.; Genovese, M.; Lopaeva, E. D.; Berchera, I. Ruo Systematic analysis of signal-to-noise ratio in bipartite ghost imaging with classical and quantum light 2 2011PhRvA..83e3808L 1.000 05/2011 A E R U Liu, Ying-Chuan; Kuang, Le-Man Theoretical scheme of thermal-light many-ghost imaging by Nth-order intensity correlation 3 2011PhRvA..83e1803D 1.000 05/2011 A E R C U Dixon, P. Ben; Howland, Gregory A.; Chan, Kam Wai Clifford; O'Sullivan-Hale, Colin; Rodenburg, Brandon; Hardy, Nicholas D.; Shapiro, Jeffrey H.; Simon, D. S.; Sergienko, A. V.; Boyd, R. W.; Howell, John C. Quantum ghost imaging through turbulence 4 2011SPIE.7961E.160O 1.000 03/2011 A E T Ohuchi, H.; Kondo, Y. Complete erasing of ghost images caused by deeply trapped electrons on computed radiography plates 5 2011ApPhL..98k1115M 1.000 03/2011 A E R U Meyers, Ronald E.; Deacon, Keith S.; Shih, Yanhua Turbulence-free ghost imaging 6 2011ApPhL..98k1102G 1.000 03/2011 A E R C U Gan, Shu; Zhang, Su-Heng; Zhao, Ting; Xiong, Jun; Zhang, Xiangdong; Wang, Kaige Cloaking of a phase object in ghost imaging 7 2011RScI...82b3110Y 1.000 02/2011 A E R U Yang, Hao; Zhao, Baosheng; Qiu
anonymous

NIAC 2014 Phase I Selections | NASA - 3 views

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    Some interesting future projects from NASA's IAC. (June 2014) NASA Innovative Advanced Concepts awards: "These proposals have been selected based on the potential of their concepts to transform future aerospace missions, enable new capabilities, or significantly alter and improve current approaches."
johannessimon81

LuminAR Bulb transforms any surface into a touch screen - 1 views

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    Really nice video! Something for the ACT? :-D
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    Why is it moving so slowly ?
johannessimon81

"Natural Light Cloaking for Aquatic and Terrestrial Creatures" - 3 views

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    Cheap and scalable invisibility cloaks being developed. The setup is so trivial that I would almost call it a "trick" (as in "Magicians trick"): 6 prisms of n=1.78 glass. Nontheless, it does the job of cloaking an object at visible wavelengths and from several directions.
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    can we build one?
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    Yes, I just did :-) It is on my desk
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    New video here (smaller file than previous): "https://dl.dropboxusercontent.com/u/58527156/20130613_101701.mp4" Note how close to the center of the field of view the hidden objects are. I am quite surprised that such poor lenses create such a sharp focus.
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    Well.. I would say that it is not "fully cloaking", as the image behind is mirrored as well
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    That just means that you have to double the setup, i.e., put 4 glasses in a row. Of course the obvious drawback is that you can only look at this cloak from one direction.
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    Is this really new? I don't know, but I know that the original idea of cloaking was pretty different. When cloaking as an application of transformation optics became popular people tried to make devices that work for any incidence angle, any polarization and in full wave optics (not just ray approximation). This is really hard to achieve and I guess that the people that tried to make such devices knew exactly that the task becomes almost trivial by dropping at least two of the three conditions above.
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    I think it is very easy to call something trivial when you're not the one who invested considerable time (5 min in my case) to design a cloaking device and fill the coffee mugs with water... Also, I did not really violate that many conditions: true I reduced the number of dimensions in which the device works to 1 (as opposed to the 2 dimensions of many metamaterial cloaks). However the polarization should not be affected in my setup as well as the wave phase and wave vector (so it works in full wave optics) - apart maybe from the imperfect lens distortion, but hey I was improvising.
fichbio

Byteflies - 1 views

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    Belgian startup company. Medical wearables will transform healthcare and patient care - they promise.
fichbio

A 3D bioprinting - 5 views

http://www.nature.com/nbt/journal/vaop/ncurrent/full/nbt.3413.html#access Amazing things happen, development of 3D bioprinting technology opens a new era in restoring people after serious injuries...

Biotechnology bioengineering transhumanism

started by fichbio on 17 Feb 16 no follow-up yet
santecarloni

the Tricorder project - Science Tricorder Mark 2 - 1 views

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    ... each act member should have one, together with the mug... :) Se also http://www.youtube.com/watch?feature=player_embedded&v=y3sHTKrGdKI
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    I want one too! On a side note, his story about transformers is a nice illustration that being able to express something in a mathematical equation is not equivalent to understanding something.
LeopoldS

Transformation of concentrated sunlight into laser radiation on small parabolic concent... - 0 views

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    Duncan aND Lionel please check this one
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