If those new airport X-ray scanners offend your modest sensibilities, you may not want to read this. A new terahertz remote sensor may soon be able to see through walls, packaging materials, and even clothing from thousands of feet away, identifying materials contained inside through their unique spectral signatures.
Terahertz waves exist in the part of the spectrum between infrared and microwave light, but they were largely thought to be a dead end for remote sensing tech because they are absorbed and degraded by moisture in the air, making them highly unreliable at distances beyond just a few inches.
But researchers at Rensselaer Polytechnic Institute decided that if terahertz waves themselves won't work across distances, they would use a laser to excite terahertz radiation at faraway targets. The detector works by zeroing two lasers at different frequencies on a target. This causes the materials the laser hits to emit terahertz radiation, which in turn emits a fluorescence that is unique to that material as well as detectable from far away.
That means that in theory, as long as there is good line of sight, a terahertz detector could check your pockets at really distant ranges – perhaps even miles away – though in the lab the researchers only demonstrated the technology at 67 feet (simply because that was as much space as they had). The researchers are currently cataloging the unique signatures of various materials so the detector can tell your car keys from your makeup compact from your Glock.
But privacy advocates, you may return to your seats. Terahertz waves are actually much lower in energy than X-rays, so while they can peek inside your pockets from a distance, they are actually far less invasive than those scanners that undress you as you walk through. And since moisture kills those terahertz signals, nothing inside the body (like a medical implant) is detectable.
Besides, the sensors won't be showing up in airports in the immediate future anyhow. Though the Department of Homeland Security did have a hand in paying for the research, the DoD will likely first deploy the tech in combat zones to help soldiers detect roadside bombs and maintain a ring of security around bases or checkpoints.
Could this type of tech work on a satalite perhaps? Either orbiting Earth to see what people dont want to be seen, or over an extraterrestrial world to see if there is life beneath the surface?
This sounds like something relatively easy to defeat - all you need is something to mask the scan results and give a reading of something else - turning your "glock" into "bubblegum." Perhaps by encasing it in a water balloon? ;-)
Terrahertz radiation reacts differently for different materials, can be used as a chemical detector I understand. so it would be tough to trick it into seeing something else. Easy just to block like you said with a water balloon.
@Clay Dillow and John Mahoney - story idea - off topic
There's been so much debate about climate. Only one world wide "solution" proposed by politicians, cap and trade. Noone that I've seen in the media has put up any information about it. How it works, if it will work, hard numbers how fast will co2 drop or even will they.
With so much debate lots of scientists have surely researched cap and trade's efficacy. With so much debate they've surely researched outcomes and modeled the co2 drop. Right? If not, makes you wonder why not.
May be I'm wrong and cap and trade is a panacea for all things climate related, or may be I'm right and it's just a scam, oil and green stuck together irrevocably like a tar ball on the gulf coast. Either way I get the feeling both skeptics and believers are being played off each other so noone questions will it actually work. In fact I think we're just being played in general.
I think either of you would write a fair, researched even article about it. I think it's past time for someone to, we're about to change the entire world and control the means of production in one legislative swoop. We should understand what we are about to do, shouldn't we.
"use a laser to excite terahertz radiation"
Ummmm... could we not excite radiation please.
I agree with Thor...
Something about combining the Glock in my pocket with "exciting radiation" is a little unnerving. I always figured when I shot myself in the foot it would be because I was doing something dumb...not because the NSA was being nosy.
Although....if the put these in airports that might make things MUCH more interesting for bored baggage scanners. Swing it through a crowd and see if anyone's pockets assplode. HA!
"Easy just to block like you said with a water balloon."
Though if there is visibly *something* in your pocket and the system returns nothing [except maybe the latex balloon with the liquid inside], that might somethign that tips them off to take a closer look at you...