Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: mriver8 on 11/09/2014 00:59:14

Title: Can someone explain to the relationship between EMF radiaition and sound waves?
Post by: mriver8 on 11/09/2014 00:59:14
Can someone explain to the relationship between EMF radiaition and sound waves in a brief summary please?
Title: Re: Can someone explain to the relationship between EMF radiaition and sound waves?
Post by: PmbPhy on 11/09/2014 03:54:39
Quote from: mriver8
Can someone explain to the relationship between EMF radiaition and sound waves in a brief summary please?
No. The reason being is that a relationship between two or more things are connected. EMF radiation and sound waves are not connected at all. At most they have certain things in common such as frequency, wave speed, phase speed and amplitude.
Title: Re: Can someone explain to the relationship between EMF radiaition and sound waves?
Post by: evan_au on 11/09/2014 12:16:33
What is vibrating?
Sound waves are carried as a physical vibration of matter particles (atoms and molecules). If a sound reaches a place where there are no molecules (such as the edge of space), it dies out.

Electromagnetic radiation is carried as an oscillation of electric and magnetic fields. It does not need any matter to vibrate, and travels quite well through a vacuum. That is why we can see the Sun and other stars.

Types of Vibration?
In a gas, sound waves are carried as a longitudinal vibration, with the atoms moving backwards and forwards in the direction that the sound wave is traveling.
Electromagnetic waves have the electric and magnetic fields at right angles to each other, and at right angles to the direction of travel.
In a solid, it is possible to have sound waves that vibrate at right angles to the direction of travel.
Title: Re: Can someone explain to the relationship between EMF radiaition and sound waves?
Post by: PmbPhy on 11/09/2014 12:33:47
What is vibrating?
Sound waves are carried as a physical vibration of matter particles (atoms and molecules). If a sound reaches a place where there are no molecules (such as the edge of space), it dies out.

Electromagnetic radiation is carried as an oscillation of electric and magnetic fields. It does not need any matter to vibrate, and travels quite well through a vacuum. That is why we can see the Sun and other stars.

Types of Vibration?
In a gas, sound waves are carried as a longitudinal vibration, with the atoms moving backwards and forwards in the direction that the sound wave is traveling.
Electromagnetic waves have the electric and magnetic fields at right angles to each other, and at right angles to the direction of travel.
In a solid, it is possible to have sound waves that vibrate at right angles to the direction of travel.
FYI - That's not a description of the relationship between the two. That's a compare and contrast between them.
Title: Re: Can someone explain to the relationship between EMF radiaition and sound waves?
Post by: yor_on on 11/09/2014 14:05:52
Well, they are often presented as relating to each other in their behavior, but It's like Pete said, and Evan described. They are different phenomena, although I've seen a lot of sites using normal 'physical' waves to describe, for example, lights duality. But there is a relation somehow in their behavior, so you have a point there mr :) If there was no relation between ordinary waves and Electro magnetic waves physics sites wouldn't use it I think? Then again, we started from physical matter once upon a time, as water and waves. From that we went into electricity and found a similarity in its behavior. We love to find patterns :)
Title: Re: Can someone explain to the relationship between EMF radiaition and sound waves?
Post by: mriver8 on 21/09/2014 03:48:55
I'm referring to the Frey Effect can you explain this in simpler terms?


Microwave auditory effect
The microwave auditory effect, also known as the microwave hearing effect or the Frey effect, consists of audible clicks (or, with speech modulation, spoken words) induced by pulsed/modulated microwave frequencies. The clicks are generated directly inside the human head without the need of any receiving electronic device. The effect was first reported by persons working in the vicinity of radar transponders during World War II. These induced sounds are not audible to other people nearby. The microwave auditory effect was later discovered to be inducible with shorter-wavelength portions of the electromagnetic spectrum. During the Cold War era, the American neuroscientist Allan H. Frey studied this phenomenon and was the first to publish[1] information on the nature of the microwave auditory effect.

Pulsed microwave radiation can be heard by some workers; the irradiated personnel perceive auditory sensations of clicking or buzzing. The cause is thought to be thermoelastic expansion of portions of auditory apparatus.[2] The auditory system response occurs at least from 200 MHz to at least 3 GHz. In the tests, repetition rate of 50 Hz was used, with pulse width between 10–70 microseconds. The perceived loudness was found to be linked to the peak power density instead of average power density. At 1.245 GHz, the peak power density for perception was below 80 mW/cm2.[citation needed] However, competing theories explain the results of interferometric holography tests differently. [3]

In 2003, the US Navy conducted research on an MAE system they called MEDUSA (Mob Excess Deterrent Using Silent Audio) as a way to remotely, temporarily incapacitate personnel.[4][5][6] The system was designed by WaveBand Corporation in 2003-2004.[5] The system relied on the principle of MAE, varying the power and parameters of the microwave pulses “to raise the auditory sensation to the ‘discomfort’ level, deterring personnel from entering a protected perimeter or, if necessary, temporarily incapacitating particular individuals.”