Because you use light to communicate in sign language, and light is just an electromagnetic wave like radio but on another frequency. You just need to be in line of sight

  • @mykl
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    931 year ago

    Really, radio communication is about creating and transmitting those radio waves. Sign language relies on reflected light waves so it’s actually a form of RADAR 😀

    • Lux
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      121 year ago

      Ok, but technically, it would actually be more like LIDAR, since we use visible light rather than radio waves

      • astrsk
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        61 year ago

        RADAR: RA(dio) D(etection) A(nd) R(anging)

        It doesn’t rely on self transmission. It can but you can detect and range other sources without generating it yourself.

        • @[email protected]
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          31 year ago

          That’s just what the acronym means, it doesn’t describes the actual process. I don’t think there is a single RADAR that doesn’t have a transmitter. At that point it would just be a… radio.

            • @[email protected]
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              21 year ago

              Fair enough, though I would argue that’s a very specific subtype of radar and anyone saying “radar” refers to the type that is used in 99.999% of the cases.

              • @Atrabiliousaurus
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                31 year ago

                Yeah probably true. I only thought to look it up because I knew active and passive sonar was a thing.