Become a fan of Slashdot on Facebook

 


Forgot your password?
Close
typodupeerror
×
Science Technology

Fastest-Ever Flashgun Captures Image of Light Wave 175

Posted by ScuttleMonkey from the fastest-flash-in-the-west dept.
loconet writes to tell us that a team of researchers have created the shortest-ever flash of light. Weighing in at just 80 attoseconds, this flash has already been used to capture an image of a laser pulse and could possibly be used in the future to capture the electron movement around large atoms.
This discussion has been archived. No new comments can be posted.

Fastest-Ever Flashgun Captures Image of Light Wave More

Fastest-Ever Flashgun Captures Image of Light Wave

Comments Filter:

  • Who woulda thought? (Score:5, Funny)

    by rumblin'rabbit ( 711865 ) on Friday June 20, 2008 @12:50PM (#23875979) Journal
    My God, James Clerk Maxwell was right after all!

  • Duckhunt (Score:4, Funny)

    by AioKits ( 1235070 ) on Friday June 20, 2008 @12:51PM (#23876003)
    Can I get one of these flashguns for that? I'll show those ducks who the boss is!

  • Sounds impossible (Score:4, Insightful)

    by Carewolf ( 581105 ) on Friday June 20, 2008 @12:54PM (#23876051) Homepage

    Using light to take pictures of light in motion?

    This is either a hoax, or the the article is skipping some really important part.

    • Yep, it's hoax. (Score:5, Funny)

      by Anonymous Coward on Friday June 20, 2008 @01:00PM (#23876143)

      It is a hoax. see the picture of the light pulse? Well, for one, it's only showing a wave and we all know from physics that light is both a wave and and particle. So where's the particle? Hmmm?

      Secondly, the wave is, well, wavy. And we know, again from physics, that light only travels in a straight line.

      Those damn scientists always trying to fool us! And engineers too!

      • Re: (Score:3, Funny)

        by SQLGuru ( 980662 )

        Dude, it's camera shake......they should have used a tripod.

        Layne

      • It is a hoax. see the picture of the light pulse? Well, for one, it's only showing a wave and we all know from physics that light is both a wave and and particle.

        Hey, I _am_ a particle, you insensitive clod!

    • Re:Sounds impossible (Score:5, Interesting)

      by bugnuts ( 94678 ) on Friday June 20, 2008 @01:01PM (#23876163) Journal

      from TFA, I believe it's imaging a laser pulse shot through neon gas. It's the laser pulse that triggered the flash in the first place.

      Bizarrely, the article states

      As each flash is intense enough to completely ionise a neon atom and release an electron, the researchers could use those electrons like a flashgun, to illuminate some of the original 2.5 femtosecond trigger pulses of laser light.
      This is interesting, because the neon is releasing electrons, not photons.

      I agree that snapping a photo of light sounds dubious, but it looks like an electron flash, so maybe it's just making something visible that wouldn't have been seen otherwise.

      • Re: (Score:2, Informative)

        by theun4gven ( 1024069 )

        I agree that snapping a photo of light sounds dubious, but it looks like an electron flash, so maybe it's just making something visible that wouldn't have been seen otherwise.
        All photos are photos of light.

      • Re: (Score:2)

        by n6kuy ( 172098 )

        So, basically, it's a scintillator. The neon gas glows with secondary photon emission for a short while when bombarded by a few photons of laser light.
        Nothing new here.

    • "The light pulses are produced by firing longer, but still very short laser pulses into a cloud of neon gas. The laser gives a kick of energy to the neon atoms, which then release this energy in the form of brief pulses of extreme ultraviolet light"
      Sorry I RTFA yesterday. I know that's against the rules... Please sir, take pity!

    • Using light to take pictures of light in motion?

      Actually this is theoretically possible. You can make two photons interact but it is not a first order effect and in fact is very heavily suppressed at low energies. So it is possible but incredibly unlikely (and certainly not how they did it here).

  • P.E.T.A will be pissed (Score:1, Funny)

    by Anonymous Coward

    a captured atom is an unhappy atom?

  • Um... What? (Score:5, Interesting)

    by barfy ( 256323 ) on Friday June 20, 2008 @01:06PM (#23876233)

    Ok, Internet Physicists out there, please help me.

    Ok, first you have this coherent photon beam. This means that they are all traveling at the same direction. So how do you take a picture of THAT?

    You are bombarding the photon beam with photons, are the photons opaque, reflective, or TRANSPARENT? How do the photons from the flash, BOUNCE BACK at the camera. When they bounce back, how do you get color?

    Is it just me, or does this make any sense at all?

    • Re: (Score:1)

      by sp332 ( 781207 )
      In the article (and I'm not claiming to understand this completely), they send the photon pulse into a cloud of neon atoms, and image the electrical burst resulting from a completely ionized neon atom.

    • Re: (Score:2)

      by bugnuts ( 94678 )

      Apparently it's not a flash of photons, but a flash of electrons.

      Maybe it's measuring the magnetic deflection? I know that both photons and electrons can be moved with a charge, so they may have an effect on each other.

      If you remove the scatter and noise, you can probably get a pattern of electrons passing by photons ... but I am not a physicist!

    • Re: (Score:2, Informative)

      by Benbrizzi ( 1295505 )
      That's not what happens. You only see a laser because the photons reflect off particles (neon in this case). The photons which hit your camera all come from (almost) parallel lines so what you see is where the photons hit by your beam were.

    • Possible explanaition (Score:1, Interesting)

      by Anonymous Coward

      Here's a thought. You have a coherent photon beam. This doesn't just mean they are all traveling in the same direction, this also means that they are perfectly in phase with one another. Probably better to think about it as a single wave with a large amplitude. Anyways, you shine another pulse of light at it, the light passes through the laser beam, and hits a detector. Perhaps they are measuring the interference between the laser light and the light pulse or some such. Not exactly a reflective pictur

    • Re:Um... What? (Score:5, Informative)

      by Btarlinian ( 922732 ) <tarlinian@gmai[ ]om ['l.c' in gap]> on Friday June 20, 2008 @01:31PM (#23876595)
      From the article it sounds like a pump-probe experiment. They excite the neon with a 2.5 femtosecond pulse and then image the excited state with a 80 attosecond pulse. (You obviously need the imaging pulse to be shorter than the excitation pulse.) I'm not sure how much detail you would be able to get from this though, as the wavelength and brightness of the light source would be a limiting factor.

    • Re:Um... What? (Score:5, Informative)

      by againjj ( 1132651 ) on Friday June 20, 2008 @01:53PM (#23876941)

      Ok, first you have this coherent photon beam. This means that they are all traveling at the same direction. So how do you take a picture of THAT?

      In a different way that a standard photograph.

      You are bombarding the photon beam with photons,

      No, you aren't. That doesn't make sense.

      What they do is have the laser pulse travel through something they call a "chirped mirror". This packs the photos from the laser pulse into a smaller space. This then travels through a neon cloud, which then creates a flash of light. This flash of light is the "shortest-ever flash of light".

      To photograph this flash of light, they direct it into a second neon cloud, which ionizes atoms, releasing electrons. Those electrons are then recorded. Multiple flashes were required to produce enough electrons to build up the image shown in the article, so what you really have is an image of many flashes overlaid.

      • Re: (Score:2)

        by barfy ( 256323 )

        Thank you, thank you...

        I have not fully parsed what you said. But... You have me actually thinking more correctly about this, and that is what was important. I had obviously fallen off the bus somewhere, but I had no idea where.

        I think I am getting my head around this. Now I have problems with "shortest, and how that coincides with singular, chance and cloud" and the need to have an electron sensor rather than a photon sensor. But I am much closer to the end than to the beginning. Thank you again!

    • Re:Um... What? (Score:4, Insightful)

      by barfy ( 256323 ) on Friday June 20, 2008 @02:04PM (#23877087)

      Thanks, but I think there is something I have hopelessly never figured out, and that something would also let me understand how reflection works. How does an atom know the direction that the photon was traveling and and what does it bump off of? And isn't the atom round, so how come reflection works like the atoms are a plane. And how does the atom know the relative position of the atoms around it, so that it can reflect the photon in the right direction?

      This is also the problem with lenses. How does the atom know the surface of the greater object, so that it knows what directions to send the photons that are passing through?

      I am sure if I understood this, it would make the underlying question here easier. But as many of these answers so far show, this is be far, not a trivial question.

      • Re:Um... What? (Score:5, Interesting)

        by TigerNut ( 718742 ) on Friday June 20, 2008 @02:33PM (#23877433) Homepage Journal
        Richard Feynman once pondered, if moisture molecules in the atmosphere scatter light, and presumably this is a random effect because the molecules are randomly distributed, why is it that buildings, etc. when they're viewed through mist, do they still have sharp edges? You'd think all the random scatter would blur the edges.

        That thought train led him to do some fundamental work in particle scattering and path integrals, IIRC, and eventually to the Feynman diagrams that are now commonly used to describe some aspects of particle interactions.

        So you're thinking some good deep thoughts there, but I can't give you a good answer other than "they just know". Basically the "proper" reflection is the only one that is coherent to the observer and the other reflected beams are all out of phase so they might as well not happen... and therefore they don't. Or something like that.

        • Re:Um... What? (Score:4, Funny)

          by Anpheus ( 908711 ) on Friday June 20, 2008 @04:50PM (#23879669)

          God dammit, now what's the answer? Why are the building edges sharp?

          Feynman would never have left me hanging like that.

        • Re:Um... What? (Score:4, Informative)

          by BlackLungPop ( 1307317 ) on Saturday June 21, 2008 @11:26AM (#23885989)
          Check out the book QED: The Strange Theory of Light and Matter, by Richard Feynman. The answer is basically that the photon doesn't bounce off of anything! It "interacts" with an electron, and another photon is emitted. Why is it emitted at the particular angle? That's what the book is all about. Way too much to explain here. But if you want to understand in layman's terms how reflection and refraction work, and why glass is transparent, get that book, it's wonderful.

    • Re: (Score:2)

      by xPsi ( 851544 ) *
      Note light WILL interact weakly with light [wikipedia.org] via virtual charged particles. This is the principle behind gamma-gamma studies and their ilk [ucl.ac.uk]. Keep in mind, this isn't what the researchers the /. article are doing (see elsewhere in the article and thread for that explanation).

    • Seems that the description in TFA is a bit simplified for non-physicists, which makes it really confusing to physicists who are after the removed information :P

      In the situation you describe, however, the wave model of light says that they are "transparent" to each other, ie. if you sent 2 beams through each other at right angles you would detect them out the other side exactly the same as if they didn't cross. The only difference would be if you measured the intensity at the point where they intersect, the

  • FLASH! Ahhhhh (Score:3, Funny)

    by Anonymous Coward on Friday June 20, 2008 @01:09PM (#23876273)

    Savior of the universe!

  • Do we care how short a flash of light can be created?

    Can't you just illuminate something brightly for any length of time when taking a picture?

    Isn't shutter speed the problem?

    Someone educate me.
    • They're effectively the same thing. If no light falls on your detector, it's essentially the same as having a closed shutter. When you can figure out how to open and close a shutter in less than a trillionth of a second you can let them know. It's far easier to create a short pulse of light.

      • Re: (Score:2)

        by SQLGuru ( 980662 )

        Since you are only worried about blocking or not blocking light, could you do something with multiple LCD's (2 to 6ms response time) stacked and "timed" such that you get down to something approaching the 1 trillionth of a second goal? You'd lose some of the light just because of going through the medium, but that can be dealt with.

        Layne

    • Re: (Score:2, Informative)

      by Anonymous Coward

      No, shutters are used to limit the ambient light from reaching the film (or sensor). In a situation like this you are limiting the light being produced. So no shutter is needed - just leave the film exposed for the whole experement, when the light is produced it will be recorded (you record the rest of it too, but it records as nothing).

    • Isn't shutter speed the problem?

      They set their camera to the B (bulb) setting which keeps the lens open as long as the button is depressed. Set your camera to where you want to take a picture, screw a cable release into the shutter release button of a camera, turn off all lights in the room, depress cable release button and tighten the screw to keep the shutter open, trigger your action and the flash to capture the action, loosen the cable release so the shutter now closes, turn on lights in room. Ri

    • Re: (Score:1, Informative)

      by Anonymous Coward

      Do we care how short a flash of light can be created?
      Can't you just illuminate something brightly for any length of time when taking a picture?
      Isn't shutter speed the problem?
      Someone educate me.

      As with so many things, the laws of physics are the problem. The duration of light is the path of least resistance.
      The fundamental reason behind using strobe light in photography is to freeze action.

      Consider a 35mm film camera with a mechanical shutter... what degree of force and mechanism would be required to move that shutter to open AND close the height of 24mm in 80 attoseconds? IANAPhysicist, but I doubt human hands could hang on to it.

      Meanwhile, I can take my old Leica*, lock the shutter open on a

      • Re:What about shutter speed? (Score:5, Informative)

        by egomaniac ( 105476 ) on Friday June 20, 2008 @01:53PM (#23876943) Homepage

        Consider a 35mm film camera with a mechanical shutter... what degree of force and mechanism would be required to move that shutter to open AND close the height of 24mm in 80 attoseconds? IANAPhysicist, but I doubt human hands could hang on to it.

        Apparently we're not realizing just how short 80 attoseconds is. You doubt human hands could hang on to it? Moving 24mm in 80 attoseconds is faster than the speed of light. Not only is it faster than the speed of light, it's a million times faster than the speed of light.

        Light only travels 24 nanometers in 80 attoseconds. [google.com]

        • ...is that the photograph is taken before he presses the shutter. However, you can never know this for certain, as his finger now weighs an almost an infinite amount (albeit as an imaginary mass), which will result in the camera undergoing gravitational collapse into the finger.

  • I have a flashlight that will shoot a beam out in 1 nottasecond. Also, imagine the stop-motion sports photos you could get with 80-attosecond film speed!

    • Forget sports...
      how about those "Khaaaaaaaaaaaaaan!" moments in the movies?

      Hours and hours enjoyment!

  • Ummm.. (Score:5, Funny)

    by InlawBiker ( 1124825 ) on Friday June 20, 2008 @01:30PM (#23876581)

    I hate to be a pedantic killjoy, but on that film the light flash lasted about 3 seconds. I could see it pretty well with my naked eye.

    Try again, science!

  • Electron movement? (Score:3, Funny)

    by Thelasko ( 1196535 ) on Friday June 20, 2008 @01:32PM (#23876617) Journal

    Jonathan Marangos at Imperial College London, UK, says the super-short flashes could let researchers image the movement of electrons around large atoms.
    So, you take a picture of it. Now you know where it is. But how fast is it going?

    Does anybody else see the problem here?

    • I have a gut feeling quantum mechanics will have to say something about that. Is somebody back to 'God doesn't play dice'? Orbitals, anybody?

  • I am SO going to use this in a speech about my cousin's wedding night when we throw his stag next week. "Fast, you say? I'll tell you about fast..."

  • ... it'll still take Wallgreens an hour to develop the film.

  • Image of a pulse of light that is 2.5 billionths of a millionth of a second long
    2.5 billionth of a millionth of a second? So... is that 2.5 femtoseconds, anyone want to check my math?

    billionths of a billionth of a second
    I'm going out on a limb and saying a gazillionth second?

  • Ah, sweet photons.... I don't know if you're waves or particles, but you sure do go down smooth.

  • "and could possibly be used in the future to capture the electron movement around large atoms."

    I like Einstein, never like the idea of superposition. The cat will die when factors cause it to die. It does not flip between dead and alive in a box.

    But I suppose quantum theorists will say that by observing the location of the electron it is also changing it, that had it not been measured it'd be somewhere else, thus proving black is white.

    • Fortunately Bell's Theorem [wikipedia.org] provides us with an experiment that can disprove the idea that it is just hidden variables.

      Unfortunately, while actual testing of those experiments appears to confirm Bell's Theorem, there are a few loopholes and controversies about whether the experiments actually worked.

  • hmm, looking at the pic I would say they forgot the anti-shake setting

  • The shortest ever Flash of Light? How much spell haste did that paladin have to stack? - WoW geek
  • An 80 attosecond pulse of light is about 29 nanometers wide. Google "The speed of light in nanometers per attosecond) and multiply that by 80.

Slashdot Top Deals

C'est magnifique, mais ce n'est pas l'Informatique. -- Bosquet [on seeing the IBM 4341]

Close