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The Quantum Computing Era Is Here


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I dont think they will be available to Joe public any time soon. An explainer or repeat of some of the tems in your link https://www.technologyreview.com/s/612844/what-is-quantum-computing/

 

Question

 

can entanglement transfer information over long distances instantly, or is information transfer between entangled qubits limited to c ?

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I dont think they will be available to Joe public any time soon. An explainer or repeat of some of the tems in your link https://www.technologyreview.com/s/612844/what-is-quantum-computing/

 

Question

 

can entanglement transfer information over long distances instantly, or is information transfer between entangled qubits limited to c ?

Quantum Entanglement has been shown to not be limited by the C limit, so the information limit between two entangled qubits is not limited to C however the other parts of the computer may transmit at slower than C.

Edited by VictorMedvil
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Quantum Entanglement has been shown to not be limited by the C limit, so the information limit between two entangled qubits is not limited to C however the other parts of the computer may transmit at slower than C.

 

That does not mean that information or anything is FTL (faster than c), the entanglement is when the two particles are together, no information transfer occurs between separated entanglement particles. 

 

However, you knowledge of the spin of one (local) particle gives you the knowledge of the spin of the remote particle instantly.

 

Think of it as a pair of gloves where one is sent to you and one to me, we are separated by space, when I open my box and see that I have received the left glove I know instantly that you have the right glove. The information I get about your glove is derived from the information I get from my glove. Because I know that my glove is entangled with your glove, the information about which glove you have came with the glove I have.

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Quantum Entanglement has been shown to not be limited by the C limit, so the information limit between two entangled qubits is not limited to C however the other parts of the computer may transmit at slower than C.

 

 

 

That does not mean that information or anything is FTL (faster than c), the entanglement is when the two particles are together, no information transfer occurs between separated entanglement particles. 

 

However, you knowledge of the spin of one (local) particle gives you the knowledge of the spin of the remote particle instantly.

 

Think of it as a pair of gloves where one is sent to you and one to me, we are separated by space, when I open my box and see that I have received the left glove I know instantly that you have the right glove. The information I get about your glove is derived from the information I get from my glove. Because I know that my glove is entangled with your glove, the information about which glove you have came with the glove I have.

 

I am aware of both these viewpoints, which is correct?

 

Why did Einstein refer to spooky action at a distance, if nothing weird was happening.

 

For a computer to compute, it needs to do calculations manipulating binary 1's and 0's

 

How are Qubits manipulated in a quantum computer. Switching or forcing entangled qubits to a known state, would effect entangled qubits at long distances, instantly would it not. 

 

Many photons can be entangled after passing through a beam splitter. Electron pairs are entangled via the Compton effect in super conductors. 

Edited by Flummoxed
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Here are a couple of primers on Quantum computers  

https://www.dwavesys.com/tutorials/background-reading-series/quantum-computing-primer

https://www.dwavesys.com/tutorials/background-reading-series/introduction-d-wave-quantum-hardware

 

And then if you want to program one heres a quick intro https://www.quantum-inspire.com/kbase/quick-guide/

 

The qubits dont have a fixed state until they carry out the programmed calculations instantly, which implies FTL calculations does it not which might be why einstein.

thought entanglement/superposition was spooky !.  

 

https://en.wikipedia.org/wiki/Quantum_entanglement

https://en.wikipedia.org/wiki/Principle_of_locality

 

Faster than c implies non local fixed at c implies local interpretation. so it appears both Victor and Mutex are correct in a superposition of answers.

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Flummoxed: No, the complex probability wave function superposition collapsed, gave the probability of 1 that Mutex is correct (we all know it!!)... 

 

You ask interesting questions: yet I'm sure my answers are probably a bit boring so synergy.. 

 

 

Why did Einstein refer to spooky action at a distance, if nothing weird was happening.

 

It used to just be called 'action at a distance', but sadly science tends to focus on the sensational (easier to get funding I guess).

 

Action at a distance is a problem and not just for quantum mechanics, I looked again at the old Feynman lectures where he talks about that on the subject of gravity.

 

https://youtu.be/kd0xTfdt6qw?list=PLez3PPtnpncQLg_H7f6T9yJmJ2aCIBUHS  starts to get interesting at about minute 35 or a bit before.

(The.Character,of,Physical.law. Part 2. (34 minutes.)

 

What he is talking about is how an object (like the moon orbiting the earth) 'knows' where to go and what direction and how fast to orbit? 

He is saying that gravity itself is action at a distance and yes it's spooky, we don't know what gravity is! (I do but I'm not telling yet!!) 

"The force has a non-local quality".

 

So the information of gravity is 'spooky action at a distance' (Force has a non-local quality).

 

 

I am aware of both these viewpoints, which is correct?

 

Personally I think in this case, you have to accept that nothing goes faster than the speed of light, although I have seen that someone did some kind of statistical analysis of entangled that possibly indicated otherwise it is for me not conclusive at all.

 

We detect light as a wave over time based on the constant speed of light, but if instead light has it's own frequency independent of it's speed AND the speed of light was INFINITE, would the world look much or any different?

 

The question is what would we gain by having faster than light 'something' (including light)?

 

We would still get sunlight, and it would look the say, but the light now gets to us instantly instead of after 8 minutes. You would be able to play World of Warcraft with zero latency throughout the universe, and you might be able to established two-way communications with any other life anywhere in the universe. But in real terms on earth it would not make that much difference, locally we intuitively accept that the speed of light is for all intents infinite. (So something to chew on).

 

 

For a computer to compute, it needs to do calculations manipulating binary 1's and 0's

 

Nature (the universe) is a far superior analogue computer than we can ever imagine.

 

Analogue (or Analog) computers do not do calculations on discrete values, they are linear (analog) computational devices, a water tank instantly (note that word) calculates the integral the inflow of water into it.

 

A capacitor makes a good electrical integrator, it has virtually an infinite number of possible states, so if you can represent basic math functions in nature (and you sure can) then you can resolve any computational function (that you can calculate).

 

 

The qubits dont have a fixed state until they carry out the programmed calculations instantly, which implies FTL calculations

 

When a function happens it happens as it happens and therefore sort of by definition when it happens it happens instantly! (I'll show myself out!).

 

What I am trying to say, is that when something happens the 'distance' of that event is zero, it's happening, so it is effectively 'How far can light go over zero distance?'

 

Lastly, (almost), as an engineer who designs scientific instruments and experiments I cant see how you can measure or even confirm 'instant' it would be like having a stop watch that the start button and the stop button were the same button, and hitting them at the same time. 

Or to put it another way, to measure instant you would need an infinite sample rate.

 

Really lastly: Superpositions !! They don't exist in the real world, for me they are simply an abstract concept of an interpretation of the Schrodinger equations. 

 

Hinesburg (Schrodinger's cat), is never alive and dead at the same time and does not exist as a complex quantum probability wave function in a binary (alive and dead) superposition. It's either alive or it's dead, regardless of what you know about the system or if you have looked or not.... 

 

(The entire Schrodinger's cat thing was proposed to expose the absurdity of the claim!!, originally, so there is that, now it's almost accepted science, again, science does tend to like the dramatic, it helps with grants.)..

Edited by Mutex
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I see you prefer a classical approach but if a violation of a Bell inequality could be demonstrated would you change your mind. This fella mentioned in the links above is interesting https://en.wikipedia.org/wiki/Ronald_Hanson he worked on this paper with lots of other people https://arxiv.org/abs/1508.05949 .

Experimental loophole-free violation of a Bell inequality using entangled electron spins separated by 1.3 km

 

Flummoxed: No, the complex probability wave function superposition collapsed, gave the probability of 1 that Mutex is correct (we all know it!!)... 

 

 

Perhaps the probability that Victor is correct just changed to 1 :shocked: , its a superposition of states not binary 1's and 0's.(probably)

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I see you prefer a classical approach but if a violation of a Bell inequality could be demonstrated would you change your mind. This fella mentioned in the links above is interesting https://en.wikipedia.org/wiki/Ronald_Hanson he worked on this paper with lots of other people https://arxiv.org/abs/1508.05949 .

Experimental loophole-free violation of a Bell inequality using entangled electron spins separated by 1.3 km

 

 

Perhaps the probability that Victor is correct just changed to 1 :shocked: , its a superposition of states not binary 1's and 0's.(probably)

 

I know I am usually correct about most things its a gift and a curse. Now back to genocide and world domination.

Edited by VictorMedvil
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Here you go, This might be of interest on this thread https://phys.org/news/2020-01-quantum-networks.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletter 

 

"Physicists at LMU, together with colleagues at Saarland University, have successfully demonstrated the transport of an entangled state between an atom and a photon via an optic fiber over a distance of up to 20 km—thus setting a new record."

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