Visible Light 'X-Ray' Sees Through Solid Objects 122
disco_tracy writes "Some day we may not need X-rays to see inside people, thanks to a new way to decipher light that passes through opaque surfaces. Normally visible light becomes too scattered to detect after passing through opaque surfaces. But scientists in France have developed a way to reconstruct images from light passing through such surfaces by deciphering just how the material makes the light scatter. In the short term the research will help improve the strength of telecommunications signals and fiber optics cables, but years from now the technology could supplement or even replace traditional ultrasounds for baby imaging and X-rays for weapons detection at airports."
Visible? Opaque? (Score:5, Insightful)
How does visible light make its way through an opaque object?
Re:Visible? Opaque? (Score:3, Insightful)
Re:Visible? Opaque? (Score:5, Insightful)
Re:Visible? Opaque? (Score:5, Insightful)
I know you aren't supposed to read TFA, but "'It's like putting a flashlight behind your hand,' said Sylvain Gigan... 'You cannot see an image, but you can still see a faint glow.'"
I think it would help if TFA included an actual example image, and not just a photo of someone holding their hand up behind a shower screen and a note to the effect that the actual technology might produce images sort of like that one.
Re:Visible? Opaque? (Score:3, Insightful)
I guess the first question is whether something can be truly opaque (zero light travels through) or whether all things are translucent if you've a sensitive enough detector.
Assuming that there are genuinely opaque objects, are there enough objects that are translucent (though not to the unaided eye) to make this technique interesting?
My guess is that almost everything will be translucent, though not everything. If the gaps between atoms is on the scale of the wavelength of light, then the atoms will act as a diffraction grating. Given the number of such gratings light has to pass through for any meaningful object, that's going to make a serious mess of the observations.
In order to be truly opaque, two criteria must be met - every photon has to intersect a particle and for every such intersection, the particle has to be able to absorb the photon. Since matter is mostly empty space, you'd need an awful lot of particles to absorb all photons. However, I can see no obvious reason why it would be impossible to have such an arrangement.
Re:Peeping toms will love this... (Score:5, Insightful)
Nowadays, "illegal" doesn't mean you can't do it -- it's just not admissable in court.
You can get your last dollar they still do it, but then need to come up with a pretense for anything involving the courts.
Remember, they can now slap a GPS device onto your car with absolutely no court oversight. Just imagine all of the illegal things they do and cover with sealed court proceedings.
Re:Peeping toms will love this... (Score:3, Insightful)
As is every single piece of technology that ever has, and ever will be, invented. Any progress in any field of study has both benevolent and malevolent purposes. Fire is used for cooking, also for arson. The wheel is used to transport goods, also make off with stolen goods. The hammer helps build things, and bash skulls in. Etc.
This new visible light "x-ray" can be used for spying or legitimate medical purposes.
The trick is to ensure that those in power do not abuse this technology. This is done by not allowing them to keep secrets. This is done by forcing information out of them, by deadly force if necessary.
Re:Peeping toms will love this... (Score:3, Insightful)
For the moment at least, a 4th amendment violation is still a 4th amendment violation even if they do not bother admitting any evidence they find into court. The court sanction of inadmissibility of evidence does not mean law enforcement is free to search and seize when they do not plan on admitting evidence. This came up in the past couple years when some jurisdiction started pulling people over for driving safely and giving them reward cards or coupons or something. It was still a seizure without warrant or probable cause and when this was pointed out they stopped since they were inviting a civil rights lawsuit.
If they gathered IR data without a warrant or probable cause and that lead them to further evidence gathering, the later evidence would also be inadmissible in court. As you point out of course, they can (and I am sure do) gather the IR data secretly and hide this from the court and the defense.
The circuit courts are split on the GPS tracking matter so it is likely just a matter of time before the supreme court gets involved. The secret court proceedings and administrative actions are more insidious to my mind.