Group items tagged

"...scientists in Germany have built a device that can effectively make objects invisible to sound waves. The performance of the acoustic "invisibility cloak" exceeds that of existing electromagnetic devices and could open up new ways of manipulating waves, including the development of shields against seismic waves."

shit.... they are a few months ahead of us it seems ... :-( what is the impact on our ariadna??

I guess it never really was clear what it should do (everything?!) or what it was (they also developed server communications and APIs for loads of things) ... also: "Wave was one stab at tackling our information overload, at providing a central hub for all the information we need to deal with every day. And it will be back, in one form or another." http://www.guardian.co.uk/technology/pda/2010/aug/05/google-wave

I liked the concept but it was too slow .... a pity

Again an article about the gravitational waves detected with pulsars. However its a bit fast conclusion, cause i don't know any serious article that draw this conclusion for sure...

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.

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.

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.

Interesting blog maintained by the people from D-Wave, who developed the first commercial quantum computer. The blog presents a python implementation to program the D-Wave and some examples.

"The experiments involve an oil droplet that bounces along the surface of a liquid. The droplet gently sloshes the liquid with every bounce. At the same time, ripples from past bounces affect its course. The droplet's interaction with its own ripples, which form what's known as a pilot wave, causes it to exhibit behaviors previously thought to be peculiar to elementary particles - including behaviors seen as evidence that these particles are spread through space like waves, without any specific location, until they are measured." Pilot-wave theory reresurrected. Maybe something for the next "fundamental" :P physics RF?

And for the next 'Experimental Physics Stagiaire' position why not try to do "Unpredictable Tunneling of a Classical Wave-Particle Association" http://stilton.tnw.utwente.nl/people/eddi/Papers/PhysRevLett_TUNNEL.pdf, there are some rumors online that the results of Yves Couder Experiments can be reproduced with simple DIY vibrating tables! It is very funny to see the videos of the MIT's replication of this experiment (with lightening legends for those who are uncomfortable with the concepts involved https://www.youtube.com/watch?v=YF5iHQMjcsM)

Technion researchers have demonstrated, for the first time, that laser emissions can be created through the interaction of light and water waves, in practice mechanical oscillations in fluids at the nanoscale. Interesting concept on the verge of two so far different fields!

This simulation showx that the signal measured in LIGO could come from a gravaster (objects which are believed to have their insides made of dark energy) or even a wormhole as sources of gravitacional waves. Published in PRL by friends of Jai

Here you go. You can now scrap Lisa altogether. Who's going to tell Pacome?

Awesome and exciting stuff indeed! The data pinpoint the time when inflation occurred - about 10E-37 seconds into the Universe's life - and its temperature at the time, corresponding to energies of about 10E16 gigaelectronvolts, says cosmologist Michael Turner of the University of Chicago. That is the same energy at which three of the four fundamental forces of nature - the weak, strong and electromagnetic force - are expected to become indistinguishable from one another in a model known as the grand unified theory. I expect more fundamental physics insights to come out of this in the future. A full-sky survey from space may still be an interesting addition to the measurement capabilities, so I would not rule out LISA all together I guess...

Imagine a material that only admits thermal conduction for certain temperatures. Martin Maldovan from Georgia Tech holds a tiny thermoelectric device that turns cold on one side when current is applied. Recent research has focused on the possibility of using interference effects in phonon waves to control heat transport in materials. These are exciting news (see Nature Materials paper here http://www.nature.com/nmat/journal/v14/n7/full/nmat4308.html). Heterostructure research lead to outstanding new possibilities when applied to electronic transport (e.g. in quantum well and quantum dots) and to photonics (e.g. Quantum Cascade Laser tunnable lasers). Apparently the time has come to see selective thermal control in this way! Truly exciting!!

Waves of electrons have been bent backward in a sheet of graphene, allowing physicists to focus electrons the way a lens focuses light. Electrons coursing through a sheet of carbon atoms exhibited negative refraction, bending at angles not seen in nature. By exploiting this unusual bending, the researchers created a lenslike device to focus the electrons to a tiny point. The new technique could help physicists learn how to manipulate electrons in the tight confines of miniaturized electronic devices, where the particles often behave like waves.

An overview is given on the field of the terahertz-frequency electromagnetic waves, their properties and emerging applications. Some widespread sources with their advantages and drawbacks are presented; an emphasis is placed on the parametric generation s

On detection of gravitational waves - with dedication to Pacome...

The object being imaged or stimulated with subwavelength accuracy does not need to be in the immediate proximity of the superlens or field concentrator: an optical mask can be designed that creates constructive interference of waves known as superoscillat

"The BICEP2 data would eliminate about 90% of inflationary models, Andrei Linde, a cosmologist at Stanford University in California, told a packed auditorium at MIT the day after the BICEP2 announcement (see picture below). Many of those models do not produce gravitational waves at detectable levels, said Linde, who is one of the founders of inflation theory." Is there any hope for LISA now?

Of course - the data is more proof that GWs exist!!

so you don't expect any impact on the science objectives of Lisa at all?

Very recent paper on brain wave-sensing technology, where researchers were able to communicate words from one brain to another brain over the internet. The encoded information appeared as flashes of light in the receiver's brain at the corner of their vision.

So basically we can photograph light now. Not just detect photons but photograph LIGHT WAVES. Really clever setup BTW.