(I had published originally this to a group of friends around March 2008...posting a revised version here....)
The Infrasonic 17 Hz tone experiment
*****
The Ghost in the Machine
A significant part of
my childhood was spent among the Santhals (an
ancient group of tribes inhabiting the Chhota Nagpur plateau region of eastern
India and mentioned in the Vedic texts and epics) – I used to visit their
strikingly clean villages, have some of their food, play with a special set of
bows and arrows they had made for me, and of course, listen to the numerous
stories of how they could predict the weather and future seasons by simply
observing nature….
Those were the days
when most houses were not for the humans’ exclusive use, they were shared to a
fair measure, by the flora and fauna of the immediate vicinity: frogs, snails,
lizards, insects, butterflies, bees were our constant companions both inside
and around the house, and many a happy childhood hour was spent simply watching
their antics.
I distinctly remember
watching long lines of ants scurrying from one place to another and my Santhal
gardener telling me that heavy rains were in the offing. If there was a heavy
cloud build-up and the frogs started croaking, he said the rain would be heavy,
while if the frogs remained silent, then there would be a storm and light
rain….I used to be surprised at his confidence, but do not remember now how
many of his predictions ultimately came true or not. They also told me how wild
animals and dogs howled and cats became restless before a flood or any natural
calamity, how you could predict the rain by looking at the moon the previous
night, and many such things…
Many decades have
passed in between – I do not know if those villages exist today, or, if the
“Murmu” and “Tirki” uncles of my childhood are still alive or not, or if their
knowledge of nature has been passed on to their progeny. Forget the frogs and
butterflies, you do not get to see many ants in and around the house either, in
these “fertiliser – pesticide – Lizol” – infested days…..
These thoughts came
to me as I was reading some very interesting articles recently, about which I
will talk now…. (I have deliberately
retained some hyperlinks along the way for background reference.)
*****
The Tsunami of 2004
It is a well known
fact that long before that great tsunami arrived from the Indian Ocean on 26th
December 2004, all the animals living along the coast lines had fled the area….
This was a report
published in a Sri Lankan newspaper on 30th Dec. 2004 : Reports
after Sunday's tsunami say that despite the enormous number of human
casualties—116,000 deaths and rising, at last count—many animals seem to have
survived the tidal wave unscathed. At Sri Lanka's national wildlife park at
Yala, which houses elephants, buffalo, monkeys, and wild cats, no animal
corpses were found on Wednesday.
In Phuket, Thailand,
where the north-bound tsunami wave first struck land, an elephant was seen to
trumpet wildly, break off the chains that tied it to a tree, and rush to higher
ground, quite some minutes before the disaster struck.
How did they know ?
Science, perhaps, has an answer, or perhaps, two answers – infrasound and / or
electromagnetic waves.
****
History
is littered with tales about animals acting weirdly before natural disasters,
but the phenomenon has been hard for scientists to pin down. Sometimes animals
get crazy before a quake, sometimes they don't. Here's what we know: Animals
have sensory abilities different from our own, and they might have been tipped
off to that Sunday's disaster. Do they listen to silent sounds ?
First,
it's possible that the animals may have heard the quake before the tsunami hit
land. The underwater rupture likely generated sound waves known as infrasound
or infrasonic sound. These low tones can be created by hugely energetic events,
like meteor strikes, volcanic eruptions, avalanches, and earthquakes. Humans
can't hear infrasound—the lowest key on a piano is about the lowest tone the
human ear can detect.
A
second early-warning sign the animals might have sensed is ground vibration. In
addition to spawning the tsunamis, that Sunday's quake generated massive
vibration waves that spread out from the epicentre on the floor of the Indian
Ocean to the Bay of Bengal and travelled through the surface of the Earth.
Known as Rayleigh waves (for Lord Rayleigh, who predicted their
existence in 1885), these vibrations move through the ground like waves move on
the surface of the ocean. They travel at 10 times the speed of sound. The waves
would have reached Sri Lanka hours before the water hit.
Mammals,
birds, insects, and spiders can detect Rayleigh waves. Most can feel the
movement in their bodies, although some, like snakes and salamanders, put their
ears to the ground in order to perceive it. The animals at Yala might have felt
the Rayleigh waves and run for higher ground.
*****
We all understand the
“electromagnetic waves” part to some extent. Let us talk about the other piece
: Infrasound.
Infrasound is sound with a frequency too low to be heard by the human ear. The study
of such sound waves is sometimes referred to as infrasonics, covering
sounds beneath the lowest limits of human hearing – 16 hertz down to 0.001
hertz. This frequency range is utilized by seismographs for monitoring
earthquakes. Infrasound is characterized by an ability to cover long distances
and get around obstacles with little dissipation.
Volcanoes produce low-frequency sounds : Possibly the first observation of naturally occurring infrasound was in the
aftermath of the Krakatoa eruption in 1883, when concussive acoustic waves
circled the globe seven times or more and were recorded on barometers
worldwide.
Although
volcanic eruptions are frequently reported with audible observations such as
'booms', 'roars', 'gunshots', or 'jets', these sounds form only the tip of the
iceberg in terms of the total radiated sound energy. Volcanoes are much
more prolific radiators of intense sound in the infrasonic bandwidth (i.e.,
below 20 Hz), which is below the threshold of human audibility.
Our selective hearing is perhaps fortunate because even
small eruptions can produce ~1 Hz infrasound which exceeds 100 Pa at several
kilometers from the vent. If our ears were as sensitive to this low
frequency energy as they are to audible sounds (e.g., at 1000 Hz), the
equivalent sound pressure level (SPL) of 140 dB would be loud enough to cause
pain.
Infrasound was also used by Allied
forces in World War I to locate artillery; the frequency of the muzzle blast
from firing was noticeably different than that produced by the explosion,
allowing the two sources to be discriminated.
Infrasound sometimes results
naturally from severe weather, surf, lee waves, avalanches, earthquakes,
bolides, waterfalls, calving of icebergs, aurora, lightning and sprites. Nonlinear
ocean wave interactions in ocean storms produce pervasive infrasound around 0.2
Hertz known as microbaroms.
Scientists accidentally discovered that the spinning core or
vortex of a tornado creates infrasonic waves. When the vortices are large, the
frequencies are lower; smaller vortices have higher frequencies. These
infrasonic sound waves can be detected up to 100 miles away, and are used to
provide early warning of tornadoes.
Infrasound can also be generated by
man-made processes such as sonic booms, explosions (both chemical and nuclear),
by machinery such as diesel engines and wind turbines and by specially designed
mechanical transducers (industrial vibration tables) and large-scale subwoofer
loudspeakers. The Comprehensive Nuclear-Test-Ban Treaty Organization uses
infrasound as one of its monitoring technologies (along with seismic, hydro-acoustic,
and atmospheric radionuclide monitoring).
Whales, elephants, hippopotamuses,
rhinoceros, giraffes, okapi, and alligators are known to use infrasound to
communicate over distances up to hundreds of miles. It has also been suggested
that migrating birds use naturally generated infrasound, from sources such as
turbulent airflow over mountain ranges, as a navigational aid. Elephants, in
particular, produce infrasound waves that travel through solid ground and are
sensed by other herds using their feet (although they may be separated by
hundreds of kilometers).
While we now know that animals can
detect infrasonic sound, how do humans react ?
Infrasound has been
known to cause feelings of awe or fear in humans. Since it is not consciously perceived, it can make people feel vaguely
that supernatural events are taking place.
Horror movie makers have used this for
years. Irréversible is one such movie by Gaspar Noé.
Alfred Hitchcock used infrasound to produce unease or disorientation in the
audience in some of his film soundtracks.
Is that why when we watch horror
films on television these days we are either bored or sadly amused, because the
amplifiers at the broadcasting station or the TV set would have filtered out
the infrasonic sounds in the sound track ?
The Infrasonic 17 Hz tone experiment
On
May 31, 2003, a team of UK
researchers held a mass experiment where they exposed some 700 people to music
laced with soft 17 Hz sine waves played at a level described as "near the
edge of hearing", produced by an extra-long stroke sub-woofer mounted
two-thirds of the way from the end of a seven-meter-long plastic sewer pipe.
The
experimental concert (entitled Infrasonic) took place in the Purcell Room
over the course of two performances each consisting of four musical pieces. Two
of the pieces in each concert had 17 Hz tones played underneath. In the second
concert, the pieces that were to carry a 17 Hz undertone were swapped so that
test results wouldn't focus on any specific musical piece.
The
participants were not told which pieces included the low-level 17 Hz
near-infrasonic tone. The presence of the tone resulted in a significant number
(22%) of respondents reporting anxiety, uneasiness, extreme sorrow, nervous
feelings of revulsion or fear, chills down the spine and feelings of pressure
on the chest.
In
presenting the evidence to the British Association for
the Advancement of Science (known simply as the BA), the scientists responsible said: "These results
suggest that low frequency sound can cause people to have unusual experiences
even though they cannot consciously detect infrasound.”
*****
The Ghost in the Machine
Research by the late Vic Tandy, a
lecturer at Coventry University, suggested that the frequency 19 hertz was
responsible for many ghost sightings. He was working late one night alone in a
supposedly haunted laboratory at Warwick, when he felt something was watching
over him, his anxiety was growing, and could detect a grey blob out of the
corner of his eye. When he turned to face it, there was nothing.
The following day, he was working on
his fencing foil, with the handle held in a vice. Although there was nothing
touching it, it started to vibrate wildly. Further investigation led him to
discover that a newly installed extraction fan was emitting a frequency of
18.98 Hz, very close to the resonant frequency of the eye (given as 18 Hz in
NASA Technical Report 19770013810).
He deduced that this was why he saw
a ghostly figure — it was an optical illusion caused by his eyeballs
resonating. The room was exactly half a wavelength in length, and the desk was
in the centre, thus causing a standing
wave which caused the foil to vibrate.
Vic investigated this phenomenon
further, and wrote a paper entitled The Ghost in the Machine. He carried
out a number of investigations at various sites, believed to be haunted,
including the basement of the Tourist Information Bureau next to Coventry
Cathedral and Edinburgh Castle.
*****
The “Flying Dutchmen”
This term loosely
refers to the phenomenon of abandoned ships found at sea. The most publicised
case was that of the “Maria Celesta” where investigators found the ship
completely abandoned, as if all on a sudden. There was unfinished food at the
dinner table, and there were the captain’s log entries right up to the end,
which showed everything to be perfectly normal. Not only had the crew
disappeared, they were never found.
Scientists surmise
that perhaps the infrasound from the ocean was responsible. The deep ocean,
under certain conditions, emits sound waves at 7 Hz. Apparently this matches
with the natural frequency of the human brain and the resonance can drive
people mad, even to commit suicide. But I guess this is yet to be proven under
simulated lab conditions…..
*****
While reading and
thinking about this, a thought struck me – could this also be the reason for
the famous Bermuda Triangle mystery ?
If you think about
it, most ghost stories are around empty houses, or tunnel-like structures –
structures that could typically resonate at low frequencies.
Ancient ceremonial
burial sites were commonly designed as a large room with a long, narrow tunnel
leading to the outside – was it by coincidence, or calculations based on some
ancient wisdom, that this design was adopted – one that could resonate at
infrasound frequencies and strike a sense of fear and awe among the living who
dared to enter ?
Is it possible to
theorise that when life emanated from some primordial soup, all creatures had
more or less the same faculties of sense, which got modified over time to suit
the particular immediate environment ? Mankind too, had the same aural
faculties as other animals ? And then, at some point in our evolutionary
history, our aural faculties moved into a higher frequency range to adapt to
our immediate surroundings for reasons of simple survival ? And then, the
skills of the ancestors in listening to these “silent sounds” passed into
folklore ?
Is there a science
behind the ancient folklore of different communities of the world – from the
aborigines of Australia
Can the so-called
“paranormal phenomena” be explained by these “silent sounds” ?
You decide – and let
us know….
Compiled &
collated from these sources :
Loved the article. Very well researched. But it left me with more questions.
ReplyDeleteKeep asking them... Let me try answering.
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