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santecarloni

[1010.3437] Dynamical mass generation via space compactification in graphene - 0 views

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    Is it really possible?
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    The affiliation is Saudi Arabia and Marocco, not countries famous for their contributions to physics... But nonetheless, yes this is possible, to me it even looks very plausible! But you should know that the term "mass" in this context just means a certain parameter in the dynamical equations and only has a loose relation to what we usually call "mass" in the macroscopic world.
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    ok - admit that I only read the abstract but to me the seems to be a little bit of magic happening ... even if "mass is only a certain parameter in the dynamical equations" ... I assume it still bears some "heavy" consequences in terms of their speed, interactions etc, no? and assuming that you gradually bend such a structure from a 2D to a 1D one ... does it "gain" mass gradually? all very strange to me ...
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    I think the problem is in the boundary conditions... the issue is that if you use and infinite sheet or a cylinder in the equations you always take cyclic boundary condition. If this guys are right then the mass of the quasi-particles in a crystal depends on its topology... this is a major thing...
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    BINGO!! It's almost like good ol' Kaluza-Klein...
Joris _

KodiakDailyMirror.com :: Daily newspaper of Kodiak, Alaska - 0 views

  • The NanoSailD is a solar sail designed to use light particles to accelerate. If all goes well it will be the first solar sail deployed by NASA.
  • It instead uses the sail for the humble but important mission of testing a potential orbit-cleaning tool.
terencepf

helium discussion - 0 views

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    This link has a nice concise explanation of helium escaping the atmosphere. http://www.astronomynotes.com/solarsys/s3.htm (this link describes the mechanics of particles escaping the atmosphere, this includes escape velocity, thermal and nonthermal process) http://www.springerlink.com/content/k094u75188h64516/fulltext.pdf ( and if you are really interested, this paper discuss helium in the atmosphere (production and loss) in much more detail )
pacome delva

Higgs hunters face long haul - 2 views

  • to reduce the chances of the LHC being derailed again by a similar accident, physicists at the Geneva lab have decided to run the collider at just half its design energy for the next 18-24 months.
  • Once the 7 TeV run is over, CERN will shut the LHC down in 2012 for a year or more to prepare it to go straight to maximum-energy 14 TeV collisions in 2013. This will be a complex job that will involve replacing some 10,000 superconducting magnet connections with more robust ones.
  • choosing to stay at lower energies is a big price to pay in terms of the Higgs search. "We will need more than twice the data at 7 TeV compared to that needed at 10 TeV to reach the same discovery potential," she says. "At this energy we can at best expect to exclude a Higgs with a mass between 155 and 175 GeV."
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    no Higgs boson before 2013... and a replacement of 10,000 superconducting magnet connections ! Reminds me of the the gravitational detectors... no detection before an upgrade in 2013...! There are the big announcements to make the cash flow... and reality !
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    Higgs is almost 81, so he should better invest in his health if he wants the Nobel prize... But who cares, it's another 5 years window where high-energy theorists can produce nonsense with no experimental evidence. They should be happy!
pacome delva

RHIC nets strange antimatter - 0 views

  • The antihypertriton – consisting of an antiproton, an antineutron and an antilambda particle – is the heaviest antinucleus yet produced and opens up a new realm of strange antinucluei. It could also shed light on a number of problems in astrophysics and cosmology, including the dominance of matter over antimatter in the universe.
Luzi Bergamin

Compact metallo-dielectric optical antenna for ultra directional and enhanced radiative... - 3 views

shared by Luzi Bergamin on 26 Mar 10 - Cached
LeopoldS liked it
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    A new paper related to our old Ariadna on microstructured radiators.
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    This is actually a very nice paper in my view .... José, have a look at it!! "This study demonstrates that appropriately designed metallo-dielectric systems can serve as compact, highly directive and ultra radiative antennas. Let us emphasize that contrary to fully metallic antennas, the high directivity of this antenna does not result from a plasmonic effect, and that it is efficient over a wide range of frequencies. In consequence, the high directivity does compromise the high radiative decay rate enhancement offered by two coupled metallic particles and it is possible to exploit whispering gallery modes to further enhance the radiative decay rates. This work paves the way towards the design of compact, simple and highly efficient optical antennas."
LeopoldS

Roman ingots to shield particle detector : Nature News - 1 views

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    nice story from Andrés: my only concern: "At Gran Sasso, the ingots will be melted into a 3-centimetre-thick lead lining that will surround the cubic CUORE detector. Before the ingots are melted down, the inscriptions on each one will be removed and sent back to Cagliari for preservation. "They are trademarks, bearing the names of various firms that extracted and traded lead," explains Donatella Salvi, an archaeologist at the Cagliari museum.
pacome delva

Will the LHC find supersymmetry? - 0 views

  • But not everyone is optimistic about discovering SUSY. "We will get in a crisis, I think, in a few years," Dorigo predicts, sceptical of the theory because it introduces so many new particles of which data presently show "no hints". However, even though he would lose a $1000 bet, he says that he would still be among the first celebrating if the LHC does turn up sparticles.
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    Certainly too early for a definite answer, they will keep us in suspense for another few years. But don't worry, whatever is found, Arkani-Hamed will have at least 50 models that can explain this...
Ma Ru

They got it -> Monopoles. - 1 views

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    very interesting. Quasi-particles acting as magnetic monopoles.
Nina Nadine Ridder

Essay - The Collider, the Particle and a Theory About Fate - NYTimes.com - 4 views

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    cannot access to this one...
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    Sorry, works for me though... Dunno what s wrong!
ESA ACT

Teleportation of massive particles without shared entanglement - 0 views

shared by ESA ACT on 24 Apr 09 - Cached
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    classical teleportation, sounds pretty interesting.
ESA ACT

Particle Swarm Central - 0 views

shared by ESA ACT on 24 Apr 09 - Cached
Ma Ru

Euroscience Open Forum 2010 - 2 views

shared by Ma Ru on 24 Apr 09 - Cached
LeopoldS liked it
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    A conference ACT should consider going to.
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    Perhaps some of ACTers will find this conference interesting... One of the talks: "Would Einstein be on Twitter? Exploring the potential and limits of Web 2.0 in science & science communication" [Edit] Oh, I see someone has already posted this link... a year ago. Anyway, if anyone of you plans to go, let me know - I'll be around ;-)
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    Just came back from ESOF 2010... I was on look for ACT agents undercover, but either they were not there or the cover was good enough... Anyway here's a few remarks from me (I could write a nice report... if you paid): 1) In general, to say that ESA was underrepresented on the conference as a whole is not enough (I guess ESA just failed to notice the event taking place). For instance, on the GMES presentation, ESA as such was not mentioned at all... at some point I started to wonder if ESA is actually involved in the project, but now I checked the website and apparently it is. On the other hand, GMES presentation was crap anyway, as after 1:15 of talking, I didn't gain any knowledge of what GMES is and what its contributions to the EU community will be. 2) There was a lot of talk about LHC and particle research (well, at least among those that I attended). Some of them were very good, some of them rather crap... 3) "Would Einstein be on Twitter? Exploring the potential and limits of Web 2.0 in science & science communication" talk - quite interesting, but focusing mainly on Science-to-Wide Public and Science-to-Journalists communication. Not really on Science-to-Science (as in Ariadnet). There was quite an extensive discussion with the public. You may be interested that Nature is trying to stimulate Web 2.0 communication, running blog service, but also I think a kind of social network - perhaps you'd like to have a look. In general the conclusion was that Web 2.0 is not so useful for scientific communication because practising it requires TIME (blogs, etc.) and often some professional skills (podcasts/videocasts, etc.), and scientists have neither of these. This can be run on corporation level (like ESA does actually), but then it looses the "intimate" character. 4) "How much can robots learn?" talk... very nicely presented: understandable by the wide public, but conveying the message... which is something like "we can already make the robots do stuff absolutely imp
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    Well, my comment was cut in half, and I don't feel like typing it again... the most important highlight from the rest is that the only presenter from ESA (ESTEC) did not show up on his talk because his department was undergoing some sort of audit on the same day :)
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    Fantastic comment - or better report!! thanks very much Marek! Who was the supposed no-show speaker from ESA?
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    Bernard Foing (he is actually one of the 8 ESA employees who have their own page on Wikipedia)...
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    written almost entirely by a guy called a "quest for knowledge" ... who will this be????? :-)
pacome delva

"God Machine" Critics to U.N.: Experiment an Affront to Human Rights - 3 views

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    The end of the world is for this month...
pacome delva

Heaviest ever antimatter discovered - physicsworld.com - 1 views

  • Physicists at the Relativistic Heavy Ion Collider (RHIC) in New York say they have created nuclei of antihelium-4 for the first time – the heaviest antimatter particles ever seen on Earth.
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 ...
johannessimon81

Physicists Prove Surprising Rule of Threes - 6 views

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    More than 40 years after a Soviet nuclear physicist proposed an outlandish theory that trios of particles can arrange themselves in an infinite nesting-doll configuration, experimentalists have reported strong evidence that this bizarre state of matter is real.
Thijs Versloot

Dark matter may have been detected - streaming from the sun's core - 2 views

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    An unusual signal picked up by a European space observatory could be the first direct detection of dark matter particles, astronomers say. The findings are tentative and could take several years to check, but if confirmed they would represent a dramatic advance in scientists' understanding of the universe.
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