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Nina Nadine Ridder

Surprising similarity in fly and mouse motion vision - 2 views

medicalxpress.com/...arity-mouse-motion-vision.html

BIO science evolution biomimetics vision

shared by Nina Nadine Ridder on 30 Jul 15 - No Cached
  • Nina Nadine Ridder on 30 Jul 15
     
    Loosely related to an old ACT project on optical flow (if I remember correctly but even if not still an interesting read I think): "At first glance, the eyes of mammals and those of insects do not seem to have much in common. However, a comparison of the neural circuits for detecting motion shows surprising parallels between flies and mice. Scientists have learned a lot about the visual perception of both animals in recent years."
jcunha

Nature: Spawning rings of exceptional points out of Dirac cones - 3 views

www.nature.com/...nature14889.html

technology lasers QM PHY Dirac Cone

shared by jcunha on 10 Sep 15 - No Cached
LeopoldS liked it
  • jcunha on 10 Sep 15
     
    Dirac cones, a band-structure of two cones touching each other, are the key to understand graphene exceptional properties. They also appear in the theory of photon waveguides and atoms in optical lattices. In here, the study of a Dirac cone deformation in an open system (a system that is perturbed by external agents) lead to the deformation of the Dirac cone, meaning a change in the fundamental properties of the system. This change is such that strange phenomena such as unidirectional transmission or reflection or lasers with single mode (really single) operation can be achieved. Proved experimentally in photonic crystals. New way for extremely pure lasers?
jcunha

Chemical analysis in Earth and Space via Raman Spectroscopy - 2 views

phys.org/...ical-analysis-earth-space.html

Raman chemical sensing BIO PHY space technology

shared by jcunha on 25 Sep 15 - No Cached
  • jcunha on 25 Sep 15
     
    "A new lightweight, energy-efficient tool for analyzing a material's chemical makeup could improve the detection abilities of various technologies, ranging from bomb-detecting drones to space rovers searching for signs of life". Raman Spectroscopy is about measuring vibrational modes in molecules. This vibrational modes are in the meV typically, turning Raman Spectroscopy into a high precision technique. This impressive work shows a new technique based on the use of optical fibers coupled to photomultipliers allowing its use, author's word, in extreme conditions such as unmanned aircraft vehicles (UAVs) and Mars/Moon rovers.
pacome delva

Radiation fears stalk stellar mission - 0 views

physicsworld.com/...43063

space_mission GAIA solar_radiation

shared by pacome delva on 05 Jul 10 - Cached
  • Concern over ESA's handling of the radiation issue caused Michael Perryman, former GAIA project scientist, to resign from the agency in 2008. But GAIA science-team member Lennart Lindegren, an astronomer at Lund Observatory in Sweden, is confident that GAIA's unprecedented accuracy will be feasible. GAIA researchers will continue to perform tests and calibrations until at least 2011, which will include irradiating the CCDs at space-like temperatures. Lindegren admits, however, that they can never be certain of success until the spacecraft is in orbit and starts sending back data.
  • pacome delva on 05 Jul 10
     
    metamaterials to stop radiations?
  • LeopoldS on 05 Jul 10
     
    hmm ... in the optical range it is already a bit tricky .... lets brainstorm a bit about it ... anything in the literature? Luzi?
  • pacome delva on 06 Jul 10
     
    the components of the metamaterial need to have a size inversely proportional to the wavelenght, but here we are talking about high energy protons. So the idea was: is there metamaterials that change the electrical properties to solve this problem of holes in the material... but i dont have a clue !
pacome delva

You Are Now Free to Move About the Insect - ScienceNOW - 1 views

news.sciencemag.org/...-now-free-to-move-about-t.html

bio flies optic_flow

shared by pacome delva on 24 Aug 10 - Cached
  • Researchers thought that flies chose their altitude based on optic flow, a phenomenon familiar to anyone who has ridden an airplane.
  • The team's observations, published online today in Current Biology, suggest that flies base their cruising altitude on horizontal edges and landmarks—such as table surfaces or tree tops—and not on how fast the ground is moving beneath them. The edge-tracking strategy may enable flies to keep tabs on possible landing spots.
  • This may be the general principle" for all flying insects, he says.
Juxi Leitner

Run Wired, Run Deep: Subs May Finally Get Online | Danger Room | Wired.com - 1 views

www.wired.com/...1

INF technology space connectivity internet real-time communication

shared by Juxi Leitner on 05 Aug 10 - Cached
  • LeopoldS on 07 Aug 10
     
    strange that even if optical fibre this would not compromise the submarines location ...
duncan barker

Optics InfoBase - Ultrathin, metamaterial-based laser cavities - 0 views

www.opticsinfobase.org/abstract.cfm

technology space phy NRG

shared by duncan barker on 07 Sep 10 - No Cached
LeopoldS liked it
  • duncan barker on 07 Sep 10
     
    I'm not sure if meta materials can be used to enhance lasers in space........Leopold
  • LeopoldS on 07 Sep 10
     
    well .... will have to read this more carefully, but it seems, why not, no principal difference in space on this aspect ... any idea on this José? (in case you read this, which I doubt very much) - or maybe Luzi?
Dario Izzo

World's Strangest | A Glass Bottle Will Disappear… - 4 views

www.worldsstrangest.com/...a-glass-bottle-will-disappear

NAN optics

shared by Dario Izzo on 15 Dec 09 - Cached
  • Dario Izzo on 15 Dec 09
     
    Here is a first entry for our canweuseitforspace database. Jose, apparently this invisibility cloack is not that difficult after all!!!! Watch the youtube video.....
pacome delva

"Quantum trampoline" measures gravity - 2 views

physicsworld.com/...41208

phy atom_interferometry atom_gravimeter

shared by pacome delva on 15 Dec 09 - Cached
  • Physicists in France have come up with a new way of using bouncing ultracold atoms to measure the acceleration due to gravity. The technique involves firing vertical laser pulses at a collection of free-falling atoms, which bounces some atoms higher than others. When the atoms recombine at the centre of the experiment, they create an interference pattern that reveals that g is 9.809 m/s2 – just as expected for their Paris lab.
  • pacome delva on 15 Dec 09
     
    That's the lab I worked...
  • Dario Izzo on 16 Dec 09
     
    just being cinical ... but did not we know that g = 9.809 in Paris? I can also create a complex measurement procedure that will held pi = 3.1415, just as expected!!!
  • pacome delva on 17 Dec 09
     
    well, sure... the interest of such gravimeter is to be absolute, and for now slightly more accurate than the other type of absolute gravimeter which uses retroreflector and interferometry ( http://en.wikipedia.org/wiki/Gravimeter ). While the latter ones reached their limit in term of sensitivity, the atomic ones can be enhanced in many ways (using cooler atoms, better optics, etc...)
Joris _

SPACE.com -- NASA to Boost Speed of Deep Space Communications - 1 views

www.space.com/...tion-network-speed-100122.html

MAD technology communications DSN

shared by Joris _ on 25 Jan 10 - Cached
  • a few megabits per second might someday get as much as 600 megabits per second, if not more. That could enable far more scientific payoff per mission in the long run.
  • new communication innovations such as disruption tolerant networking
  • one of the biggest communication revolutions will come from laser-driven optical communication
    • Joris _
      Joris _ on 25 Jan 10
       
      they kind-of stole my idea ;)
pacome delva

Novel negative-index metamaterial bends light 'wrong' direction - 1 views

www.sciencedaily.com/...100422153939.htm

phy nan metamaterials

shared by pacome delva on 23 Apr 10 - Cached
  • the first negative index metamaterial to operate at visible frequencies
  • By engineering a metamaterial with such properties, we are opening the door to such unusual -- but potentially useful -- phenomena as superlensing (high-resolution imaging past the diffraction limit), invisibility cloaking, and the synthesis of materials index-matched to air, for potential enhancement of light collection in solar cells
  • Luzi Bergamin on 23 Apr 10
     
    I forwarded the link to my experimental colleagues and here is the comment from Sergei (the master himself:) "this is what Igor has been doing - an array of plasmonic nanocables. This basically works as a wire-medium slab. All their epsilon and mu are rubbish." * If Sergei is as strict as in this comment, then it IS rubbish. He's not one of the notorious complainer (as e.g. myself.) * Please DO NOT FORWARD this to anybody else, Sergei's comment is NOT FOR PUBLIC USE!
  • Luzi Bergamin on 23 Apr 10
     
    UPDATE: I had a short chat with Sergei and Pekka, Sergei noticed that there is an increasing number of papers on metamaterials, especially in Nature and Science, which are simply wrong, this one being an example. * The idea is based on a very well known effect of wired media. What appears to be interesting about this paper is that they manage to make an optical analogue with aparently low losses. This could be interesting. * The whole interpretation as NIM, "wrong" refraction etc. is total nonsense.
  • pacome delva on 23 Apr 10
     
    wow, good to know ! But for the privacy you should be aware that this is a public group, so anyone has access to our comments i think !
pacome delva

Invisibility cloaks shield the large and visible - physicsworld.com - 1 views

physicsworld.com/...44641

phy metamaterials transformation_optics

shared by pacome delva on 04 Jan 11 - No Cached
  • Two independent groups of physicists have built invisibility cloaks that can shield large objects lying on a plane. These "carpet cloaks" are far closer to the intuitive idea of an invisibility cloak than devices previously built, they argue, because they hide objects that can be seen with the naked eye and do so at visible wavelengths. The cloaks are also relatively cheap and easy to make, being constructed from the natural material calcite.
  • The team used a technique known as transformation optics to design their cloak.
  • Tomas Tyc of Masaryk University in the Czech Republic, who was not a member of either group, thinks that the papers "describe important achievements in the area of experimental cloaking." But he maintains that a carpet cloak is quite different to a fully fledged Harry Potter-style invisibility cloak. He points out that a carpet cloak only really works when viewing an object – be it a rucksack or a sword on someone's back, for example – side on. Otherwise the object will appear flat but still be visible.
pandomilla

Bioinspired self-repairing slippery surfaces with pressure-stable omniphobicity : Natur... - 3 views

www.nature.com/...nature10447.html

biomimetics plant self-repairing

shared by pandomilla on 22 Sep 11 - No Cached
LeopoldS liked it
  • a strategy to create self-healing, slippery liquid-infused porous surface(s) (SLIPS) with exceptional liquid- and ice-repellency, pressure stability and enhanced optical transparency. Our approach—inspired by Nepenthes pitcher plants13—is conceptually different from the lotus effect, because we use nano/microstructured substrates to lock in place the infused lubricating fluid. We define the requirements for which the lubricant forms a stable, defect-free and inert ‘slippery’ interface.
  • ts capability to repel various simple and complex liquids (water, hydrocarbons, crude oil and blood),
  • pandomilla on 22 Sep 11
     
    ...This slippery surface was bio-inspired by the carnivorous plant I showed you sometimes ago! I was sure it was a good idea! next time I will be quicker!!
  • ...1 more comment...
  • LeopoldS on 22 Sep 11
     
    Shit. I am sure that there is more to do on this. Let's have a closer look.
  • LeopoldS on 22 Sep 11
     
    And a good lesson that it is important to proceed quickly when you have an idea and don't wait ...
  • pandomilla on 23 Sep 11
     
    Yes, I will see what we could do, but they really did a good job, from the biomimetic of the surface, up to the realization of the material, and the tests...
santecarloni

Optical measurement of cycle-dependent cell growth - 0 views

www.pnas.org/13124

cell growth BIO

shared by santecarloni on 26 Aug 11 - No Cached
  • santecarloni on 26 Aug 11
     
    Researchers developed a new imaging method that can measure cell mass using two beams of light, offering new insight into the much-debated problem of whether cells grow at a constant rate or exponentially. They found that mammalian cells show clear exponential growth only during the G2 phase of the cell cycle. This information has great implications not only for basic biology, but also for diagnostics, drug development and tissue engineering.
Tobias Seidl

Nanometric butterfly wings created (10/9/2009) - 0 views

www.biomimicrynews.com/...ic_butterfly_wings_created.asp

BIO NAN insects butterflies optics

shared by Tobias Seidl on 14 Oct 09 - Cached
  • Tobias Seidl on 14 Oct 09
     
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  • pacome delva on 19 Oct 09
     
    cool. It would be very to make a review of interesting photonic properties we could benefit from nature, and the possible use for space. It's nice to see that some structured can already be replicated...! Is there a structure to give angulaer momentum to light ?
pacome delva

Physics - Atoms in a lattice keep time - 0 views

physics.aps.org/...PhysRevLett.103.063001

phy metrology atomic_clocks atom_interferometry

shared by pacome delva on 05 Aug 09 - Cached
  • If your wristwatch was as accurate as today’s atomic clocks, it would not gain or lose a second in 80 million years.
  • The NIST group traps and cools neutral 171Yb atoms and loads them into a one-dimensional lattice, so that about 30,000 atoms fill several hundred lattice sites.
  • Lemke et al. compare their optical lattice clock with the current standard atomic fountain clock and find that the accuracy of the Yb lattice clock potentially challenges the current standard.
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