invisibility cloaks…..

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  • #15511
    XDC wild egg tamer
    Participant

    not so much sci-fi after all…

    http://projects.star.t.u-tokyo.ac.jp/projects/MEDIA/xv/images/oc-okugai3.mpg

    According to Dr. Tachi,

    “[This invisibility cloak] is made of retro-reflective material so that the coming light is reflected back to the same direction that it comes from. Microscopic beads on the surface of the coat have the function of retro-reflection. A half mirror makes it possible for a spectator to see virtually from the position of the projector. An HMP projects an image of the background scenery captured by the video camera behind the camouflaged subject. A computer calculates the appropriate perspective and transforms the captured image to the image to be projected on the subject using image-based rendering techniques. Since the cloak the subject is wearing is made of a special retro-reflective material which reflects the incident light [in] the same direction it comes from… an observer looking through a half mirror sees a very bright image of the scenery [behind the subject] so that he [becomes] virtually transparent.”

    Additional details are at http://projects.star.t.u-tokyo.ac.jp/projects/MEDIA/xv/VRIC2003.pdf .

    #40803
    Anonymous
    Participant

    Saw this 3 years ago 😛 But yeah it’s still nice 🙂 Wonder how far they came along with it since…

    #40804
    Captain_Chronic
    Participant

    Very impressive 😀

    #40805
    XDCiNSANE
    Participant

    Saw this 3 years ago

    Is there anything you didnt see 30 million years before everyone else?

    #40806
    Anonymous
    Participant

    Your bum fluff – I believe the local all-male sports teams (rugby, football, cricket etc) got there first 😉 BTW there was a video for this posted years ago too with the guy stood in the street in front of a milk float type van thing.. not sure where I saw it though… probably on http://www.NewScientist.com or http://www.gizmag.co.uk

    #40807
    VicJameson
    Participant

    @=XDC= wild egg tamer wrote:

    so that the coming light is reflected back to the same direction that it comes from.

    Um, isn’t this the description of a mirror?

    #40808
    Anonymous
    Participant

    Yeah but we know he means light is being refracted from one side around the body and out the other side, not reflected 😛

    #40809
    VicJameson
    Participant

    @LeGIt wrote:

    Yeah but we know he means light is being refracted from one side around the body and out the other side, not reflected 😛

    None of that is said in the original article (have you read it?).

    What I understand him to mean is that a camera attached to a person can capture an image of what is behind the subject, then a projector (set up beforehand) projects that image onto the front of the person, and these bead things reflect the light in the direction of the projector. This has nothing to do with refraction around a body. The invisibility effect will also be nullified if the viewer is not in a line with the subject and the projector 😕

    As a physicist it is my opinion that this bloke is talking rubbish by likening this to an invisibility cloak. I can achieve the same effect with a camcorder, a projector and a bedsheet. Science rating 1/10.

    #40810
    XDC_Wolf
    Participant

    Yeah but we know he means light is being refracted from one side around the body and out the other side, not reflected Razz

    Don’t think so Mr Legit, you should read your science stories more carefully:

    Basically you need to be stood in front of a projector, with a camera behind both linked to a laptop AND the observer needs to be looking through a half Mirror. Thats real stealth clothing there. MAy be good for static objects, but then again how are you going to have half mirrors big enough to carry into a war zone for example. The stuff has real applications, but not as camoflauge!

    #40811
    PoD1st-BW
    Participant

    Wolfman, I am impressed, where did you find this

    #40812
    XDC wild egg tamer
    Participant

    does kinda look a bit cumbersome…………. 😀

    #40813
    To0THBRU5H
    Participant

    Cool, I’ve already got the projector 😆

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