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Quantum Cloaking Makes Molecules Invisible

Posted by kdawson on Sun Nov 16, 2008 05:31 PM
from the can-you-see-me-now dept.
KentuckyFC writes "An international team of physicists has applied the ideas of cloaking to the quantum world and worked out how to hide quantum objects such as molecules. In the quantum world, seeing is equivalent to detecting a quantum object. In the case of molecules, that means looking for the terahertz radiation they produce when they vibrate (abstract). By designing a 'quantum corral,' an elliptical nanostructures that absorbs terahertz waves at a precise frequency, the team says it is possible to hide molecules that emit at exactly that frequency. They say their quantum corral would be ideally suited to detecting molecules of specific species while ignoring others. And that may mean a new generation of molecular detectors on the horizon."
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  • Ears.. (Score:5, Insightful)

    by Anonymous Coward on Sunday November 16 2008, @05:36PM (#25780403)

    By designing a 'quantum corral,' an elliptical nanostructures that absorbs terahertz waves at a precise frequency

    Sounds sort of like how the human ear works.

  • Lord have mercy! (Score:5, Interesting)

    by moniker127 (1290002) on Sunday November 16 2008, @06:03PM (#25780571)
    Last week they announced the first laser cannon, now we're working on the base technology for tricorders? Maybe startrek IS an accurate timeline.
    • by girlintraining (1395911) on Sunday November 16 2008, @06:11PM (#25780621)

      Well, the Eugenics Wars were supposed to have happened by now, also referred to as the "third world war". Also, we should have launched few more probes by now -- Voyager, which will later gain sentience and attempt to kill everything that isn't perfect, and Nomad, which later returns to blow the hell out the planet because we killed off the whales. Lastly, we've only got four years left to build a self-enclosed and self-sustaining ecosystem in Portage Creek, Indiana.

      P.S. You've been geeked. ^_^

      • Re:Lord have mercy! (Score:5, Informative)

        by Tony Hoyle (11698) * <tmh@nodomain.org> on Sunday November 16 2008, @06:19PM (#25780663) Homepage

        Voyager was launched in the 1970's. Voyager 2 left the solar system in 2007... so should be picked up by aliens just about now.

      • by Shakrai (717556) on Sunday November 16 2008, @06:39PM (#25780777) Journal

        Well, the Eugenics Wars were supposed to have happened by now, also referred to as the "third world war"

        The Third World War was not the Eugenics Wars. The Eugenics Wars happened around the time of the 90s. There's a few non-cannon novels about them and they were mentioned in the TOS Episode Space Seed. The Third World War happened around the middle of the 2000s and ended ten years before the events of First Contact in 2063.

        You must immediately turn in your geek card and exit the building. Some friendly looking security people with tasers will be escorting you out. Take heart though -- you'll be able to get chicks now.

        • Re:Lord have mercy! (Score:5, Interesting)

          by girlintraining (1395911) on Sunday November 16 2008, @06:51PM (#25780847)

          Two things sugar. First, I am a "chick", and I've been able to get them for awhile. Second, as you said, Spock referred to the Eugenics Wars in Space Seed as "the last of your so-called world wars" -- so what you're going on about is an minor plot inconsistency. zomfg! An inconsistency in Star Trek canon? Like THAT's never happened before. So about my geek card? No, not yours. And just so we're clear... Yes, there are fangirls for TOS. We're all gay though so don't get your hopes up little boy. ;) We're also responsible for most of the spock/mccoy slashfic out there.

          • I have to say.... I instantly love you! :D
            On first post. ;)

            Now the question is, who looks less geeky.
            I'm half afghani, half luxemburgish, have a light brown tan, do not live in a basement, and actually date girls.
            Gooooood luck! :P

          • I knew that too, and I'm *not* gay. I have my third baby on the way to prove it. I *am* taken though, obviously. :)

            Maybe the war pre-first-contact wasn't a world war ... I don't think they ever actually called it WW3 did they?

            Must also add, it was supposed to be Voyager VI that become V'ger (and the link that made them Borg, as alluded to above, is non-Canon). Nomad turned up in TOS, but the whale probe was alien.

            • Maybe the war pre-first-contact wasn't a world war ... I don't think they ever actually called it WW3 did they?

              They did call it the last World War in Space Seed. I just happened to have been watching this episode last week, so it was pretty fresh in my mind. I decided to play it again and double check.
              At around 3.5 minutes into the episode Mr. Spock says:
              "The mid 1990's was the era of your last so-called World War."
              I thought they called it World War 3 later on in the episode, but that might just be me misremembering this beginning part. Regardless, the poster several posts above asserted:

              The Third World War was not the Eugenics Wars. The Eugenics Wars happened around the time of the 90s. There's a few non-cannon novels about them and they were mentioned in the TOS Episode Space Seed. The Third World War happened around the middle of the 2000s and ended ten years before the events of First Contact in 2063

              According to Space Seed,

              • Maybe this was retconned later somewhere

                It was retconned in First Contact. Riker or Data has a line about arriving ten years after the "Third World War".

          • An inconsistency in Star Trek canon? Like THAT's never happened before

            I think Star Trek canon is one long line of inconsistencies ;)

            We're also responsible for most of the spock/mccoy slashfic out there.

            So which "I'm a Doctor, not a ..." variation is McCoy's safe word in those fanfics? ;)

          • Hahahah, +1 Pwn3d :-)

          • You're forgetting the cylindrical probe that "attacked" pretty much any alien life form that could arguably be described as a humanoid female. Of course it is rumoured that Jim Kirk had little problems keeping his cylindrical probe straight, so I'm not sure your use of the term all is quite accurate once we adjust for the critical ommision* either ...

            disclaimer:

            Critical ommisions not to be confused with nocturnal emmisions (that means you Kirk)
  • Tough challenge? (Score:4, Insightful)

    by PeterAitch (920670) on Sunday November 16 2008, @06:07PM (#25780601)

    The theoreticians seem have thrown down a considerable challenge here. Designing and building will likely be very different things. Makes most of the stuff fabricated so far seem almost macro-scale.

    Isn't it a bit naughty to include star-trek tags on a real-science piece (even if it IS distinctly theoretical)?

  • "suited to detecting molecules of specific species"

    Don't they mean specimens?

  • In the quantum world, seeing is equivalent to detecting a quantum object. In the case of molecules, that means looking for the terahertz radiation they produce when they vibrate (abstract). By designing a 'quantum corral,' an elliptical nanostructures that absorbs terahertz waves at a precise frequency, the team says it is possible to hide molecules that emit at exactly that frequency. They say their quantum corral would be ideally suited to detecting molecules of specific species while ignoring others. And that may mean a new generation of molecular detectors on the horizon."

    That's what I've been saying all along!

  • Duh..... (Score:3, Informative)

    by IHC Navistar (967161) on Sunday November 16 2008, @06:27PM (#25780709)

    "By designing a 'quantum corral,' an elliptical nanostructures that absorbs terahertz waves at a precise frequency, the team says it is possible to hide molecules that emit at exactly that frequency."

    -No shit. You can hide objects by thowing something that absorbs the radiation emitted by them. I can hide an LED by keeping it in my shed, with the shed's construction material absorbing the light and heat emitted by the LED.

    Basically, the nanostructure they built is nothing more than a filter that filters out terahertz wavelengths, like a red colored filter blocks out wavelengths in that frequency range.

    Not a "breakthrough" by any means, but interesting in that they developed a substance that can filter out terahertz wavelengths.

    • This drab technology is no more amazing than the "cloaking" technology that hides copper in infrared. Its ridiculous technology like this that becomes tomorrow's practical application, somehow somewhere.

      Who the hell would have thought shooting light in a beam would be so useful?
    • ". . .like a red colored filter blocks out wavelengths in that frequency range."

      From what I remember from high school physics class, a red filter blocks out *everything except for* light in the red frequency ranges. That is, it allows red to pass, but blocks green, blue, yellow, etc.

    • This was my first thought on reading the summary. That you can make a molecule invisible by shielding detection is like saying you can make the sun invisible by putting a box over your head.

    • Although, the shed example is likely to work, you came up with a better idea even eariler. The first words of your response are "No Shit". Too bad you included the word 'No'. Shit, it seems, could easily block out the light as well as a shed. And, I should add, its much cheaper.

      And based on your response, Shit, is what the scientists are full of.

      • Could be an interesting experiment. We would know the material is working by not detecting the terahertz radiation, but we'll need some way of detecting if the particles are still actually there. It may seem like common sense to say, "of course they're still there...you insensitive clod!" But unless we have the ability to turn this theoretical filter on and off we may never be sure.
  • by NoobixCube (1133473) on Sunday November 16 2008, @06:38PM (#25780773) Journal

    I know almost nothing about quantum mechanics, so correct me if I'm wrong. On this scale, isn't observation interaction? Would preventing observation also prevent interaction with what is inside the cloak? How would the cloak behave if you tried to detect what's in it with a laser (or something)?

    • I'm no quantum physicist either, but it seems to me that a cloak is a cloak... Consider a man wearing black clothing hiding in a dark room. You try to find him with a flashlight, just like you'd try to find the molecules in the cloak. So if you tried, one of two things would happen:

      1. You wouldn't detect the molecules because of the cloak.
      2. You'd detect them and the cloak would be a failure.

      Certainly nothing of universe-imploding significance, I think.
  • by hoytak (1148181) on Sunday November 16 2008, @06:49PM (#25780835) Homepage
    is the engineering. I recently attended a talk where the speaker presented a theoretical way to completely cloak a large object (i.e. person, car, etc.). It was possible to completely prevent detection within a reasonable range of the visible spectrum. (I don't think it's been published yet, or I'd post a link.) The assumption was that the object was surrounded by a material in which you had complete control of the metric space properties, i.e. the propagation coefficient of light at each point. Now there's a challenge for the engineers...
  • != Invisible (Score:3, Insightful)

    by DynaSoar (714234) on Sunday November 16 2008, @08:53PM (#25781527) Journal

    Putting something where it can't be seen is not the same as making it invisible. Making it unable to be seen at a particular frequency does not mean it can't interact with something else, for instance gravitationally with the 'corral'. That would make it detected.

    If the above were not so, all your friends who didn't happen to be within eyesight would be invisible. Nothing wrong with that as long as you're willing to accept the notion that just because your friends are invisible doesn't mean they're imaginary.

    At best, in complete isolation, the molecule would be both visible and invisible. It would be in Schroedinger's cat box.

    • I don't think they're using invisible to mean "imperceptible". More like they're using it to say "typically we detect molecules by looking for their terahertz radiation. this method makes them invisible using that method." By your definition, not being able to interact with ANYTHING else really means the object doesn't exist. My invisible friend really takes exception to that.

  • Maybe I'm conflating two different areas of "quantum" here, but here goes.

    At the quantum level of physics, if you observe something, the very act of observing will cause the quantum state to collapse, meaning you can't directly observe what ever it is you are trying to observe !?
    If you can create a filter that effectively only allows you to observe things that can pass through that filter, doesn't that mean that a quantum objects state can now be defined without direct observation ? The filter has already
  • I just love scanning for lire forms!

    Life forms!
    You tiny little life forms!
    You precious little life forms!
    Where are you?

    • TFA: "First what does it mean to see or not see a quantum object? Fransson and co say that seeing is equivalent to detecting quantum objects and in the case of molecules that means looking for the terahertz radiation they produced when they vibrate.

      "We propose a method for detecting and manipulating quantum invisibility based on THz cloaking of molecular identity in coherent nanostructures," says Fransson and buddies.

      In practice, this means designing quantum corals, elliptical nanostructures, that absorb terahertz waves of specific frequencies. When a molecule that emits this frequency is placed at the focus, it cannot be spotted. It is essentially invisible.

      Useful? You bet. Such a quantum coral would be ideally suited to detecting molecules of specific species while ignoring others. For example, if you have a particular molecular species that poisons your measurements, then what you need is a cloak that will make it invisible to your detectors

      It's ideas like this that are going to make cloaking mighty useful one of these days.

      Ref: arxiv.org/abs/0811.1782: Quantum Detection and Invisibility in Coherent Nanostructures"

      Right now they are talking 'invisible to terahertz radiation detecters they currently use, and this would be useful.

      As often happens, the summary is not real clear. This is not meant to be a 'cloak of invisibility'(D&D/RPG style), nor a 'cloaking device'(Romulan style) device, just (initially) a means to 'clean up' some lab tests.

      • In practice, this means designing quantum corals, elliptical nanostructures, that absorb terahertz waves of specific frequencies. [...] Such a quantum coral...

        If you had enough quantum corals, could you build a quantum reef?

      • This is not meant to be a 'cloak of invisibility'(D&D/RPG style), nor a 'cloaking device'(Romulan style) device, just (initially) a means to 'clean up' some lab tests.

        And I thought this is why all that dark matter, apparently so prevalent in the universe, is so difficult to detect.

      • Well, I was thinking a detector to accurately represent the wave form of any molecule, creating an equal inverted wave, and shooting it back at the molecule.

        e=mc^2

        Particles are waves - so why couldn't we just unmake the particle? Bwa ha ha! Quantum Bomb?

    • Yes, lets eat the cloaking devices.

      "Where's my shit, I knew I shit in the toilet, I even heard it!"

      • You sir, are a dispicable human being, and a poor excuse for a sentient life form. Your mother cried when you were born because she thought you were an abortion. She cried "baaaaaaaa." Your father spent his life on a farm, until he was neutered and sent to the grand canyon to carry tourists on his back. When he saw the pretty colors he jumped off the cliff. There was no mourning. The crow that started to eat his carcass threw up, and the remainder of it killed three colonies of ants. His poisonous and filt
    • Re: (Score:3, Insightful)

      No, that was hideously visible. If it were invisible, that would be creepy, but seeing that guy's very much opaque intestines is worse.

    • I know! I only read the title (don't have time to RTFS) but I just gotta say, mollecules are already pretty much invisible! I mean, when's the last time you were all like "There's too much oxygen mollecules, I can't see the strippers!" Probably never.