AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency
"isw" wrote in message
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In article ,
Jeff Liebermann wrote:
"Bob Myers" hath wroth:
"Ron Baker, Pluralitas!" wrote in message
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No nonlinearity is necessary in order to hear
a beat?
Where does the beat come from?
An audible beat tone is produced by the constructive and destructive
interference between two sound waves in air. Look at a pictorial
representation (in the time domain) of the sum of sine waves,of similar
amplitudes, one at, say, 1000 Hz and the other at 1005, and you'll
see it.
Bob M.
I beg to differ. There's no mixing happening in the air. compression
of air is very linear (Boyles Law or PV=constant).
In general, that's true, but take a look at what happens in the throats
of high-powered horn loudspeakers. You can find info in e.g. "Acoustics"
by Beranek.
Isaac
Red herring.
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