none of it is a recording
every sound on this site is a synthesiser running on one machine right
now, built out of oscillators and filters by
a patch file you can read. there is no audio
file behind any of it. for the eighteen real stations, what is being
reconstructed is the format and the path — the interval signal, the
pace of the reading, the voice, and the six hundred miles of atmosphere in
between. the other seven were never on the air anywhere: they were invented
here, out of the same parts, and each one says so.
every station's empty channel is its own
an empty frequency is not silence, it is a place. the static between
transmissions is built from the weather over that transmitter right now:
live readings of atmospheric instability decide how much lightning is
within reach, so havana crackles when havana is unstable and moscow does
not. that sits on a floor of distant tropical storms, because most of the
crashes you hear on shortwave were never local — after dark they
arrive from the tropics wherever you are standing.
on top of that: auroral flutter on the northern paths, which is what a
signal sounds like after it has crossed the auroral oval; the
transmitter's own mains hum at 50 or 60 hz depending on whose grid it is
on; the man-made noise of wherever the receiver is imagined to sit; and
particle counts from NOAA's GOES satellites, one pop per proton.
and its own neighbours
whoever else is on the frequency differs too, at pitches and intervals
belonging to that station, changing through the day: an over-the-horizon
radar pulsing ten times a second, a teleprinter warbling two tones a
hundred and seventy hertz apart, somebody sending morse, or one
unmodulated carrier sliding as the far end tunes up. and often a second
one of another kind: a military radio sounding the band in short
bubbling bursts, a data modem hissing steadily round 1800 hz, an
ionosonde's chirp sweeping through every half minute, the garbled
sidebands of a broadcaster on the next channel, a weather-fax scanning
its lines — or nobody at all. how crowded the channel is, whether
anybody is talking a kilohertz off, how fast its floor wanders and where
its hiss is brightest belong to the channel as well, not to the
receiver.
the randomness is real
the synthesiser cannot roll a die — it has no random number
generator and no clock, by design, so that its tests can assert on audio.
so the entropy comes from outside it: the crashes are seeded off NASA's
record of the last thirty days of solar flares, the same flares that
disturb the real ionosphere. a station relighting an hour from now will
not crackle the way it is crackling now — though what it reads comes
round in the same order every time it starts.
schedules
the real stations keep their real schedules, which means real dead air.
some of them are off for sixteen hours at a stretch. that is not a bug and
it is most of the point. the seven invented ones keep schedules written in
the same idiom.
what is being measured
what the sun is doing ·
where each station stands ·
the catalogue ·
the patch code
privacy
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