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Apparently the peer review process is no better than chance.

"In an effort to help solve the black hole information paradox that has immersed theoretical physics in an ocean of soul searching for the past two years, two researchers have thrown their hats into the ring with a novel solution: Lasers. Technically, we're not talking about the little flashy devices you use to keep your cat entertained, we're talking about the underlying physics that produces laser light and applying it to information that falls into a black hole. According to the researchers, who published a paper earlier this month to the journal Classical and Quantum Gravity (abstract), the secret to sidestepping the black hole information paradox (and, by extension, the 'firewall' hypothesis that was recently argued against by Stephen Hawking) lies in stimulated emission of radiation (the underlying physics that generates laser light) at the event horizon that is distinct from Hawking radiation, but preserves information as matter falls into a black hole."

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 .

Recently, it was shown that slowly rotating neutron stars exhibit an interesting correlation between their moment of inertia I, their quadrupole moment Q, and their tidal deformation Love number λ (the I-Love-Q relations), independently of the equation of state of the compact object. By exploiting this relation, we can describe quite accurately the geometry around a neutron star with fewer parameters, even if we don't know precisely the equation of state. Side note: I-Love-Q relations? Some inner chuckles in the Fundamental Physicist community.. :)

The problem is that the light cone angle has a limit - all particles with high momentum (mass x velocity) generate light cones with the same angle. Hence, these particles are indistinguishable. Now Chalmers researcher Philippe Tassin and his colleagues at the Free University of Brussels have designed a material that manipulates the Cherenkov cone so that also particles with high momentum get a distinct light cone angle too. The work is on the cover of this week's issue of the journal Physical Review Letters ("Controlling Cherenkov Radiation with Transformation-Optical Metamaterials").

where real power sits ...

A new, sponge-like material developed engineers at MIT can convert water to steam using just 1% of the sunlight required by conventional steam-producing solar generators.

A handy feature that allows linking of over 300 online apps. For example, generating Trello cards from calendar events automatically (and vice versa).

The first complete theory of how plasmons produce "hot carriers" has been developed by researchers in the US. The new model could help make this process of producing carriers more efficient, which would be good news for enhancing solar-energy conversion in photovoltaic devices.

I did not read the paper but what is further down written in the article, does not give much hope that this actually gives much more insight than what we had nor that it could be used in any way to improve current PV cells soon: e.g. "To fully exploit these carriers for such applications, researchers need to understand the physical processes behind plasmon-induced hot-carrier generation. Nordlander's team has now developed a simple model that describes how plasmons produce hot carriers in spherical silver nanoparticles and nanoshells. The model describes the conduction electrons in the metal as free particles and then analyses how plasmons excite hot carriers using Fermi's golden rule - a way to calculate how a quantum system transitions from one state into another following a perturbation. The model allows the researchers to calculate how many hot carriers are produced as a function of the light frequency used to excite the metal, as well as the rate at which they are produced. The spectral profile obtained is, to all intents and purposes, the "plasmonic spectrum" of the material. Particle size and hot-carrier lifetimes "Our analyses reveal that particle size and hot-carrier lifetimes are central for determining both the production rate and the energies of the hot carriers," says Nordlander. "Larger particles and shorter lifetimes produce more carriers with lower energies and smaller particles produce fewer carriers, but with higher energies."

TensorFlow is an open source software library for numerical computation using data flow graphs. Nodes in the graph represent mathematical operations, while the graph edges represent the multidimensional data arrays (tensors) communicated between them. The flexible architecture allows you to deploy computation to one or more CPUs or GPUs in a desktop, server, or mobile device with a single API. TensorFlow was originally developed by researchers and engineers working on the Google Brain Team within Google's Machine Intelligence research organization for the purposes of conducting machine learning and deep neural networks research, but the system is general enough to be applicable in a wide variety of other domains as well.

And the interface even looks a bit less retarded than theano

Nature paper showing a new photo-bioelectrochemical cell with a new photon-driven biocatalytic fuel cell method achieving electrical power generation from solar energy.

do you have the pdf?

This is the biggest breakthrough in game AI (and one of the biggest in AI in general) since Deep Blue beat Kasparov in chess: For the first time, a human professional player was defeated in the game of Go. The approach was a combination of tree search and deep neural networks. Very proud of a former colleague on the team at Google Deepmind!

Funny enough, facebook also had a very similar paper around the same time.

Super cool html5 site (crowdfunded) to describe a space mission.

The functional principle is similar to ordinary pumped storage plants: when power is needed, water flows into the sphere and drives the turbine thus generating power. If surplus power is available (usually during the night), water can be pumped out of the sphere again, thus effectively charging the storage system.

From the section Science & Environment Scientists are claiming a stunning discovery in their quest to fully understand gravity. They have observed the warping of space-time generated by the collision of two black holes more than a billion light-years from Earth.

A new experiment proved the existence of a new effect in nanomaterials: flexo-electric effect. The material has built-in mechanical tension that changes shape when you apply electrical voltage, or that generates electricity if you change its shape and was theorized some decades ago. Now, SrTiO3 allowed to observe this new effect, being comparable with piezoelectric effect.

My old twente university group! :)

Isn't muscle wire quite old technology though?

Quoted from one of the authors in a separate interview: "We know that the spin states of atomic nuclei associated with semiconductor defects have excellent quantum properties at room temperature," said Awschalom, Liew Family Professor in Molecular Engineering and a senior scientist at Argonne National Laboratory. "They are coherent, long-lived and controllable with photonics and electronics. Given these quantum 'pieces,' creating entangled quantum states seemed like an attainable goal." Bringing the quantum world to the macroscopic scale could see some interesting applications in sensors, or generally entanglement-enhanced applications.

They were previously working on the same concept in N-V centers in diamond (as a semiconductor). Here the advantage is that SiC could in principle be integrated with Si or Ge. Anyway its all about controlling coherence. In the next 10 years some breakthroughs are expected in the field of semiconductor spintronics, but quantum computing in this way lies still in the horizon

A rectenna at infrared wavelength. They authors mention a potential application in RTGs

Our work sheds light on many interesting directions of future exploration in the development of quantum-inspired algorithms for unsupervised machine learning, which are promisingly possible to realize on quantum devices.

How many people to we actually need put on that ship?

We should invite these people to the AF special issue

sounds really interesting. their simulations don't account for biological issues (mutation, migration, selection, drift, founder effect) though, so the numbers are very low. this paper (https://ac.els-cdn.com/S0094576513004669/1-s2.0-S0094576513004669-main.pdf?_tid=6bec2a5c-f05f-4024-b4de-af78ab06fd42&acdnat=1531827379_d4f0be1b193873890d6e5b4574e82f2e) takes those effects and their implications on genetic composition of populations into account, but the numbers are enormous. do you have an idea why they (marin and beluffi) wouldn't put those effects into the simulations?