Instant Quantum Communication Is Near 287
fljmayer writes "In this experiment, researchers in Australia and Japan were able to transfer quantum information from one place to another without having to physically move it. It was destroyed in one place and instantly resurrected in another, 'alive' again and unchanged. This is a major advance, as previous teleportation experiments were either very slow or caused some information to be lost."
Re:Physics (Score:4, Informative)
Hint: the title is unrelated to both the summary and the article.
Re:Physics (Score:3, Informative)
Yes, it's in the details,I haven't read this article, but I assume it's similar to other methods than seem to invoke FTL.
You can't be sure what state you have before you transfer it, and if you do measure it, it changes the state. Therefore, when you teleport the current state, the receiver can see what state it's in, let's say 0 or 1. But since the sender didn't know if it was a 0 or a 1, the information is useless.
Personally I think spooky action at a distance isn't spooky at all. Consider the time-honored classic of two electrons in a correlated state being shot out of some device. Assume they are entangled in such a way that when you measure one to be up, you instantly know the other is down. Physicists will say, how could the other electron possibly know this, instantly. But a very simple explanation is that the device always shoots 1 up, 1 down. Sure you don't know if it's up or down until you measure it, but that doesn't make it spooky at all.
The actual spookiness is in the details, like what if I now measure it's spin with respect to a different axis, the classical and quantum results differ then, but I cannot think of any practical application this provides us.
That's not how quantum entanglement works (Score:3, Informative)
Transferring information faster than the speed of light through the use of quantum entanglement is impossible. Only through the use of a second, traditionally light-speed-bound communication channel one make any use of the oddness that is quantum entanglement.
That said, it might still have practical uses, but instantaneous communication to the other side of the galaxy is not one of them.
Re:HU? (Score:2, Informative)
Don't worry, no USEFUL information was transferred
Holy cow, they're broadcasting CNN on a quantum teleportation channel now?
Re:Physics (Score:5, Informative)
This article is awful. Terribly written, incoherent and obviously inaccurate.
This sounds like an extension of previous quantum state "teleportation" via entanglement. These are interesting phenomena, but cannot be used to transmit information faster than the speed of light.
It's not really quite clear what the breakthrough is here. But I'm fairly certain it doesn't involve a group velocity (i.e. information transmission) greater than c.
Re:Near? (Score:4, Informative)
And if you are near Australia, the PopSci website force-redirects you to the .au URL where this article is 404, so you can't find out about it.
Re:The Upshot: (Score:3, Informative)
Re:Physics (Score:5, Informative)
Isn't it easier to assume that they're not separate entities and that we just don't know how the universe is put together [...]
Sure, you can do that. But if you stop there, you'll know nothing; so we have to go on and keep trying to understand.
[...] than to assume that we understand the universe and there's a 'magical' force communicating across infinite distance?
The thing is, that's not what physicists are saying -- that's just a bastardized explanation used when you can't make someone take a few classes that require quite a bit of math to understand[1]. In fact, most physicists, if pressed, will admit no one knows what is really going on. For example, there's a famous quote by Richard Feynman: "I think I can safely say that nobody understands quantum mechanics".
What physicists do know is a theory that allows us to very successfully predict the outcome of many experiments and understand many phenomena better than any classical (completely understood) theory; and certainly better than if we just give up and assume that "we just don't know how the universe is put together", as you suggest. The amazing thing is that this theory can explain every phenomena we have ever seen (except gravity) and predict the outcome of any experiment we can perform.
The problem is, this theory (quantum mechanics) just doesn't make clear what's really going on. There are many tentative interpretations [wikipedia.org] that are consistent with the theory and the experimental results, each of them having at least one very strange feature (instant collapse of the wavefunction -- which I guess would be the "magical force" you mentioned --, or parallel universes, etc.) that fails to convince most people, including physicists.
Most (all?) physicists working with quantum physics know this very well. But since "what's really going on" is not very important to do research, they don't think about it that much. What they really want is to predict more stuff and come up with new ways to use the strange behavior we see for our advantage.
[1] By the way: there's an excellent very basic course on YouTube about quantum entanglement: http://www.youtube.com/view_play_list?p=A27CEA1B8B27EB67 [youtube.com]. It only requires high-school algebra (including complex numbers, I don't know it everyone takes that in high school), and patience to follow it through. I guarantee you that you'll end up having a good idea of how this quantum stuff works (at a very basic level) without any mention of magical forces communicating across infinite distances.