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Seeing 2.4 GHz Radio Waves

Posted by samzenpus on from the take-a-look dept.

szczys writes: There was this art piece that circled the internet a few weeks ago which used a tablet to visualize WiFi and other signals and it was complete fake. It was cool, and it approximated where radio waves emanated from, but it wasn't actually measuring them for display. Greg Charvat has built his career on Radar and other RF design. Seeing that demo he realized he could show you what actual microwaves look like. He used a radar that he built himself from coffee cans. By altering the circuit just a bit he is able to move the receiver around the room and illuminate different LEDs based on the signal traits. A long exposure photograph captures this and lets you see the radio waves. It's like a charcoal rubbing but for electromagnetic waves.

11 of 43 comments (clear)

  1. I'm coming mother by pr0t0 · · Score: 2

    I didn't know Norman from Bates Motel was into radar and em waves. Cool.

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    I'm sorry, but your opinion seems to be wrong.
  2. I don't get it by Anonymous Coward · · Score: 4, Funny

    What does this have to do with the new iPad Pro? This site is supposed to be news for nerds...not this boring gobbledygook!!

    1. Re:I don't get it by david_bonn · · Score: 5, Insightful

      I actually think this is one of the most awesome things I have seen on slashdot in a long time.

      Someone did a real science experiment with fifty bucks worth of parts and two coffee cans.

    2. Re:I don't get it by fisted · · Score: 2

      Highest-modded whoosh i've seen on slashdot in a long time.

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      CLI paste? paste.pr0.tips!
  3. Re: OK, that's pretty damn nifty. by JohnNemesh · · Score: 2

    There are several wifi sniffing apps you can download for your smartphone that will accomplish.

  4. Cool, but it's been done better by Anonymous Coward · · Score: 5, Interesting

    7 months ago on Hackaday's own site:

    http://hackaday.com/2015/02/17/mapping-wifi-signals-in-3-dimensions/

  5. not really what microwave would look like. by Wycliffe · · Score: 3, Interesting

    Microwave and light wave are on the same spectrum so if you could see in microwave then it would just illuminate objects just like
    regular light or ultraviolet light but with the awesome effect that it would actually penetrate some objects. A camera that shifted
    microwave down to visible light would be really cool similar to how a ultraviolet camera lets you see ultraviolet light.

    1. Re:not really what microwave would look like. by Tony+Isaac · · Score: 4, Insightful

      A big difference from regular light would be blurriness. WiFi, at 2.5 GHz, has a wavelength of about 5 inches. This would lead to an extremely foggy, blurry image of everything around you.

    2. Re:not really what microwave would look like. by dotancohen · · Score: 2

      A big difference from regular light would be blurriness. WiFi, at 2.5 GHz, has a wavelength of about 5 inches. This would lead to an extremely foggy, blurry image of everything around you.

      This is actually terribly insightful. I just googled "c / 2.4 Ghz" and Google came back with "12.4913524 centimeters".

      --
      It is dangerous to be right when the government is wrong.
    3. Re:not really what microwave would look like. by Anonymous Coward · · Score: 2, Interesting

      Fun fact, humans can actually see UV light pretty well if you remove our lens that obscures it.

      Many people who have had one of their lenses removed have noticed it, and many have reproduced what it approximately looks like and how it affects the world they see around them.
      Their sensitivity to bluer frequencies is still the same though, no increase in fidelity, just opens up more of the spectrum to see.
      For the most part, it increased how vibrant everything looked, a whitish blue-violet filter being applied to everything. An artist even painted in it, Monet I think.

      Of course, this does mean that their eyes are being exposed to damaging UV, which is A Bad Thing.
      They'd probably be recommended to wear sunglasses wherever possible now, outside of new surgeries which I hope have UV-blocking coatings if requested.

  6. Re: Can't wait for conspiracy theorists by myrdos2 · · Score: 3, Interesting

    I've often wanted something that could produce an image from EM emissions, in the same way that our eyes create an image from light. It would make finding EM interference and shielding problems a breeze. But when I Google it all I can find is ghost detection equipment and cameras that are supposed to take a picture of your aura and other nonsense. So there's at least two kinds of crazy at play here.