5 ms·

Can computers read through a book page by page without opening it?

192 points by triplesec 10y ago

triplesec 10y ago
Journalism about this research: http://www.ibtimes.com/mit-georgia-tech-develop-system-read-closed-books-using-terahertz-radiation-2414140 http://www.ibtimes.com/mit-georgia-tech-develop-system-read-...
amelius 10y ago
> Statistics of the electric field in THz TDS can provide much better results for layer localization at deeper layers (lower SNRs) than conventional deconvolution techniques. Could this technique also be useful for crystallography, or electron microscopy?
- skykooler 10y ago
  Terahertz waves range in length from 1 micrometer to 1 millimeter. These are far too large to be able to image things at the scales of crystals. (That's part of why X-rays are used for crystallography - they provide higher resolution than visible light, because the wavelength is shorter.)
  - amelius 10y ago
    Petahertz (or higher) is not an option, I presume?
    - kragen 10y ago
      Petahertz electromagnetic radiation is what's currently used for diffraction crystallography; it's conventionally known as "X-rays" (or "gamma rays" if it comes from radioactive decay instead of from Bremsstrahlung.)
      - amelius 10y ago
        Yes, can we use time-domain techniques on this frequency range?
        kragen 10y ago
        You want to measure the instantaneous amplitudes of a wave packet in the petahertz range at above the Nyquist frequency? I don't want to say it's impossible, but I think you'd have to improve the capabilities of our instruments by about four orders of magnitude, which means you would have to invent several new major technologies. Maybe if you digitize the time-domain pulses using some kind of controlled nuclear reaction? Electronics are far too slow (although I don't really understand why, so maybe that can be fixed). X-ray-stimulated nuclear reactions are going to be tricky to get to happen at all, much less to chain together into computational circuits, although in that case maybe you can use α particles or neutrons to carry the information around between the computational elements, simplifying the task somewhat. It seems like, however you manage to measure it, the quantization of the radiation is going to pose really significant problems to measuring its amplitude accurately as a function of time, but maybe you can get around that by repeating the pulses a lot of times. But you'll need to make sure that you're emitting pulses of the same shape, rather than just pulses with a similar frequency spectrum and envelope but varying relative phases among the frequencies. On the other hand, if you just want to measure the time-of-flight for X-ray wavepackets to sub-picosecond precision, without worrying about the time-domain waveform within the packet, I don't think that gets any harder or easier depending on the "carrier frequency" of the wavepacket — X-rays should be just as easy as terahertz light. You do need a few terahertz of bandwidth, so you aren't going to be able to do this with bursts of gigahertz microwaves. X-rays' interaction with the material you're trying to image might be less or more convenient; their cross-section for backscattering is pretty small, but maybe you could scan the book from different angles and use total internal reflection to find interfaces between materials in the book with different refractive indices. This would also reduce your requirements for time-domain precision down into the hundreds of GHz range, which is a lot easier to deal with.
        eternauta3k 10y ago
cdevs 10y ago
"Write it down on paper I don't trust passwords in computers.. All that's left is thought scanning and then we will think about rethinking passwords.
- sova 10y ago
  or just abandoning the notion of passwords entirely
  - Houshalter 10y ago
    I hope that never happens. I don't want to be tied to a specific Facebook account and computer for everyone I do online for the rest of my life.
- flashman 10y ago
  Subvocal microphones work (to some extent) by detecting the electrical impulses sent to speech muscles when somebody speaks mentally instead of physically. I wonder if this would work with involuntary recollection - I ask you to think of your password, and even though you won't divulge it to me, the signals for speaking it would leak to my electrodes. Still mostly science fiction, but plausible.
asdfologist 10y ago
Where are all the Betteridge fanboys on this one?
- coldtea 10y ago
  Rules must have a few exceptions, else they are not rules but universal laws that go without saying...
  - asdfologist 10y ago
    I'm not convinced that Betteridge is right even 50% of the time.
- breck 10y ago
  Actually this is another example of Betteridge's law. If you replace "book" in the headline with "one letter flipbooks of 9 pages or less" (from the paper), then we'd have a counterexample. Still really cool, but a long way to go before we can actually do what the headline teases.
- dang 10y ago
  Please don't do this here.
gus_massa 10y ago
Somewhat related: "X-Rays Expose a Hidden Medieval Library" https://medievalbooks.nl/2015/12/18/x-rays-expose-a-hidden-medieval-library/ https://medievalbooks.nl/2015/12/18/x-rays-expose-a-hidden-m... HN discussion: https://news.ycombinator.com/item?id=10758257 https://news.ycombinator.com/item?id=10758257 (86 points, 267 days ago, 6 comments)
fma 10y ago
The research has interests of museums that want to read books without opening and damaging them. Is there any chance the scans can damage them? Also, what are the laws of the US government applied this to reading our letters. Our mail is protected by law from opening, but what if they aren't physically opened?
- posterboy 10y ago
  if it is that literal, I'm sure this would be against the spirit of the law, anyway.
  - fma 10y ago
    Yep, that is my exact train of thought. To me, examining email is against the spirit of the law - however, that is allowed because the law did not exactly forbid email (email didn't exist few hundred years back...)
- vladus2000 10y ago
  IANAL but I believe it is illegal to read mail in this way. You have an expectation of privacy with a letter. Same with your house, you have a reasonable expectation of privacy within it. That being said, I believe if this is cheap enough they will start doing it in secret and the courts probably will not stop it. Whether or not they will attempt to use anything gained from it directly in court is debatable but it could lead to parallel construction cases.
  - rurban 10y ago
    That's not true. According to US interpretation of law they may scan every IMAP mail which was not deleted. So in their analogy any book in a public or cooperate museum may be scanned, there is no privacy protection. Only in democratic countries you can expect some privacy.
    - bhickey 10y ago
      Mail and e-mail are legally distinct.
alanz1223 10y ago
Does anyone know what kind of oscillator is used to produce the signal? And how they managed to get such a high sample rate?
- eternauta3k 10y ago
  They use an ultra-short laser pulse which "gates" (enables/disables) the detector for a very short window of time. They repeat the stimulus+gated detection with different offsets in order to sample different parts of the signal. The ultra-short laser pulse can be generated through purely-optical means. You have a laser pulse traveling around a cavity. Due to a combination of non-linear optical effects, each round-trip tends to shorten and concentrate the pulse. The resulting pulses can be much shorter than what's achievable with electronic generators.
rwmj 10y ago
Might this be used to read the famous burned scrolls of Pompeii and Herculaneum? (Although according to this article, current thinking is they might be able to read them with X-rays: http://www.smithsonianmag.com/history/ancient-scrolls-blackened-vesuvius-are-readable-last-herculaneum-papyri-180953950/?no-ist http://www.smithsonianmag.com/history/ancient-scrolls-blacke...)
kirykl 10y ago
useful technology for the MIT blackjack team
- astrodust 10y ago
  Scan the shoe and know the optimal betting strategy? You'd need some pretty serious technology to hide your knowledge and come up with a betting strategy that's optimally undetectable as well.
DavidWanjiru 10y ago
I find this interesting because I've ever thought of it conceptually, the idea of a scanner that instantly scans closed books (instantly because one pulse of whatever EM wave you're using suffices). I thought about it after reading about the Timbuktu manuscripts that were saved from Boko Haram in Mali. I hear many of them are too delicate to open. I hope this works. It'd be awesome for so many use cases.
ianai 10y ago
Of course I love the premise. But I also fear what this could allow to be surveilled.
neom 10y ago
I wonder if you could use a chemoreceptor for this also.
Animats 10y ago
The sensing system used was from "Zomega Terahertz Corporation", which had a web site "z-thz.com". That company seems to have disappeared at the end of 2015, but it's still in archive.org. Can't find any info that indicates what happened to them. Zomega was one of the few companies with a true terahertz system, at 2THz, or 0.006in wavelength. Other "terahertz" products seem to be around 100GHz, which is much easier to reach; there are 77GHz automotive radars. Zomega systems had already been used to image hidden layers in paintings, so looking into a stack of paper wasn't a big stretch. This new paper is mostly about a data reduction technique. Overview of terahertz technology.[2] [1] https://web.archive.org/web/20151220072732/http://z-thz.com/ https://web.archive.org/web/20151220072732/http://z-thz.com/ [2] http://spectrum.ieee.org/aerospace/military/the-truth-about-terahertz http://spectrum.ieee.org/aerospace/military/the-truth-about-...
sterex 10y ago
Could this be implemented to scan through layers of other material, say clothing, and used for real-time scanning at sensitive areas such as airports?

192 points by triplesec 10y ago

Journalism about this research: http://www.ibtimes.com/mit-georgia-tech-develop-system-read-closed-books-using-terahertz-radiation-2414140 http://www.ibtimes.com/mit-georgia-tech-develop-system-read-...

amelius 10y ago

> Statistics of the electric field in THz TDS can provide much better results for layer localization at deeper layers (lower SNRs) than conventional deconvolution techniques. Could this technique also be useful for crystallography, or electron microscopy?

skykooler 10y ago
Terahertz waves range in length from 1 micrometer to 1 millimeter. These are far too large to be able to image things at the scales of crystals. (That's part of why X-rays are used for crystallography - they provide higher resolution than visible light, because the wavelength is shorter.)
- amelius 10y ago
  Petahertz (or higher) is not an option, I presume?
  - kragen 10y ago
    Petahertz electromagnetic radiation is what's currently used for diffraction crystallography; it's conventionally known as "X-rays" (or "gamma rays" if it comes from radioactive decay instead of from Bremsstrahlung.)
    - amelius 10y ago
      Yes, can we use time-domain techniques on this frequency range?
      - kragen 10y ago
        You want to measure the instantaneous amplitudes of a wave packet in the petahertz range at above the Nyquist frequency? I don't want to say it's impossible, but I think you'd have to improve the capabilities of our instruments by about four orders of magnitude, which means you would have to invent several new major technologies. Maybe if you digitize the time-domain pulses using some kind of controlled nuclear reaction? Electronics are far too slow (although I don't really understand why, so maybe that can be fixed). X-ray-stimulated nuclear reactions are going to be tricky to get to happen at all, much less to chain together into computational circuits, although in that case maybe you can use α particles or neutrons to carry the information around between the computational elements, simplifying the task somewhat. It seems like, however you manage to measure it, the quantization of the radiation is going to pose really significant problems to measuring its amplitude accurately as a function of time, but maybe you can get around that by repeating the pulses a lot of times. But you'll need to make sure that you're emitting pulses of the same shape, rather than just pulses with a similar frequency spectrum and envelope but varying relative phases among the frequencies. On the other hand, if you just want to measure the time-of-flight for X-ray wavepackets to sub-picosecond precision, without worrying about the time-domain waveform within the packet, I don't think that gets any harder or easier depending on the "carrier frequency" of the wavepacket — X-rays should be just as easy as terahertz light. You do need a few terahertz of bandwidth, so you aren't going to be able to do this with bursts of gigahertz microwaves. X-rays' interaction with the material you're trying to image might be less or more convenient; their cross-section for backscattering is pretty small, but maybe you could scan the book from different angles and use total internal reflection to find interfaces between materials in the book with different refractive indices. This would also reduce your requirements for time-domain precision down into the hundreds of GHz range, which is a lot easier to deal with.
        eternauta3k 10y ago

cdevs 10y ago

"Write it down on paper I don't trust passwords in computers.. All that's left is thought scanning and then we will think about rethinking passwords.

sova 10y ago
or just abandoning the notion of passwords entirely
- Houshalter 10y ago
  I hope that never happens. I don't want to be tied to a specific Facebook account and computer for everyone I do online for the rest of my life.
flashman 10y ago
Subvocal microphones work (to some extent) by detecting the electrical impulses sent to speech muscles when somebody speaks mentally instead of physically. I wonder if this would work with involuntary recollection - I ask you to think of your password, and even though you won't divulge it to me, the signals for speaking it would leak to my electrodes. Still mostly science fiction, but plausible.

asdfologist 10y ago

Where are all the Betteridge fanboys on this one?

coldtea 10y ago
Rules must have a few exceptions, else they are not rules but universal laws that go without saying...
- asdfologist 10y ago
  I'm not convinced that Betteridge is right even 50% of the time.
breck 10y ago
Actually this is another example of Betteridge's law. If you replace "book" in the headline with "one letter flipbooks of 9 pages or less" (from the paper), then we'd have a counterexample. Still really cool, but a long way to go before we can actually do what the headline teases.
dang 10y ago
Please don't do this here.

gus_massa 10y ago

Somewhat related: "X-Rays Expose a Hidden Medieval Library" https://medievalbooks.nl/2015/12/18/x-rays-expose-a-hidden-medieval-library/ https://medievalbooks.nl/2015/12/18/x-rays-expose-a-hidden-m... HN discussion: https://news.ycombinator.com/item?id=10758257 https://news.ycombinator.com/item?id=10758257 (86 points, 267 days ago, 6 comments)

fma 10y ago

The research has interests of museums that want to read books without opening and damaging them. Is there any chance the scans can damage them? Also, what are the laws of the US government applied this to reading our letters. Our mail is protected by law from opening, but what if they aren't physically opened?

posterboy 10y ago
if it is that literal, I'm sure this would be against the spirit of the law, anyway.
- fma 10y ago
  Yep, that is my exact train of thought. To me, examining email is against the spirit of the law - however, that is allowed because the law did not exactly forbid email (email didn't exist few hundred years back...)
vladus2000 10y ago
IANAL but I believe it is illegal to read mail in this way. You have an expectation of privacy with a letter. Same with your house, you have a reasonable expectation of privacy within it. That being said, I believe if this is cheap enough they will start doing it in secret and the courts probably will not stop it. Whether or not they will attempt to use anything gained from it directly in court is debatable but it could lead to parallel construction cases.
- rurban 10y ago
  That's not true. According to US interpretation of law they may scan every IMAP mail which was not deleted. So in their analogy any book in a public or cooperate museum may be scanned, there is no privacy protection. Only in democratic countries you can expect some privacy.
  - bhickey 10y ago
    Mail and e-mail are legally distinct.

alanz1223 10y ago

Does anyone know what kind of oscillator is used to produce the signal? And how they managed to get such a high sample rate?

eternauta3k 10y ago
They use an ultra-short laser pulse which "gates" (enables/disables) the detector for a very short window of time. They repeat the stimulus+gated detection with different offsets in order to sample different parts of the signal. The ultra-short laser pulse can be generated through purely-optical means. You have a laser pulse traveling around a cavity. Due to a combination of non-linear optical effects, each round-trip tends to shorten and concentrate the pulse. The resulting pulses can be much shorter than what's achievable with electronic generators.

rwmj 10y ago

Might this be used to read the famous burned scrolls of Pompeii and Herculaneum? (Although according to this article, current thinking is they might be able to read them with X-rays: http://www.smithsonianmag.com/history/ancient-scrolls-blackened-vesuvius-are-readable-last-herculaneum-papyri-180953950/?no-ist http://www.smithsonianmag.com/history/ancient-scrolls-blacke...)

kirykl 10y ago

useful technology for the MIT blackjack team

astrodust 10y ago
Scan the shoe and know the optimal betting strategy? You'd need some pretty serious technology to hide your knowledge and come up with a betting strategy that's optimally undetectable as well.

DavidWanjiru 10y ago

I find this interesting because I've ever thought of it conceptually, the idea of a scanner that instantly scans closed books (instantly because one pulse of whatever EM wave you're using suffices). I thought about it after reading about the Timbuktu manuscripts that were saved from Boko Haram in Mali. I hear many of them are too delicate to open. I hope this works. It'd be awesome for so many use cases.

ianai 10y ago

Of course I love the premise. But I also fear what this could allow to be surveilled.

neom 10y ago

I wonder if you could use a chemoreceptor for this also.

Animats 10y ago

The sensing system used was from "Zomega Terahertz Corporation", which had a web site "z-thz.com". That company seems to have disappeared at the end of 2015, but it's still in archive.org. Can't find any info that indicates what happened to them. Zomega was one of the few companies with a true terahertz system, at 2THz, or 0.006in wavelength. Other "terahertz" products seem to be around 100GHz, which is much easier to reach; there are 77GHz automotive radars. Zomega systems had already been used to image hidden layers in paintings, so looking into a stack of paper wasn't a big stretch. This new paper is mostly about a data reduction technique. Overview of terahertz technology.[2] [1] https://web.archive.org/web/20151220072732/http://z-thz.com/ https://web.archive.org/web/20151220072732/http://z-thz.com/ [2] http://spectrum.ieee.org/aerospace/military/the-truth-about-terahertz http://spectrum.ieee.org/aerospace/military/the-truth-about-...

sterex 10y ago

Could this be implemented to scan through layers of other material, say clothing, and used for real-time scanning at sensitive areas such as airports?