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submitted 1 year ago* (last edited 1 year ago) by wipasoda@lemmy.world to c/showerthoughts@lemmy.world

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

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[-] jonatan83@lemmy.fmhy.ml 5 points 1 year ago

Alas, RADAR relies on transmitting and then reading the reflected waves.

[-] astrsk@kbin.social 6 points 1 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.

[-] jonatan83@lemmy.fmhy.ml 3 points 1 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.

[-] Atrabiliousaurus@lemmy.world 18 points 1 year ago
[-] jonatan83@lemmy.fmhy.ml 2 points 1 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@lemmy.world 3 points 1 year ago

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

[-] skillissuer@lemmy.world 6 points 1 year ago

unless you're communicating by waving glowsticks, it's passive radar

this post was submitted on 19 Jul 2023
164 points (88.0% liked)

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