|
|
 | | From: | eric bazan | | Subject: | Directed sonic weapons - new info | | Date: | 22 Nov 2004 15:38:49 -0800 |
|
|
 | (...)
Deafening silence. Well, I knew this would be a hard sell.
Let me take one more stab at this, then I'll f*ck off.
Below is a very interesting link I've uploaded to my site. Keep in mind this is from 2000. It talks about new breakthroughs by an MIT student (F. Joseph Pompei ) regarding creating, focusing, and controlling ultrasound:
http://www.fractalfreak.com/harass/AudioLight.html
They talk about new transducers, which, while only a foot in diameter, can produce a focused ultrsonic beam with a spread of about 3 degrees, and range of 100 meters:
" In order to obtain such narrow directivity from a traditional loudspeaker system, one would need a loudspeaker array fifty meters across! "
And:
" The directivity, or narrowness, of an acoustic wave generated by a circular transducer is proportional to the ratio of the diameter of the transducer to the wavelength of the sound. So a transducer much larger than the wavelength of the sound creates a very narrow beam. "
" Audible sound contains wavelengths reaching lengths of several feet, so a reasonably sized loudspeaker will always produce a very wide, non-directional source at lower frequencies. The Audio Spotlight, in contrast, outputs short, millimeter sized ultrasonic waves, which form a very narrow beam even in a small transducer, which in turn generates audible sound. The nature of the nonlinear transformation also essentially eliminates sidelobes in the resulting beam, and maintains relatively uniform directivity across the entire audible frequency range. "
I'll try to be more specific.
Could these ultrasonic beams of sound be focused through commonly used builing materials, perhaps just a floor or a wall, without losing much coherence? (especially if a computer tailored the signal?) I'm just talking about a brief second or two burst, because I assume the power needed would be high.
What would be the effects, to the body, of being hit by one of these ultrasonic waves? How would it feel? Keep in mind these beams can be modulated anyway desired.
Apparently, using interference, or beats, two or more of these beams can be focused to an area of space. Infrasound, and audible sound, can be created at the point in space where they interfere. This apparently can already be done.
So already it would be possible to create rumbles or vibrations by focusing these ultrasonic beams.
Assuming they could be targeted through a house, most of the effects I speculated would be possible.
I'm talking about a short burst type weapon. Just enough to deliver a tap, poke or jolt to the body. Enough to wake someone up. This needn't take much energy. I see many possibilites using this scheme.
Am I way off base? Opinions?
-Eric B
|
|
 | | From: | Cyrus | | Subject: | Re: Directed sonic weapons - new info | | Date: | Tue, 23 Nov 2004 06:39:22 GMT |
|
|
 | In article , boo@fractalfreak.com (eric bazan) wrote:
> (...) > > Deafening silence. Well, I knew this would be a hard sell. > > Let me take one more stab at this, then I'll f*ck off. > > Below is a very interesting link I've uploaded to my site. > Keep in mind this is from 2000. It talks about new breakthroughs > by an MIT student (F. Joseph Pompei ) regarding creating, > focusing, and controlling ultrasound: > > http://www.fractalfreak.com/harass/AudioLight.html > > They talk about new transducers, which, while only a foot in > diameter, can produce a focused ultrsonic beam with a spread > of about 3 degrees, and range of 100 meters: > > " > In order to obtain such narrow directivity from a traditional > loudspeaker system, one would need a loudspeaker array fifty > meters across! > " > > And: > > " > The directivity, or narrowness, of an acoustic wave generated > by a circular transducer is proportional to the ratio of the > diameter of the transducer to the wavelength of the sound. So > a transducer much larger than the wavelength of the sound > creates a very narrow beam. > " > > " > Audible sound contains wavelengths reaching lengths of several > feet, so a reasonably sized loudspeaker will always produce a > very wide, non-directional source at lower frequencies. The > Audio Spotlight, in contrast, outputs short, millimeter sized > ultrasonic waves, which form a very narrow beam even in a > small transducer, which in turn generates audible sound. The > nature of the nonlinear transformation also essentially > eliminates sidelobes in the resulting beam, and maintains > relatively uniform directivity across the entire audible > frequency range. > " > > I'll try to be more specific. > > Could these ultrasonic beams of sound be focused through commonly > used builing materials, perhaps just a floor or a wall, without > losing much coherence? (especially if a computer tailored the signal?) > I'm just talking about a brief second or two burst, because I > assume the power needed would be high. > > What would be the effects, to the body, of being hit by one > of these ultrasonic waves? How would it feel? Keep in mind > these beams can be modulated anyway desired. > > Apparently, using interference, or beats, two or more of these > beams can be focused to an area of space. Infrasound, and audible > sound, can be created at the point in space where they interfere. This > apparently can already be done. > > So already it would be possible to create rumbles or vibrations > by focusing these ultrasonic beams. > > Assuming they could be targeted through a house, most of the > effects I speculated would be possible. > > I'm talking about a short burst type weapon. Just enough to > deliver a tap, poke or jolt to the body. Enough to wake someone > up. This needn't take much energy. I see many possibilites using > this scheme. > > Am I way off base? Opinions? > > -Eric B
Perhaps you yourself would better understand things if you picked up a book that deals with the subjects of human ears, sound, air and electricity.
I am by no means an expert or an MIT graduate. But reading further into the link on your site only points to basically a directed 'full range' speaker for public address systems or for background music in a shopping mall etc.
Usually, in order to shake things or disturb people/animals you need lower frequencies. In the link you provided, the "Audio Spotlight" 'extends down to a few hundred Hertz' which is about the mid to lower midrange frequencies of human hearing. It also states that it can reach upwards beyond the range of human hearing.. which is basically sending out radio waves. There are more frequencies traveling through the air at any given time than you'll ever know.
Humans can feel lower frequencies (1hz-50hz) (broad generalization for those in the know.). Humans can hear midrange frequencies to the lower khz region (100hz-20khz~) (another broad generalization.). Anything above that (megahertz-gigahertz range) is in the operation range of ham radio, cell phones, cordless phones etc.
Lower frequencies can travel through objects, walls, buildings but usually are very omnidirectional. Higher frequencies that are audible to humans don't travel all that well through anything. Play your stereo, walk into another room and close the door. You hear more bass than the higher frequencies. Some higher frequencies that are audible to humans bounce off of objects.. the link you provided mentions that as well. For sound to seem like its coming from another source.
Another thing to mention is loudness.. as measured in db. The link you provided mentions this device going to about 90db. I could be wrong but i remember the OSHA regulations state that 115db is dangerous for workers to be around constantly. Which IMO isn't very loud at all.. but can be when listened to for long periods of time.
I didn't go entirely through your site about the things keeping you awake at night. My first ideas are the building settling strucuturally, neighbors playing bassheavy music elsewhere in the building(because buildings aren't built with noise transmission taken into account)and rattling things around you. Or it could simply be tinnitus.. the ringing in your ears when the noise floor around you gets obscenely low. In other words, don't listen to music so loud anymore. There is no cure for tinnitus and it only gets worse with age.
hth,
-- Cyrus
*coughcasaucedoprodigynetcough*
|
|
 | | From: | eric bazan | | Subject: | Re: Directed sonic weapons - new info | | Date: | 24 Nov 2004 12:45:19 -0800 |
|
|
 | Cyrus wrote in message news:... > In article , > boo@fractalfreak.com (eric bazan) wrote: > > > (...) > > (...) > > Lower frequencies can travel through objects, walls, buildings but > usually are very omnidirectional. Higher frequencies that are audible to > humans don't travel all that well through anything. Play your stereo, > walk into another room and close the door. You hear more bass than the > higher frequencies. Some higher frequencies that are audible to humans > bounce off of objects.. the link you provided mentions that as well. For > sound to seem like its coming from another source. > (...)
Sounds like what I'd be looking for is something with the penetrating power of infrasound, but the directionality of ultrasound.
I agree, I just can't see how ultrasonic beams could be directed through solids without losing nearly all their coherence, or even simply being reflected.
I don't know if the 'loudness' is necessarily a factor with ultrasound, as the vibrations are far above humane hearing.
Anyway, thanks for the response.
-Eric B
|
|
 | | From: | Jay Kadis | | Subject: | Re: Directed sonic weapons - new info | | Date: | Tue, 23 Nov 2004 09:28:11 -0800 |
|
|
 | In article , boo@fractalfreak.com (eric bazan) wrote:
[snip]
> > Am I way off base? Opinions? > > -Eric B
Have you been checked for sleep problems? There are known neurological syndromes that result in sleep disturbances not unlike what you are describing. I would think that might be a more likely cause than ultrasonic interference from outside. Sleep clinics are available in many areas of the country.
-Jay -- x------- Jay Kadis ------- x---- Jay's Attic Studio ------x x Lecturer, Audio Engineer x Dexter Records x x CCRMA, Stanford University x http://www.offbeats.com/ x x---------- http://ccrma.stanford.edu/~jay/ ------------x
|
|
 | | From: | boo at fractalfreak.com | | Subject: | Re: Directed sonic weapons - some patents | | Date: | 16 Jan 2005 00:59:28 -0800 |
|
|
 | Well, apparently some of the sonic weapons I speculated on are possible. Check out the patents below, which employ various means (including interfering waves) to create directed sonic pulses and 'effects'.
You can do a patent search on these patents at the USPTO search page: (type in the patent # for more info) http://patft.uspto.gov/netahtml/srchnum.htm
3,612,211 (** unable to lookup) method of produciung locally ocurring infrasound 4,349,898 sonic lens - ('phased array') - to focus high energy, low frequency sonic signal at arbitrary point 5,864,517 pulsed combustion acoustic wave generator 5,973,999 acoustic canon
(...)
3,951,134 !! Apparatus and method for remotely monitoring and altering brain waves
I got these links off this page: http://www.us-government-torture.com/techie.html
-Eric B
|
|
 | | From: | Matt Giwer | | Subject: | Re: Directed sonic weapons - new info | | Date: | Sat, 27 Nov 2004 08:03:45 GMT |
|
|
 | eric bazan wrote: > (...) > > Deafening silence. Well, I knew this would be a hard sell. > > Let me take one more stab at this, then I'll f*ck off. > > Below is a very interesting link I've uploaded to my site. > Keep in mind this is from 2000. It talks about new breakthroughs > by an MIT student (F. Joseph Pompei ) regarding creating, > focusing, and controlling ultrasound: > > http://www.fractalfreak.com/harass/AudioLight.html > > They talk about new transducers, which, while only a foot in > diameter, can produce a focused ultrsonic beam with a spread > of about 3 degrees, and range of 100 meters: > > " > In order to obtain such narrow directivity from a traditional > loudspeaker system, one would need a loudspeaker array fifty > meters across! > " > > And: > > " > The directivity, or narrowness, of an acoustic wave generated > by a circular transducer is proportional to the ratio of the > diameter of the transducer to the wavelength of the sound. So > a transducer much larger than the wavelength of the sound > creates a very narrow beam. > " > > " > Audible sound contains wavelengths reaching lengths of several > feet, so a reasonably sized loudspeaker will always produce a > very wide, non-directional source at lower frequencies. The > Audio Spotlight, in contrast, outputs short, millimeter sized > ultrasonic waves, which form a very narrow beam even in a > small transducer, which in turn generates audible sound. The > nature of the nonlinear transformation also essentially > eliminates sidelobes in the resulting beam, and maintains > relatively uniform directivity across the entire audible > frequency range. > "
> I'll try to be more specific.
> Could these ultrasonic beams of sound be focused through commonly > used builing materials, perhaps just a floor or a wall, without > losing much coherence? (especially if a computer tailored the signal?) > I'm just talking about a brief second or two burst, because I > assume the power needed would be high.
They are not focused. They simply are in phase and thus have the equivalent of antenna gain.
The higher the frequency the less transmission through solid material because of the mismatch in acoustic impedance. And it doubles if it has to pass through it and come out the other side. For a normal wall there are panels on both sides and maybe insulation in between. That is a lot of losses. And insulation at those frequencies makes a great sound absorber. Going through glass is a better bet.
> What would be the effects, to the body, of being hit by one > of these ultrasonic waves? How would it feel? Keep in mind > these beams can be modulated anyway desired.
> Apparently, using interference, or beats, two or more of these > beams can be focused to an area of space. Infrasound, and audible > sound, can be created at the point in space where they interfere. This > apparently can already be done.
> So already it would be possible to create rumbles or vibrations > by focusing these ultrasonic beams.
Not in any practical sense. The conversion efficiency of the production of the lower frequency is on the order of 1%. The sound source has a conversion efficiency turning electricity into sound and the rest into heat, maybe 30-40%. At some point you cause significant heating in the ultrasonic source. You are also talking something that gets larger as power and range increase.
> Assuming they could be targeted through a house, most of the > effects I speculated would be possible.
> I'm talking about a short burst type weapon. Just enough to > deliver a tap, poke or jolt to the body. Enough to wake someone > up. This needn't take much energy. I see many possibilites using > this scheme.
No taps, pokes or jolts. It is otherwise just like any other sound. It doesn't matter how the sound is generated it is still just sound.
> Am I way off base? Opinions?
You need to look for some other explanation for your experience. I don't see this getting you any place.
And frankly there are probably less than a hundred people in the world who are familiar enough with this phenomenon to talk about it. Of those maybe a dozen can design equipment using it.
-- Israel is the only nation in the world which brags about having assasination squads. And Israel brags about the assasinations. -- The Iron Webmaster, 3299
|
|
|