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pacome delva

Slowed light breaks record - 0 views

physicsworld.com/...41246

phy slow_light quantum_computation quantum_cryptography BEC

shared by pacome delva on 16 Dec 09 - Cached
  • Kilometre-long pulses of light have been stored for over one second in a 0.1 mm cloud of ultracold atoms – before being revived and sent on their way. This latest demonstration of light storage using electromagnetically induced transparency (EIT) is the first to break the second barrier – using ultracold atoms and has the added bonus of preserving the quantum state of the incoming pulse. The physicists in the US who carried out the experiment say that the work could play a key role in quantum information technology.
pacome delva

Generation of light bullets - 1 views

physics.aps.org/...107

phy electromagnetism

shared by pacome delva on 22 Dec 10 - No Cached
  • Ma Ru on 22 Dec 10
     
    We have the bullets, so when we'll have the gun?
pacome delva

Spinning black holes twist light - 1 views

physicsworld.com/...45104

general_relativity black_holes electromagnetism

shared by pacome delva on 16 Feb 11 - No Cached
Nicholas Lan liked it
  • pacome delva on 16 Feb 11
     
    so coool ! an application for the rototenna :)
LeopoldS

[0812.2633] Ghost imaging with a single detector - 2 views

arxiv.org/0812.2633

PHY NAN

shared by LeopoldS on 20 Sep 11 - No Cached
  • LeopoldS on 20 Sep 11
     
    anything happening on this since 3 years?
  • pacome delva on 28 Sep 11
     
    yes it seems like. most of it seems however directed toward understanding this effect, and not toward applications. But i'm still convinced that we could find many very interesting applications !!! a few references from ADS: 1 2011PhRvA..83f3807B 1.000 06/2011 A E X R C U Brida, G.; Chekhova, M. V.; Fornaro, G. A.; Genovese, M.; Lopaeva, E. D.; Berchera, I. Ruo Systematic analysis of signal-to-noise ratio in bipartite ghost imaging with classical and quantum light 2 2011PhRvA..83e3808L 1.000 05/2011 A E R U Liu, Ying-Chuan; Kuang, Le-Man Theoretical scheme of thermal-light many-ghost imaging by Nth-order intensity correlation 3 2011PhRvA..83e1803D 1.000 05/2011 A E R C U Dixon, P. Ben; Howland, Gregory A.; Chan, Kam Wai Clifford; O'Sullivan-Hale, Colin; Rodenburg, Brandon; Hardy, Nicholas D.; Shapiro, Jeffrey H.; Simon, D. S.; Sergienko, A. V.; Boyd, R. W.; Howell, John C. Quantum ghost imaging through turbulence 4 2011SPIE.7961E.160O 1.000 03/2011 A E T Ohuchi, H.; Kondo, Y. Complete erasing of ghost images caused by deeply trapped electrons on computed radiography plates 5 2011ApPhL..98k1115M 1.000 03/2011 A E R U Meyers, Ronald E.; Deacon, Keith S.; Shih, Yanhua Turbulence-free ghost imaging 6 2011ApPhL..98k1102G 1.000 03/2011 A E R C U Gan, Shu; Zhang, Su-Heng; Zhao, Ting; Xiong, Jun; Zhang, Xiangdong; Wang, Kaige Cloaking of a phase object in ghost imaging 7 2011RScI...82b3110Y 1.000 02/2011 A E R U Yang, Hao; Zhao, Baosheng; Qiu
Dario Izzo

ESA Portal - ESA to launch two large observatories to look deep into space and time - 0 views

www.esa.int/...SEMEOSZXDUF_index_0.html

shared by Dario Izzo on 11 May 09 - Cached
  • s in space, in a part of the electromagnetic spectrum still mostly unexplored. Planck is a telescope that will map the fossil light of the Universe - light from the Big Bang
    • Dario Izzo
      Dario Izzo on 11 May 09
       
      try izzo
    • LeopoldS
      LeopoldS on 12 May 09
       
      strange entries here ? just testing the system???
  • jmlloren on 11 May 09
     
    Amazing "to look deep into space and time". What a nice pun!
  • Ma Ru on 12 May 09
     
    Coooool!
ESA ACT

Compromising Electromagnetic Emanations of Wired Keyboard - Martin Vuagnoux and Sylvain... - 0 views

lasecwww.epfl.ch/keyboard

shared by ESA ACT on 24 Apr 09 - Cached
  • ESA ACT on 24 Apr 09
     
    interception of keyboard typing
Ma Ru

Dark Matter or Black Hole Propulsion? - 1 views

www.newscientist.com/...s-for-interstellar-travel.html

NRG propulsion star travel space PHY

shared by Ma Ru on 25 Nov 09 - Cached
  • Ma Ru on 25 Nov 09
     
    Anyone out there still doing propulsion stuff? Two more papers just waiting to get busted... http://arxiv.org/abs/0908.1429v1 http://arxiv.org/abs/0908.1803
  • ...5 more comments...
  • Luzi Bergamin on 26 Nov 09
     
    What an awful bunch of complete nonsense!!! But I don't think anybody wants to hear MY opinion on this...
  • pacome delva on 26 Nov 09
     
    wow, is this serious at all...!?
  • Luzi Bergamin on 26 Nov 09
     
    Are you joking?? The BH drive propses a BH with a lifetime of about an year, just 10^7 tons, peanuts!! Then you have to produce it, better not on Earth, so you do this in space, with a laser that produces an equivalent of 10^9 tons highly foucussed, even more peanuts!! Reasonable losses in the production process (probably 99,999%) are not yet taken into account. Engineering problems... :-) The DM drive is even better, they want to collect DM and compress it in a propulsion chamber. Very easy to collect and compress a gas of particles that traverse the Earth without any interaction. Perhaps if the walls of the chamber are made of artificial BHs?? Who knows??
  • LeopoldS on 26 Nov 09
     
    WRONG!!! we are all just WAITING for your opinion on this ....!!!
  • pacome delva on 27 Nov 09
     
    well, yes my remark was ironic... I'm surprised they did a magazine on these concepts...! But the press is always waiting for sensational. They do not even wait for the work to be peer-reviewed now to make an article on it ! This is one of the bad sides of arxiv in my opinion. It's like a journalist that make an article with a copy-paste in wikipedia ! Anyway, this is of course complete bullsh..., and I would have laughed if I had read this in a sci-fi book... but in a "serious" article i'm crying... For the DM i do not agree with your remark Luzi. It's not dark energy they want to use. The DM is baryonic, it's dark just because it's cold so we don't see it by usual means. If you believe the in the standard model of cosmology, then the DM should be somewhere around the galaxies. But it's of course not uniformly distributed, so a DM engine would work (if at all...) only in the periphery of galaxies. It's already impossible to get there...
  • Luzi Bergamin on 27 Nov 09
     
    One reply to Pacome, though the discussion exceeds by far the relevance of the topic already. Baryonic DM is strictly limited by cosomology, if one believes in these models, of course. Anyway, even though most DM is cold, we are constantly bombarded by some DM particles that come together with cosmic radiation, solar wind etc. etc. If DM easily interacted with normal matter, we would have found it long ago. In the paper they consider DM as neutralinos, which are neither baryonic nor strongly or electromagnetically interacting.
  • pacome delva on 27 Nov 09
     
    well then I agree, how the fu.. they want to collect them !!!
Joris _

A Fusion Thruster for Space Travel - IEEE Spectrum - 4 views

spectrum.ieee.org/...0

Thruster PHY NRG NASA

shared by Joris _ on 29 Jun 11 - No Cached
LeopoldS liked it
  • Now a NASA engineer has come up with a new way to fling satellites through space on mere grams of fuel, tens of times as efficiently as today’s best space probe thrusters.
  • Instead of using deuterium and tritium as the fuel stocks, the new motor extracts energy from boron fuel.
  • Joris _ on 29 Jun 11
     
    "And according to his calculations, improvements in short-pulse laser systems could make this form of thruster more than 40 times as efficient as even the best of today's ionic propulsion systems that push spacecraft around. "
  • LeopoldS on 02 Jul 11
     
    Dejan please have a look at this also ...
  • LeopoldS on 02 Jul 11
     
    while the nuclear reaction seems to be sound at first view, I am not so sure how this would work: "Electromagnetic forces push the target and the alpha particles in the opposite directions, and the particles exit the spacecraft through a nozzle, providing the vehicle's thrust. "
anonymous

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

www.wired.co.uk/...lidates-impossible-space-drive

PHY space nasa propulsion emdrive

shared by anonymous on 31 Jul 14 - No Cached
  • anonymous on 31 Jul 14
     
    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.")
  • ...3 more comments...
  • LeopoldS on 01 Aug 14
     
    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.
  • anonymous on 02 Aug 14
     
    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
  • Thijs Versloot on 04 Aug 14
     
    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?
  • annaheffernan on 04 Aug 14
     
    I have to join the skeptics on this one ...
  • Marcus Maertens on 09 Aug 14
jaihobah

DARPA Advanced Plant Technologies project - 2 views

events.sa-meetings.com/...632471

technology BIO plants?

shared by jaihobah on 22 Nov 17 - No Cached
  • jaihobah on 22 Nov 17
     
    " The goal of the APT program is to control and direct plant physiology to detect chemical, biological, radiological, and/or nuclear threats, as well as electromagnetic signals. " Now that is an advanced concept...
  • LeopoldS on 04 Jan 18
     
    and look at this exceptional insight: "plants are easily deployed, self-powering, and ubiquitous in the environment, and the combination of these native abilities with specifically engineered sense-and-report traits will produce sensors occupying new and unique operational spaces" :-)
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