TIL that radios can pick up AM signals from stations broadcasting from beyond the horizon because the signals are reflected in the Heaviside Layer, a layer of ionised gas in the Earth’s atmosphere, about 60-90 miles up. The Heaviside Layer acts like a mirror in the sky for radio waves.

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Amateur radio operators refer to it as the ionosphere.


Also doubles as cat heaven


…like in Cats?


In the 1930s a quack doctor named John Brinkley who had been stripped of his medical license in his home state of Kansas bought a radio station in Villa Acuña, Mexico called XERA and gave it a 1 million watt broadcast tower. Due to the powerful signal and this effect it could be heard in Canada on a clear night and was the first radio station that could be heard nationwide. To fill the time between pseudoscientific rants he hired The Carter Family to be his house band for a spell, introducing the nation as a whole to country music.


Hams and DX-ers used to (still?) call it “talking skip”.