• ivan@piefed.social
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    10 hours ago

    So, you may have noticed that 5 GHz Wi-Fi has smaller coverage area than 2.4 GHz.

    It works that way all the way down to infrasound, which is <20 Hz, and natural examples would be whale communications (thousands of kilometers) or volcano eruptions (infrasound wave from Krakatoa eruption lapped around entire globe multiple times).

    As for human factors - basically any big industrial tech object is gonna be the source of ultrasound. So it’s kind of safe to assume that infrasound from data centers may be “heard” from at least several kilometers away. Dunno how it compares to refineries and power substations - but they’re also source of that.

    • boonhet@sopuli.xyz
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      9 hours ago

      At night I could hear a train idle from a kilometer away through town easily. That was still in the audible range, not infrasound, and also it was literally just the engine idling, not the train being driven - not super loud even if standing next to it. A bit louder than a car.