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jsw

Moderator emeritus
Original poster
Mar 16, 2004
22,910
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Andover, MA
The Danube River is known for its beauty and has been immortalized in song. Now researchers have employed the water body as a testing ground for quantum teleportation. Scientists report today in the journal Nature that they have successfully teleported photons more than 600 meters across the famous waterway.

...

“Our result,” they write, “is a step towards the implementation of a quantum repeater, which will enable pure entanglement to be shared between distant parties in a public environment and eventually on worldwide scale.”

Source here.
 
Particle entanglement theory ROCKS! Still a long ways from even sending useful amounts of information though. The first application would be on rover missions I guess. Right now it's what 15 minutes to Mars and 15 back to communicate with our rovers by light waves. 30 minute delay sucks for exploring. If we could have communication in realtime based on particle entanglement, wow! Though I guess by time this tech develops that far, we'll have our men ON Mars. I don't really think that this really relates to teleportation as seen in sci-fi movies. Especially because of this:
Over the course of a 28-hour experimental run, the system was correct 97 percent of the time.

I don't like that 97% deal. If you are going to be teleporting me, I don't want 97% accuracy, I'd need a perfect 100%. :D ;)


Still though, I wonder if this could ever be used in global communications. Latency is a thing of the past.
 
Um, as far as I can tell from reading elsewhere, the quantum repeater is not instantaneous, you still are limited to the speed of light. What it does is provide for totally secret communications.

So no transporting to Mars yet :D

D
 
Mr. Anderson said:
Um, as far as I can tell from reading elsewhere, the quantum repeater is not instantaneous, you still are limited to the speed of light.
Yup.

But some work on entanglement theory (not teleportation, although entanglement plays a key role there as well) suggests possibilities of instantaneous transfer of information - of course, though, one would have had to separate the entangled elements at less than the speed of light. Still, once separated, some suggest that there might be ways to transmit information instantaneously. Sort of like having a pair of walkie-talkies, having to walk apart with them, but then being able to converse - only, in the case of entangled items, it truly would - if some approaches prove themselves - be instantaneous.
 
jsw said:
Yup.

But some work on entanglement theory (not teleportation, although entanglement plays a key role there as well) suggests possibilities of instantaneous transfer of information - of course, though, one would have had to separate the entangled elements at less than the speed of light. Still, once separated, some suggest that there might be ways to transmit information instantaneously. Sort of like having a pair of walkie-talkies, having to walk apart with them, but then being able to converse - only, in the case of entangled items, it truly would - if some approaches prove themselves - be instantaneous.

Ha - which makes the whole SETI program a waste of time. If this is real, no good alien would do with out his quantum repeater to phone home. And we wouldn't be hearing anything from the stars.....

D
 
Mr. Anderson said:
Um, as far as I can tell from reading elsewhere, the quantum repeater is not instantaneous, you still are limited to the speed of light. What it does is provide for totally secret communications.

So no transporting to Mars yet :D

D

Yeah, but just the thought of it is very cool, be many years before its perfected, but its gettin there. I am all for the technology
 
Mr. Anderson said:
Ha - which makes the whole SETI program a waste of time. If this is real, no good alien would do with out his quantum repeater to phone home. And we wouldn't be hearing anything from the stars.....

D
Unless they're all trying to send us directions on how to join in so they can truly IM us! ;)
 
jsw said:
Unless they're all trying to send us directions on how to join in so they can truly IM us! ;)

quantum repeaters are a closed system - who knows if there is an open version of it we just haven't figured out. Again, that would mean we're looking for the wrong thing :D

I totally agree that this is a great technology with huge potential.

When they get the distance beyond 12 km, that's when it gets good :D

D
 
The system was correct 97% of the time.

Sounds like that's a good start for being able to turn a man into a monkey during transport. :p
 
Sun Baked said:
The system was correct 97% of the time.

Sounds like that's a good start for being able to turn a man into a monkey during transport. :p
Or a man into a woman... ;)
 
ARE YOU PEOPLE CRAZY...

I would think that if that fine science documentary "DOOM III" has taught us anything its the danger of fooling around with quantum teleportation. Heck, why don't we just send the Cacodemons an invitation to come and turn us all into mindless zombies? No RSVP required! :eek:
 
There is nothing wrong with testing a theory. I'm sure that they increase the accuracy. Sounds like it has potential.
 
And the "I Don't Get It" Award goes to wdlove :D ;)

He's talking about a game - quite far from reality. Although, part of it is a good warning. You need near 100% accuracy for this to be a viable medium if its ever developed to be more than a communication device.

There are decades of testing ahead for this, and probably even more after that :D

D
 
Don't forget, though, that quantum teleportation and Star Trek teleportation have nothing in common, save the word "teleportation". Quantum teleportation has to do with reproducing quantum states (transfering information of a sort), whereas Star Trek teleportation has to do with, um... something else, matter transfer, I suppose.

So, to make a long story short, quantum teleportation does not equal beam me up, Scotty.
 
telecomm said:
Don't forget, though, that quantum teleportation and Star Trek teleportation have nothing in common, save the word "teleportation". Quantum teleportation has to do with reproducing quantum states (transfering information of a sort), whereas Star Trek teleportation has to do with, um... something else, matter transfer, I suppose.

So, to make a long story short, quantum teleportation does not equal beam me up, Scotty.
Well, actually, they're essentially the same thing. Quantum teleportation destroys atoms in one place and recreates them elsewhere. In effect, you'd destroy your body in place A and recreate it from a exactly similar mass of atoms at place B. In the "real" world, you'd have matter in a sort of random state left over at A, and you'd require matter to be positioned ahead of time at B, but it's a similar concept. If it ever is perfected - and there are huge obstacles, including a number of theoretical objections - quantum transportation would let you move an object instantly from A to B in the sense that we define objects in our world. I mean, there are practically zero atoms in your body which were there a decade ago, and yet you are still "you". So, except for not showing leftover atoms and not requiring them at the beam-to point, Star Trek was reasonably close to the real thing. For a TV show. From almost 40 years ago.
 
This could also bring about replicators - once you download a steak dinner, what's to keep you from making more than just one :D

I don't think we'll see this in our lifetime, and as for beaming people hither and yon, the whole idea of destroying them and recreating them somewhere else doesn't seem right. The same thing with the steak dinner - what's to keep you from making copies of yourself?

D
 
jsw said:
Well, actually, they're essentially the same thing. Quantum teleportation destroys atoms in one place and recreates them elsewhere. In effect, you'd destroy your body in place A and recreate it from a exactly similar mass of atoms at place B.

OK, I see where you're coming from, but there are a couple of concerns. (I wish I could remember more from my quantum mechanics course, but one thing I do recall was that my professor was quite adamant about the distinction between the two sorts of "teleportation".)

I think the concern might be an insurmountable problem of scale. Quantum teleportation exploits the quantum entanglement of particles, in the case of the experiment mentioned above, photons. I would expect this sort of result could also be reproduced with electrons, but I'm not sure about that (I can recall a poster who was studying physics a while back, he/she could probably clear things up for us). The move to actual atoms, though, would be a big leap, from what I understand. Photons can be entangled, people can't. Or, to be more accurate, physicists aren't even really sure what it would be like for someone (or any macroscopic object) to be in an entangled state, hence the famed Schrödinger's cat thought experiment. I'm pretty sure the "one particle at a time" reproduction method wouldn't work either, but I'm less well-equipped to give you any explanation here.

Maybe I'll ask my former professor about this sometime in the next while... If I manage to talk with him and get a better explanation I'll post it.
 
Mr. Anderson said:
This could also bring about replicators - once you download a steak dinner, what's to keep you from making more than just one :D

I don't think we'll see this in our lifetime, and as for beaming people hither and yon, the whole idea of destroying them and recreating them somewhere else doesn't seem right. The same thing with the steak dinner - what's to keep you from making copies of yourself?

D
Yourself & steaks, shows you how stale your vision of the future is. :rolleyes:

There's one member here that wouldn't think twice about Xeroxing Kiera for his own twisted pleasures, and those of us who think twins, triplets, etc. might be more interesting.

But alas we're years away from a viable human Xerox, and with our luck the process would be owned by Microsoft anyways -- which would give Gateways a bad name.
 
Sun Baked said:
But alas we're years away from a viable human Xerox,

well, aside from the moral debate, it will be interesting to see if its viable. We don't know if there is a soul attached to the body and if it would survive the transmission. And what would happen to duplicates? I think the latter was used in a zombie movie once....:D

D
 
Mr. Anderson said:
well, aside from the moral debate, it will be interesting to see if its viable. We don't know if there is a soul attached to the body and if it would survive the transmission. And what would happen to duplicates? I think the latter was used in a zombie movie once....:D

D

That's the thing about quantum theory, start asking the difficult questions and it rapidly becomes indistinguishable from Zen Buddism, Evangelical Christianity or the Matrix Movies 1->3 :rolleyes:
 
jsw said:
I mean, there are practically zero atoms in your body which were there a decade ago, and yet you are still "you".

interesting. i never thought about it that way before. after thinking about that, the thought of teleportation doesn't seem so bad...
 
Dr. Dastardly said:
I would love a food delivery service to use this technology.

Your pizza will be at your house 30 seconds or less or its free. :p

However, your toppings may vary - remember the 97 % correctness ? :D
 
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