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It has been known for a century that electromagnetic fields can transport not only energy and linear momentum but also angular momentum. However, it was not until twenty years ago, with the discovery in laser optics of experimental techniques for the generation, detection and manipulation of photons in well-defined, pure orbital angular momentum (OAM) states, that twisted light and its pertinent optical vorticity and phase singularities began to come into widespread use in science and technology. We have now shown experimentally how OAM and vorticity can be readily imparted onto radio beams. Our results extend those of earlier experiments on angular momentum and vorticity in radio in that we used a single antenna and reflector to directly generate twisted radio beams and verified that their topological properties agree with theoretical predictions. This opens the possibility to work with photon OAM at frequencies low enough to allow the use of antennas and digital signal processing, thus enabling software controlled experimentation also with first-order quantities, and not only second (and higher) order quantities as in optics-type experiments. Since the OAM state space is infinite, our findings provide new tools for achieving high efficiency in radio communications and radar technology.

and how can we use this?

Extending quantum communication to space environments would enable us to perform fundamental experiments on quantum physics as well as applications of quantum information at planetary and interplanetary scales. Here, we report on the first experimental study of the conditions for the implementation of the single-photon exchange between a satellite and an Earth-based station. We built an experiment that mimics a single photon source on a satellite, exploiting the telescope at the Matera Laser Ranging Observatory of the Italian Space Agency to detect the transmitted photons. Weak laser pulses, emitted by the ground-based station, are directed toward a satellite equipped with cube-corner retroreflectors. These reflect a small portion of the pulse, with an average of less-than-one photon per pulse directed to our receiver, as required for faint-pulse quantum communication. We were able to detect returns from satellite Ajisai, a low-Earth orbit geodetic satellite, whose orbit has a perigee height of 1485 km.

hello Jose! Interesting it was proposed to do the same with the ISS as part of the ACES experiment. I don't remember the paper but i can look if you're interested

Amazing: you can now publish lecture videos of experiments and special techniques.

Theoretized 80 years ago was Breit-Wheeler pair production in which two photons result in an electron-positron pair (via a virtual electron). It is a relatively simple Feynmann diagram, but the problem is/was how to produce in practice a high energy photon-photon collider... The collider experiment that the scientists have proposed involves two key steps. First, the scientists would use an extremely powerful high-intensity laser to speed up electrons to just below the speed of light. They would then fire these electrons into a slab of gold to create a beam of photons a billion times more energetic than visible light. The next stage of the experiment involves a tiny gold can called a hohlraum (German for 'empty room'). Scientists would fire a high-energy laser at the inner surface of this gold can, to create a thermal radiation field, generating light similar to the light emitted by stars. They would then direct the photon beam from the first stage of the experiment through the centre of the can, causing the photons from the two sources to collide and form electrons and positrons. It would then be possible to detect the formation of the electrons and positrons when they exited the can. Now this is a good experiment... :)

True, but isnt it E2=(pc)^2 + (m0c^2)^2 such that for photons E\propto{pc} and for mass E\propto{mc^2}. I agree it will take a lot of energy, but this assumes that that wont be the problem at least. The question therefore is whether the mass flow of the photon rocket (fuel consumed to create photons, eg fission/fusion) is higher/lower than the mass flow for e-p creation. You are probably right that the low e-p cross-section will favour direct use of photons to create low thrust for long periods of time, but with significant power available the ISP might be higher for e-p pair creation.

In essence the equation tells you that for photons with zero rest mass m0 all the energy will be converted to momentum of the particles. If you want to accelerate e-p then you first spend part of the energy on creating them (~511 keV each) and you can only use the remaining energy to accelerate them. In this case the equation gives you a lower particle momentum which leads to lower thrust (even when assuming 100% acceleration efficiency). ISP is a tricky concept in this case because there are different definitions which clash in the relativistic context (due to the concept of mass flow). R. Tinder gets to a I_SP = c (speed of light) for a photon rocket (using the relativistic mass of the photons) which is the maximum possible relativistic I_SP: http://goo.gl/Zz5gyC .

The only extraterrestrial life detection experiments ever conducted were the three which were components of the 1976 Viking Mission to Mars. Of these, only the Labeled Release experiment obtained a clearly positive response. [...] These analyses support the interpretation that the Viking LR experiment did detect extant microbial life on Mars.

...unless life arrived together with the nutrients...

Viking was one of the best sterilised sc we have ever launched! Just strange to read such an article published in an obscure Korean journal ...

part of the bbc's citizen sciene thingy 'so you want to be a scientist. it's like a game show for science experiments if you're not familiar. the bookmark will take you to the online participation part of one of the experiments selected. here's the main page. http://www.bbc.co.uk/radio4/features/sywtbas/ "This experiment is being run by citizen scientist Izzy Thomlinson for BBC Radio 4's So You Want To Be A Scientist?. It aims to find out what you think about unpleasant sounds. Please read the following statement and click Take Part Now! if you agree to participate."

another Zeilinger experiment ...

And what if the freedom-of-choice is corrupted due to yet another hidden variable in past lightcone of the whole experiment that triggers Alice and Bob's choice as well as the pair creation? Then we can design yet another experiment that will have yet another loophole. I guess this is experimentally interesting work, but the introduction rather reads like an article from the "Institut für Grenzgebiete der Psychologie und Psychohygiene"...

essentially they made an experiment that does not prove or disprove anything -big deal-... what is the scientific value of "strongly disfavour"??? I also like the sentence "most models do not have exact predictions for the energy scale associated with this violation of Lorentz invariance" ... but if this is true WHAT IS THE POINT OF THE EXPERIMENT!!!! God, physics is in trouble ....

hum, null result experiments are not useless !!! there is always the hope of finding "something wrong", which would lead to a great discovery. For the state of theoretical physics (the "no exact predictions" quote), i totally agree that physics is in trouble... That's what happen when physicists don't care anymore about experiments...! All you can do now is drawing "nice"graph with upper bounds on some parameters of an all tunable weird theory !

Although it may seem like the above two experiments violate the uncertainty principle because the results show a smaller-than-required degree of uncertainty, Shih and his coauthors explain that no violation has occurred due to the fact that the experiments involve photon pairs rather than individual photons. The scientists argue that Popper's original thought experiment was based on a misunderstanding of the proper context of the uncertainty principle: it governs the behavior of single particles only, not the "correlation" of two particles.

I think there are a few difficulties when assuming that the macroscopic block of glass will accelerate instantaneously. Also, if I prevent the block from moving would it become perfectly reflective as no momentum can be transferred to it? One could say that the momentum is then transferred to the larger system that holds the glass. But surely I could make that system (or even the block of glass) so heavy that it would not move more than Planck's length during the passage of the photon - especially if the glass is very thin or the light is very red.

Very nice experiment on the verge of Condensed matter Physics! The presence of Landau levels is a necessary condition to obtain a Quantum Hall state. Quantum Hall states have first appeared in 2D electronic gases when applied a perpendicular magnetic field that induces a new topological state of the "electronic gas". This new topological state is believed to "protect" some parameters of the system, such as conductance making it possible to measure fundamental constants with very high precision even in imperfect experimental conditions. In this fundamental experiment, a synthetic magnetic field was created that acts in continuum photons, producing "an integer quantum Hall system in curved space, a long-standing challenge in condensed matter physics".

The ASACUSA experiment at CERN has succeeded for the first time in producing a beam of antihydrogen atoms. The ASACUSA collaboration reports the unambiguous detection of 80 antihydrogen atoms 2.7 metres downstream of their production, where the perturbing influence of the magnetic fields used initially to produce the antiatoms is small. http://www.nature.com/ncomms/2014/140121/ncomms4089/full/ncomms4089.html

They were able to compare the ticking rates of two optical clocks separated by 2000 km, with the objective of computing sea level based on the effect gravity has on the clock ticking rate. They did the experiment using glass optical fibers, but I wonder if we could one day do the same from orbit, to measure the gravitational field around Earth.

isn't this is effectively what pacome has been doing with his time for the last few years? e.g. http://arxiv.org/pdf/1308.6766v1.pdf also mentioning the ACES experiment

I doubt that Shnoll is really the first one making such experiments, but perhaps they are more complete than any others done before. Similar things are very popular in the context of Psychology and more exotic fields. If I remember correctly someone ran long experiments with random number generators... Mostly the stories died after a short time, since the experiments are not reproducable. Anyway, why do these guys always have to claim that their work is somehow fundamentally changing our view of physics, notoriously referring to Einstein-Bohr debates and this stuff. That's nonsense! If these effects exist the first explanation is always much simpler. There is somewhere something that influences physics on Earth in a defined way. But this influence depends on the relative position or whatever of the Earth to that whatever-it-is. No problem with absolute time and all that sh...

Two years ago, nearly unnoticed in the West, the Russian biophysicist S.E. Shnoll published a paper in the prominent Russian physics journal Uspekhi Fisicheskikh Nauk ..... ah then ...

You are right, Leo, they are mostly Russians that publish in some unspellable Journals nobody knows.... or then they are supported by Templeton Foundation.

"competitively select a domestic nonprofit organization to manage experiments aboard the international space station (ISS)" nice

Unexplained annual variations in nuclear decay rates have been reported in recent years by a number of groups. We show that data from these experiments exhibit not only variations in time related to Earth-Sun distance, but also periodicities attributable to solar rotation. Additionally, anomalous decay rates coincident in time with a series of solar flares in December 2006 also point to a solar influence on nuclear decay rates....

can we use space to make a smart experiment to solve this riddle? e.g. sending a decay detecter on a close solar orbit and one to Pluto and then compare decay rates? or a highly elliptical trajectory and compare during peri and apoapsis?

I think it could be possible. I need to look into the details. In fact it could probably be done already with the nuclear generators on the Voyager and Pioneer and other nuclear powered probes. That is if the data are precise enough...

Rock Festival as Human Experiment: Hip Hopping for Science

"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)

an experiment at the University of Pennsylvania. It might be a bit far-fetched but I thought it might be useful when exploring new planets. Combined with AI the robot would able to assess the terrain and deploy another robot the shape of which would be chosen to best suit its environment. I was thinking of this in the context of exploring places on other planets which are inaccessible by regular rovers (e.g. caves on Mars).

The partnership brings together leading IT providers and three of Europe's leading research centres, CERN, EMBL and ESA in order to provide computing capacity and services that elastically meet big science's growing demand for computing power.

Helix Nebula provides an unprecedented opportunity for the global cloud services industry to work closely on the Large Hadron Collider through the large-scale, international ATLAS experiment, as well as with the molecular biology and earth observation. The three flagship use cases will be used to validate the approach and to enable a cost-benefit analysis. Helix Nebula will lead these communities through a two year pilot-phase, during which procurement processes and governance issues for the public/private partnership will be addressed.

This game-changing strategy will boost scientific innovation and bring new discoveries through novel services and products. At the same time, Helix Nebula will ensure valuable scientific data is protected by a secure data layer that is interoperable across all member states. In addition, the pan-European partnership fits in with the Digital Agenda of the European Commission and its strategy for cloud computing on the continent. It will ensure that services comply with Europe's stringent privacy and security regulations and satisfy the many requirements of policy makers, standards bodies, scientific and research communities, industrial suppliers and SMEs.

Initially based on the needs of European big-science, Helix Nebula ultimately paves the way for a Cloud Computing platform that offers a unique resource to governments, businesses and citizens.

"Helix Nebula will lead these communities through a two year pilot-phase, during which procurement processes and governance issues for the public/private partnership will be addressed." And here I was thinking cloud computing was old news 3 years ago :)