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Thijs Versloot

Is Westeros orbiting a binary star system? #ArXiv - 5 views

shared by Thijs Versloot on 21 May 14 - No Cached
Nicholas Lan liked it
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    To right that appalling wrong, here we attempt to explain the apparently erratic seasonal changes in the world of G.R.R.M. A natural explanation for such phenomena is the unique behavior of a circumbinary planet. Thus, by speculating that the planet under scrutiny is orbiting a pair of stars, we utilize the power of numerical three-body dynamics to predict that, unfortunately, it is not possible to predict either the length, or the severity of any coming winter.
jcunha

Why Quantum "Clippers" Will Distribute Entanglement Across The Oceans - 0 views

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    Quantum internet will enable perfectly secure communications, but the technology and means to build the required quantum memories and routers are still many years distant. The proposal here is to store qubits and send them in containers over the oceans. Researchers claim that it is possible to send information at bandwidths measured in teraahertz outperforming the predictions of a quantum router internet. It can be thought in space systems as well. Then the problem is still for how long are we able to store a qubit, without dephasing... PS: As a curiosity, you can find a very interesting book about containers and how in some way they changed our world: Mark Levinson's book 'The Box' http://press.princeton.edu/titles/9383.html Maybe they will do it again
LeopoldS

Microsoft's Strange Quest for the Topological Qubit | MIT Technology Review - 2 views

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    loads of nice passwords - should we have a closer look at it? anybody volunteering? e.g. Anna and Daniel?
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    Just to add to this possible discussion, two important breakthroughs in Quantum Computing using Silicon were published last week (October 12th). Check it here: http://phys.org/news/2014-10-physicists-silicon-quantum.html
H H

Lockheed Claims Breakthrough on Fusion Energy - 3 views

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    Lockheed Martin Corp said on Wednesday it had made a technological breakthrough in developing a power source based on nuclear fusion, and the first reactors, small enough to fit on the back of a truck, could be ready in a decade.
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    Is positive news definitely, but when it comes to fusion energy being skeptic is the wisest course of action. On the back of a truck basically means that the energy density of the device is such that the surface energy of a (steady state) plasma is beyond currents materials limits. It is probably a pulsed (ignitor-type) device, which are prone to instabilities. That could therefore refer to their breakthrough claim, of which they hardly say anything though. Lets see
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    Since there were already a lot of false alarms on the field, one should definitively be careful about it. However not a single detail about its structure or how it works in this new... Here http://www.fusenet.eu/node/400 you can find a bit more of information about it.
annaheffernan

Physicsworld top 10 breakthroughs of the year - at the top Rosetta - 3 views

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    Physicsworld releases their top 10 breakthroughs of the year 2014, ESA's Rosetta mission tops the list with the achievement of landing on a comet.
johannessimon81

Integral catches dead star exploding in a blaze of glory - 1 views

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    Astronomers using ESA's Integral gamma-ray observatory have demonstrated beyond doubt that dead stars known as white dwarfs can reignite and explode as supernovae. The finding came after the unique signature of gamma rays from the radioactive elements created in one of these ex...
LeopoldS

Athena: Europe plans huge X-ray space telescope - 2 views

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    good news for x-ray astronomers
anonymous

Nasa validates 'impossible' space drive (Wired UK) - 3 views

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    NASA validates the EmDrive (http://emdrive.com/) technology for converting electrical energy into thrust. (from the website: "Thrust is produced by the amplification of the radiation pressure of an electromagnetic wave propagated through a resonant waveguide assembly.")
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    I would be very very skeptic on this results and am actually ready to take bets that they are victims of something else than "new physics" ... some measurement error e.g.
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    Assuming that this system is feasible, and taking the results of Chinese team (Thrust of 720 mN http://www.wired.co.uk/news/archive/2013-02/06/emdrive-and-cold-fusion), I wonder whether this would allow for some actual trajectory maneuvers (and to which degree). If so, can we simulate some possible trajectories, e.g. compare the current solutions to this one ? For example, Shawyer (original author) claims that this system would be capable of stabilizing ISS without need for refueling. Other article on the same topic: http://www.theverge.com/2014/8/1/5959637/nasa-cannae-drive-tests-have-promising-results
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    To be exact, the chinese reported 720mN and the americans found ~50microN. The first one I simply do not believe and the second one seems more credible, yet it has to be said that measuring such low thrust levels on a thrust-stand is very difficult and prone to measurement errors. @Krzys, the thrust level of 720mN is within the same range of other electric propulsion systems which are considered - and even used in some cases - for station keeping, also for the ISS actually (for which there are also ideas to use a high power system delivering several Newtons of thrust). Then on the idea, I do not rule out that an interaction between the EM waves and 'vacuum' could be possible, however if this would be true then this surely would be detectable in any particle accelerator as it would produce background events/noise. The energy densities involved and the conversion to thrust via some form of interaction with the vacuum surely could not provide thrusts in the range reported by the chinese, nor the americans. The laws of momentum conservation would still need to apply. Finally, 'quantum vacuum virtual plasma'.. really?
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    I have to join the skeptics on this one ...
Thijs Versloot

Improved Saturn Positions Help Spacecraft Navigation, Planet Studies, Fundamental Physics - 0 views

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    Scientists have used the National Science Foundation's Very Long Baseline Array (VLBA) radio-telescope system and NASA's Cassini spacecraft to measure the position of Saturn and its family of moons to within about a mile -- at a range of nearly a billion miles.
annaheffernan

How to make tiny 3D flowers and peacocks from silicon - 1 views

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    "Tilted table", "peacock" and "triple-floor building" are just three of many fantastical 3D structures that have been created by compressing simple 2D patterns. The new technique for creating these objects is called compressive buckling, and has been developed by researchers in the US, China and South Korea.
annaheffernan

New apps allow smartphone users to join the hunt for ultrahigh-energy cosmic rays - 0 views

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    Two apps - the Distributed Electronic Cosmic-ray Observatory (DECO) and Cosmic Rays Found in Smartphones (CRAYFIS) - transform smartphones into miniature cosmic-ray detectors. They use the CMOS chips inside phones' onboard cameras to detect the secondary particles produced when cosmic rays - energetic, charged subatomic particles arriving from beyond the solar system - collide with air molecules in the Earth's atmosphere
Christophe Praz

Scientific method: Defend the integrity of physics - 2 views

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    Interesting article about theoretical physics theories vs. experimental verification. Can we state that a theory can be so good that its existence supplants the need for data and testing ? If a theory is proved to be untestable experimentally, can we still say that it is a scientific theory ? (not in my opinion)
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    There is an interesting approach by Feynman that it does not make sense to describe something of which we cannot measure the consequences. So a theory that is so removed from experiment that it cannot be backed by it is pointless and of no consequence. It is a bit as with the statement "if a tree falls in the forrest and nobody is there to hear it, does it make a sound?". We would typically extrapolate to say that it does make a sound. But actually nobody knows - you would have to take some kind of measurement. But even more fundamentally it does not make any difference! For all intents and purposes there is no point in forcing a prediction that you cannot measure and that therefore has noto reflect an event in your world.
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    "Mathematics is the model of the universe, not the other way round" - M. R.
annaheffernan

Filamentous laser beams point to new type of phase transition - applications in weather... - 2 views

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    Filaments of plasma created by a high-powered laser beam undergo a similar type of phase transition as liquid percolating through a porous material - that is the conclusion of physicists in Switzerland. The also describe the application of laser filamentation for directed lightening and encouraged rainfall - Isabelle should come back to take a closer look :p
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    Christophe? Isabelle?
annaheffernan

How to make droplets chase each other and self-assemble into devices - 0 views

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    Droplets can be made to chase each other around a track and even self-assemble into devices, simply by mixing two everyday liquids. This remarkable discovery made by scientists in the US has already been used to create beautiful shapes and patterns, and could also be exploited to create optical components that assemble themselves and even to clean surfaces. It looks very like Jojo's self-assembling balls :p
annaheffernan

How to make a tougher quantum computer - 0 views

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    A system of nine quantum bits (qubits) that is robust to errors that would normally destroy a quantum computation has been created by researchers at the University of California, Santa Barbara (UCSB) and Google. The device relies on a quantum error-correction protocol, which the team says could be deployed in practical quantum computers of the future.
Thijs Versloot

Watch uranium radiation inside a cloud chamber - 6 views

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    Ever wondered what radiation looks like? If you have, I bet you didn't think it would look as cool as this. This is a small piece of uranium mineral sitting in a cloud chamber, which means you can see the process of decay and radiation emission....
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    Once I saw a DIY spark chamber in LIP (CERN associated laboratory). It was the work of a bunch of BSc students, they made it all from scratch, so it seemed to be not that difficult to have one at home. Yet another project for the future 'Experimental Physics' stagiare maybe :)
Tom Gheysens

Quantum biology: Algae evolved to switch quantum coherence on and off -- ScienceDaily - 3 views

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    Scientists have discovered how algae that survive in very low levels of light are able to switch on and off a weird quantum phenomenon that occurs during photosynthesis. The function in the algae of this quantum effect, known as coherence, remains a mystery, but it is thought it could help them harvest energy from the sun much more efficiently. Working out its role in a living organism could lead to advances such as better organic solar cells.
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    very very nice! we tried already a few years back to find an angle to see how we could study quantum phenomena occuring in plants and photosynthsis is one of the great examples since somehow plants manage to make the phenomena work for them at elevated temperatures, a feat in itself ... any good idea most welcome!!!
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    Anna maybe? Joe?
Nicholas Lan

Coupled to the main reactor: Physicists create tractor beam for boats - 3 views

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    even confining spatially harmful phytoplankton blooms, away from coastal areas
annaheffernan

Plasmons excite hot carriers - 1 views

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    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.
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    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."
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