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Frequently Asked Questions
'; document.write(strContentBuffer1323); var strContentBuffer1323 = ''; strContentBuffer1323 += ''; document.write(strContentBuffer1323); var strContentBuffer1323 = ''; document.write(strContentBuffer1323); var strContentBuffer1323 = ''; document.write(strContentBuffer1323); var strContentBuffer1323 = ''; document.write(strContentBuffer1323); var strContentBuffer1323 = ''; strContentBuffer1323 += ''; document.write(strContentBuffer1323); var strContentBuffer1323 = ''; strContentBuffer1323 += 'Please see new Article below added 1/2/10
This is about hearing differences in people. Autistic..
All of my life I hear too much-and require allot of quiet alone
time or I am overwhelmed not only from daily noise but
the Earth/rock/space sounds. My son once commented to me
that I was the only person he\'d ever known who required so much
alone time other than someone locked up in solitary confinement.
I also sing and write music and when I do not I get agitated.
I not only hear more than others-I feel the sounds and electromagnetic
energy. This has been part of my testings done on this site.
I wish to be scientifically tested someday in the near future.
It doesn\'t end there, in the hearing. It is sights, colors,
smells, having to avoid certain clothing, as I itch all over and
have to wear mostly cotton and nothing with tags left on the clothing.
My eldest son is this way too. I have very good smell and taste.
Others who cannot smell or taste bad food, I can and they usually have
me smell it before they prepare it if there is some doubt on their part.
Please See New Article Below added 12/24/09
Please See New Articles below added 11/20/09
Work in Progress Not an official earthquake, storm or volcano prediction site.
Projecting and Tracking Our Planetary Changes; Research: Study with Trial and
Error Testing and Mapping: Earth to Human Body Indicators/Precursors for Quakes, volcanoes
Severe Weather and Other Earth related events including Bomb /
mine blasts and some firestorm events, because body will pick up more than
just quakes and have stated so since this site began in 2005. I do not pick up precursor indicators for bombs, mine blasts or firestorms- these are instantaneous with event. But I do pick up these feelings at the time of event- which I believe to be infra-sound.
Body to Earth Sensing conducted by Pam Wiseman since Feb 2002
I will not always post for every earthquake, storm or volcano indicator I get.
Why? I am human. I need sleep and or I am busy living
See Intro
I post the quake, volcano, severe storm forecasts in Comments GRAY
shaded area, for mag, window, place and or other events, and the program server
in PA time and date stamps it, then I post the follow up and results above it .
If a window is given for the next month, or later it will be copy pasted and transposedno longer doing this)
for that month and results posted.(
New as of Oct 2009: I am not copy pasting original predictions- one has to look in archives for original post- but I am posting info of the prediction on top of page for clear reading.
You can look for the date and time stamp of original post
in archives- thanks.
When I give an approximate magnitude with a number and a + sign it means:
for example: 4+, it is for a mag of 4.0 to 9.9. when I write
"TO a certain mag with +,
it means smaller mag to that and exceeding that mag.
NEW As of Oct 2009: All quake, severe storm & volcano predictions are posted with 85% probability. I will not post probability for each quake prediction.
When I name multiple
place areas, I mean all the areas listed or approximate.
I try to do follow ups asap but usually fall behind as I have limited time. If anyone wants to volunteer to help me hunt down the quakes, storms and volcano
data for my follow-ups and results- please e-mail me.
pam_wiseman@yahoo.com thanks.
Any failure to understand what is already posted here- contact Pam Wiseman
and also see copyright notice here at bottom of page. Again, this is a trial and error work in progress I am doing as research.
********************************
Ra Ma Da™ Sun Moon Earth in Sanskrit, & My Spirit name given in 2002.
Copyright © 2002 to 2010 Pam Wiseman All Rights Reserved
No out of context paraphrasing, personal mis-interpretations or malicious falsifying
statements permitted. No copying or pasting permitted without express permission
by Pam Wiseman. If you have trouble understanding my comments or anything on
this site, please contact author, Pam Wiseman, on COMMUNICATE page or in e-mail
which is also posted there. Links to site are permitted and encouraged.
- What is Body/Earth Sensitivity?
- What is the energy the body picks up on?
I am posting some background information on what the human body and animals may be sensitive to. I have been researching this since I learned I am sensitive to whatever hits me in various areas of my body which tells me where the quake, storm or volcano is going to be. This includes feeling the bomb blasts too.
At first I thought it was ALL infra sound and then I got to looking more into it. It is infra sound, electromagnetic wave energy, and can also be gamma rays.
My first article I found today written by NASA, written today, Oct 26th 2005. Quite revealing and timely. Of course, they only mention what astronauts have to worry about in space. Well I must inform you, that we are not as protected here on Earth as one might hope. After I post this NASA article I will provide link to the Ozone Depletion site. This will help explain and you will see for yourself.
"An Odd List of Body Parts"
"Researchers are making a list: Which parts of an astronaut are most sensitive to solar flares?"
Science@NASA
In case this page gets lost on the internet and link no longer works, I will post the body parts affected by Solar Flares: Hips, shoulders, spine, thighs, sternum and skull.
It is the bone marrow which is affected according to NASA in these bone areas of the body.
They suggest using "a layer of plastic-like material called polyethlene, 1 cm thick could prevent acute radiation sickness."
And now to the Ozone site
While they name body parts here affected by radiation directly caused by the lack of ozone protection, such as the skin and the eyes, this website does not go into mentioning the bone marrow and body areas as does the above article. One should keep in mind the possibility, it is much worse than what we have been told.
I will be posting items I have looked into over the years such as infra sound and EMF sensitivity which have helped me to understand just what I am picking up on when I get body symptoms for various areas of the world.
I have NO idea why my body or anyone else\'s body has certain areas which pick up on this energy correlating to certain areas. I do understand the infra sound waves and how my ears pick up the sounds of the rocks cracking. Why left ear picks up east and right ear picks up west- I have not a clue. I also know that not EVERYBODY is the same, and what one person may pick up in one ear another may pick up in opposite ear and this is the same for body symptoms.
Pam Wiseman
Oct 26 2005
Myth: Ozone Depletion Occurs Only in Antarctica
More links to Earth/Electromagnetic
/Infrasound Sensitivity
Auditory Processing Differences
Earth Stress-Earth Sensitive People
Added 12/24/09
Electromagnetic Field Sensitivity
William J. Rea, MD, FACS
Environmental Health Center, Dallas
8345 Walnut Hill Lane, Suite 205
Dallas, TX 75231
Yaqin Pan, MD
Dept. of Allergy, Beijing Union Medical College Hospital Beijing, PRC
Ervin J. Yenyves, PhD
Dept. of Physics, University of Texas at Dallas
Iehiko Sujisawa, MD. and Hideo Suyama, MD
Dept. of Ophthamology, Kitasato University Kitasato, Japan
Nasrola Samadi, PhD
Jacksonville State University, Jacksonville, Florida
Gerald H. Ross, M.D., CCFP
Environmental Health Center, Dallas
Source: This article was first published in 1991 in the Journal of Bioelectricity, 10(1&2), 241-256. Figure 1is not included here, but can be obtained by writing Dr. W. J. Rea at the Environmental Health Center, Dallas, 8345 Walnut Hill Lane, Suite 205, Dallas, TX 75231.
Abstract
A multiphase study was performed to find an effective method to evaluate electromagnetic field (EMF) sensitivity of patients. The first phase developed criteria for controlled testing using an environment low in chemical, particulate, and EMF pollution. Monitoring devices were used in an effort to ensure that extraneous EMF would not interfere with the tests. A second phase involved a single-blind challenge of 100 patients who complained of EMF sensitivity to a series of fields ranging from 0 to 5 MHz in frequency, plus 5 blank challenges. Twenty-five patients were found who were sensitive to the fields, but did not react to the blanks. These were compared in the third phase to 25 healthy naive volunteer controls. None of the volunteers reacted to any challenge, active or blank, but 16 of the EMF-sensitive patients (64%) had positive signs and symptoms scores, plus autonomic nervous system changes. In the fourth phase, the 16 EMF-sensitive patients wer rechallengd twice to the frequencies to which they were most sensitive during the previous challenge. The active frequency was found to be positive in 100% of the challenges, while all of the placebo tests were negative. We concluded that this study gives strong evidence that electromagnetic field sensitivity exists, and can be elicited under environmentally controlled conditions.
Introduction
Interaction mechanisms that underlie the health and biological effects of electromagnetic fields (EMF) on humans have been studied by many authors.1,2,3,4,5,6 This subject was reviewed recently at the 1990 spring meeting of the American Physical Society .7 Choy et. al.8 investigated individuals with multiple sensitivities who reported reactions to various types of electrical equipment, including power lines, electronic office equipment such as typewriters and computer terminals, video display terminals, household appliances (such as hair dryers), and fluorescent lights.
This paper presents preliminary data on electromagnetic field tests using a square wave generator to evaluate the EMF sensitivity of patients reporting such sensitivities under environmentally controlled and monitored conditions.
Materials and Methods
This study was carried out in four phases.
The major emphasis of this phase of the studies was the evaluation of the effects of the magnetic field generated by a coil fed from a sweep/function generator (Model 3030, B.K. Precision Dynascan Corp.). This equipment allowed us to test square wave frequencies from 0.1 Hz to 5 MHz.
The patients were tested while they were sitting comfortably upright in a chair with the generator on a desk at least 2 m away, with its output connected to a coil 6 cm in diameter and 15 cm tall, made of 35 m of cable and positioned on the floor with its center approximately 0.3 m from the feet of the person tested. The mean values of the alternating magnetic field generated by this arrangement were approximately 2900 nT at floor level, approximately 350 nT at the level of the chair seat and patients’ knees, and about 70 nT at hand level. The exposure period lasted approximately 3 minutes per challenge.
Before the EMF challenge, blood pressure, pulse rate, respiratory rate, temperature, sign and symptom scores, and autonomic nervous system functions were tested. The autonomic nervous system function was tested with a binocular iriscorder (Model C2515, Hamamatsu Photonics), which measured pupil area, time at which constriction and dilation occurred, and rate of constriction/dilation.9
All patients had been previously evaluated and treated for biological inhalant, food, and chemical sensitivities in order to minimize possible confusion from coexisting problems. The patients were stabilized on a healthy diet in a constant low-pollution environment. In addition, they had their overall body load reduced and stabilized in a controlled environment.
II. This was a single-blind screening of 100 patients who cornplained of being EMF-sensitive. They were challenged under low-pollution conditions using the sweep/function generator at 0.1, 0.5, 1, 2.5, 5, 10, 20, 40, 50, 60, and 100 Hz; then at 1, 5, 10, 20, 35, 50, 75, and 100 KHz; and finally at I and 5 MHz. There were twenty-one active challenges and five blanks (placebos) per person, giving a total of 2600 challenges. When the number and/or intensity of symptoms were 20% over baseline, the result was considered positive, and were recorded as such under the various criteria used. A change in the iriscorder readings more than two standard deviations from baseline was also recorded as a positive result.
III. Twenty-five patients who were found to be positive in phase II challenges and who had no more than one placebo reaction were then selected for a third phase of the study. In addition, 25 healthy naive volunteers were challenged. Double-blind EMF challenges and placebos using the aforementioned parameters were performed. There were 1300 total challenges, of which 1050 were active and 250 were blanks. The tests averaged 21 active frequencies and 5 blanks per subject.
IV. Sixteen patients who reacted in phase III were then rechallenged on two separate occasions in a double-blind manner, using only the frequencies to which they had responded most strongly. For each subject, the frequency of maximum sensitivity was inserted randomly into a series of 5 placebo challenges. Thus, there were a total of 32 active challenges and 160 blanks.
Results
Phase I. The EMF measurements were quite reproducible. We found that the lights. and air handling equipment had to be off during the tests because of their electromagnetic field output. Baseline studies on patients were completed without remarkable result.
Phase III. The 25 subjects selected from phase II were rechallenqed, and 16 (64%) reacted positively to the active challenges. The total number of positive reactions to the 336 active challenges in the 16 patients was 179 (53%), as compared to 6 positive reactions out of 60 blanks (7.5%). There were no reactions to any challenge, active or placebo, in the volunteer group of naive subjects (Table 2).
When evaluating frequency response, 75% of the 16 patients reacted to 1 Hz, 75% to 2.5 Hz, 69% to 5 Hz, 69 % to 10 Hz, 69% to 20 Hz, and 69% to 10 KHz (Table 3). No patient reacted to all 21 of the active frequencies in the challenges. The average was 11 reactive frequencies per patient, with a range of 1 to 19 positive responses.
The principal signs and symptoms produced were neurological (tingling, sleepiness, headache, dizziness, unconsciousness), musculoskeletal (pain, tightness, spasm, fibrillation), cardiovascular (palpitation, flushing, tachycardia, edema), oral/respiratory (pressure in earss tooth pains, tightness in chest, dyspnea), gastrointestinal (nausea, belching), ocular (burning), and dermal (itching, burning5 prickling pain) (Table 4). Most reactions were neurological.
Phase IV. In the 16 patients again rechallenged in a double-blind manner, using only the single frequency to which they were most sensitive, all reported reactions to the active frequencies when challenged. None reacted to the placebos (Table 5). Signs and symptoms in all 16 patients were positive as was the autonomic nervous system dysfunction, as measured by the iriscorder (Table 6, Figure 1). Examples of changes were a 20% decrease in pulmonary function and a 40% increase in heart rate. In the 16 patients with positive reactions to EMF challenges, two had delayed reactions; gradually became depressed and finally became unconscious. Eventually, they awoke without treatment. Symptoms lasted from 5 hours to 3 days.
Discussion
Several factors have led us to believe that we have reproducible results. Meticulous construction of environmental rooms made a great difference in the reproducibility of test results. Prior to the use of such facilities and careful monitoring, a variety of factors, such as diet, exposure to chemicals, EMF, or dust gave rise to symptoms which would have been mistaken for placebo reactions. Such effects were minimized here, as evidenced by the sinail number of placebo reactions. A few patients reacted to the tields generated by the monitoring devices (Iriscorder, EKG, and computers) and had to be dropped from the study as too fragile for accurate analysis. Some patients reacted to the fields generated by the fluorescent lights, and others did not present the same signs and symptoms at each challenge, even though the reactions were significant when contrasted with the blank responses. The Iriscorder data were objective, however, and were always reproducible (Figure 1).
In this study, of the 100 patients who expressed suspicion of EMF sensitivity, 75 actually responded to fields, whereas none of the controls did. Of the 75, 25 had no reactions to blanks, whereas 50 did, and thus were discarded from the study; even though we felt that some of the reactions to blanks might be evidence of delayed reaction to previous frequencies, or prolonged response to the previous positive challenge, as well as true placebo reactions.
We learned that challenge with 21 frequencies was impossible on many sensitive patients. They were often unwell for several hours or days, which confused the data from repeat challenges on subsequent days. Hence, we selected the one frequency of maximum sensitivity for repeat challenges in the phase IV studies.
When one compares the various groups to controls, it is clear that there is a group of patients who have unstable response systems which appear different from those of the individuals who acted as controls. These studies show that EMF sensitivity could be elicited under environmentally controlled conditions. As a result of the weak field levels and short exposure time, the responses were mild except in two patients whose symptoms were so severe (e.g., drop attack, severe itching) that they received intravenous vitamin C, magnesium, and oxygen as a result of the prolonged and delayed reactions.
Signs and symptoms appeared similar to those seen in food or chemically sensitive patients at the Environmental Health Center-Dallas, and included neurological, musculoskeletal, cardiovascular, respiratory, gastrointestinal, dermal, and ocular changes. The neurological symptoms were most comon. Similar responses have been recorded by others in the literature.5,6,7,6,13,14 In 1972, after the Soviets reported that electrical utility workers were suffering from listlessness, fatigue, and nausea, Subrohmangam and coworkers13 investigated and reported decisive changes in cardiac function and bioamine levels when pulses of 0.01 and 0.1 Hz were used. They found significant changes in the hypothalamus in response to the EMF fields.
In these studies, the preponderance of reactions occurred at one to 10 Hz, which accords well with their observations. However, many reactions also occurred at 50 and 60 Hz, as well as some up to 5 MHz. We conclude that in any given individual susceptibility may develop to any frequency and produce reactions.
Static magnetic fields are known to cause increased blood pressure on some individuals.14 Choy and coworkers8 found that EMF reactions in EMF sensitive patients were not limited to the nervous system, but occurred in the same systems as in these studies, which basically corroborate theirs, though neurological symptoms predominated in our experiments.
Over the past 30 years, numerous investigations with animals and a few epidemiological studies of human populations have been devoted to assessing the relationship of microwave exposure to cataract development. The severity and speed of formation depends not only on intensity, but also on wavelength and duration of exposure.16-21 McCally et al.22 reported damage to corneal epithelium in Cynomolgus monkeys after 2.45 GHz irradiation for 6everal hours at only 20-30 mW/cm2 (CW) or even 10-15 mW/cm2 with pulsed fields. Therefore, the results of Paz23 strongly suggests that the potential for eye injury exists in surgery where EMF fields are present.
In our experience, the patients’ clinical responses could not always be reproduced completely, but the objective Iriscorder, EKG, and respirometer could be. However, the responses were definitely different from controls or placebo challenges. In our experience over the years, we have found partial reproduction of symptoms on repeat challenge to be as significant as total reproduction. Therefore, significant differences from controls in objective ineasurementa were deemed valid.
Thus far, definitive information has not been sufficient to identify a plausible mechanism for EMF interactions with biological tissue. Interactions appear to take place at the cell surface, perhaps acting on receptor sites and altering ion and molecular transport across the membranes.25 Further work remains to be done in the field.
It is clear that EMF sensitivity is a real phenomenon in some environmentally sensitive patients, because some had consistent reactions while none of the controls did. This study must be considered as only preliminary, but the evidence clearly points to sensitivity in some people.
In conclusion, it is evident that EMF testing is at a rudimentary stage; but clearly EMF sensitivity exists and can be elicited under environmentally controlled conditions. Further studies are needed to investigate the effects of EMF fields on human health.
References
2. Wever, R. A. (1973). Human circadian rhythms under the influence of weak electric fields and the different aspects of these studies. Int. J. Biometeor., 17, 227-232.
3. Smith, C. W. (1985). Superconducting areas in living systems. In R. K. Mishra (Ed.), The living state II (pp. 404-420). Singapore: World Scientific.
4. Phillips, R. D. (1986, Sept.). Health effects of ELM fields: Research and communications regulation. Toronto, Int’l Utilities Symp.
5. Smith, C. W., Jafarg-Asl, A. H., Choy, R.Y.S., & Monro, J.A. (Year?). The emission of low-intensity electromagnetic radiation from multiple allergy patients and other biological systems. In B. Jezowska-Trzebiatowska, B. Kochel, J. Slawinski, and W. Streck (Eds.) Proc. int’l. symp. on photon emission from biological systems (pp. 110-126), Wroclaw, Poland. Singapore: World Scientific.
6. Ketchenm, E. E., Porter, W. E., & Bolton, N. E. (1978). The biological effects of magnetic fields on man. J. Am. Ind. Hyg. Assoc., 39, 1-11.
7. Smith, C.W., & Best, S. (1989). Electromagnetic man. New York: St. Martins Press.
9. Shirakawa, S., Rea, W. J., Ishikawa, S., & Johnson, A.R. (Year?). Evaluation of the autonomic nervous system response by pupillographical study in the chemically sensitive patient. What is this? Where was it published?
10. Microwave News, (1986, Sept./Oct.). (pp. 5, 14)
12. Bullock, T. H. (1977). Electromagnetic sensing in fish. Neurosci. Res. Program Bull., 15, 17-22.
14. Easterly, C. E. (1982). Cardiovascular risk from exposure to static magnetic fields. J. Am. Ind. Hyg. Assoc., 43, 533-539.
15. Randegger, E. (1988). Electromagnetic pollution. Environ., 7, 22-26,
16. Silverman, C. (1980). Epidemiological studies of microwave effects. Proc. I.E.E.E., 68, 78-84.
17. Petersen, R. C. (1980). Bioeffects of microwaves: A review of current knowledge. J. Occup. Med., 25, 103-111.
19. Michaelson, S. M. (1980). Microwave biological overview. Proc. I.E.E.E., 68, 60-69.
20. Carpenter, R. L., & Van Ummersen, C.A. (1968). The effects of 2.4 Ghz radiation. J. Microwave Pwr., 3, 3-19.
21. Clealry, S. (1980). Microwave cataractogenesis. Proc. I.E.E.E., 68, 49-55.
23. Paz, J.D., Milliken, R., Ingram, W.T.,Arthur, F., and Atkin, A. (1987). Potential ocular damage from microwave exposure during electrosurgery: Dosimetric survey. J. Occup. Med., 29, 580-583.
24. Zimmerman, I. (1985). Dry and wet skin resistance: Cow’s lumbosacral regions under 750 KV lines. Int. J. Bio. Meteor., 29, 184.
25. Banks, R.S. (1988). Electric and magnetic fields: A new health issue. Health and Environ., 2, 1-3.
Another Related Article to the Above:
Added 12/24/09
ELECTROMAGNETIC SENSITIVITY (EMS) IS A WORLDWIDE EPIDEMIC
Christiane Tourtet B.A
Feb 19, 2009
Added 12/24/09
EQ-Forecasting Home Page
Infrasound:
Sound waves, particularly in the atmosphere, whose frequencies of pressure variation and of vibration are below the audible range, that is, lower than about 20 Hz. Earthquake and seismic waves are elastic waves which occur at infrasonic frequencies in the Earth\'s crust and in the oceans and seas. The physical laws of propagation in the atmosphere are essentially the same as for audible sound. The local speed of infrasound in air at ambient temperatures near 20°C (68°F) is about 340 m/s (1115 ft/s), the same as for audible sound.
At frequencies less than about 1.0 Hz, infrasound propagates through the atmosphere for distances of thousands of kilometers without substantial loss of energy. Sounds at these frequencies are almost always present at measurable intensities. Those of natural origin have many causes, including tomadoes, volcanic explosions, earthquakes, the aurora borealis, waves on the seas, large meteorites, and lightning discharges. When the wind blows, turbulent pressure fluctuations in the atmosphere occur at amplitudes up to tens of pascals, at infrasonic frequencies. People are unaware of these pressures via the sensation of hearing.
Sufficiently strong infrasound is “audible,” contrary to simple acoustic tradition. The threshold sound pressure level (the least intensity for audibility) is about 92 dB at 16 Hz, and increases 12 dB per octave to about 140 dB at 1.0 Hz. However, there is no sensation of tone. Listeners variously describe audible infrasound as pumping, popping effect, or chugging. For vibration at very low frequencies, motion sickness of people in boats must have been one of the earliest noticeable effects. The human body is particularly sensitive to vibrations and infrasound near 7 Hz, at which frequency there is an overall mechanical resonance of organs in the abdominal and chest cavities. See also Atmospheric acoustics;
Wikipedia: Infrasound:
Infrasound is sound that is lower in frequency than 20 Hz (Hertz) or cycles per second, the normal limit of human hearing. Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high. The ear is the primary organ for sensing infrasound, but at higher levels it is possible to feel infrasound vibrations in various parts of the body.
The study of such sound waves is sometimes referred to as infrasonics, covering sounds beneath 20 Hz down to 0.001 Hz. This frequency range is utilized for monitoring earthquakes, charting rock and petroleum formations below the earth, and also in ballistocardiography and seismocardiography to study the mechanics of the heart. Infrasound is characterized by an ability to cover long distances and get around obstacles with little dissipation.
Contents
[hide]- 1 About infrasound
- 2 Animal reactions to infrasound
- 3 Human reactions to infrasound
- 4 See also
- 5 References
- 6 External links
About infrasound
Possibly the first observation of naturally occurring infrasound was in the aftermath of the 1883 eruption of Krakatoa, when concussive acoustic waves circled the globe seven times or more and were recorded on barometers worldwide. Infrasound was also used by Allied forces in World War I to locate artillery. One of the pioneers in infrasonic research was French scientist Vladimir Gavreau, born in Russia as Vladimir Gavronsky.[1] His interest in infrasonic waves first came about in his lab during the 1960s, when he and his lab assistants experienced pain in the ear drums and shaking lab equipment, but no audible sound was picked up on his microphones. He concluded it was infrasound and soon got to work preparing tests in the labs. One of his experiments was an infrasonic whistle.[2][3][4]
Infrasound sometimes results naturally from severe weather, surf,[5] lee waves, avalanches, earthquakes, volcanoes, bolides,[6] waterfalls, calving of icebergs, aurora, lightning and upper-atmospheric lightning.[7] Nonlinear ocean wave interactions in ocean storms produce pervasive infrasound vibrations around 0.2 Hz, known as microbaroms.[8] Infrasound can also be generated by man-made processes such as sonic booms and explosions (both chemical and nuclear), by machinery such as diesel engines and older designs of down tower wind turbines and by specially designed mechanical transducers (industrial vibration tables) and large-scale subwoofer loudspeakers.[9] The Comprehensive Nuclear-Test-Ban Treaty Organization uses infrasound as one of its monitoring technologies (along with seismic, hydroacoustic, 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 in the case of whales. 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.[10] 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 kilometres.
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, though still infrasonic, frequencies. These low frequency sound waves can be detected for up to 160 kilometres (100 mi) away and can help provide early warning of tornadoes.
A number of American universities have active research programs in infrasound, including the University of Mississippi, Southern Methodist University, the University of California at San Diego, the University of Alaska Fairbanks, and the University of Hawaii at Manoa.
Animal reactions to infrasound
Animals have been known to perceive the infrasonic waves carried through the earth by natural disasters and can use these as an early warning. A recent example of this is the 2004 Indian Ocean earthquake and tsunami. Animals were reported to flee the area long before the actual tsunami hit the shores of Asia.[11] It is not known for sure if this is the exact reason, as some have suggested that it was the influence of electromagnetic waves, and not of infrasonic waves, that prompted these animals to flee.[12]
Infrasound may also be used for long-distance communication in African elephants.[13] These calls range from 15–35 Hz and can be as loud as 117 dB, allowing communication for many kilometres, with a possible maximum range of around 10 km (6 mi).[14] These calls may be used to coordinate the movement of herds and allow male elephants to find mates.
Human reactions to infrasound
20 Hz is considered the normal low frequency limit of human hearing. When pure sine waves are reproduced under ideal conditions and at very high volume, a human listener will be able to identify tones as low as 12 Hz.[15] Below 10 Hz it is possible to perceive the single cycles of the sound, along with a sensation of pressure at the eardrums.
The dynamic range of the auditory system decreases with decreasing frequency. This compression can be seen in the equal-loudness-level contours, and it implies that a slight increase in level can change the perceived loudness from barely audible to loud. Combined with the natural spread in thresholds within a population, it may have the effect that a very low frequency sound which is inaudible to some people may be loud to others.
Infrasound has been known to cause feelings of awe or fear in humans.[16][17] Since it is not consciously perceived, it can make people feel vaguely that supernatural events are taking place.
Some film soundtracks make use of infrasound to produce unease or disorientation in the audience. Irréversible is one such movie.
The infrasound and low-frequency noise produced by some wind turbines is believed to cause certain breathing and digestive problems in humans and other animals in close proximity to the turbines.[18]
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 would not 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.[19][20] In presenting the evidence to British Association for the Advancement of Science, one of 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. Some scientists have suggested that this level of sound may be present at some allegedly haunted sites and so cause people to have odd sensations that they attribute to a ghost—our findings support these ideas."
See also
References
- ^ Chapter 8 "Deadly Sounds" — Dr. Vladimir Gavreau "Lost Science" by Gerry Vassilatos ISBN 0-932813-75-5 © 1999 SIGNALS
- ^ *Gavreau V., Infra Sons: Générateurs, Détecteurs, Propriétés physiques, Effets biologiques, in: Acustica, Vol .17, No. 1 (1966), p.1–10
- ^ Gavreau V.,infrasound,in: science journal 4(1) 1968,S.33
- ^ Gavreau V., "Sons graves intenses et infrasons" in: Scientific Progres – la Nature (Sept. 1968) p. 336–344
- ^ Garces, M.; Hetzer C., Merrifield M., Willis M. and Aucan J. (2003). Observations of surf infrasound in Hawai’i. http://www.agu.org/pubs/crossref/2003/2003GL018614.shtml. Retrieved 2007-12-15. "Comparison of ocean buoy measurements with infrasonic array data collected during the epic winter of 2002–2003 shows a clear relationship between breaking ocean wave height and infrasonic signal levels.".
- ^ Garces, M.; Willis, M. (2006). Modeling and Characterization of Microbarom Signals in the Pacific. http://stinet.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA456958. Retrieved 2007-11-24. "Naturally occurring sources of infrasound include (but are not limited to) severe weather, volcanoes, bolides, earthquakes, surf, mountain waves, and, the focus of this research, nonlinear ocean wave interactions.".
- ^ Haak, Hein (2006-09-01). "Probing the Atmosphere with Infrasound : Infrasound as a tool" (pdf). CTBT: Synergies with Science, 1996–2006 and Beyond. Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization. http://www.ctbto.org/reference/symposiums/2006/haak/0901probingtheatmosphere.pdf. Retrieved 2007-11-24.
- ^ "Microbaroms". Infrasonic Signals. University of Alaska Fairbanks, Geophysical Institute, Infrasound Research Group. http://www.gi.alaska.edu/infrasound/Infrasound254.htm. Retrieved 2007-11-22. "The ubiquitous five second period infrasonic signals called “microbaroms”, which are generated by standing sea waves in marine storms, are the cause of the low-level natural-infrasound background in the passband from 0.02 to 10 Hz."
- ^ Chen, C.H., ed (2007). Signal and Image Processing for Remote Sensing. Boca Raton: CRC. pp. 33. ISBN 0-8493-5091-3.
- ^ Goddard Space Flight Center[dead link]
- ^ How did animals survive the tsunami? - By Christine Kenneally - Slate Magazine:Posted Thursday, Dec. 30, 2004, at 5:47 PM ET
- ^ Nature . Can Animals Predict Disaster? - PBS: posted November 2005.
- ^ Langbauer, W.R.; Payne, K.B.; Charif, R.A.; Rapaport, L.; Osborn, F. (1991), "African elephants respond to distant playbacks of low-frequency conspecific calls", Journal of Experimental Biology 157 (1): 35–46, http://jeb.biologists.org/cgi/reprint/157/1/35.pdf, retrieved 2009-05-27
- ^ Larom, D.; Garstang, M.; Payne, K.; Raspet, R.; Lindeque, M. (1997), "The influence of surface atmospheric conditions on the range and area reached by animal vocalizations", Journal of experimental biology 200 (3): 421–431, http://jeb.biologists.org/cgi/reprint/200/3/421.pdf, retrieved 2009-05-27
- ^ Olson, Harry F. (1967). Music, Physics and Engineering. Dover Publications. p. 249. ISBN 0486217698. http://books.google.com/books?id=RUDTFBbb7jAC.
- ^ John D. Cody. Infrasound Borderland Science Research Foundation
- ^ V. Tandy & T. Lawrence - \'The ghost in the machine\', Journal of the Society for Psychical Research #62, pp.360–364. 1998. AND S. Angliss, GeNIA, C. O\'Keeffe, R. Wiseman & R. Lord - \'Soundless music\', in B. Arends & D. Thackara (eds), Experiments: Conversations in art and science, pp.139–71. The Wellcome Trust: London, 2003. Quote from R. Wiseman, "Quirkology - How We Discover the Big Truths in Small Things", Basic Books, 2007
- ^ HowStuffWorks. Do wind turbines cause health problems?
- ^ Infrasonic concert, Purcell Room, London, 31 May, 2003, sponsored by the sciart Consortium with additional support by the National Physical Laboratory (NPL)
- ^ Sounds like terror in the air Sydney Morning Herald, September 9 2003.
- ^ infrasound
- ^ Guardian Unlimited Archive Search
- ^ Who ya gonna call? Vic Tandy! - Coventry Telegraph
- ^ Internet Archive Wayback Machine. 2007 version of Vic Tandy\'s Ghost Experiment webpage
- "infrasound". Collins English Dictionary, 2000. Retrieved 25 October 2005, from xreferplus. http://www.xreferplus.com/entry/2657949
- Gundersen, P. Erik. The Handy Physics Answer Book. Visible Ink Press, 2003.
- Chedd, Graham. Sound; From Communications to Noise Pollution. Doubleday & Company Inc, 1970.
- O\'Keefe, Ciaran, and Sarah Angliss. "The Subjective Effects of Infrasound in a Live Concert Setting". CIM04: Conference on Interdisciplinary Musicology. Graz, Germany: Graz UP, 2004. 132–133.
- Discovery\'s Biggest Shows aired at 8:00 pm (Indian Standard Time) on The Discovery Channel, India on Sunday, 7 October 2007
External links
![\"\"](\"http://wpcontent.answers.com/wikipedia/en/thumb/f/f2/Edit-clear.svg/40px-Edit-clear.svg.png\"){kind=spacer} | This article\'s external links may not follow Wikipedia\'s content policies or guidelines. Please improve this article by removing excessive or inappropriate external links. (September 2009) |
- Inframatics, an international infrasound monitoring organization
- National Center for Physical Acoustics
- Infrasound Laboratory, University of Hawaii
- Southern Methodist University infrasound studies
- NOAA Infrasonics Program
- US Army Space and Missile Defense Command Monitoring Research Program
- Laboratory for Atmospheric Acoustics, University of California, San Diego
- Los Alamos Infrasound Monitoring Laboratory
- University of Alaska Infrasonics Page
- Infrasound: Air Seismology - from About.com
- Infrasonic and Acoustic-Gravity Waves Generated by the Mount Pinatubo Eruption of June 15, 1991, Makoto Tahira, Masahiro Nomura, Yosihiro Sawada and Kosuke Kamo
- How did animals survive the tsunami?
- Can animals predict disaster?
- "The Acoustics of War", article on infrasound in Cabinet magazine, issue 5
Nov 20/2009WebNews 8.9.2005
http://www.linturi.fi/100_phenomena/2005.html#4
White House and Pentagon to get protective infrasound "overcoat"
Well-placed sources in Washington report that the U.S. Budget for 2006 will contain outlays of some USD 4,200 million for the protection of the nation\'s important strategic sites with infrasound fields.
The decision on infrasound protection was taken after the successful quelling of the Los Angeles AIDS riots during the summer. L.A. police riot squads used portable infrasound generators on the rioters and looters, and brought the disturbance to a relatively peaceful end within an hour. On the strength of these field-trials, such key sites as the White House complex, the Pentagon, the most important foreign legations, and the UN Headquarters in New York will all be equipped with a chain of generators.
Infrasound is known as a very powerful stunning and paralysing agent, and carries the added advantage of not being lethal in use. The principle is based on very low sounds at frequencies well below the 20 hertz threshold of normal human hearing. At high volumes, however, these sound waves cause the hearer to lose all sense of time and place, and also provoke intense nausea. If the intensity of sound is sufficient, any person struck by the infrasound waves also loses control of his bowels, and will become completely incontinent. After the recent incident in Los Angeles, which was suffering a heatwave at the time, the L.A. Police Department noted that the device was extremely effective in operation, but that the stench left behind was enough to turn one\'s stomach. The aim in shielding important strategic buildings with an infrasound "overcoat" is to prevent - without bloodshed - possible attacks by terrorist groups or crowds of rioters.
The United States Army began the development of battlefield infrasound equipment some ten years ago, and reportedly infrasound was also tested in the seige of the headquarters of the Branch Davidian cult in Waco, Texas in 1993. Installation of the first generator networks around buildings in the capital and New York is expected to get under way next spring.
Nov 20, 2009
Plasma\'s Produce Acoustic &Electromagnetic Waves
http://twistedphysics.typepad.com/cocktail_party_physics/astrophysics/
In fact, according to Don Gurnett, a physicist at the University of Iowa who builds plasma wave receivers for NASA, the sounds of space are far more varied and complex than on Earth, because of the ionization: plasmas produce a mixture of acoustic and electromagnetic waves (the latter usually in the radio frequency of the spectrum). Gurnett says that when his team first launched a plasma wave receiver into Earth\'s orbit in 1962, they were "astonished to find that space is filled with a rich variety of sounds." He\'s been collecting recordings of space sounds ever since (more than 40 years now!), from all the major missions, including Voyager I, Galileo, and Cassini. What do plasma waves sound like? It depends. Lightning produces whistling sounds, regardless of whether it strikes on Earth or on Jupiter, and of course, so do the charged particles in Hill\'s aurora borealis. The magnetic fields surrounding the planets can trap electrons, producing bird-like chirps. And the sun emits high-velocity plasma known colloquially as the solar wind, which produces turbulent shock waves and an accompanying roaring boom.
To Gurnett\'s ears, it sounded a lot like music. Minimalist composer Terry Riley agreed when he heard them: he drew inspiration from Gurnett\'s recorded space sounds while composing "Sun Rings" for the Kronos Quartet several years ago. "Sun Rings" is a suite of 10 "spacescapes," each a complex layering of musical elements combining Gurnett\'s celestial sounds with projected space images and the world-famous string quartet in a live multimedia production. (Note that multimedia seems to be all the rage when it comes to making music from the sounds of space -- the marriage of visual and aural is an unbeatable combination!) Composing the piece took Riley over a year, and made for some interesting inspirations. He\'s said in interviews that the crackling and squealing sonic patterns from the magnetic field around Ganymede reminded him of a voice saying "beebopterismo" -- and that became the starting point for one of the movements in the "Sun Rings" suite.
"Sun Rings" first debuted in 2002, and has been performed all over the world since then, garnering rave reviews. For instance, the Los Angeles Times dubbed it "an empyrean masterpiece" that ushered in "a whole new chapter in the age-old quest for a music of the spheres." (You knew someone had to bring up that Pythagorean chestnut, right? If they hadn\'t, I certainly would have done so. Jen-Luc Piquant would never forgive such a lapse.) Alas, the Kronos Quartet has yet to make an official commercial recording of the suite -- they\'re very busy people, in high demand -- but it\'s only a matter of time. I hope. It could be an expensive proposition given the multimedia aspect. Why can\'t NOVA team up with Masterpiece Theater or that PBS staple, "Great Performances," to share the costs? Granted, Riley isn\'t the most mainstream of composers, but I don\'t see how you go wrong with Kronos + Pretty Pictures of Space + Weird Cosmic Sounds. While we\'re waiting, you can listen to some samples at Gurnett\'s Website and on NPR.
David Harrington, artistic director for Kronos Quartet, told the Tucson Weekly in 2002 that he considered Gurnett "an instrument maker.... He made an instrument that was able to translate plasma waves into sound. Gurnett is more circumspect, insisting that he\'s no musician, and doesn\'t even play an instrument. But he admits that he must have some innate musical sensibility: "I always recognized these sounds as having a musical quality. That\'s why I started collecting them in the first place."
As with the aurora borealis, the exact mechanisms by which these sounds are produced remain something of a mystery. "If you\'re sitting in an absolutely quiet room, you don\'t expect the molecules in one particular corner to the room to suddenly start singing at you, but this actually happens in a plasma," says Gurnett. And studying this unique acoustical feature of plasma does have some bearing on a far more practical concern: making controlled fusion a viable energy source here one earth. One of the biggest problems with generating nuclear fusion in our big terrestrial machines (like ITER, still under construction) is that the machine starts generating these plasma waves, thereby disturbing the orbits of the subatomic particles. The result is massive energy losses, which is one of the main reasons why we have yet to tap into the sun\'s energy source to meet our own growing energy demands. The conversion rates (and economies of scale) just aren\'t up to par yet.
Riley\'s suite, and Hill\'s multimedia installation, might challenge some people\'s concept of the kinds of sounds we consider to be "musical," i.e., aesthetically pleasing. But the underlying physical observations -- the sounds of the cosmos -- challenge our basic assumptions of what constitutes "sound." Most of us think of sounds as something we can hear, but in truth, our range of hearing is limited to a very narrow frequency range. In fact, we\'re talking about simple pressure waves traveling through a medium, at frequencies that are both too high and too low for the human ear to detect -- not just those waves whose frequencies we can hear directly. As such, acoustics provides a useful new lens through which to view celestial phenomena. That\'s why studying the acoustics of celestial bodies is pretty much all the rage these days in astrophysics circles. For instance, check out Paul Burke\'s sonification of a pulsar, or this analysis of ultrabass sounds of the giant star Xi Hya. Artists like Hill, and composers like Riley, are just taking that fundamental research and putting it to excellent aesthetic/creative use. ![\"Perseus_xray\"](\"http://twistedphysics.typepad.com/.shared/image.html?/photos/uncategorized/2008/03/03/perseus_xray.jpg\" "\\"Perseus_xray\\"")
Paint It Black
My personal favorite acoustical object in the cosmos is "singing" black holes. NASA\'s Chandra X-Ray Observatory first detected sound waves from a super-massive black hole in the Perseus cluster in 2003 -- revealed via ripples in the gas filling the cluster. (I\'d bet a nonfat latte that Phil Plait covered this when the news first broke.) Translated into musical terminology, the pitch of the sound is equivalent to the note of B flat -- albeit a B flat 57 octaves below middle C. A typical piano, if you care, only has about seven octaves. So we\'re talking about a frequency over "a million billion times deeper than the limits of human hearing." The press release claims it is "the deepest note ever detected from an object in the universe." (Jen-Luc opines that at least it isn\'t the infamous "brown note," which corresponds to F sharp, or 46.25 Hz.)
In this case, scientists think they understand the mechanism at work to produce the "sounds": the supermassive black hole\'s greedy, guzzling eating habits. Basically, objects that pass beyond the event horizon fall toward the center of the black hole, and as they do so, they produce a magnetized jet of high-energy particles powerful enough to blast away from the black hole close to the speed of light. (How this fits in with the notion that nothing can escape a black hole, not even light, is a bit puzzling to me, but we\'ll go with it for now. Feel free to offer clarifications!) That jet plows into the surrounding gas, creating a magnetized bubble of high-energy particles, and as often happens with a collision, this in turn creates a shock wave -- intense sound waves rush ahead of the expanding bubble. The rippling remnants of that shock wave are what Chandra detected.
A Primal Scream
Finally, how can we not mention Mark Whittle? Whittle is a humble astronomy professor at the University of Virginia who made headlines around the world in 2005 when he unveiled his simulated soundtrack to the birth of our universe 13.7 billion years ago. The Big Bang is a bit of a misnomer: technically, it was neither big, nor a bang, and Whittle\'s analysis reflects that. He describes the associated birthing cries as "a descending scream, building into a deep rasping roar and ending in a deafening hiss" -- which sounds an awful lot like the sounds made by mothers giving birth, to the terror of anyone in the delivery room with them at the time. As with mothers, so with our cosmos. In the first 380,000 years of the universe, it was filled with a "rapidly expanding, hot glowing fog" -- essentially a primordial cosmic atmosphere. So yes, there could be sound in the early universe.
The Cosmic Microwave Background Radiation, first detected in 1963 by Bell Labs scientists, is the "echo" of that first primal scream... a kind of "hiss" that permeates the universe uniformly. In 2003, the Wilkinson Microwave Anisotropy Probe (WMAP) generated its own headline when it provided the most detailed microwave map of space to date. It revealed minute variations in the background radiation, and the peaks and troughs of sound waves traveling through the early universe. The sound spectrum spans about 10 octaves, all well out of the range of human hearing, and thanks to computing technology, Whittle was able to translate that into an audible version and condense that first 380,000 years into five seconds. Have a listen here. It sounds rather like a jet engine slowly turning into static or white noise.
See? There\'s an entire universe of sound out there, just beyond our ken, that most of us never stop to think about. Adjust our thinking just a tad bit more, and we can view the quantum world in an acoustical light (pun unintended, but a propos) as well. Since they phrase it better than I ever could in a mere blog post, I leave you with this prescient quotation from a 1988 book by Frank Wilczek and Betsy Divine, Longing for Harmonies: Themes and Variations from Modern Physics, in which the authors describe the spectrum of light at various wavelengths emitted from an object (an atom, for instance) as "its own unique chord":
"[the] marvelous dream [of the music of the spheres] is in fact closely realized in the physical world. The spheres, however, are not planets, but electrons and atomic nuclei, and the music they emit is not in sound but in light.... If our eyes were more perfect, we would see the atoms sing."
Thanks to the glories of modern science, we can not only see unprecedented images of our universe that would otherwise be beyond our limited sensory ken -- we can also hear (literally!) the age-old "music of the spheres."
Nov 20, 2009
http://www.johnholland.ws/home/acousticwave/infobooklet
![\"Information](\"http://www.johnholland.ws/images/titles/acoustic.gif\")
Sound Waves
Sound waves propagate in a variety of media, unaffected by the limits of human hearing, and range from tiny microacoustic waves in a plasma, to large-scale galactic waves in the interstellar medium. The presence of various sound waves in the surrounding media produces a continuum of interactive sound events which occur throughout the universe at various orders of magnitude and scale.
Sound waves occur in gas, liquids, organic and inorganic solids, in plasmas and superconductors, and in interplanetary, interstellar, and intergalactic media. Various sound waves are propagated in the Earth¹s atmosphere, hydrosphere, biosphere, and lithosphere, as well as on or near other planetary bodies and satellites, in the stellar wind, on the surface of stars, in interstellar dust clouds, in spiral galaxies, and in intergalactic clouds which occur in the regions between galaxies and clusters of galaxies.
Sound waves in the surrounding media oscillate at frequencies which range from billions of cycles per second, to a single cycle within a period of several days, months, or years. Sound waves propagate at speeds ranging from subsonic velocities of several feet per second, to hypersonic velocities which approach the speed of light.
The detectable range of sound extends from microacoustic waves produced by fluctuations of particles trapped within a sound field, to macroacoustic wave disturbances including weather patterns, ocean waves, seismic waves, global waves, solar waves, and galactic waves.
Sound Sources
Sound waves are generated by a variety of sound sources in which oscillations produced at the source are transmitted outward into the surrounding medium.
The physical dimensions, material substance, density, and elasticity of a sound source, and the actions and forces which cause the source to vibrate, determine the vibrational properties of the corresponding sound wave.
Normally an acoustic sound source vibrates at a frequency which is related to the length or diameter of the source, and depends upon its various dimensions, mass, density, and tension. The intensity of the action or force which causes a sound source to vibrate determines the amplitude of the corresponding sound wave.
Acoustic wave disturbances in the surrounding media are caused by stationary or moving sound sources which vibrate freely or by a forced agitation, by the angular rotation of solid bodies which are large compared to the particles in the medium in which they are contained, by the translation of objects or steady flow of wind or other substance through a medium, by compressional or magnetic lines of tension or stress, by interactions which occur at the boundary interface between different media or between different regions of the same medium, or by electromagnetic or electromechanical oscillation.
Wave Forms
Various generic wave forms are graphically represented by the symbols in the Acoustic Wave Spectrum. These waves propagate in a variety of media at different speeds, and have different vibrational characteristics depending on their source. They include traveling waves, standing waves, internal waves, surface waves, trapped waves, thermal waves, shock waves, and plasma waves.
Every sound wave propagates as a traveling wave or a standing wave. In addition sound waves may propagate in other forms sush as on the surface of a medium, as a shock wave, etc. Symbols for traveling and standing waves are graphically displayed to the left of each wave form on the chart. Symbols for the other wave forms are displayed to the right.
Traveling Wave
A traveling wave is a progressive wave which propagates in a linear direction within a medium, or within a confined region of a medium. A normal sound produced in air forms a typical traveling wave.
Standing Wave
A standing wave is a nonlinear traveling wave which is produced within a confined medium or region of a medium.
Standing waves travel in a cyclical path within the region of a medium in which the wave is confined. Standing waves propagate by continuous or partial reflection, by dispersion, as radial waves which travel a short distance from the source, or as periodic formations which evolve over time. Internal Wave
An internal wave is a sound disturbance caused by spontaneous fluctuations within a medium. Internal waves are normally produced by interaction at the boundaries between the various layers of a medium, or by turbulence or heat sources. Internal waves propagate as global and local thermal cycles in crystalline solids, including seismic waves caused by earthquakes and underground nuclear explosions.
Internal waves are also spontaneously generated in organic substances such as bone tissue and trees, in plasmas, and in electrically conductive solids, including various metals, semiconductors, and superconductors.
Surface Wave
A surface wave propagates on the free surface of a liquid or solid. In liquids, surface waves describe a forward rolling motion, such as ocean waves, in which crests and troughs are generated in the free space just above the surface. Surface waves in liquids also propagate as ring-shaped waves which travel outward as an expanding series of concentric circles.
In solids, waves are dispersed on the surface of a sound source forming standing waves which travel in a nonlinear path along the surface boundary, or along tensional nodes associated with various areas of the surface. In addition there are small-scale stress waves which travel along the surface of crystalline solids, sand and snow waves, and seismic waves which propagate along the surface of a planetary body.
Trapped Wave
A trapped wave is a deflected wave which is continuously reflected or trapped within an enclosed boundary. Trapped waves occur between layers of the atmosphere of the Earth or other planets, within the Earth\'s liquid core, as microthermal waves trapped within normal sound waves in air, liquids, and organic substances, and within the interior of the Sun or other hot stars.
Thermal Wave
A thermal wave is a sound disturbance caused by periodic fluctuations in the temperature or velocity of the particles in a confined medium, as opposed to normal sound waves which are distinguished by pressure disturbances.
Microthermal waves are infinitesimal fluctuations in the velocity of the trapped particles which accompany normal sound waves in air, electron waves in a plasma, small-scale stress waves in a superconductive solids, and so-called second sound waves in supercooled liquid helium. Macrothermal waves are large-scale fluctuations of the atmo-sphere or hydrosphere of the Earth or other planetary bodies.
Shock Wave
A shock wave is caused by a violent disturbance of the particles in a medium.
When a vibrating force causes a sound disturbance of sufficient strength that the amplitude of the disturbance is nearly unrestricted, the rapid acceleration caused by the strength of the initial disturbance piles up a density of particles in front of the wave which rapidly steepens, producing a sudden discontinuity in the path of travel. The discontinuity in a shock wave creates an irregular vibration of the wave which travels outward in all directions at supersonic speed without further disruption.
Shocked sound waves are produced by small disturbances such as the bursting of a balloon or a small explosion, or by large disturbances such as a flash of lightning causing a thunderous sound, the motion of a foreign object such as an airship or meteorite traveling at supersonic speed, or by various chemical or nuclear explosions.
In addition, large-scale radial waves, or so-called standing shock waves, are produced by the rotation of stars or galaxies, and by stellar explosions including supernovas.
Plasma Wave
A plasma wave is produced by a local disturbance caused by instabilities of the motions in a plasma medium.
A plasma is a medium of gaseous matter which differs from other gas by its high temperatures, electrical and thermal conductivity, by complex particle and wave interactions, and by the emission of electromagnetic radiation.
Plasma media include stars, the solar and galactic wind, the upper atmospheres of various planetary bodies, flames, chemical and nuclear explosions, electrical discharges, and certain metals including copper, silver, and gold.
A plasma medium may contain electromagnetic waves, as well as sound waves of various kinds.
When sound waves and electromagnetic waves interact in a plasma medium, they produce normal, electroacoustic, and magnetoacoustic waves which travel at or near the speed of sound, or at hypersonic speeds.
© John Holland Acoustic Wave Spectrum 1997,
Graphic Symbols: Amy Robinson
American Sound Press U.S.A.
All material Copyright © 1990-2007 John Holland :: We