Is faster than light communication possible? Yes

Originally posted by neoholographic
What is it you don't understand??

So... we repeat the same question again:

Provide sources, specifics on exactly which experiment and which detector does this.

Dont be vague and say "they all do it" or "there are many ways".
Be specific. Which specific detector?

reply to post by neoholographic


means of detection, physically interact with that which is being detected, especially quantum particles on that small scale.

if there is a detector in bobs device, how can it be detecting and not collapse the particles wave function?

Originally posted by neoholographic
reply to post by Arbitrageur

 

There's several ways this can happen. You have a Geiger counter that can detect radiation when an atom decays. A light source that emits photons. A magnetic moment when the particle interacts with an external magnetic field. A SPLEED which is a spin-polarization detector and other ways.

I don't recall asking about Geiger counters. You claimed that Bob knows when the particle on his end has a collapsed state due to Alice's measurement. I asked for references to support this claim. You've provided nothing responsive to my specific request. Geiger counters don't help here.

How do you think these experiments work without a detector LOL???

If you cite the experiment you're referring to, we will find out, because the experiment should describe how the detector works and then we will have some specifics to discuss. Without a citation of a specific source, it seems apparent to me that you've created a fictional device in your imagination that doesn't exist and has never been used in any experiment. But if I'm wrong and you have a real detector in mind, let's examine how that works.

Wow,

If you guys don't know about a detector used in these experiments then you need to not only go read and learn about entanglement but how these experiments are carried out.

I already listed a few ways but you can use a magnetic moment. There's experiments where a single electron spin is detected in the gate oxide of a silicon transistor and converted to an electrical charge. A photon detector. A quantum dot. Here's an experiment that was described in Nature.

Quantum dots entangled with single photons

Quantum dots are tiny pieces of semiconductor that are compatible with conventional electronics and therefore offer a practical way forward. Both teams used quantum dots formed at the interface between two different semiconductors. A single electron can become trapped in the dot – and because the dot is so small, the electron inhabits a set of atom-like energy levels.

Quantum information can be stored in the spin of the electron – with "0" corresponding to spin up and "1" to spin down for example. In both the Stanford and ETH experiments the value of the qubit was set to the spin-up state by firing a "pump" laser pulse at the dots. Then, a second laser pulse is fired at the dot, which pops the electron into a higher energy state. This state can then decay to either a spin-up state with the emission of a "blue" vertically polarized photon or a spin-down state and a "red" photon that is horizontally polarized. Red and blue simply refer to the wavelengths of the photons, with the latter shorter than the former.

physicsworld.com...

The beauty in this device is Bob doesn't need to know if it's spin up or spin down because both = the same thing. He just needs to measure spin resonance.

Here's a paper titled:

Detection of single electron spin resonance in a double quantum dot

Spin-dependent transport measurements through a double quantum dot are a valuable tool for detecting both the coherent evolution of the spin state of a single electron, as well as the hybridization of two-electron spin states. In this article, we discuss a model that describes the transport cycle in this regime, including the effects of an oscillating magnetic field (causing electron spin resonance) and the effective nuclear fields on the spin states in the two dots. We numerically calculate the current flow due to the induced spin flips via electron spin resonance, and we study the DETECTOR efficiency for a range of parameters. The experimental data are compared with the model and we find a reasonable agreement.

jap.aip.org...

At the end of the day there are different ways it could be carried out and again, Bob doesn't need to know if it's spin up or spin down because both states equal the same thing. You guys must have heard something about quantum computing and you didn't understand what you heard.

In quantum computing, you carry out calculation on both states so of course you have to hold superposition long enough to carry out both calculations. With Bob, he just needs to detect whether the particle is in a spin state which will occur when Alice carries out a measurement.

I hope you guys do some actually reading and research and you would know about ways detection occurs in these experiments. You would also know the difference between quantum computing and what I'm talking about if you just take the time to study what you're debating. It doesn't take long to at least read a few published articles on the subject and watch a few videos.

Originally posted by neoholographic
physicsworld.com...

In both set-ups the spin of the quantum dot is measured by firing a second laser pulse at the quantum dot. The result involves the emission of a photon with a polarization that is related to the spin state of the quantum dot. By measuring the correlations between the spin-measurement photon and either the colour or polarization of the qubit photon, both teams were able to prove entanglement.

So they are measuring (or observing) both entangled particles at both ends which is the only way they can determine correlations and prove entanglement. You said this:

Originally posted by neoholographic
If Bob had to make an observation, then it wouldn't be entanglement. You could just say Bob caused a measurement to occur.

The reason Einstein called it spooky action at a distance is because a measurement on one causes a measurement to occur on the other.

Bob's device can register when his particle takes a spin state of up or down.

There is nothing in either source about anything like what you refer to as "Bob's device".

You are correct that Bob doesn't have to make an observation or measurement but in this case he has no information thus there is no communication. The reason the researchers are able to make correlations proving entanglement is because they are measuring both ends.

And I have absolutely no idea how to interpret "If Bob had to make an observation, then it wouldn't be entanglement. You could just say Bob caused a measurement to occur." Do you want to try and clarify what you mean by that? What is the difference between measurement and observation in this context, if there is one? To me they mean pretty close to the same thing in this context.

reply to post by Arbitrageur


Bob isn't trying to prove entanglement, he's just detecting that a spin state has occurred. Bob is not looking for a spin up/spin down state and that's why I talked about spin resonance in quantum dots or spin state detection in gate oxide in silicon transistors among other things.

There's a difference between knowing which measured state has occurred (spin up/spin down) and detecting that a spin state has occurred. I will say it again:

BOB DOESN'T NEED TO KNOW WHICH SPIN STATE OCCURRED BECAUSE SPIN UP/SPIN DOWN OR SPIN DOWN/SPIN UP = THE SAME THING!

reply to post by neoholographic


Ok I'm going to try to make this easy let's do away with the measurement stuff for a minute. I you observe a paricle you'll collapse the wave function by geiger counter magnetic oscillation a camera looking for a flash passing it through paper and counting the dots it doesn't matter what you do observation collapses the wave function.Making it impossible to know if it was you or the other person. And so you know there would never be any detectuon device made that wouldn't cause the wave function to collapse

reply to post by dragonridr


This is a lack of understanding of entanglement.

Entanglement occurs because a measurement on one particle cause a measurement to occur on the particle pair. BOB CAN"T BE THE CAUSE OF HIS PARTICLE BEING SPIN UP OR SPIN DOWN!

I keep saying this but you're not willing to take the time to learn.

It's entanglement because Particle A being measured is the cause of Particle B being in a spin state. HOW DO YOU THINK THEY KNOW PARTICLE A BEING MEASURED IS THE CAUSE OF PARTICLE B BEING IN A SPIN STATE IF PARTICLE B CAN"T BE DETECTED?????

What you and others are describing isn't entanglement. Bob can't be the cause of particle B's spin state. If Bob had to carry out a measurement to detect a spin state has occurred then how would you know Alice and not Bob caused the measurement? What you and others are describing isn't entanglement.

Originally posted by neoholographic

The beauty in this device is Bob doesn't need to know if it's spin up or spin down because both = the same thing. He just needs to measure spin resonance.

In an example, what would his measuring of spin resonance do, and what do you mean both=same thing?

alice measures her particle, bobs particle reverting to an exact state notifies the device somehow, how? what is the device that it can be aware of that activity what is it sensing for and how is it doing its sensing? and then the device notifies the spin state it received? And so you are imagining alices device for sending information, would be like a keyboard, and by pressing a button, it would measure an entangled particle, and trigger bobs device? do particles lose their entangled states over time, or entangled forever? Is it known if particles become entangled naturally?

Hypothetically how many channels would alice and bob need to send meaningful information FTL, and hypothetically how would it work?

Originally posted by neoholographic
reply to post by dragonridr

 

This is a lack of understanding of entanglement.

Entanglement occurs because a measurement on one particle cause a measurement to occur on the particle pair. BOB CAN"T BE THE CAUSE OF HIS PARTICLE BEING SPIN UP OR SPIN DOWN!

I keep saying this but you're not willing to take the time to learn.

It's entanglement because Particle A being measured is the cause of Particle B being in a spin state. HOW DO YOU THINK THEY KNOW PARTICLE A BEING MEASURED IS THE CAUSE OF PARTICLE B BEING IN A SPIN STATE IF PARTICLE B CAN"T BE DETECTED?????

What you and others are describing isn't entanglement. Bob can't be the cause of particle B's spin state. If Bob had to carry out a measurement to detect a spin state has occurred then how would you know Alice and not Bob caused the measurement? What you and others are describing isn't entanglement.

How many bits of information have been sent using photonic entanglement since the first Bell tests in the early 70s? 40 years of development, all the way through the information age must have produced at least one experiment which communicated via photon entanglement? Which would that be, specifically? How much information was sent? What kind was it? Please elaborate about the detectors in this specific experiment.

afaik, 80 years of research into entanglement and the bps of this experiment is still 0bps.

I also feel obliged to point out how ridiculous you look when you point out Einstein was calling this thought experiment 'spooky'. Because he was deriding the conclusions of Quantum Mechanics when he said 'spooky'. He thought people who believed in it were wrong and would later be disproved by a more mechanical theory of photon motion. You seem to be missing this point.

Originally posted by neoholographic
reply to post by dragonridr

 

This is a lack of understanding of entanglement.

Entanglement occurs because a measurement on one particle cause a measurement to occur on the particle pair. BOB CAN"T BE THE CAUSE OF HIS PARTICLE BEING SPIN UP OR SPIN DOWN!

I keep saying this but you're not willing to take the time to learn.

It's entanglement because Particle A being measured is the cause of Particle B being in a spin state. HOW DO YOU THINK THEY KNOW PARTICLE A BEING MEASURED IS THE CAUSE OF PARTICLE B BEING IN A SPIN STATE IF PARTICLE B CAN"T BE DETECTED?????

What you and others are describing isn't entanglement. Bob can't be the cause of particle B's spin state. If Bob had to carry out a measurement to detect a spin state has occurred then how would you know Alice and not Bob caused the measurement? What you and others are describing isn't entanglement.

I think you meant this for someone else because ive been trying to tell them the same thing!!! Ok first entanglement doesn’t guarantee the other particle is measured do you even realize how stupid that sound??? Look we have two particles a and b and they are entangled. So I measure a say spin up this means I know the other particle will be spin down period. Now the only way I can verify what I know to be true is in fact to look at b as well. Particle b isn’t going to tell me what state it’s in it the only way I will know is if observe b. But when I observe b there is no way I can tell a was observed unless of course I did it. The only thing I can observe is the particle chose a state and they are all ways the same. Now please explain how observing a particle in any way sends any useful information if the only thing I can ever tell is that the particle is the same as the other. By observing a I cant tell if b was observed all I can show is yes indeed these particles are entangled. You’re giving magical powers to this particle that when you observe one the others going to announce to the world what state it’s in. Though I commend your trying to grasp entanglement because it is very confusing to say the least you keep forgetting one of the main tenants of quantum physics.

So a quick run down first particles exist as a wave function this is the core of quantum mechanics. Its called wave particle duality and this state that a particle exists as both a wave and a particle and even when it decides that there's still location and momentum. Now which state it ends up in is truly a random thing as far as we currently know anyway. There is a theory that the observer themselves affects the outcome but that really gets in deep because then the universe basically customizes itself to the observer. But back to our pesky particles There is a built in uncertainty to a particle they don’t have an exact position. The particles act as a wave so like plucking the string on a guitar you can't tell where the wave is on the string and momentum is also the same you can't tell how fast a particle is moving, just like you can't watch a wave travel down a guitar string. So we know particles hate to be nailed down and they are random. The reason there random is a particle exists in all its possible states until we look at it then the particle says oh there watching I need to act this way. Now we move on to entangle pairs well they're not random at all they are linked look at one and we know the others the same. However without observing both you have no way of knowing this and when you observe a particle again we force it to choose a state the minute we stop looking at it goes right back into a wave function. So the act of observing our pesky particle collapses the wave function but we have know way to look at it unless we observe it. So no form of communication is truly possible because all we can do is observe it if we change it well then they're no longer entangled. So it’s like two people watching the clouds we both can observe the same thing but we can’t pass any messages through it.

The reason quantum computers can be faster is not because they operate faster than light speed, it's because they don't have the limitation of binary computers where each data bit must be a 1 or a 0. This link explains the advantage:

Quantum Computing

In October 2012, Nobel Prizes were presented to David J. Wineland and Serge Haroche for their basic work on understanding the quantum world - work which may eventually help make quantum computing possible.

So I don't think the claim about a superfast computer being possible is overstated and they may have made a contribution toward this end if their work is verified in experiment. But that is not a result of FTL communication, which still remains elusive, even in theoretical models, including theirs, as far as I can tell.

Logically the noble prize isn't offered because of a quantum computer, the increases offered from using colours instead of 0's and 1's makes this pale in comparison. The reason we have digital is so that we can easily transfer information using fibre optics being light either on or off (0 or 1). Using 200,000 identifiable colours as a base makes this look silly.

This is actually do able now, problem being is maintaining the purity of the colour over distance to remove distortion. Which gets down to cost, you would need repeater stations built into the fibre optic lines. This of course is also applicable to satellites.

What I am saying is that the quantum computer is a red herring, possibly it is instantaneous control at a distance that has the powers that be handing out noble prizes - it certainly is what interests me. Which is why I want the conversation to go a bit further then the struggle with how. (Got an idea for how as well)

Originally posted by neoholographic
There's a difference between knowing which measured state has occurred (spin up/spin down) and detecting that a spin state has occurred.

So... we repeat the same question again:

Provide sources, specifics on exactly which experiment and which detector does this.

Dont be vague and say "they all do it" or "there are many ways".
Be specific. Which specific detector?

Originally posted by alfa1

Originally posted by neoholographic
There's a difference between knowing which measured state has occurred (spin up/spin down) and detecting that a spin state has occurred.

So... we repeat the same question again:

Provide sources, specifics on exactly which experiment and which detector does this.

Dont be vague and say "they all do it" or "there are many ways".
Be specific. Which specific detector?

He's a lot like a particle he doesn't like to be nailed down either. And he's deffinately in his waveform function at the moment.

Dont be vague and say "they all do it" or "there are many ways".
Be specific. Which specific detector?

He's a lot like a particle he doesn't like to be nailed down either. And he's deffinately in his waveform function at the moment.

Okay since no one is biting - one way that the communication can be received without looking, is waiting for the photon to dissipate. I've seen it reported that after reading the orientation of a particle they quickly disperse. Presumably this means that the other of the pair would also dissipate. The orientation or spin direction (given a healthy number of photons) becomes irrelevant, the important information is which photon pair has been looked at and this is known by which photon has dispersed.