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Send messages to the future with Quantum Entanglement

19 points by wicknicks 16y ago

deleted 16y ago
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jarin 16y ago
Not to diminish the scientific value of this discovery, but there's also another way to send messages to the future: http://en.wikipedia.org/wiki/Writing http://en.wikipedia.org/wiki/Writing
- sorbus 16y ago
  The advantage of this would be sending a message which cannot be known until a point in the future - sort of like a time capsule with a lock that only opens on a certain day, but way more secure. While, for most purposes, merely storing encrypted information and only revealing the key later might be better, there are probably some things very paranoid people could use this for (a message that arrives after 100 years, for instance, could reveal all sorts of things, as the author would know that he would be dead by then). However, it's not very useful for practical purposes.
  - MartinCron 16y ago
    I'm reminded about how Mark Twain put an embargo on parts of his autobiography, not to be released for 100 years after his death.
- shaggyfrog 16y ago
  I'm not sure writing is a great analogy to the discovery, unless you're describing a writing process where you can immediately destroy the medium used to fixate the information and have it spontaneously reassemble itself somehow in N years time.
lisper 16y ago
There are prosaic (by which I mean classical, non-quantum) means of accomplishing the same thing, e.g. encrypt a classical message using a one-time pad and send the resulting ciphertext and keystreams in opposite directions at the speed of light. The original data can be recovered if and only iff both data streams are reflected back to some common point in space and recombined. If the initial transmission is at time T0, and the first reflection happens at time T1, then the recombination cannot happen until T1+(T1-T0). I'm not sure if this is 100% analogous to what is being done in this paper (the math is kinda furry) but I'm pretty sure it's close.
codex 16y ago
Forgive my ignorance of quantum physics, but would it be possible to use entanglement to send messages back in time? If not, why would entanglement work in only one direction (forwards)? There is a causality argument, but I don't why it would be impossible that reading a message from the future cannot alter that future. Just because a future universe occurred once doesn't mean that it has to occur again once particles have been entangled, does it? Aside from being very strange, would such a scenario violate any known laws of physics? There is this: http://en.wikipedia.org/wiki/No-communication_theorem http://en.wikipedia.org/wiki/No-communication_theorem, which, unfortunately, is beyond me.
geuis 16y ago
Ugh, typical poor science journalism strikes again. Quantum entanglement can absolutely not be used to transfer information. Two problems are you can't travel faster than light, information included, and second is measuring the spin of an entangled particle only works if you know the state of the other one. So no, you cannot transmit encyclopedias of data using quantum entanglement. As for the rest of the story, it sounds like entanglement can work across time. Flipping the state in the past instantly flips it in the future. However, in either direction of time the observer already knows the state so no info transfer, no causality breakage.
MichaelApproved 16y ago
I don't believe the Star Trek analogy was correct. In the episode, Scotty had his pattern repeat in some sort of cycle that kept his pattern safe. He didn't send himself to a specific point in time, he could have pulled out of it at any point. In fact, his crewmate died because he wasn't pulled out soon enough and his pattern degraded. Scotty in the transporter was more like stasis and not a teleport to the future.

19 points by wicknicks 16y ago

deleted 16y ago

[deleted]

jarin 16y ago

Not to diminish the scientific value of this discovery, but there's also another way to send messages to the future: http://en.wikipedia.org/wiki/Writing http://en.wikipedia.org/wiki/Writing

sorbus 16y ago
The advantage of this would be sending a message which cannot be known until a point in the future - sort of like a time capsule with a lock that only opens on a certain day, but way more secure. While, for most purposes, merely storing encrypted information and only revealing the key later might be better, there are probably some things very paranoid people could use this for (a message that arrives after 100 years, for instance, could reveal all sorts of things, as the author would know that he would be dead by then). However, it's not very useful for practical purposes.
- MartinCron 16y ago
  I'm reminded about how Mark Twain put an embargo on parts of his autobiography, not to be released for 100 years after his death.
shaggyfrog 16y ago
I'm not sure writing is a great analogy to the discovery, unless you're describing a writing process where you can immediately destroy the medium used to fixate the information and have it spontaneously reassemble itself somehow in N years time.

lisper 16y ago

There are prosaic (by which I mean classical, non-quantum) means of accomplishing the same thing, e.g. encrypt a classical message using a one-time pad and send the resulting ciphertext and keystreams in opposite directions at the speed of light. The original data can be recovered if and only iff both data streams are reflected back to some common point in space and recombined. If the initial transmission is at time T0, and the first reflection happens at time T1, then the recombination cannot happen until T1+(T1-T0). I'm not sure if this is 100% analogous to what is being done in this paper (the math is kinda furry) but I'm pretty sure it's close.

codex 16y ago

Forgive my ignorance of quantum physics, but would it be possible to use entanglement to send messages back in time? If not, why would entanglement work in only one direction (forwards)? There is a causality argument, but I don't why it would be impossible that reading a message from the future cannot alter that future. Just because a future universe occurred once doesn't mean that it has to occur again once particles have been entangled, does it? Aside from being very strange, would such a scenario violate any known laws of physics? There is this: http://en.wikipedia.org/wiki/No-communication_theorem http://en.wikipedia.org/wiki/No-communication_theorem, which, unfortunately, is beyond me.

geuis 16y ago

Ugh, typical poor science journalism strikes again. Quantum entanglement can absolutely not be used to transfer information. Two problems are you can't travel faster than light, information included, and second is measuring the spin of an entangled particle only works if you know the state of the other one. So no, you cannot transmit encyclopedias of data using quantum entanglement. As for the rest of the story, it sounds like entanglement can work across time. Flipping the state in the past instantly flips it in the future. However, in either direction of time the observer already knows the state so no info transfer, no causality breakage.

MichaelApproved 16y ago

I don't believe the Star Trek analogy was correct. In the episode, Scotty had his pattern repeat in some sort of cycle that kept his pattern safe. He didn't send himself to a specific point in time, he could have pulled out of it at any point. In fact, his crewmate died because he wasn't pulled out soon enough and his pattern degraded. Scotty in the transporter was more like stasis and not a teleport to the future.