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Comment Re: "quantum" computing (Score 1) 45

"Using non-local quantum entanglement to instantaneously transmit information indeed would be faster-than-light."

Yes, and entanglement can't do that as I tried to explain in my earlier post.

You do not transport information but quantum information with entanglement. They are as far removed from each other as Schroedinger's cat from any pet you've ever owned.

BTW tachyon are hypothetical faster than light particles. Of course you could signal into the past if such a resource existed and could be technologically controlled.

And once again, nature has no concept of "instantaneous" it's a human approximation to a constant frame without relativistic speeds. Whenever a physicist uses this word in connection with entanglement its an unscientific shortcut that has no real physical meaning.

I'd highly recommend you to draw up some Minkowski diagrams, until this clicks for you.

Understanding the nature of quantum information is a bit more tricky, because it all comes down to how quantum correlations will look like perfect random noise until you get the information from a corresponding measurement on entangled systems. The way this is experimentally tested is via Bell's inequality violations.

Bell was much later than Einstein. Bell essentially codified the latter's reservations and wanted to prove Einstein right, but nature did not cooperate.

BTW the only quantum spookiness that QM allows are Quantum Erasers.

And please note, that all these oddities are not hypothetical but demonstrated in experiments. It's these weird experimental results that have brow beaten physicists into accepting entanglement as a fundamentally non-local phenomenon, against the marked resistance of some of the best and brightest minds like Einstein and Bell.

Comment Re: "quantum" computing (Score 1) 45

The ERP paradox that you are alluding two was solved by Niels Bohr just two days after Einstein presented it to him.

Quantum Information is fundamentally different than classical Information. A pure quantum information channel that only establishes entanglement does not transport classical information, it just established a quantum correlation. But this correlation can only be confirmed after corresponding classical information over the measured state on one end of the channel reaches the other end.

That classical signal of course obeys relativity and cannot propagate faster than light. Hence causality is preserved.

The common statement, (that many physicist who should know better make as well), that entanglement establishes an instantaneous signalling is grossly wrong. For spacelike separated events, linked via a quantum channel, instantaneous is not even defined. It is completely meaningless as the temporal order is relative to an observer's inertial frame. So I guess I shouldn't say it's grossly wrong, but stick to Pauli's formulation. It's not even wrong, it's worse, it carries no scientific meaning whatsoever.

(BTW I am physicist and dabble in quantum computing).

Comment Re: "quantum" computing (Score 2) 45

The hedging in the paper is the typical verbiage that you get with any data driven study.

At any rate, it wouldn't be classical computing in the digital sense but reduce to a mostly analog annealer. The original claim was that the D-Wave machine was essentially a fake, and this has been discredited three ways till Sunday.

They set out to build a quantum annealer and it acts like one. What is unclear is how useful this process will actually be in practice. Quantum speed-ups are not at all guaranteed with this design. That's were the focus should be. Not some rehashed conspiracy theory that D-Wave is faking their hardware.

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