Physicists Made a Flying Army of Laser 'Schrodinger's Cats' (livescience.com) 58
PolygamousRanchKid quotes LiveScience: A laser pulse bounced off a rubidium atom and entered the quantum world -- taking on the weird physics of "Schrodinger's cat." The laser pulses didn't grow whiskers or paws. But they became like the famous quantum-physics thought experiment Schrodinger's cat in an important way: They were large objects that acted like the simultaneously dead-and-alive creatures of subatomic physics -- existing in a limbo between two simultaneous, contradictory states.
"In our experiment, the [laser cat] was sent to the detector immediately, so it was destroyed right after its creation," said Bastian Hacker, a researcher at the Max Planck Institute of Quantum Optics in Germany, who worked on the experiment. But it didn't have to be that way, Hacker told Live Science. "An optical state can live forever. So if we had sent the pulse out into the night sky, it could live for billions of years in its [cat-like] state." That longevity is part of what makes these pulses so useful, he added. A long-lived laser cat can survive long-term travel through an optical fiber, making it a good unit of information for a network of quantum computers... In the new experiment, described in a paper published Jan. 14 in the journal Nature Photonics, researchers created laser pulses that are in superposition between two possible quantum states. They called the little pulses "flying optical cat states...."
"Cat states can encode quantum information in a way that allows [us] to detect optical loss and correct for it. Although every optical transmission has losses, the information can be transmitted perfectly."
"In our experiment, the [laser cat] was sent to the detector immediately, so it was destroyed right after its creation," said Bastian Hacker, a researcher at the Max Planck Institute of Quantum Optics in Germany, who worked on the experiment. But it didn't have to be that way, Hacker told Live Science. "An optical state can live forever. So if we had sent the pulse out into the night sky, it could live for billions of years in its [cat-like] state." That longevity is part of what makes these pulses so useful, he added. A long-lived laser cat can survive long-term travel through an optical fiber, making it a good unit of information for a network of quantum computers... In the new experiment, described in a paper published Jan. 14 in the journal Nature Photonics, researchers created laser pulses that are in superposition between two possible quantum states. They called the little pulses "flying optical cat states...."
"Cat states can encode quantum information in a way that allows [us] to detect optical loss and correct for it. Although every optical transmission has losses, the information can be transmitted perfectly."
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One thing it means (claims...not really tested, but certainly made plausible) is that quantum uncertainty can persist in ways that are macroscopically significant.
To me this is an argument in favor of the EWG multiworld interpretation of quantum physics, but I'm no expert, and others may well see this as an argument in favor of some other interpretation. That I can't see this as favoring the Copenhagen interpretation doesn't mean that someone else can't.
OTOH, one needs to remember that an interpretation is
Re: yeah (Score:5, Funny)
I prefer to think that both the Copenhagen and Many-worlds interpretations are correct.
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one needs to remember that an interpretation is just that, and doesn't in and of itself predict any particular physical realization.
Superposition isn't an interpretation, it's an experimentally verified fact of nature. [wikipedia.org]
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But what does it mean? How do you interpret it?
Every interpretation of quantum physics predicts the same experimental results, but the interpretation of them is less clear. And the English translation of the math differs wildly depending on which interpretation you use.
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All I can say is that "Flying Army of Laser 'Schrodinger's Cats" sure sounds cool!
Maybe they can take on the Sharknado.
Can someone please explain. (Score:2)
I read the article, and still don't understand a thing. I think it is not because i am so stupid, but because the article has been so dumbed down that it no longer contains any useful information. So, if someone please can explain what this is about, without using a cat or car analogy, please feel free to do so.
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The summary made my head hurt. The article made me dumber.
As far as I can tell, they bounced a few (up to four) photons off a specially prepared rubidium atom and demonstrated that those photons were in a state of superposition... maybe the same state? They speculate that this might be useful for quantum networking because if you can send four photons instead of one, you've got a better chance of receiving some on the other end.
They make a big deal about the four photons being like Schrödinger's cat, a
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If the physicists involved in the experiment actually described anything as "flying optical cat states" then they, and their lab, should be burned to the ground, with the 'journalist' inside.
Maybe that would prevent the stupidity infection from spreading any further.
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If the physicists involved in the experiment actually described anything as "flying optical cat states" then they, and their lab, should be burned to the ground, with the 'journalist' inside.
They do in fact use that phase, here in context: "We then employ the entanglement to control the flying optical cat state by means of a coherent rotation and subsequent measurement of the atomic spin direction." [nature.com] But don't get out your torch and pitchfork just yet, it seems that cat state [wikipedia.org] is actually accepted terminology.
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So we listen for radio signals for alien communications. We have huge dish arrays, radio-silent areas, all in a quest to listen for alien music.
We should be watching for entangled photonic emissions instead? Should we be sending entangled photons at a signal that might be detected?
We should learn to listen to the flying optical cat states, silly as that sounds. At some point, their very presence says there's intelligence, as this isn't a natural state of the universe.
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Yes, that seems like a potential issue. I get the feeling that these guys did something cool with quantum optics and then added "and yeah, it could be useful for, um, encryption!"
I get the feeling quantum encryption generally is a way optics geeks have figured out how to get governments to give them money without having to build laser weapons though.
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Somehow it always seems to be the case that "theoretical promises of secure communication are always broken by the actual implementation". So this shouldn't be a surprise. Merely unwelcome.
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On a quick scan and with my limited knowledge of the field, it seems that they verify the photons are in superposition by virtual of conforming to quantum as opposed to classical statistics. They don't attempt to transmit information via individual photons.
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Miraculously, the original Nature article isn't paywalled: https://www.nature.com/article... [nature.com]
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What happens when it hits a prism?
No idea, but when you shoot it at a Prizm [wikipedia.org], the driver gets out and yells at you.
Re:Can someone please explain. (Score:5, Informative)
Try this [nature.com]. This is the actual article (in a reputable journal, no less) that was swallowed to make that pile of shit that is TFA.
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Folks must have modded you up before noticing that your link is paywalled. $8.99 for a 48 hour "rental" would make Blockbuster jealous.
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Yeah, here's a preprint link [arxiv.org]. I was actually fooled myself, because the first page looked fine. Sneaky bastards. (I mean, I can get the full article from the publisher's site through my library subscription, but that's beside the point.)
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What part of "flying army of laser cats" didn't you understand?
So they sent laser 'info' in an unknown state. (Score:2)
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Well, it's a preliminary lab result, so it doesn't promise anything directly. But it indicates that quantum states can be maintained indefinitely, and this has strong relationship to scaling quantum computing. I'm rather sure, however, that any quantum computer would use a different source of entanglement.
Thought experiment ends thought (Score:3)
The cat has jumped the shark.
Question (Score:3)
In what state is the obligatory cat chasing this laser beam?
How is this good for quantum computers? (Score:3)
If it's a cat then won't it just ignore you when you want something from it?
That's nothing... (Score:2)
Cats (Score:2)
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The livescience article is dumb, while the Nature article [nature.com] is serious. The terminology used is cat state [wikipedia.org], not laser cat.
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I agree. Next they'll replace 'pulse' with 'plush'. And optical fiber with 'hugging'.
Headline (Score:3)
How can a story that starts out with an army of laser cats turn out to be so disappointing?
live for billions of years ???? (Score:2)
An optical state can live forever. So if we had sent the pulse out into the night sky, it could live for billions of years in its [cat-like] state.
As I understand it, an optical pulse travels at the speed of light and is thus not an instant older when it is billions of light years away than it was at the moment it was produced. No optical pulse ever "lives" beyond a single quanta of time. From its point of view, it "lives" along its entire path from production to destruction in the same instant of time. Am I wrong?
Puts new meaning into... (Score:2)
Cat5 cable
drywall repair (Score:1)
panama property (Score:1)