Slashdot Mirror
Laser Beam Teleported
Michael Wardle writes "ABC Australia reports that a team of scientists from the Australian National University have successfully teleported a laser beam. It seems that teleportation of solid bodies is still a way off, but at least we're a little closer to Slashdot's favorite super power." Another Australian newspaper has a more detailed story.
Say, does the party doing the duplication of the laser have to exchange information with the party doing the reading of the laser for this process to work?
If not, why not stick a duplicating end on Mars or someting, read it on Earth, and let the spookiness do the rest?
Because when we're talking about a beam of light, the notion of analyzing it, transmitting the information, and reproducing the original seems more like television than teleportation.
Like most of the non-hoax science stories on Slashdot that relate to fantastic-sounding possibilities (teleportation, time travel, etc.), this is most likely a breakthrough of some sort but not nearly as cool as the summary makes it sound.
Getting to the subject of destroying an object and creating an exact duplicate, it's a hazy issue. I understand how I'd theoretically be the same person if you were to reproduce me at the most detailed level, but I'm still nervous about potential problems with it.
For example, should the destruction of the original me fail, there are suddenly two of me in the Universe, each with a full claim to being me and each slightly different (based on the brief experiences that occur after the duplication). One interesting exploration of this scenario was featured in James Patrick Kelly's story, "Think Like a Dinosaur".
Well, if the person created was the exact same down to the quantum level, it would be you, exactly. Your last memory would be a strange tingling as your body was torn apart at the quantum level to be stored, then once you were recreated your memories would begin again. Now this raises all sorts of philosophical questions, like what happened to your soul when you were torn apart, but really, I dont believe in any of that mumbo-jumbo :P If it was proven to be safe i'd use it, sure.
From someone else's point of view, the other guy may as well be me, However, from my point of view, I've been murdered, my body vaporized, and some other guy is now walking around with my memories.
Yeah I thought that was pretty funny too. I think the reporter is wrong, though -- the spooky part is that it happens *faster* than the speed of light. I'm pretty sure about this, in fact, because there's a famous Einstein line about "spooky action at a distance" referring to faster-than-light quantum effects, which I'm pretty sure the scientists quoted would be aware of.
That being the case, everyone here is totally missing the point. And in fact, the reporters who wrote the linked-to story missed it to, despite this quote:
The bits about teleporting solid objects (including humans) were just humoring the reporter -- sort of like the whole "could this experiment destroy the universe" thing surrounding supercolliders. The true interesting practical application of this is FTL communication -- vital for any space missions going much further than, say, Mars -- and pretty handy even if you're only that far away.
The "spooky action at a distance" is a weird consequense of the heisenberg uncertainity principle. It 'appears' to be an interaction, but in fact it's just the result of the coherency between two 'entangled' wavefunctions.
the 'yes' part is that to receive a teleportation, you have to have one of the entagled particles, and a measured quantity.
the 'no' part is that since the measured quantity is transmitted classicaly, there's no FTL transfer of anything.
-Kz-
The blueprint analogy shows a lack of understanding of entanglement. There is no blueprint at the receiving end, and no measurement and communication of instructions to replicate the properties of the sending photon. What happens is a seemingly spontaneous change in the properties of the receiving photon.
Whether this is teleportation or replication is more of a philosophical question, or maybe a matter of semantics. Is an object (or a laser beam) equal to the sum of its properties? If you can make the sum total of an object's quantum properties disappear from one place and reappear in another place, have you merely copied the object or have you moved it?
I think you've moved it, but questions like these deserve more than offhanded answers.
wouldn't you still need to transport the data regarding light beam... which leaves you back to square one. IMO, telecommunications would be the last place you'd see transportation. Think about it.
If the process involves ripping apart the object and getting the information so that you can reassemble that object later. Couldn't you just store the template and create as many copies as you want? Then not only have you created a teleporter, but also a replicator as well.
Right.. except the original beam no longer exists.. it's state has been frozen in something, and re-emitted later.
As for the difference... no science we have yet teleports actual particles.
It does bring up an interesting dilemma though...
if we COULD make a precise, quantum copy of a person, which one would be the 'real' person? Both would percieve they are real, both would be for ALL purposes, identical. If one were destroyed immediately after quantum duplication, there would be no way to find out which is the original.
So if someone duplicates you.. which one is really you? what happens to your sense of continuity?
That's the whole point.
The "spooky interaction" postulate was based on the fact that these things seem to be interacting at faster than the speed of light.
As other posts say, the re-constituted object appears (essentially) before the old one is destroyed.
A more effective moderation scheme would require several votes to increment/decriment the value of a post. The really good posts would be more likely to be really good, and the bad posts would be more likely to be bad. And as a bonus, the chances of vindictive moderation decrease as well since one vote alone could not move a score below the default threshold.
Requiring multiple votes to increment or decrement a score would also reduce some of the satisfaction people get from moderating. I imagine some folks moderate not because of percieved quality of a post but how moderation makes them feel. Requiring multiple votes to change the value of a score would mean that the person would not immediatly see a change of score with the votes they cast. This breaks the cause effect relationship, since the reward of seeing the score change is removed. This should reduce the number of people who moderate impuslively for shallow reasons.
I could go on but already the old addage about the futility of advice giving is reverberating in my mind, and this little postage stamp sized editing box is...unpleasant.
I'm still considering very fast traveling of the light. If there was an impediment between the 1 meter, I'd consider teleportation.
There's a relativly (pun intended) interesting experiment on NEC Institute's web page. It proves that light can go faster than C. Here for NEC Faster than C webpage
It seems that this beam of light traveled about 3C. However, there's conjecture that it traveled slower, but time dilation made it seem 3C. That's unprovable at the time though.
I think the article is incorrect, the Quantum Entanglment interactions are instantaneous, not delayed.
The article says:
Using a process known as quantum entanglement, the researchers, led by 34-year-old physicist Ping Koy Lam, have disassembled a laser at one end of an optical communications system and recreated a replica a metre away
and
But the radio signal survives and is sent electronically to a receiving station, where within a nanosecond an exact replica of the beam - with the radio signal intact - is retrieved and decoded.
I'm having trouble working out whether that nano-second is the elapsed time from when the original beam is destroyed and the new one is created, or whether it's the amount of time required to recreate the beam from the received radio signal.
If it's the former then we're talking faster-than-light teleportation here because it takes light 3 nanoseconds to travel a yard.
It would be even better if it didn't have propagation time but hell, I'll settle for the speed at which a laser normally travels through a fiberoptic cable. That wouldn't disappoint me at all.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The idea behind Quantum entanglement is that two particles are generated and entangled at a single source and then split and sent off in different directions.
The spooky part happens when someone fiddles with one of the entangled particles, the other particle immediately reflects that same fiddle in Zero time FTL communications.
This effect was discovered back in the early days of Quantum physics with the 2-slot experiment, causing Hiesenburg to postulate his uncertantly principle.
The reason it hasn't been exploited until now is that the technology has not been available to detect these changes without causing interference.
Who ever wrote the popularist teleportation thing is on some serious bad "PR drugs".
Bruce
I am surprised to see so many unenlightened comments on slashdot, so i just had to make a post (first post. as in my first post).
This is just taken from my memory (and as usual i cannot guarantee it is 100% correct):
Quantum entanglement was one of the parts of quantum physics that Einstein couldnt come to terms with and hence he didnt believe in quantum physics. He used quantum entanglement as a "demonstration" as to why it was unlikely. It would mean that you could transmit information instantaneously between unlimited distances, and that didnt sound too well with Einsteins theory of relativity where the speed of light was the fastest things could travel.
There is a "though" though. For quantum entanglement to work there must be two entangled parts of a photon at the two different locations and the only way to get those parts separated is to physically move these to their respective places (unless you teleport them, but then, whats the point). And this is all done under Einsteins theories (maximum speed = speed of light).
The point i am trying to make is that information can be transferred over distances with speed > light, but you have to prepare the tranfer, and that with the speed = light.
There's plenty of self. You're capable of saying "I am". You remember what you did 10 minutes ago. You don't remember what someone in Saigon did 10 minutes ago. This is the aforementioned sense of continuity. It's the basis of sentience. You're misinterpreting Buddhism if you believe it says otherwise. And you're also judging all Buddhism based on Zen Buddhism, which is not really Buddhism. It's Taoism. The Heart Sutra states that everything is "the same". That there's no ultimate division between you and me. That's not the same as saying there is no you and there is no me. To your statements, I say "mu".