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Austrian Physicists 'Teleport' Light Over 600m
openSoar writes "The BBC is reporting that: 'Physicists have carried out successful teleportation with particles of light over a distance of 600m across the River Danube in Austria. When physicists say 'teleportation', they are describing the transfer of key properties from one particle to another without a physical link.'"
Haven't we learned anything from Half-Life or Doom? Teleportaion can only lead to some race trying to enslave humans. Ya, science is soooooo great.
What they did NOT do is teleport particles of light. That just makes no sense. Light was used as the means of conveying the information used to teleport the quantum properties from one particle to another, without the particle having to travel.
By the way, the reason this is called "teleportation" is that the particle effectively travels at the speed of light -- its properties can be transferred by light. If this could be applied to humans, for example, it would allow for light-speed travel, without all the nuisances of acceleration. It should be noted that this does NOT violate the universal speed limit.
Oh, and before someone asks, this is entirely different from quantum tunnelling....
Err, there was a fibre link, ie a physical link. RTFA submitter?
My email addy? should be easy enough.
I decided to do a little googling instead:
How this relates to quantum computing:
When a single photon is split by a beam splitter, its two `halves' can entangle two distant atoms into an EPR pair.
How to entangle a photon pair: There are certain nonlinear (BBO) crystals, such as are used in optical parametric oscillators, that will supply entangles photon pairs.
"I assumed blithely that there were no elves out there in the darkness"
Could the article have it wrong? Perhaps they misunderstood the scientists. The photons move at the speed of light, but the entanglement effect ought to be instantaneous since from one way of thinking the distant photon was already in the same state as the input photon.
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Cloning! OMG they've cloned light. Hopefully the US Gov't won't make it illegal.
..........FULL STOP.
One interesting point to note is that, if it were possible to transport a person via this process, the trip would appear to be instantaneous. Although travel would occur at the speed of light, no time would appear to pass for the traveller. Cool.
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If you read either the article or existing comments you'd notice that this process is limited by the speed of light. The latency is still there with this system. Removing it would be wonderful, yes, but this will not do it. Nothing currently known to physics will. Nothing currently known to be knowable by physics will. And precious little thought to be possibly knowable by physics will either.
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rsync at the speed of light. ;)
:D
I could find some uses for that. My brother in law would like to rsync music collections for backup purposes for example.
Karma: Chameleon (mostly due to the fact that you come and go).
It's really more than that, because you have to remember that each photon is neither fully in one state or the other. It is a combination of the two. This is "quantum superposition", or the concept that a particle is really a manifestation of discrete possibilities.
I think a good example of what is really happening is to imagine a pair of dice guaranteed by nature always to roll a 7. If you see a "3" on one die, then there absolutely must be a "4" on the other. Anything else would be a violation of several fundamental laws. Now imagine taking the two dice and seperating them by a large distance, and then rolling one of the dice. Even though there is a large distance, and even though the speed of light is the limit at which information may be sent, the other die will show the other number pair when measured. (Debate about whether one measurement happens before another is meaningless due to special relativity. In other words, one measurement cannot cause another to be so.) So if you roll a 3, the other die will roll (or has rolled) a 4. If you happen to roll a 1, then the other die will roll (has rolled) a 6. Spooky, huh? Welcome to the crazy world of quantum mechanics! Just when you thought you understood it all, nature throws a curveball.
Now your first instinct is that somehow those dice decided on something befor they were seperated. This is not how quantum mechanics works. The two particles can't "decide" on anything until measurement. Every observation and every calculation tells you that the particles did not decide on a specific state beforehand. I could show you why this is so, but it's pretty complicated and involves higher level mathematics than the average slashdot reader can understand. If you're really interested, I suggest reading a QM textbook. They keep this topic in one of the last chapters, so you have a lot of studying ahead of you.
Finally, your next reaction is going to be, "Wow, we can communicate at speeds faster than the speed of light!" Unfortunately, the way this works you can't "force" the particle to a particular state. If the particle comes in with a preference for one state or the other, then the complement will be true for the other particle. (By preference, I mean the chance of one state is 90%, and the other is 10%, or 99.99% and 0.01%, not something pre-decided. See the above paragraph.) And thanks to special relativity, it is fruitless to try and decide whether one measurement occured before or after another, so a causality link cannot be established.
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> When physicists say 'teleportation', they are describing the transfer of key properties from one particle to another without a physical link.
So some morning when you wake up with a suddenly teeny weenie, you'll know you've been had by a physicist.
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Since, obviously, you are not actually teleporting the photon itself, but rather its properties. Why can't we use this as a sort of limitless instantaneous data transfer method?
I.E. Use the manipulation of these properties to single a sort of photonic 1's and 0's (or potentially much more, possibly instead of binary, it might be possible to make it trinary, or better).
Think about it, you put a pack of these entangled photons into a sort of "storage" device, stick it on your next mars rover, and instead of there being a huge delay, your commands are sent instantaneously. Obviously eventually these entangled photons would be all used up (or could you continue to modify them after the first time?) but still, rovers, for example, are a consumable at this point too.
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