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Earthquakes And Ionospheric Noises On CD
"Among the Cook recordings, not listed in their online catalog but available nonetheless (telephone 1-888-FOLKWAYS) is Cook Laboratories Catalog Number 5012. The Smithsonian's internal listing calls it simply "Earthquake," but it is actually a full transcription "Out of This World," with earthquakes on a 20-minute-long track 1 and ionospheric noises on a 20-minute-long track 2.
"Earthquake" is not an audio recording of the actual sounds that would be heard by a human being on an earthquake site. It is more cerebral than that.
In the 1950s, Hugo Benioff of CalTech devised a seismometer that recorded seismometer data on analog tape at a speed of 0.02 inches per second. The "Earthquakes" side delivers of the results of playing these tapes at standard playback speeds, speeding them up by factors of 187 to 750 times normal speed and converting subsonic earthquake vibrations into audible sound. The results are intriguing, indescribable, and curious to hear. Nearby earthquakes have a fairly sharp and brittle sound; distant ones sound dull and echoey.
The original LP contains a very strange track in which an earthquake recording is reproduced "to within 2 or 3 times original speed" and at a high amplitude. The narration notes that you will not be able to hear much of anything, but if you bend over and watch the tonearm you will be able to see it move. In fact, few tonearms, apparently including the one used by the Smithsonian to transcribe this segment, are able to play this band without skipping grooves.
The second side of the LP, "Sounds from the ionosphere," records the sounds that are heard when an antenna, with its signal suitably filtered, is connected to an amplifier rather than to a radio receiving set. The propagation characteristics of the ionosphere cause different audio frequencies to propagate at different speeds. The result is that the impulse created by a static discharge is heard, not as a click, but as a descending or ascending whistle. The sounds on this recordings are strange, melodious--almost like a mass of birds or spring peepers--and literally unearthly.
(If the ionospheric noises on Cook catalog #5012 are not enough, the Smithsonian also has Cook catalog #5013. This is a stereo recording combining ionospheric noises recorded simultaneously in Hanover, NH and Washington, D. C.)"
I wonder if there are any coincedents out there where one could examine music record wax recordings from the 20's and detect distant earthquakes that the engineers never noticed.
My father had this recording when I was growing up in the '50s. A very weird listen, especially for that era. I guess I'll have to shell out just for the nostalgia value.
Now that my memories have kicked in, I'll also have to try to track down a recording called "Bull in a Chime Shop", which was a bizarre all-percussion ensemble. This LP would cause all the neighbors to close their windows and cower under their beds.
The '50s were the golden age of Hi Fidelity. Tubes ruled, small Hi-Fi shops were like temples, and the shelves were full of recordings intended purely to show off the quality of your equipment.
No sig? Sigh...
theremin noise can be violently irritating
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Good info, I only have one issue. When you say the 'stronger the interaction, the faster the radio wave propagates', I assume you mean the phase speed of the wave and not the group velocity. The group velocity (which carries the energy of the wave and therefore all the information about the wave) travels slower than in a vacuum.
I am talking here about the group velocity. All plasma waves have a group velocity slower than the speed of light in vacuum; it is the difference in group velocity between different frequencies that leads to the whistler effect. (In this regieme, the phase and group velocities happen to be roughly proportional.)
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