China manages a new record in quantum teleportation - Sensationalist Headlines

[QUOTE=da space core;52372659] Just don't think about it too hard[/QUOTE] Or you could just try and explain it to him or point him in the direction of where to go in order to understand it since that's generally how learning works. If your going to be condescending because he doesn't get something might as well not even post it.

[QUOTE=Segab;52372736]yeah I was wondering about something like that. We don't have control on what the coin flip will be, but can we detect IF it happens? So if we have particle A and A¹ linked, and B and B¹ linked, couldn't we just tell which of A¹ or B¹ changed by looking at A and B? If we can't detect IF a coin was flipped, then we can only know the opposite of a coin flip light years away, which serves no purpose[/QUOTE] From how I understand it, you can't tell if the coin flip happened without flipping it in the process, so there's no way to measure it without destroying the information.

[QUOTE=Bernie Buddy;52372624]If they only have a state when they're observed, what's the difference between that and them just having a state all the time? How did they figure out the state of when it's not measured without measuring it?[/QUOTE] That is part of the Uncertainty Principle. In short, it says you can't measure position and momentum at the same time, and said particle can be in two or more places at the same time, and even interfere with itself. It is freaky how experts have to explain by saying words like "this particle appears into existence by measuring it" just because there is no better way to say it.

[QUOTE=archival;52372963]Or you could just try and explain it to him or point him in the direction of where to go in order to understand it since that's generally how learning works. If your going to be condescending because he doesn't get something might as well not even post it.[/QUOTE] why would I spend half an hour making a textbook of a post just to be condescending in replies? that response i made was obviously a joke jabbing at the fact that lots of quantum mechanics defies common sense im no physicist, so if you really want to know more in depth information, I suggest asking someone professionally knowledgeable in the field of physics (some of whom are on this forum). I would be wary about googling around since there is a lot of misinformation out there (not out of malice, just that a lot of people dont understand the topic themselves)

You can't transmit specific information, but you can observe the states changing and apply that as a sort of interpreter. You don't need ones and zeros if you just have it so that once it changes states, regardless of it being a one or zero, that to goes from the superposition, an interpreted 0, to just be an interpreted 1 regardless of true or false. So in a way you could transmit information by the interpretation of what is presented. But that's just my train of thought with what I know. I don't know if this a possibility due to my lack of knowledge about quantum physics such as multiple particles being entangled in close proximity.

[QUOTE=choco cookie;52373108]You can't transmit specific information, but you can observe the states changing and apply that as a sort of interpreter. You don't need ones and zeros if you just have it so that once it changes states, regardless of it being a one or zero, that to goes from the superposition, an interpreted 0, to just be an interpreted 1 regardless of true or false. So in a way you could transmit information by the interpretation of what is presented. But that's just my train of thought with what I know. I don't know if this a possibility due to my lack of knowledge about quantum physics such as multiple particles being entangled in close proximity.[/QUOTE] The problem is that there's no way to check whether a particle is in a superposition. As soon as it's measured, it becomes a 0 or a 1, and is indistinguishable from a particle that flipped because its entangled particle flipped.

[QUOTE=Helix Snake;52373147]The problem is that there's no way to check whether a particle is in a superposition. As soon as it's measured, it becomes a 0 or a 1, and is indistinguishable from a particle that flipped because its entangled particle flipped.[/QUOTE] Well there actually are [URL="http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time"]working quantum computers[/URL] so there must be something that can be done with these superpositions [editline]18th June 2017[/editline] Funnily it only produces the right answer 50% of the time :v:

[QUOTE=download;52372665]The stereotype is that only light can travel at the speed of light (or faster). Trying to be a smartass doesn't really work you're wrong. [/QUOTE] I'm attempting to shed light on the fact your posts don't make sense friendo

[QUOTE=Riutet;52372674]Sure you can, rather than measuring the outcome of the coin flips, you simply measure how many coinflips happen per interval and use that to send information. If you say one coin flip was A, two was B, three was C etc, by someone flipping coins at set intervals you could transmit messages by paying attention not to the outcome of the coin flip but the frequency at set intervals. I don't think that applies in this thread's situation though.[/QUOTE] [QUOTE=Agent_Wesker;52372712]Yes, someone explain why you can't have 4 particles, flip 1 (first set) for no and 2 (second set) for yes... or something.[/QUOTE] These are very natural schemes to try to send information, but it doesn't work with entanglement. The reason is there's no way to know if an entangled pair was measured without comparing with the other end of the pair via some classical (limited by light speed) channel. Say you have an entangled pair, and your friend has the other half, and there's a 50% chance of it being in either state A or state B when observed on one end, and it will be the opposite state on the other end. Your friend observes his end first. He sees State B. You observe your end. You see state A. Okay, but did you collapse the wave function, or did he? How do you know that without asking your friend when he observed his via some slower-than-light channel? How can you tell this outcome apart from the scenario where you observed yours first, and it just came out in state A from the 50% chance? Moreover, you can't send a signal by controlling which state the other party sees, since you aren't in control of the outcome of a measurement. It's determined by probability.

[QUOTE=LennyPenny;52373161]Well there actually are [URL="http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time"]working quantum computers[/URL] so there must be something that can be done with these superpositions [editline]18th June 2017[/editline] Funnily it only produces the right answer 50% of the time :v:[/QUOTE] Because you can phrase a problem such that all results, including incorrect ones, have a probability. Just ensure that the real answer has the highest probability and run the program numerous times. The most frequent result is the answer. [video]https://youtu.be/IrbJYsep45E[/video]

[QUOTE=Bernie Buddy;52372624]This part will forever confuse me. If they only have a state when they're observed, what's the difference between that and them just having a state all the time?[/QUOTE] Descriptions of particles for which this is true (i.e. the particle has all definite observables all the time) have to satisfy the Bell inequalities: [url]https://en.wikipedia.org/wiki/Bell%27s_theorem#Bell_inequalities[/url] But quantum mechanics violates these. [QUOTE=Bernie Buddy;52372624]How did they figure out the state of when it's not measured without measuring it? All this stuff make me brain hurty[/QUOTE] States of particles which are not being observed evolve via the Schrodinger equation. This is a nice, deterministic differential equation that tells you how a state changes in time. It's actually measurement that's the weird bit. When you measure things is when god starts playing dice with the universe.

[QUOTE=da space core;52372579]im no physicist myself, but ill try to explain. Imagine we have two particles, named A and B, each that can hold a binary value (1 or 0, true or false, etc). If particles A and B are entangled, particle B will be the opposite of whatever we [I]measure[/I] Particle A to be. So we find Particle A to be 0, B will be 1. First thing to understand is that the "states" of A and B are not determined when they are created. If we create entangled particles A and B, its not that we dont "know" what state they each have, it is that they dont [I]have[/I] a binary state until we actually measure them. Until we actually measure one of the particles, both particles A and B are in the 1 and 0 state simultaneously,they are both "true false". However, say, we measure particle A, and it collapses into state of "1" (of which it had a 50% chance of doing since it can be either 1 or 0, much like flipping a coin). Particle B will [I]instantly[/I] go from the state "1 and 0 (true false)" and become state 0. (or vice versa). This will happen instantly regardless of how far particles A and B are from each other, even if they are light years apart. This means that particle A "told" particle B its state, so particle B can become the opposite state, instantly. that "message" from A went to B instantly, which is faster than light (which does have a speed limit). Now, for the disappointing bit of why this cannot be used for communication. Say I had the entangled particles A and B, and I put particle A on a satellite probe and kept B home here on earth. I send this satellite out to a planet light years away to see if that planet can sustain life. If I were to put the satellite with some radio transmitter or something, the radio waves would be slow since they travel at the speed of light, which would take years to cross a distance of light years. But the entangled particles A and B can send "messages" instantly, right? So say the satellite measured the planet as habitable. instead of using the slow radio transmitter, Just make particle A say "0" so particle B here at home instantly goes "1", giving us the green light (and vice versa should the planet be not habitable, where we would make A 1 and thus B would 0). Well, recall earlier when I said particle A had a 50% chance of becoming 1, and a 50% chance of becoming 0. we cannot "force" a state on a particle, we just measure it and see, by chance, which one it became. so back to the satellite example. what would happen is that we would just know, from the measured state of B, what A happened to be. The satellite can have no control of the outcome, the planet could have actually been covered in lava, but A became 0 anyways (making B 1) because it had a 50% chance of doing so. So, Tl;Dr, in terms of "communication," all that entanglement allows us to do is know the results of a coinflip light years away instantly. We cant actually control what data gets sent. Its random. Not to say that quantum mechanics is useless, it has some use in computing and particularly encryption (and cracking encryption), but we will not see its use in sending intergalactic messages[/QUOTE] Couldn't you just set up a Braille board or use Morse code, watching for the actual presence of a confirmed measurable state rather then encoding the message in the actual state? If particle A1 causes particle A2 to collapse into a confirmed state then: Else if particle B1 causes particle B2 to etc etc Obviously real scientists (not me) will have considered this, but I'm interested to know why it wouldn't work Edit: late

[QUOTE=JohnnyMo1;52373207]These are very natural schemes to try to send information, but it doesn't work with entanglement. The reason is there's no way to know if an entangled pair was measured without comparing with the other end of the pair via some classical (limited by light speed) channel. Say you have an entangled pair, and your friend has the other half, and there's a 50% chance of it being in either state A or state B when observed on one end, and it will be the opposite state on the other end. Your friend observes his end first. He sees State B. You observe your end. You see state A. Okay, but did you collapse the wave function, or did he? How do you know that without asking your friend when he observed his via some slower-than-light channel? How can you tell this outcome apart from the scenario where you observed yours first, and it just came out in state A from the 50% chance? Moreover, you can't send a signal by controlling which state the other party sees, since you aren't in control of the outcome of a measurement. It's determined by probability.[/QUOTE] Forgive me for my idiocy, but would a series of pre-set ''watches'' (or perhaps the launching/of the particles itself) set very precisely (by a computer or such) affect the outcome of your example? If the first level of timed particles launched (previous factor: both launching systems were preset with some type of timing mechanism at the same place at the same time), and a result was revealed, indicating a sort of base-line for communication (Go to the store, tell me once you're there), followed by a second launch by the far-away sender (indicative of a response to the baseline, like ''I'm there''. Or if the baseline statement was ''Go to Roseland and tell us if the Sea is Green''), wouldn't rudimentary communication be possible? Or would the second surprise variable be unviewable by the local sender/general receiver?

Not long now before God makes a divine intervention and bans us from his universe simulator for trying to glitch abuse the system.

[QUOTE=V12US;52373658]Not long now before God makes a divine intervention and bans us from his universe simulator for trying to glitch abuse the system.[/QUOTE] Umm no??? We're just climbing the tech tree.

[QUOTE=Segab;52372736]yeah I was wondering about something like that. We don't have control on what the coin flip will be, [B]but can we detect IF it happens?[/B] So if we have particle A and A¹ linked, and B and B¹ linked, couldn't we just tell which of A¹ or B¹ changed by looking at A and B? If we can't detect IF a coin was flipped, then we can only know the opposite of a coin flip light years away, which serves no purpose[/QUOTE] By trying to detect it we make it happen, so there's that

[QUOTE=LennyPenny;52373161]Well there actually are [URL="http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time"]working quantum computers[/URL] so there must be something that can be done with these superpositions [editline]18th June 2017[/editline] Funnily it only produces the right answer 50% of the time :v:[/QUOTE] Quantum computers wouldn't be helpful in this situation; they are simply computing devices that exploit the superposition principle in their calculations, they can't actually take a superposition as an input ( for the time being anyway ). None of the current quantum computing algorithms would be of help either; and they're already having a tough time making enough qubits to operate with. I'd like to add as well that observation is very broadly defined; seen some people mention stuff like "not observing directly but seeing when the result changes" - this is still observing. Anything that could potentially extract information about the particles is an observation in itself and would cause the collapse of the superpositions the particles are in. As Jonnymo has said, it all boils down to verification of what you have observed; of which will [B] always [/B] rely on classical communication - limited by the speed of light. This has not been circumvented yet, and judging by research to date, cannot be circumvented

[QUOTE=Bernie Buddy;52372624]This part will forever confuse me.[/QUOTE] The part that always gets me is just what entanglement even is. I've looked it up on several occasions and I just never see a satisfactory explanation. Cause logically it can be assumed that entanglement is probably something artificial in nature since two random nearby particles in the entire universe being entangled is incredibly unlikely. But if that's the case then how do we entangle two particles and what exactly does that entail? If it's not true then how do we even find two entangled particles to begin with? And both of those still gloss over exactly what being entangled means to begin with.

So I can send a couple friends a pair of quantum encoded messages that will either collapse into being a dick pic or being a cat video and live with the knowledge that exactly one of them will get a cat video and one of them a dick pic, just not which got what. Science never ceases to amaze me

[QUOTE=daigennki;52372502]So do correct me if I am misunderstanding this, by doing this are they trying to create a satellite communications network faster than optical fiber? :johnnymo1: [editline]18th June 2017[/editline] And faster as in bandwidth, latency, or both?[/QUOTE] My dreams of no peeking advantage are true?!

[QUOTE=Instant Mix;52374087]I'd like to add as well that observation is very broadly defined; seen some people mention stuff like "not observing directly but seeing when the result changes" - this is still observing. Anything that could potentially extract information about the particles is an observation in itself and would cause the collapse of the superpositions the particles are in.[/QUOTE] As I think Kurzgesagt put it recently, even the air in the room can cause the superposition to collapse. When you think of [I]any[/I] interaction as the exchange of information it becomes quite clear. Unfortunately the media has done a poor job at explaining that.

it- ITS NOT SHUTTING DOWN!

The question is can I use quantum physics to reach the perfect cooking times for everything. Like I don't care about all this civilization changing teleportation timey whimey stuff, I just want to eat the world's best boiled eggs.

[QUOTE=DOG-GY;52374614]As I think Kurzgesagt put it recently, even the air in the room can cause the superposition to collapse. When you think of [I]any[/I] interaction as the exchange of information it becomes quite clear. Unfortunately the media has done a poor job at explaining that.[/QUOTE] Quantum error correction is a very real issue that's halting the progression of Quantum computing just now; qubits will begin to experience decoherence fairly quickly.

Here's my question; if this can't be used for faster than light communication, what CAN it be used for?

[QUOTE=Helix Snake;52375071]Here's my question; if this can't be used for faster than light communication, what CAN it be used for?[/QUOTE] Slightly slower than light communications? On a serious note I think right now it's just proof of concept. I don't think we know enough to make much practical use of this yet

That's what I don't get though, if any interaction whatsoever with an entangled particle causes it to collapse, why even call it a superposition? Why not just say "it is either state A or state B", rather than say "it is both state A and B until you measure it"? How do we know that superpositions even exist if there is no way for them to interact with the universe without collapsing?

[QUOTE=Kylel999;52375098]Slightly slower than light communications?[/QUOTE] My imagination is failing me, how could it be used for even that? If you can't choose which state the particle collapses to I can't imagine there's any way you could sent any amount of information using it.

[QUOTE=LennyPenny;52373161]Well there actually are [URL="http://www.popsci.com/science/article/2012-08/quantum-processor-calculates-15-3x5-about-half-time"]working quantum computers[/URL] so there must be something that can be done with these superpositions [editline]18th June 2017[/editline] Funnily it only produces the right answer 50% of the time :v:[/QUOTE] It produces all of the answers actually. They're just selecting one of the wrong answers. See [url]https://www.youtube.com/watch?v=JhHMJCUmq28[/url]

[QUOTE=Ardosos;52375273]That's what I don't get though, if any interaction whatsoever with an entangled particle causes it to collapse, why even call it a superposition? Why not just say "it is either state A or state B", rather than say "it is both state A and B until you measure it"? How do we know that superpositions even exist if there is no way for them to interact with the universe without collapsing?[/QUOTE] [hd]https://www.youtube.com/watch?v=IrbJYsep45E[/hd] This one really helps Basically you only collapse it right at the end, after you were able to achieve very high concurrency calculations [editline]18th June 2017[/editline] Also they don't collapse from "any interaction whatsoever", only ones that would require it to have a state, like when measuring its momentum. If it doesn't need to collapse it just follows schrödingers equation. [url]https://en.wikipedia.org/wiki/Wave_function_collapse[/url]