Earthquakes And Ionospheric Noises On CD 25
"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.)"
Pygmies of the Ituri Rainforest (Score:5, Informative)
Among Folkways highlights is this highly regarded collection of field recordings of traditional songs of the Mbuti Pygmies. (Quiet, in the back there.) Crazy multi-voiced harmony and polyrhythm which stands out as among the oldest surviving human cultural achievements.
how ionospheric noise comes about (Score:5, Informative)
The ionosphere is a plasma: it is made up of electrons and protons that are sufficiently diffuse that they spend most of their time unbound from each other (incident radiation keeps ionizing atoms; once their ionized, the two particles have a great deal of trouble finding each other.)
Because light waves are just propagating electric and magnetic fields, they interact with charged particles. In solids (and most gases, where the electrons are bound), they don't really "see" the charge: the electrons are very close to the protons and the configuration "looks" neutral. It is only at very shortwavelength that the light can "discover" that these atoms aren't neutral, but have, rather, two charged components. In plasmas, where the electrons and protons are very far apart, much longer wavelength -- radio -- waves discover this fact.
The particular density and temperature of the plasma defines a resonant frequency. Near this resonance, the radio waves have difficulty propagating: they start to interact strongly with the medium. Roughly (OK, very roughly) speaking, the stronger the interaction, the faster the radio wave propagates.
But wait! I thought light travelled at a constant speed regardless of wavelength! Well, yes, in vacuo. Here, because of the interactions with the plasma, all frequencies of interest are slowed down. Off-resonant frequencies are slowed more, because the plasma moves about in response to the fields of the light wave to partly cancel the wavefront (imagine trying to send a pressure wave through silly putty.)
The whistler comes about when you pump a large spectrum of radio frequencies into the ionosphere from something like a thunderclap. These waves then start travelling over the Earth. The higher frequency waves are closer to the resonant frequency of the ionosphere plasma, and so get to you sooner. You literally have to wait for the lower frequency waves to arrive.
The plasma is sufficiently ''dispersive'' that, for average ionosphere conditions, the lowest and highest frequency waves will be 10,000 km apart. A pretty large musical instrument!
A final, neat point: while the whistlers are somewhat like a prisoner tapping on a radiator pipe, you can under certain circumstances get enough energy into the ultra-long wavelength modes to get a cavity resonance (make the Earth's ionosphere ring like a bell.) Could it be? Yes, indeed: this cavity resonance is detected after the detonantion of nuclear bomb (the EMP provides the lightning strike.)
Expensive! (Score:5, Informative)
Folkways is a legendary label, and I'm happy to say I have a few Fokways CDs (Woody Guthrie -- and given the present administration, I appreciate all the more "I Dreamed I Saw Joe Hill").
I'd love to buy more, but frankly, at 19.95 for CDR, it's a bit pricier than I can bear, especially considering that the CDRs being copies the original albums that predate the LP -- Long Playing album --, tend to be brief.
I'd rather see my money go to the Smithsonian that to RIIA plutocrats any day, so I wish they could find a better price point. At $5 per album, they'd see a lot of business form me. At $10, I'd be willing to take a chance, given Folkways's reputation. At $20 per, I have to consider saving three bucks and getting a two-CD Gilbert & Sullivan opera at 78s2CD [78s2cd.com].
More info and the Cook catalog (Score:5, Informative)
Re: Bull in a Chime Shop: good news (Score:3, Informative)
The title was actually "Speed the Parting Guest" and yes, indeed, the Smithsonian has it, too. Cook catalog number 01041. It is paired with an even weirder recording called "The Hot-Tempered Clavichord," of a jazz pianist playing a clavichord.
My copy of the Smithsonian had the tracks mis-numbered in the printed insert, and it appeared as if some of the tracks from "Speed the Parting Guest" were missing, but in fact they are all there.
I rather liked that recording then, and I rather like it now. I can't say the same for "The Hot-Tempered Clavichord."
Another nifty: Bell Labs "The Science of Sound" (Score:5, Informative)
Anyway.
This was a tutorial produced by Bell Labs which has dozens of sonic examples of the effects of filtering out high and low frequencies, overtones, "subjective tones," and so forth and so on. All accompanied by fifties-style authority-figure Edward-R-Murrow type narration...
Re:how ionospheric noise comes about (Score:3, Informative)