141–150 of 219 posts
Earlier quoted context omitted.
It's easier to think these as random number generators seeded with same value, taken six kilometers apart from each other, and then fetching values from them. No data is transmitted when fetching values from these.
Are we witnessing the first steps towards interplanetary turn-based seed driven gaming?!
Cue endless discussions such as: What does teleport REALLY mean?
Earlier quoted context omitted.
Yes, and as others pointed out below, this is essentially entanglement.
This is an effect that uses entanglement to move the state of one particle to a different particle. You're describing only entanglement, so that's only half the puzzle. And you're describing entanglement in a misleading way. The most important part of entanglement is that you can't model it as two particles sharing secret data. When you touch one, you affect the output of the other. And this happens faster than light…
My sense was that quantum physics basically makes sense if you go really small and have an understanding of how the particles interact. But entanglement is weird, because somehow there's also a mechanism for them to interact at distance?
(I know, I could try to look it up, but hopefully other people here have the same silly question)
My understanding is this:
1. send entangled bits to two separate locations A and B
2. determine their states (which will always be exactly opposite) on both sides
3. send data using classical means from A to B, xor'd with the quantum measurements
4. decrypt the data at B, with: data ^ quantum_measurements ^ 111111 (the last step being "invert all bits and ^ representing xor).
If that's it, how is this much better than sending block of identical entropy to A and B, and using a OTP? Theoretial tamper-proofness?
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It is not absolutely certain. Quantum theory is an incomplete description of the physical laws of our universe, and the mechanism behind quantum teleportation is not even fully understood within the framework of that theory. So, it is most certainly not absolutely certain that FTL communication by this means is impossible, though it would be fairly surprising. The premise upon which the idea that it is impossible is…
It is as certain as anything in science. Yes, QM is incomplete, but it places hard constraints on the space of possible completions, and none of them allow FTL communications. FTL would break not only QM and relativity, but causality: it would allow you to send information backwards in time.
This is entirely incorrect. All of the proofs about broken causality (all of which stem from special relativity, since non-relativistic QM doesn't put the speed of light on a pedestal) assume that the laws of special or general relativity hold everywhere.
What you're saying is the equivalent of claiming in 1914 that the theory of special relativity proves that physics cannot operate without an intertial reference frame.
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This is probably also why SETI-like projects turn up nothing. It's likely that almost no advanced civilizations are using radio waves for communication.
I'm only a layman who's mildly interested in this, but this contradicts my understanding... Someone correct me if I'm wrong here. You can't communicate with quantum teleportation. It sends random "information" (not information at all), because you can't control how the quantum waveform collapses. So you have to collapse the waveform, create a key that encodes your collapsed form to the information you want to transmi…
> it is not possible for one observer, by making a measurement of a subsystem of the total state, to communicate information to another observer. The theorem is important because, in quantum mechanics, quantum entanglement is an effect by which certain widely separated events can be correlated in ways that suggest the possibility of instantaneous communication. The no-communication theorem gives conditions under which such transfer of information between two observers is impossible.
Not satisfied with asking me to subscribe to their newsletter before I've even read one article, this site _also_ popped up a request that I allow them to send me desktop notifications. Do people actually fill these things out? Why does ScienceBulletin think I might even want these things?
These ubiquitous subscribe forms provide a vector for inflating the size of mailing lists. Mailing lists with more addresses sell for real money, and sell well.
It doesn't matter if the data is accurate. Only the perception of the data matters. The more addresses the better, the more datapoints per address, the higher the quality of data. The age and activity against the data matters.
There are reputable companies that trade on these details and pay the salaries of expensive developers.
Not quite as impressive when you know, and if you don't you should before opening this link, that "quantum teleportation" is not teleportation. It was a cool-sounding name at the time, but has nothing to do with sci-fi style teleportation: nothing disappears from one place and then shows up in another. "Quantum teleportation" is a process of information duplication using particles that already exist, and have been po…
I don't think I understand it right. My understanding is this: 1. send entangled bits to two separate locations A and B 2. determine their states (which will always be exactly opposite) on both sides 3. send data using classical means from A to B, xor'd with the quantum measurements 4. decrypt the data at B, with: data ^ quantum_measurements ^ 111111 (the last step being "invert all bits and ^ representing xor). If t…
If you have a secure way to distribute your OTP I'm not sure there'd be a benefit to using quantum teleportation at all.
I don't think I understand it right. My understanding is this: 1. send entangled bits to two separate locations A and B 2. determine their states (which will always be exactly opposite) on both sides 3. send data using classical means from A to B, xor'd with the quantum measurements 4. decrypt the data at B, with: data ^ quantum_measurements ^ 111111 (the last step being "invert all bits and ^ representing xor). If t…
My understanding is that it's snooping-evident, at least in theory. If someone takes a peek at the entangled bits in transit, the entanglement will be broken and when A and B compare notes, their states will no longer be correlated. This is good for key distribution because if someone snoops a key, you know the key is compromised and throw it away. If you have a secure way to distribute your OTP I'm not sure there'd…