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Teleportation Gets a Boost
saavyone writes to tell us Yahoo! News is reporting that while teleportation may not quite be a reality yet a team of Danish scientists have raised the bar on this line of research. From the article: "The experiment involved for the first time a macroscopic atomic object containing thousands of billions of atoms. They also teleported the information a distance of half a meter but believe it can be extended further. 'Teleportation between two single atoms had been done two years ago by two teams but this was done at a distance of a fraction of a millimeter,' Polzik, of the Danish National Research Foundation Center for Quantum Optics, explained. 'Our method allows teleportation to be taken over longer distances because it involves light as the carrier of entanglement,' he added."
Here is Scientific American's article on the matter.
First Teleportation Between Light and Matter
Nope, but this is their site.
http://www.nbi.ku.dk/side39251.htm
Deleted
This process allows you to copy quantum information from one set of atoms to another without measuring it, and thereby destroying it.
It's still isn't anywhere near dematerializing the matter and poof`ing it across the room/planet. However, what is happening is the quantum information (in this case, the spin state) of the matter has been instantly transported. That is a essential step in building a quantum computer or cryptography network.
A technical explanation would take too long and people would just argue with me anyways so heres a summary -This is not 'traditional' teleportation -It works at the speed of light, there's nothing strange going on here, although it is related to what you might have heard referred to as 'spooky action at a distance' With quantum teleportation you aren't teleporting a THING, you're teleporting a property of that thing without actually measuring that property. Sounds crazy but here's an example: suppose you have two helium atoms and using light you are somehow able to give the second atom the momentum and spin of the first atom but in the process you change the momentum/spin of the first atom. You've basically changed the second atom to be exactly like the first but they call that teleportation. And effectively it is. The reason its so nifty is you don't have to measure or know these properties to transfer them. Thats the quantum part of quantum teleportation. Beyond that, I have no clue how they're applying a property of light to an atom.
http://en.wikipedia.org/wiki/Quantum_teleportation
e orem). So you can teleport, but you can't teleport at greater than the speed of light because you still have to send the data to the destination.
Put simply you can record the quantum states of an atom/particle(or your entire body) and then send this information using a classical channel like radio. Once this information gets to your destination(eg Mars) the guys at that end can use that information to affect some particles over there, and because of Quantum Entanglement, those particles on Mars will instantly take on the recorded state. The particles at the start will then lose their state due to the no cloning therom(http://en.wikipedia.org/wiki/No_cloning_th
Note that it's not technically "Teleportation", you are just changing the states at the quantum level.
I don't need to test my programs.. I have an error correcting modem.
Actually it is a
h eorem) which "forbids the creation of identical copies of an arbitrary unknown quantum state"
$ mv source target
Because of the No cloning theorem(http://en.wikipedia.org/wiki/No_cloning_t
I don't need to test my programs.. I have an error correcting modem.
It isn't. Despite the regular press idiocy on this subject, quantum teleportation has got absolutely nothing to do with Star Trek-style transporters. This is a form of communication link, teleporting information from one place to another at the speed of light. It cannot operate on people, rocks, or any other tangible object. We may someday invent a matter transporter, but it won't be using this technology and it certainly isn't what they're studying. To quote from the opening paragraph in the Wikipedia article, which is the very least any ignorant reporter should read before posting nonsense on the subject:
Quantum teleportation does not transport energy or matter, nor does it allow communication of information at superluminal speed.
This is about the next generation of technology that may someday replace optic fibre for long-distance communication links (and may also be useful in the construction of quantum computers, should we ever find a use for them). Nothing to do with Star Trek. If you ever catch a reporter confusing the two again, please hurt them. Badly.
$ cp source target ; rm -rf source :-) )
(actually, I think mv does exactly this, but just to be explicit
And nobody has corrected this yet? Is this really Slashdot?
The "cp" operation will temporarily consume twice as much space as the original before the original is removed. Actual data is being replicated. "mv" (at least within the same file system) will leave the data where it is and merely change where the pointer (i.e. directory entry) that points to it is stored. With your version you have two files temporarily and a possible duplication if the operation fails due to a power outage somewhere in the middle. The normal "mv" operation could leave you with NO files (the data is still there but unaccessible) depending on how it's implemented. (No, not on journalling file systems, but thats something else again).
In particular, a "cp ; rm" will delete your original if the cp fails due to, say, a full destination disk. So at least a "cp && rm" is advised. Which can fail, for example, if some of your source data is unreadable. While "mv" will still work, since the source data is never actually touched. Depending on your filesystem, default flags and implementation, "mv" will often also not change the last-access or creation-timestamps, file ownership and/or file permissions which may or may not be changed by cp. Also the permissions needed in the source and destination directories can be different for the two.
Really - what's up with you folks out there? Why aren't there 20 posts pointing this out already?
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