Cointelegraph: Experts Split on Practical Implications of Quantum Cryptography
gmkarl at gmail.com
Mon Jun 29 09:48:36 PDT 2020
Jim put a lot of energy here into replying to a joke.
Jim appears to be an electronics supergenius.
On Mon, Jun 29, 2020, 4:48 AM jim bell <jdb10987 at yahoo.com> wrote:
> Albert Einstein called it "spooky action at a distance". He hated the
> concept of quantum mechanics, saying "God does not play dice with the
> Universe". Unfortunately, Einstein was quite wrong.
> The idea is that pairs of photons can be generated and can go virtually
> any distance, and then a measurement made on one of these photons
> essentially instantaneously determines the equivalent value of the other
> photon. There is apparently no limit to the distance over which this can
> be done. A few years ago I read that the apparent velocity of this
> connection is at least 10,000 times c, or the speed of light in a vacuum.
> "The photons were indeed entangled, the group reports in *Nature*
> But in reality, no experiment is perfect, so what they end up with is a
> lower limit on how fast the entanglement could be traveling: 10,000 times
> the speed of light."
> I'm not a good person to be explaining this to you: My degree is in
> chemistry, not physics.
> But read up on Bell's inequalities. (different Bell!)
> *"Bell's theorem* proves that quantum physics
> <https://en.wikipedia.org/wiki/Quantum_physics> is incompatible with local
> hidden variable theories
> <https://en.wikipedia.org/wiki/Local_hidden_variable_theory>. It was
> introduced by physicist John Stewart Bell
> <https://en.wikipedia.org/wiki/John_Stewart_Bell> in a 1964 paper titled
> "On the Einstein Podolsky Rosen Paradox
> <https://en.wikipedia.org/wiki/EPR_paradox>", referring to a 1935 thought
> experiment <https://en.wikipedia.org/wiki/Thought_experiment> that Albert
> Einstein <https://en.wikipedia.org/wiki/Albert_Einstein>, Boris Podolsky
> <https://en.wikipedia.org/wiki/Boris_Podolsky> and Nathan Rosen
> <https://en.wikipedia.org/wiki/Nathan_Rosen> used to argue that quantum
> physics is an "incomplete" theory.
> <https://en.wikipedia.org/wiki/Bell%27s_theorem#cite_note-Bell1964-2> By
> 1935, it was already recognized that the predictions of quantum physics are
> probabilistic <https://en.wikipedia.org/wiki/Probability>. Einstein,
> Podolsky and Rosen presented a scenario that, in their view, indicated that
> quantum particles, like electrons <https://en.wikipedia.org/wiki/Electron>
> and photons <https://en.wikipedia.org/wiki/Photon>, must carry physical
> properties or attributes not included in quantum theory, and the
> uncertainties in quantum theory's predictions are due to ignorance of these
> properties, later termed "hidden variables". Their scenario involves a pair
> of widely separated physical objects, prepared in such a way that the quantum
> state <https://en.wikipedia.org/wiki/Quantum_state> of the pair is
> entangled <https://en.wikipedia.org/wiki/Quantum_entanglement>. "
> [partial quote]
> Quantum communication over fiber optics has been done to a record distance
> of 50 kilometers.
> Ironically, I have actually made a major contribution to this field,
> although almost nobody realizes it yet. The limit to the distance of
> quantum entanglement, 50 kilometers above, is based on the amount of
> optical loss present in the fiber. Prior to my invention, and currently,
> the record for a low-loss single-mode optical fiber is by Sumitomo
> Electric, and is 0.1419 db/kilometer.
> Fiber optics scientists and engineers achieved a fiber loss of about 0.200
> db/km in 1978, and about 0.160 by the mid-1980's. They are apparently
> approaching a limit asymptotically, the limit defined by the presence of
> natural-quantities of spin-containing isotopes in silica.
> In about December 2008, while stuck in a Federal prison cell at USP
> Tucson, Arizona, I realized that the cause of the residual loss in these
> fibers is the Si-29 and O-17 isotope atoms, and for Corning-type fibers
> (containing germania, or GeO2, dopant), the Ge-73 isotope atoms. Remove
> these spin-containing isotopes from optical fiber silica, and it should be
> possible to drop the loss by at least a factor of 100, or to about
> (Corning-type fibers use a core of 8% GeO2 and 92% SiO2, and pure silica
> in the cladding. Sumitomo-type fibers use(s) a pure-silica core, and a
> fluorine-doped cladding. Since there are fewer spin-containing isotopes in
> pure silica than in germania-doped silica, Sumitomo had/has a small loss
> advantage over Corning.)
> If this fiber is used for comunication between New York and Ireland, the
> hop should be achievable by a single, continuous fiber. It will not need
> to contain the 40-odd EDFA
> https://en.wikipedia.org/wiki/Optical_amplifier amplifiers currently
> Similarly, if such fiber is used for a quantum link, it should be possible
> to do the link at least at a distance of 5000 kilometers, 100x better than
> the recent (2019) record.
> The Chinese have been doing entanglement experiments on a satellite named
> Micius. https://en.wikipedia.org/wiki/Quantum_Experiments_at_Space_Scale
> "QUESS is a proof-of-concept mission designed to facilitate quantum optics
> <https://en.wikipedia.org/wiki/Quantum_optics> experiments over long
> distances to allow the development of quantum encryption
> <https://en.wikipedia.org/wiki/Quantum_encryption> and quantum
> teleportation <https://en.wikipedia.org/wiki/Quantum_teleportation>
> <https://en.wikipedia.org/wiki/Quantum_Experiments_at_Space_Scale#cite_note-Spacecom-7> Quantum
> encryption uses the principle of entanglement
> <https://en.wikipedia.org/wiki/Quantum_entanglement> to facilitate
> communication that is totally safe against eavesdropping
> <https://en.wikipedia.org/wiki/Eavesdropping>, let alone decryption
> <https://en.wikipedia.org/wiki/Cryptanalysis>, by a third party. By
> producing pairs of entangled photons
> <https://en.wikipedia.org/wiki/Photons>, QUESS will allow ground stations
> separated by many thousands of kilometres to establish secure quantum
> channels <https://en.wikipedia.org/wiki/Quantum_channel>.
> <https://en.wikipedia.org/wiki/Quantum_Experiments_at_Space_Scale#cite_note-IOP-3> QUESS
> itself has limited communication capabilities: it needs line-of-sight
> <https://en.wikipedia.org/wiki/Line-of-sight_propagation>, and can only
> operate when not in sunlight.
> Jim Bell
> On Monday, June 29, 2020, 12:43:08 AM PDT, таракан <
> cryptoanalyzers at protonmail.com> wrote:
> I quote the main title of the article:
> "*Scientists in China managed to exchange a crypto key at a distance of
> over 1,000 kilometers*"
> How can they do that?
> On Monday, 29 June 2020 г., 2:54, jim bell <jdb10987 at yahoo.com> wrote:
> Cointelegraph: Experts Split on Practical Implications of Quantum Cryptography.https://cointelegraph.com/news/experts-split-on-practical-implications-of-quantum-cryptography
There is proof inside many peoples' electronics. Proof that a marketing
group would contract development of a frightening virus. A virus that
responds to peoples' keystrokes and browsing habits, and changes what
people see on their devices. A virus that alters political behavior en
masse, for profit.
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