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What is this called? (Warning - mathematics involved)

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Hi all,

I'm looking for the English word to describe a mathematical phenomenon.

When you superimpose two (co)sines of slightly different frequencies (say, y1=sin(9x) and y2=sin(8x) or something), the resulting waveform consists of periodic blob-kind of thingies, the amplitude kinda like a waveform itself.

In Dutch, it's called "zweving" which literally means floatation, but I doubt it's called that in English.

Thanks in advance,

Alphons
And five hundred entirely naked women dropped out of the sky on parachutes.
-- The Hitchhiker's Guide to the Galaxy

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dissonance, is the term that comes to my uneducated mind. The sum of the difference. For example: if a twin engine jump plane pilot has the left engine producing a 220Hz and the right producing a 225Hz, one would hear a 5Hz wawa. Assuming one listened.

Or maybe resonance would be better now that I reread your post. That is when 2 overlapping wave forms peak periodically at the same time.
take care,
space

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if a twin engine jump plane pilot has the left engine producing a 220Hz and the right producing a 225Hz, one would hear a 5Hz wawa. Assuming one listened.



Nice example B|

Btw: I finally managed to find a reference. The word I was looking for is "beat(ing)", apparently.

Thanks,

Alphons
And five hundred entirely naked women dropped out of the sky on parachutes.
-- The Hitchhiker's Guide to the Galaxy

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Hi all,

I'm looking for the English word to describe a mathematical phenomenon.

When you superimpose two (co)sines of slightly different frequencies (say, y1=sin(9x) and y2=sin(8x) or something), the resulting waveform consists of periodic blob-kind of thingies, the amplitude kinda like a waveform itself.

In Dutch, it's called "zweving" which literally means floatation, but I doubt it's called that in English.

Thanks in advance,

Alphons



EEs would call it heterodyning, physicists and musicians would call it "beats" or "beating", mathematicians call it a superposition of two waves.
...

The only sure way to survive a canopy collision is not to have one.

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Hi all,

I'm looking for the English word to describe a mathematical phenomenon.

When you superimpose two (co)sines of slightly different frequencies (say, y1=sin(9x) and y2=sin(8x) or something), the resulting waveform consists of periodic blob-kind of thingies, the amplitude kinda like a waveform itself.

In Dutch, it's called "zweving" which literally means floatation, but I doubt it's called that in English.

Thanks in advance,

Alphons



It is called beating, and the frequency between the maxima of the superimposed sine waves is the beat frequency

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Hi all,

I'm looking for the English word to describe a mathematical phenomenon.

When you superimpose two (co)sines of slightly different frequencies (say, y1=sin(9x) and y2=sin(8x) or something), the resulting waveform consists of periodic blob-kind of thingies, the amplitude kinda like a waveform itself.

In Dutch, it's called "zweving" which literally means floatation, but I doubt it's called that in English.

Thanks in advance,

Alphons



EEs would call it heterodyning, physicists and musicians would call it "beats" or "beating", mathematicians call it a superposition of two waves.




Now I come to think of it, short wave radio hams in the old days used to use this technique to detect morse code sent with carrier wave (CW) only. The gizmo on the ham radio was called a Beat Frequency Oscillator or BFO. It would create an audio signal when mixed with the incoming radio frequency (inaudible) carrier. It is also used to make audible the station ID on aircraft VOR and ILS navigation radios.
...

The only sure way to survive a canopy collision is not to have one.

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