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Science

Scientists Freeze Pulse Of Light 343

Posted by simoniker
from the mr-bigglesworth-looks-on dept.
Smitty825 writes "After slowing down light to slow speeds, scientists at Harvard University have been able to stop light for a very brief period of time without destroying its energy. The article explains how it is different from this previous light-stopping science story - this will hopefully help the development of quantum computers and ways to communicate over long distances without being eavesdropped on."
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Scientists Freeze Pulse Of Light

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  • Okay... (Score:3, Insightful)

    by autopr0n (534291) on Thursday December 11, 2003 @05:43AM (#7688180) Homepage Journal
    One of the most annoying things about slashdot is their tendency to post completely vacuous science stories. Would it have been that hard to look up the actual paper before posting, or at least any information at all? All this story tells us is that it doesn't involve storing the photons in an atom as other researchers did. Oh, and that it's "very clever". How nice.

    Does the laziness of slashdot "editors" truly know no bounds? If you're not interested in doing the work, why not find people who are?
  • Color == frequency (Score:5, Insightful)

    by flakac (307921) on Thursday December 11, 2003 @06:41AM (#7688385)
    Light doesn't actually have "color". Color is our perception of the wavelength of the light. There's another article on BBC [bbc.co.uk] that explains the experiment in greater detail. Essentially, they didn't actually freeze the photons, ie. made them stop moving, but used a different method to make the photons bounce back and forth in place. So the "color" should have remained the same.
  • by pnagel (107544) on Thursday December 11, 2003 @07:03AM (#7688443)
    What do you mean by "then everything is pre-determined?" In one sense, obviously the previse nature of the past events of the past you see are pre-determined, because they already happened. Or do you mean that viewing the past confirms a Deterministic view of the universe? How so?

  • by LordLucless (582312) on Thursday December 11, 2003 @07:04AM (#7688446)
    Well, "destroying its energy" would be a rather major accomplishment, if I remember my highschool lessons regarding conservation of energy...
  • by leoaugust (665240) <leoaugust&gmail,com> on Thursday December 11, 2003 @07:06AM (#7688451) Journal
    have been able to stop light for a very brief period of time
    a very brief period of time ? .. I think it depends on what perspective you look at it from.

    I am just building my reasoning backwards. To understand what happens to the Photon when it stops, let's first see what happens to the photon when it moves at - well - the speed of light.

    From the quickest reference I could dig thru [wired.com] http://www.wired.com/wired/archive/6.07/es_warp.ht ml?pg=3&topic=

    Einstein also predicted that time itself must slow down for objects in motion.
    The faster you move, the slower your clocks would appear to tick - relative to someone watching from a remote location. If you could actually reach light speed, time would crawl to a stop. It's wildly counterintuitive, but experiments have proved it true.

    So, the faster the photon moves the slower the clocks would appear to move. Then, I guess, the slower the Photon moves the faster the clock would appear to move. And when the photon STOPS, the clock must be moving INSANELY FAST. So how could it be a very brief period of time ? .. I think it is a very very very long period of time.

    Guess, it all depends on which perspective you are looking at, and how you are measuring time ...

  • by LilJC (680315) on Thursday December 11, 2003 @09:43AM (#7689015)
    Well, "destroying its energy" would be a rather major accomplishment, if I remember my highschool lessons regarding conservation of energy...

    Yes, but that's not how it would read. Destroying light is no major accomplishment at all, even if it means it is normally converted into heat. If light were not destroyed in this sense all the time, you would only need to flash on the lights in your room and shut the door, because the same light would continue to illuminate the room.

    It's really the same concept as destroying lighter fluid by burning it, except light has a curious tendancy to burn itself out.

  • by n3z0rf (171055) on Thursday December 11, 2003 @09:57AM (#7689113)
    Correct me if this is wrong but wound't stopped light be dark... So in turn they have effectively made very expensive and complex light switch??
  • Re:Harvest time (Score:2, Insightful)

    by angusr (718699) on Thursday December 11, 2003 @10:44AM (#7689498)

    We aleady do harvest light (or at least part of the energy of light) for later use anyway - solar cells connected to batteries (as used on satellites, ISS, etc). I don't think storing the light and then converting to required power is going to be that much more effcient than converting to power and storing in batteries.

    Generating power in space and then "transmitting" back with lasers isn't a new idea, but does have certain drawbacks if anything goes wrong.

    Probably safer to use a Dyson shell [nada.kth.se]... lots more power available on one of those. Ringworlds just don't cut it.

  • Re:Stopped photons (Score:2, Insightful)

    by FooAtWFU (699187) on Thursday December 11, 2003 @11:19AM (#7689809) Homepage
    See, the stopped light isn't stored as photons... it's stored as energy in a gas, which will then produce another pulse of light identical to the incoming one when tickled with a laser. If you tried to jam too many photons in there, the gas would stop absorbing the photons, what you'd end up is a gas that's probably rather hot and has lost all the data of the incoming light pulses. Rather useless.

    Photons are quanta of energy; they are quite incapable of being split or combined. Consult your local library for books on quantam physics...

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