U.S. CitiesCity-Data Forum Index
Go Back   City-Data Forum > General Forums > Science and Technology
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
View detailed profile (Advanced) or search
site with Google Custom Search

Search Forums  (Advanced)
Reply Start New Thread
Old 05-25-2011, 07:08 AM
Location: Hopewell New Jersey
1,393 posts, read 6,898,679 times
Reputation: 1010


Much easier to do now adays with pretty powerfull DSP chips but you're correct..been around for awhile.

One bounces a beam / laser off a window pane. The small vibrations of the window glass modulates the beam reflected off the surface and detectors intercepting the reflection one can evesdrop on the conversation inside the room. In real world though it's a bit more complicated than that. Obviously the sound from local traffic for example "modulates" the window pain much more than the low volume chat inside the room. What can be nowadays, easily done (so I've heard ) is to also bounce another beam off another nearby window with no chat etc. Now you know the sound of the traffic + chat and you know the sound of just the external noise. Processs the two signals,such as the outside noise to cancel out the noise plus chat and what's left is just the chat.

Again, an over simplification but you get the idea. BTW...the laser beams don't have to be in the visible spectrum.

here's another one to ponder...
The sound (acoustic vibrations) in a room also effect light bulbs in the room.As well as other devices) As the bulb, and of course the media inside the bulb "modulate' there is a small effect induced upon the electrical supply going to the bulb. IE...one can (with the right processing of course) listen to a conversation in a room just by evsdropping on the power lines feeding the structure. Again been done years ago...just easier today.

Further reading...
google "Tempest security "...... measures,requirements and the like..

Last edited by JBrown; 05-25-2011 at 07:25 AM..
Reply With Quote Quick reply to this message

Old 06-12-2013, 06:26 AM
1 posts, read 1,084 times
Reputation: 10
Default spyware to see interior of house

This actually happened to me, but I'm at a loss as to what type of technology was used. I live in Buffalo, NY, and did not realize that this was taking place until a certain person began to mimic things that I had done in private. i.e. exercising, etc. There are some VERY sick people out there!
Reply With Quote Quick reply to this message
Old 08-10-2013, 10:44 AM
1 posts, read 1,012 times
Reputation: 10
I understand your concern... but if they are truly "a bunch of low lifes" as you say... they cannot afford that kind of IR camera. When a lot of IR technicians say they can "see through walls," they don't mean literally all the way through. They are referring to right underneath the surface which is still not technically "seeing" as it is now represented by a bunch of colors and outlines.

So your concern may be a bit different than IR.
Reply With Quote Quick reply to this message
Old 12-15-2017, 09:39 AM
Location: Raleigh
8,007 posts, read 5,261,837 times
Reputation: 9641
Originally Posted by tripod View Post
<>I've seen that some police and the military have sophisticated + expensive equipment that in effect can see through walls<>
Only in movies and on TV. Oh, and in TSA exam rooms.
Reply With Quote Quick reply to this message
Old 12-16-2017, 08:16 AM
6,032 posts, read 1,468,120 times
Reputation: 4428
There are certain technologies that the public will never be allowed to have access to, mainly for the sake of protecting the level of control and authority Govt has over the people.

the invisibility cloak is a great example, the last I heard they are getting close to having a working model, one that truly bends light and makes it invisible to the naked eye...think a minute about if anyone could go to wally world and buy one of these....that would be disastrous for law enforcement on so many levels!

This same mentality applies to many other new technologies too, in the end, if its a little 'too good' for the people, it will never see the light of day.

There are even regulations in place that actually prevent certain new inventions or technologies from being available to the public if they have any potential to cause problems like this.
Reply With Quote Quick reply to this message
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.

Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.

Please update this thread with any new information or opinions. This open thread is still read by thousands of people, so we encourage all additional points of view.

Quick Reply

Over $104,000 in prizes was already given out to active posters on our forum and additional giveaways are planned!

Go Back   City-Data Forum > General Forums > Science and Technology
Similar Threads
Follow City-Data.com founder on our Forum or

All times are GMT -6. The time now is 11:02 PM.

2005-2018, Advameg, Inc.

City-Data.com - Archive 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 - Top