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Thijs Versloot

Light bending material facilitates the search for new particles - 0 views

www.nanowerk.com/...newsid=37760.php

physics cherenkov high energy metamaterials

shared by Thijs Versloot on 17 Oct 14 - No Cached
  • Thijs Versloot on 17 Oct 14
     
    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").
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
LeopoldS

Evidence for extensive horizontal gene transfer from the draft genome of a tardigrade - 3 views

www.pnas.org/...15976.abstract

radiation biomimetics

shared by LeopoldS on 19 Jan 16 - No Cached
jcunha liked it
  • LeopoldS on 19 Jan 16
     
    recent paper on tardigrades taking others genes as mentioned by Riccarda
gpetit

To Sleep, Perchance to Clean - University of Rochester Medical Center - 2 views

www.urmc.rochester.edu/...-sleep-perchance-to-clean.aspx

BIO

shared by gpetit on 04 Jul 17 - No Cached
LeopoldS liked it
  • gpetit on 04 Jul 17
     
    Why do we sleep? One answer could be: to clear waste products accumulated during the day. To prevent aging and neurodegeneration, the body must maintain homeostasis. What would happen if we experience chronic sleep loss? What would happen if microgravity impairs the cerebrospinal fluid to flush the brain? What would happen if cosmic radiations increase the amount of daily waste products?
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