7 ms·

RF/Microwave EE here. I actually tried this on myself several years ago with no effect. Specifically 20W at C-band into a 10 dBi standard gain horn a few feet

RF/Microwave EE here. I actually tried this on myself several years ago with no effect. Specifically 20W at C-band into a 10 dBi standard gain horn a few feet away, pulse mod to 1 kHz. That was still not near enough power density. While it’s plausible, it would take a big effort to affect this many people. The peak power densities, as described in the paper, would be tens of W/cm^2; e.g. radar transmitters and big antennas. To direct this power, you’d have to track someone with a high gain antenna, and once you are non line of sight, it would attenuate greatly. That, or you’d have to place covert equipment in close proximity, in many locations. It would also be very easy to detect with basic test equipment, as the desired peak power levels are huge. Maybe there could be some organ resonance effect with mmWaves, such as bones in the ear, but that is sketchy too. Here is the link from the article: https://braincontrolhedge.files.wordpress.com/2013/05/auditory-system-response-to-radio-frequency-energy-technical-note.pdf https://braincontrolhedge.files.wordpress.com/2013/05/audito...

baybal2 8y ago
Moreover, that would've certainly affected all unshielded electronics. Even older GSM phones had enough power to some times hang well shielded desktop PCs. And at the time all laptops were plasticky unshielded contraptions, that was even more evident.
- tomjakubowski 8y ago
  I miss being able to hear incoming calls over my car's stereo before the phone even rang.
  - raziel2701 8y ago
    I can still do that with my cheap computer speakers!
    - subcosmos 8y ago
      In my headphones, when I pause any music that is playing, I can hear data transferring too/from my nvidia GPU while training deep neural networks. Ive used this technique to get a greater sense of the memory performance.
      - maxander 8y ago
        That's interesting. Certainly, we've all been cued by the sound of our hard disks that something in our code was wrong or that our computer is up to something unexpected; now that disks are getting quieter and/or replaced by SSDs we lose that important "feature." As code-relevant hardware gets more complex (GPUs and other outboard processors, interaction with robotics or media headsets, etc what-have-you) that sort of hardware-level diagnostic should become more useful, rather than less. Has anyone tried to get this to happen on purpose? E.g., little electrical taps on relevant bus cables, with an audio jack.
aswanson 8y ago
Why in the world did you try this on yourself?
- madengr 8y ago
  Curiosity. Why not? It’s not inherently dangerous. I’ve had real RF burns from tuning high power microwave amps. The RADAR tick is EE folklore, from your brain expanding a few microns at the pulse rate. As I said, takes a huge power density to do this. Cataracts are an issue with long term exposure. I guess we’ll know in the near future if this group of people has a higher incidence of cataracts.
  - subcosmos 8y ago
    If it weren't for this kind of experimentation, the microwave oven would have never been invented!
  - nickysielicki 8y ago
    Tell me more about your microwave amp RF burns, are you into amateur EME comms?
    - madengr 8y ago
      Ham, yes. EME no (yet). Putting fingers down on 0.5 mm traces carrying 50W at S-band will char your skin. Just tuning amps with golf tees and copper lead frames.
      - nickysielicki 8y ago
        I suppose you work in aerospace and/or DoD? Sounds like you are up to some very fun stuff. Man, I wish I has the foresight at 18 to study EE instead of going for CS.
themodelplumber 8y ago
Great comment. I was also wondering about detection--it ought to be trivial. I'm surprised that government buildings in places like this don't already have simple sensor arrays up and running, especially knowing of the potential for RF use in espionage (information transfer) etc.
- madengr 8y ago
  Yes, it would be trivial. These kinds of power levels are probably enough to light an LED with it’s leads bent into a dipole. Pocket spectrum analyzers can be had for cheap these days.
escherplex 8y ago
Good commentary but I wonder if inadvertently you may have been out-of-band in your research. In 'Auditory Response to Pulsed Radiofrequency Energy - Elder (2003)' URL: http://www.beperkdestraling.org/images/stories/Wetenschap/Tinnitus http://www.beperkdestraling.org/images/stories/Wetenschap/Ti... Auditory_Response_to_Pulsed_radiofrequency_energy.pdf Two salient points crop up: 1) 'The fundamental frequency of RF induced sounds is independent of the frequency of the radiowaves but dependent upon head dimensions.' 2) 'RF hearing has been reported at frequencies ranging from 2.4 to 10 000 MHz (see Table 1). Although Ingalls [1967] mentioned 10 000 MHz as an effective frequency, other investigators found that lower frequencies (8900 and 9500 MHz) at very high exposure levels did not induce RF sounds In Table 2 the experimental frequency range appears to have been 900MHz to 3GHz so C-band at 4 – 8 GHz (7.5 – 3.75 cm) may have be a too short a wavelength to elicit the effect. - but ham radio operators should be worried :-)
- escherplex 8y ago
  aside: given it's a long link you have to add Auditory_Response_to_Pulsed_radiofrequency_energy.pdf to the address
  - no_identd 8y ago
    That... shouldn't break? Let me try: http://www.beperkdestraling.org/images/stories/Wetenschap/Tinnitus/Auditory_Response_to_Pulsed_radiofrequency_energy.pdf http://www.beperkdestraling.org/images/stories/Wetenschap/Ti... Edit: Link seems to work. :)
- madengr 8y ago
  Ha ha, probably so. It wasn’t research, I was just testing some equipment and figured I try it. It probably works best starting at 1/2 wavelength resonance of the brain, then maybe higher modes where a certain region may be stimulated. Just a hunch.
deleted 8y ago
[deleted]
sandworm101 8y ago
>> It would also be very easy to detect with basic test equipment Like laptops, cellphones not working. Sparks from coke cans. Chocolate bars melting in pockets. I'd think the fire risk would be too great to attempt this in an uncontrolled public space.
- madengr 8y ago
  It doesn’t take THAT much power. The paper says effects took an average power of ~1 mW/cm^2, with a 0.0001 duty factor. That’s not much from a heating standpoint, but extremely strong for detectability. That average power is about what your phone delivers to your head. The peak power is massive, but it doesn’t last long, so the energy is weak. To get the equivalent peak power, you’d have to put 10k phones against your head. If you put your head in a 1 kW microwave oven, and pulse modulated the magnetron, your could maybe get the effect. It would make an entertaining YouTube video.
  - plmpsu 8y ago
    > If you put your head in a 1 kW microwave oven, and pulse modulated the magnetron, your could maybe get the effect. It would make an entertaining YouTube video. Sound like an Infinite Jest footnote.
no_identd 8y ago
I'll quote Allan H. Frey, who more-or-less(preceeded by some italian engineers, iirc) invented the entire field, from 1996 on usenet: >There is a microwave hearing effect that occurs at very low power densities and a skull vibration effect that occurs when very high energies are applied to the head. There is some confusion in the literature because the vibration effect has often been referred to as a microwave hearing effect, but it is not the same phenomena. And, quoting from a different page: >In fact, Frey and Hackett said the microwave hearing effect does not occur with millimeter waves (which range from 3 to 300 GHz). > >"On the other hand, if your millimeter waves have enough energy density, are powerful enough, there are other phenomena where you could cause sort of a concussion kind of effect which could conceivably be heard by bone conduction. It would transfer through skin to bone and bone into the inner ear," Frey said. He said it might be possible to modulate such energy to create the perception of some intelligible sounds. "But off hand, I can't tell you what kind of power levels you might need to do that," he said. Hackett dismissed the idea of transmitting intelligible sounds to the head with MMWs as pure speculation. Note how the mythbusters episode where they 'busted' that myth seems like an (unintentional) sham: They used a 9.4 GHz radar dish (courtesy of the DoD) with ultra short impulses spread out over long periods. That fits NEITHER of the above. Someone, on, OF FUCKING COURSE, /r/conspiracy, quite a while ago, pointed out something related: https://www.reddit.com/r/conspiracy/comments/77v6t1/reddit_detectives_recent_news_about_the_cuba/ https://www.reddit.com/r/conspiracy/comments/77v6t1/reddit_d... Which points out that the boxspring mattresses used in many Hotels might strongly amplify the ability to induce tissue damage, which would explain this part: "The blaring, grinding noise jolted the American diplomat from his bed in a Havana hotel. He moved just a few feet, and there was silence. He climbed back into bed. Inexplicably, the agonizing sound hit him again. It was as if he’d walked through some invisible wall cutting straight through his room." From https://www.apnews.com/697536f065e6470eaa5ccfc35061e7ce https://www.apnews.com/697536f065e6470eaa5ccfc35061e7ce Of course, back then, almost everyone dismissed this. Or did they? (Insert dramatic music here) Here, some more quotes from Allan H. Frey, via http://www.the-scientist.com/?articles.view/articleNo/32648/title/Opinion--Cell-Phone-Health-Risk-/ http://www.the-scientist.com/?articles.view/articleNo/32648/...: >For example, after my colleagues and I published in 1975 that exposure to very weak microwave radiation opens the regulatory interface known as the blood brain barrier (bbb), a critical protection for the brain, the Brooks AFB group selected a contractor to supposedly replicate our experiment. For 2 years, this contractor presented data at scientific conferences stating that microwave radiation had no effect on the bbb. After much pressure from the scientific community, he finally revealed that he had not, in fact, replicated our work. We had injected dye into the femoral vein of lab rats after exposure to microwaves and observed the dye in the brain within 5 minutes. The Brooks contractor had stuck a needle into the animals’ bellies and sprayed the dye onto their intestines. Thus it is no surprise that when he looked at the brain 5 minutes later, he did not see any dye; the dye had yet to make it into the circulatory system. Some more points: https://nyaspubs.onlinelibrary.wiley.com/doi/full/10.1111/j.1749-6632.1975.tb36019.x https://nyaspubs.onlinelibrary.wiley.com/doi/full/10.1111/j.... From 1975 presumably what Frey refers to in the above paragraph, entitled "NEURAL FUNCTION AND BEHAVIOR: DEFINING THE RELATIONSHIP" http://www.tandfonline.com/doi/abs/10.3109/15368378209040347 http://www.tandfonline.com/doi/abs/10.3109/15368378209040347 here, a review from 1982, very much related to the previous quote, entitled "Microwaves and the Blood-Brain Barrier: A Review" http://www.tandfonline.com/doi/pdf/10.3109/15368378309040355 http://www.tandfonline.com/doi/pdf/10.3109/15368378309040355 and here is a letter correcting that review, sort of. Unfortunately, this letter never got cited in the scientific literature, while the above review did. For more bibliographical information, one might also wish to examine this email by Allen L. Barker from 2002: https://archive.fo/V3r0Y https://archive.fo/V3r0Y (THEORETICALLY also available here, but the domain behind this, http://iubio.bio.indiana.edu/ http://iubio.bio.indiana.edu/, is unreachable from large parts of the internet from what I can tell: http://www.bio.net/mm/neur-sci/2002-May/048366.html http://www.bio.net/mm/neur-sci/2002-May/048366.html) Of course, EVERYTHING surrounding this (but NOT the subject matter ITSELF) involves a hell of a lot of: * conspiracy theory * fringe science (aka protoscience) * pseudoscience levels of insanity, as you can likely tell from some of the above. This makes it extremely hard to filter through any of this. The EU did a large report on RF safety a while ago: https://ec.europa.eu/health/sites/health/files/scientific_committees/emerging/docs/scenihr_o_041.pdf https://ec.europa.eu/health/sites/health/files/scientific_co... If you check it, Frey's papers on this remain oddly absent from it. Oh and... We could likely find a lot more existing discussion on this, but unfortunately, the emf-bio archives got expunged from ftp://iubio.bio.indiana.edu/usenet/bionet/emf-bio without explanation. If anyone at the University of Indiana wants to go digging into backup tapes, I'd appreciate it.
pgt 8y ago
Could higher-frequency harmonics be resonating in cavities acting as waveguides?

baybal2 8y ago

Moreover, that would've certainly affected all unshielded electronics. Even older GSM phones had enough power to some times hang well shielded desktop PCs. And at the time all laptops were plasticky unshielded contraptions, that was even more evident.

tomjakubowski 8y ago
I miss being able to hear incoming calls over my car's stereo before the phone even rang.
- raziel2701 8y ago
  I can still do that with my cheap computer speakers!
  - subcosmos 8y ago
    In my headphones, when I pause any music that is playing, I can hear data transferring too/from my nvidia GPU while training deep neural networks. Ive used this technique to get a greater sense of the memory performance.
    - maxander 8y ago
      That's interesting. Certainly, we've all been cued by the sound of our hard disks that something in our code was wrong or that our computer is up to something unexpected; now that disks are getting quieter and/or replaced by SSDs we lose that important "feature." As code-relevant hardware gets more complex (GPUs and other outboard processors, interaction with robotics or media headsets, etc what-have-you) that sort of hardware-level diagnostic should become more useful, rather than less. Has anyone tried to get this to happen on purpose? E.g., little electrical taps on relevant bus cables, with an audio jack.

aswanson 8y ago

Why in the world did you try this on yourself?

madengr 8y ago
Curiosity. Why not? It’s not inherently dangerous. I’ve had real RF burns from tuning high power microwave amps. The RADAR tick is EE folklore, from your brain expanding a few microns at the pulse rate. As I said, takes a huge power density to do this. Cataracts are an issue with long term exposure. I guess we’ll know in the near future if this group of people has a higher incidence of cataracts.
- subcosmos 8y ago
  If it weren't for this kind of experimentation, the microwave oven would have never been invented!
- nickysielicki 8y ago
  Tell me more about your microwave amp RF burns, are you into amateur EME comms?
  - madengr 8y ago
    Ham, yes. EME no (yet). Putting fingers down on 0.5 mm traces carrying 50W at S-band will char your skin. Just tuning amps with golf tees and copper lead frames.
    - nickysielicki 8y ago
      I suppose you work in aerospace and/or DoD? Sounds like you are up to some very fun stuff. Man, I wish I has the foresight at 18 to study EE instead of going for CS.

themodelplumber 8y ago

Great comment. I was also wondering about detection--it ought to be trivial. I'm surprised that government buildings in places like this don't already have simple sensor arrays up and running, especially knowing of the potential for RF use in espionage (information transfer) etc.

madengr 8y ago
Yes, it would be trivial. These kinds of power levels are probably enough to light an LED with it’s leads bent into a dipole. Pocket spectrum analyzers can be had for cheap these days.

escherplex 8y ago

Good commentary but I wonder if inadvertently you may have been out-of-band in your research. In 'Auditory Response to Pulsed Radiofrequency Energy - Elder (2003)' URL: http://www.beperkdestraling.org/images/stories/Wetenschap/Tinnitus http://www.beperkdestraling.org/images/stories/Wetenschap/Ti... Auditory_Response_to_Pulsed_radiofrequency_energy.pdf Two salient points crop up: 1) 'The fundamental frequency of RF induced sounds is independent of the frequency of the radiowaves but dependent upon head dimensions.' 2) 'RF hearing has been reported at frequencies ranging from 2.4 to 10 000 MHz (see Table 1). Although Ingalls [1967] mentioned 10 000 MHz as an effective frequency, other investigators found that lower frequencies (8900 and 9500 MHz) at very high exposure levels did not induce RF sounds In Table 2 the experimental frequency range appears to have been 900MHz to 3GHz so C-band at 4 – 8 GHz (7.5 – 3.75 cm) may have be a too short a wavelength to elicit the effect. - but ham radio operators should be worried :-)

escherplex 8y ago
aside: given it's a long link you have to add Auditory_Response_to_Pulsed_radiofrequency_energy.pdf to the address
- no_identd 8y ago
  That... shouldn't break? Let me try: http://www.beperkdestraling.org/images/stories/Wetenschap/Tinnitus/Auditory_Response_to_Pulsed_radiofrequency_energy.pdf http://www.beperkdestraling.org/images/stories/Wetenschap/Ti... Edit: Link seems to work. :)
madengr 8y ago
Ha ha, probably so. It wasn’t research, I was just testing some equipment and figured I try it. It probably works best starting at 1/2 wavelength resonance of the brain, then maybe higher modes where a certain region may be stimulated. Just a hunch.

deleted 8y ago

[deleted]

sandworm101 8y ago

>> It would also be very easy to detect with basic test equipment Like laptops, cellphones not working. Sparks from coke cans. Chocolate bars melting in pockets. I'd think the fire risk would be too great to attempt this in an uncontrolled public space.

madengr 8y ago
It doesn’t take THAT much power. The paper says effects took an average power of ~1 mW/cm^2, with a 0.0001 duty factor. That’s not much from a heating standpoint, but extremely strong for detectability. That average power is about what your phone delivers to your head. The peak power is massive, but it doesn’t last long, so the energy is weak. To get the equivalent peak power, you’d have to put 10k phones against your head. If you put your head in a 1 kW microwave oven, and pulse modulated the magnetron, your could maybe get the effect. It would make an entertaining YouTube video.
- plmpsu 8y ago
  > If you put your head in a 1 kW microwave oven, and pulse modulated the magnetron, your could maybe get the effect. It would make an entertaining YouTube video. Sound like an Infinite Jest footnote.

no_identd 8y ago

I'll quote Allan H. Frey, who more-or-less(preceeded by some italian engineers, iirc) invented the entire field, from 1996 on usenet: >There is a microwave hearing effect that occurs at very low power densities and a skull vibration effect that occurs when very high energies are applied to the head. There is some confusion in the literature because the vibration effect has often been referred to as a microwave hearing effect, but it is not the same phenomena. And, quoting from a different page: >In fact, Frey and Hackett said the microwave hearing effect does not occur with millimeter waves (which range from 3 to 300 GHz). > >"On the other hand, if your millimeter waves have enough energy density, are powerful enough, there are other phenomena where you could cause sort of a concussion kind of effect which could conceivably be heard by bone conduction. It would transfer through skin to bone and bone into the inner ear," Frey said. He said it might be possible to modulate such energy to create the perception of some intelligible sounds. "But off hand, I can't tell you what kind of power levels you might need to do that," he said. Hackett dismissed the idea of transmitting intelligible sounds to the head with MMWs as pure speculation. Note how the mythbusters episode where they 'busted' that myth seems like an (unintentional) sham: They used a 9.4 GHz radar dish (courtesy of the DoD) with ultra short impulses spread out over long periods. That fits NEITHER of the above. Someone, on, OF FUCKING COURSE, /r/conspiracy, quite a while ago, pointed out something related: https://www.reddit.com/r/conspiracy/comments/77v6t1/reddit_detectives_recent_news_about_the_cuba/ https://www.reddit.com/r/conspiracy/comments/77v6t1/reddit_d... Which points out that the boxspring mattresses used in many Hotels might strongly amplify the ability to induce tissue damage, which would explain this part: "The blaring, grinding noise jolted the American diplomat from his bed in a Havana hotel. He moved just a few feet, and there was silence. He climbed back into bed. Inexplicably, the agonizing sound hit him again. It was as if he’d walked through some invisible wall cutting straight through his room." From https://www.apnews.com/697536f065e6470eaa5ccfc35061e7ce https://www.apnews.com/697536f065e6470eaa5ccfc35061e7ce Of course, back then, almost everyone dismissed this. Or did they? (Insert dramatic music here) Here, some more quotes from Allan H. Frey, via http://www.the-scientist.com/?articles.view/articleNo/32648/title/Opinion--Cell-Phone-Health-Risk-/ http://www.the-scientist.com/?articles.view/articleNo/32648/...: >For example, after my colleagues and I published in 1975 that exposure to very weak microwave radiation opens the regulatory interface known as the blood brain barrier (bbb), a critical protection for the brain, the Brooks AFB group selected a contractor to supposedly replicate our experiment. For 2 years, this contractor presented data at scientific conferences stating that microwave radiation had no effect on the bbb. After much pressure from the scientific community, he finally revealed that he had not, in fact, replicated our work. We had injected dye into the femoral vein of lab rats after exposure to microwaves and observed the dye in the brain within 5 minutes. The Brooks contractor had stuck a needle into the animals’ bellies and sprayed the dye onto their intestines. Thus it is no surprise that when he looked at the brain 5 minutes later, he did not see any dye; the dye had yet to make it into the circulatory system. Some more points: https://nyaspubs.onlinelibrary.wiley.com/doi/full/10.1111/j.1749-6632.1975.tb36019.x https://nyaspubs.onlinelibrary.wiley.com/doi/full/10.1111/j.... From 1975 presumably what Frey refers to in the above paragraph, entitled "NEURAL FUNCTION AND BEHAVIOR: DEFINING THE RELATIONSHIP" http://www.tandfonline.com/doi/abs/10.3109/15368378209040347 http://www.tandfonline.com/doi/abs/10.3109/15368378209040347 here, a review from 1982, very much related to the previous quote, entitled "Microwaves and the Blood-Brain Barrier: A Review" http://www.tandfonline.com/doi/pdf/10.3109/15368378309040355 http://www.tandfonline.com/doi/pdf/10.3109/15368378309040355 and here is a letter correcting that review, sort of. Unfortunately, this letter never got cited in the scientific literature, while the above review did. For more bibliographical information, one might also wish to examine this email by Allen L. Barker from 2002: https://archive.fo/V3r0Y https://archive.fo/V3r0Y (THEORETICALLY also available here, but the domain behind this, http://iubio.bio.indiana.edu/ http://iubio.bio.indiana.edu/, is unreachable from large parts of the internet from what I can tell: http://www.bio.net/mm/neur-sci/2002-May/048366.html http://www.bio.net/mm/neur-sci/2002-May/048366.html) Of course, EVERYTHING surrounding this (but NOT the subject matter ITSELF) involves a hell of a lot of: * conspiracy theory * fringe science (aka protoscience) * pseudoscience levels of insanity, as you can likely tell from some of the above. This makes it extremely hard to filter through any of this. The EU did a large report on RF safety a while ago: https://ec.europa.eu/health/sites/health/files/scientific_committees/emerging/docs/scenihr_o_041.pdf https://ec.europa.eu/health/sites/health/files/scientific_co... If you check it, Frey's papers on this remain oddly absent from it. Oh and... We could likely find a lot more existing discussion on this, but unfortunately, the emf-bio archives got expunged from ftp://iubio.bio.indiana.edu/usenet/bionet/emf-bio without explanation. If anyone at the University of Indiana wants to go digging into backup tapes, I'd appreciate it.

pgt 8y ago

Could higher-frequency harmonics be resonating in cavities acting as waveguides?