No, the state that describes the system is the electrons together with the photons, you are doing a measurement on the photons, you are doing a measurement in a part of the state.
Look, this is a very fundamental property of quantum mechanics, it just doesn't make any sense for it to fail. The whole thing would go down in flames.
How do you communicate a bit using this distinction? Let's say I want to send '0', how do I do it?
It is a problem. Let's say the probability of getting them entangled is 0.5 (I'm too lazy to look it up now). Then you do the thing one time, you don't entangled the electrons, awesome, and they read '0'. Then you want to send them another '0', you do the thing, now they do get entangled, and they read '1'. Shit, now what? You cannot control what they are going to read! They do know the results of your measurements (first not entangled, then entangled), but this is just classical correlation, not communication.
It is easy to prove that it is not possible to send information by doing measurements on a part of an entangled state, so no, I'm afraid this is completely useless for FTL communication.
Your scheme would work, if one could deterministically entangle the electrons at a distance, but one can not.
The issue is that this technique (called entanglement swapping, look it up), gets the photons, and tries to entangle them; sometimes you succeed, sometimes you fail. For them, this is not a problem, because they can just discard the cases where they failed and do the experiment with the other electrons, but for you it is, as you need to be able to entangle them or not at will.
In general, it is a simple theorem to prove that you cannot send information by doing measurements on a part of an entangled quantum system, so any similar scheme is doomed to fail.
This is true, superdeterminism is a way out of the conclusion of the experiment.
That is why I said they only did the experiment without using "the most questionable extra assumptions". The assumption that the world is not superdeterministic is very reasonable, IMHO. Without it, one cannot even do science. For example, in a superdeterministic world, the wavefunction of a photon will depend on which measurements you are making on it, so there isn't such a thing as "the" wavefunction of the photon, and it is not possible to learn anything about it. It is this kind of conspiratorial correlation that superdeterminism uses to produce the violation of a Bell inequality. For me, it's insanity on the level of Last Thursdayism: logically consistent, unfalsifiable, and nobody will ever take seriously.
But I'm troubled by your last sentence:
that there would be no need for either instantaneous communication or a hidden variable in order to have 'entanglement'.
We don't need this stuff to have entanglement. Entanglement is just a property of Nature, it's there whether you want it or not. What we need instantaneous communication for is to create the appearance of entanglement in a hypothetical world that would be classical (or, technically speaking, has hidden variables). Since our world is quantum, this is of no concern.
Guys, this is huge. People have been doing versions of this experiment for decades, every time making it more refined, in order to be able to reach the striking conclusion with the fewest possible assumptions: that the world is not deterministic. The quantum randomness is not our ignorance, is a fundamental property of nature.
What they did was to violate a Bell inequality, without using the most questionable extra assumptions (called loopholes) people normally use to extract a conclusion from this experiment: that the separated laboratories are not somehow communicating to conspire to produce the desired outcome, or that the photons they detect are indeed a good representative of all the photons that were emitted in the experiment (normally people can detect only a small fraction of the photons).
I am a quantum physicist, and I know the science behind this experiment very well. If anybody wants to ask me anything, I'd be glad to oblige.
What they did was to violate a Bell inequality, without cutting any corners (is this corner-cutting that is named as "loopholes" in the experiment). This proves that the world is not deterministic (if you believe in relativity).
Humm yes? This is because people vote for the greens, the commies, and the crazy nationalists. Do you think people shouldn't be allowed to vote for them?
Now seriously, Italy has a lot of problems, but at least bipartidarism is not one of them. They are one of the most disfunctional European democracies, but even they managed to avoid being so absurdly disfunctional as to shut down their own government.
I think this is just being realist. The US is a two-party state, and voting for a third party is wasting your vote. This is a simple consequence of the archaic electoral system you have, it has nothing to do with the "culture seeing two possibilities" or people being stupid.
A useful comparison can be drawn with European democracies, as the crushing majority are multi-party. Unlike the Europeans, I don't think this is because they are smarter than the yankees. I think the reason is that most European countries have a more or less recent political system (Germany, France, Italy, Spain, Poland, etc. have political systems that date from after world war 2), and when it came the time for deciding what it should be they chose something that is not so absolutely stone-age as a first-past-the-post system with an electoral college.
Hum, I believe the problem is that most of the world is not christian, but they would still like to be able to refer to the year according to the Gregorian calendar, since it is almost universally used.
AD is kinda heavy for non-christians; it means in full "Anno Domini Nostri Iesu Christi", or in english "In the Year of Our Lord Jesus Christ", so if you are very pedantic writing 2015 AD is actually a lie for them.
What do you suggest the Chinese and Japanese to do, for example?
8/10 trolling, I'd say. The strawman is a bit of a long shot, but it connects well with the Godwin line, and so it is likely to give you passionate replies.
It is creating a legal framework for deciding these things, because the law currently lacks one.
And why is that a good thing? More lawyers, regulations, court cases? I don't think creating rules is something good in itself, on the contrary.
But anyway, don't you think parliament is the proper place to debate such a deep question? I feel that a judge really shouldn't have the power to decide whether chimps deserve to be treated as humans.
Matlab is the worst piece of shit I ever had the displeasure of working with. I only use this crap because the SDP interpreters I like (YALMIP and CVX) don't support anything else.
Once I had a bug in a code I had been writing for more than a month, and after lots of work I tracked it down to a vector declaration of the kind
v = [a, b +c];
You know what Matlab thought this meant?
v = [a, b, c];
Yep. It interpreted a whitespace between 'b' and '+' as creating a new vector element. And it's not even consistent, if I type [a, b + c] if gives again a two-element vector instead of a three-element one.
The fact that the programmer who introduced this "feature" was not instantly smitten by a thunder is proof that Zeus does not exist.
Btw, if you know any sensible SDP interpreter that does not require Matlab, I'd really like to know.
Thanks for the book reference, seems cool, I'll check it out.
Well, there will be major social changes, that's for sure. But bringing people back from the dead it's a minor thing, as realistically we'll never be able to bring back anyone that did not take precautions to be ressucistable, and these will remain a small minority for the foreseeable future.
I think the largest impact will be when technology to radically extend lifespan and life quality (cure ageing) becomes widespread.
Honestly, I think the whole religious industry ought to be frogmarched to jail and never let out. Is it quackery, fraud, and cruel, preying on grieving relatives, selling false hopes, engaging in grotesque experiments with human remains.
There, fixed that for you. The major point of most religions is to comfort people from their fear of death. All the religions I can think of prey of grieving relatives, sell them false hopes of an afterlife, and perform some grotesque ritual with human remains.
The difference is that unlike religions, cryonics is actually based in reality. Everything else is guaranteed to not work; but according to our current knowledge, cryonics is the best shot we have to actually cure death.
Of course it is highly unlikely to work, but it is a completely different league than burying (or burning) a body and hoping that some god will grant that soul eternal life in some paradise.
Sounds strange, I use owncloud to collaborate on my papers between 4 authors and nobody reported this problem. I guess it depends on the server you're using (mine is the University itself), rather than the software owncloud.
Typical case of religion obstructing the progress of science. Luckily in this case it is a minority religion that the local administration does not take seriously anymore. Imagine if that was a place sacred to christians, like the Mount of Olives, or to buddhists, like Sri Pada (also known as Sri Kanda). The poor telescope would never have a chance.
This is true; a measurement always returns a definite result, never a "smearing" or a "blur". But I'd like to point out that the issue is a bit deeper, as there is no physical distinction between "determinate" and "indeterminate" states. For example, a photon with vertical polarization is in a "determinate" state if you measure it in the vertical/horizontal basis. But if you measure it in the diagonal/antidiagonal basis it is in a "indeterminate" state, a equal superposition of diagonal and antidiagonal.
I wish people would stop speculating about the fucking cat and just read what Schrödinger wrote. Come on, it's four paragraphs.
What Schrödinger is doing is pointing out how ridiculous it is to accept the "quantum blurring" because "it only affects microscopical particles anyway and they're just weird". The problem is that one cannot consistently keep the blurring confined to the atomic domain. As Schrödinger points out very clearly, if we accept that the atomic nucleus is "blurred", then this blurring can be easily amplified to the macroscopic domain and make the cat be simultaneously dead and alive. Since we don't observe cats to be blurred, we cannot accept atomic nucleus to be blurred.
That's what Schrödinger states one line after introducing the fucking cat. Since I know nobody is gonna click the link and RFTA I'm going to quote:
It is typical of these cases that an indeterminacy originally restricted to the atomic domain becomes transformed into macroscopic indeterminacy, which can then be resolved by direct observation. That prevents us from so naively accepting as valid a "blurred model" for representing reality.
I never knew that Schrödinger joined at some point in Einstein quixotic quest for a classical unified field theory. Cool story, bro.
But I'm annoyed about the portrait of Schrödinger as Sancho Panza to Einstein's Don Quixote. Schrödinger was a major genius! He invented quantum mechanics, for fuck's sake! I'm particularly riled up by the statement
Embarrassed by the incident, Schrödinger would give up his quest for unity altogether and turn to other topics. Similarly, he would never collaborate again with a prominent physicist.
This seems to imply that Schrödinger never accomplished anything after he stopped collaborating with Einstein. Well, he helped discover DNA.
As far as I know the Cuban government wanted to exchange this guy for Cuban prisioners kept by the US, the Cuban Five. The US refused.
These Cubans went to the US to disrupt the operations of anti-Castro terrorist organizations based on Miami, and for that they were sentenced to 15 years in jail, the same sentence that befell the American guy.
So I do understand that Cuba wouldn't want to give up on their only bargaining chip to free its agents. It's a sad state of affairs, really. So much could be gained if there were a little bit of goodwill on both sides.
I'm finding quite curious the contrast between the comments that appeared the first time this story was discussed in/. and now. Whereas in the first time the comments were balanced and generally positive, now most comments are violently against it. I wonder what caused this change. Perhaps now that it is clear that they are getting money and have a chance of making a difference the corporate shills have woken up?
Slashdot Mirror
No, the state that describes the system is the electrons together with the photons, you are doing a measurement on the photons, you are doing a measurement in a part of the state.
Look, this is a very fundamental property of quantum mechanics, it just doesn't make any sense for it to fail. The whole thing would go down in flames.
How do you communicate a bit using this distinction? Let's say I want to send '0', how do I do it?
It is a problem. Let's say the probability of getting them entangled is 0.5 (I'm too lazy to look it up now). Then you do the thing one time, you don't entangled the electrons, awesome, and they read '0'. Then you want to send them another '0', you do the thing, now they do get entangled, and they read '1'. Shit, now what? You cannot control what they are going to read! They do know the results of your measurements (first not entangled, then entangled), but this is just classical correlation, not communication.
It is easy to prove that it is not possible to send information by doing measurements on a part of an entangled state, so no, I'm afraid this is completely useless for FTL communication.
Your scheme would work, if one could deterministically entangle the electrons at a distance, but one can not.
The issue is that this technique (called entanglement swapping, look it up), gets the photons, and tries to entangle them; sometimes you succeed, sometimes you fail. For them, this is not a problem, because they can just discard the cases where they failed and do the experiment with the other electrons, but for you it is, as you need to be able to entangle them or not at will.
In general, it is a simple theorem to prove that you cannot send information by doing measurements on a part of an entangled quantum system, so any similar scheme is doomed to fail.
This is true, superdeterminism is a way out of the conclusion of the experiment.
That is why I said they only did the experiment without using "the most questionable extra assumptions". The assumption that the world is not superdeterministic is very reasonable, IMHO. Without it, one cannot even do science. For example, in a superdeterministic world, the wavefunction of a photon will depend on which measurements you are making on it, so there isn't such a thing as "the" wavefunction of the photon, and it is not possible to learn anything about it. It is this kind of conspiratorial correlation that superdeterminism uses to produce the violation of a Bell inequality. For me, it's insanity on the level of Last Thursdayism: logically consistent, unfalsifiable, and nobody will ever take seriously.
But I'm troubled by your last sentence:
that there would be no need for either instantaneous communication or a hidden variable in order to have 'entanglement'.
We don't need this stuff to have entanglement. Entanglement is just a property of Nature, it's there whether you want it or not. What we need instantaneous communication for is to create the appearance of entanglement in a hypothetical world that would be classical (or, technically speaking, has hidden variables). Since our world is quantum, this is of no concern.
Guys, this is huge. People have been doing versions of this experiment for decades, every time making it more refined, in order to be able to reach the striking conclusion with the fewest possible assumptions: that the world is not deterministic. The quantum randomness is not our ignorance, is a fundamental property of nature.
What they did was to violate a Bell inequality, without using the most questionable extra assumptions (called loopholes) people normally use to extract a conclusion from this experiment: that the separated laboratories are not somehow communicating to conspire to produce the desired outcome, or that the photons they detect are indeed a good representative of all the photons that were emitted in the experiment (normally people can detect only a small fraction of the photons).
I am a quantum physicist, and I know the science behind this experiment very well. If anybody wants to ask me anything, I'd be glad to oblige.
obvious troll is obvious.
No. And no. This is just plain impossible.
What they did was to violate a Bell inequality, without cutting any corners (is this corner-cutting that is named as "loopholes" in the experiment). This proves that the world is not deterministic (if you believe in relativity).
Humm yes? This is because people vote for the greens, the commies, and the crazy nationalists. Do you think people shouldn't be allowed to vote for them?
Now seriously, Italy has a lot of problems, but at least bipartidarism is not one of them. They are one of the most disfunctional European democracies, but even they managed to avoid being so absurdly disfunctional as to shut down their own government.
I think this is just being realist. The US is a two-party state, and voting for a third party is wasting your vote. This is a simple consequence of the archaic electoral system you have, it has nothing to do with the "culture seeing two possibilities" or people being stupid.
A useful comparison can be drawn with European democracies, as the crushing majority are multi-party. Unlike the Europeans, I don't think this is because they are smarter than the yankees. I think the reason is that most European countries have a more or less recent political system (Germany, France, Italy, Spain, Poland, etc. have political systems that date from after world war 2), and when it came the time for deciding what it should be they chose something that is not so absolutely stone-age as a first-past-the-post system with an electoral college.
Humm, both did get royally fucked by christian powers. Still wasn't enough to get them to use AD, though ;p
Hum, I believe the problem is that most of the world is not christian, but they would still like to be able to refer to the year according to the Gregorian calendar, since it is almost universally used.
AD is kinda heavy for non-christians; it means in full "Anno Domini Nostri Iesu Christi", or in english "In the Year of Our Lord Jesus Christ", so if you are very pedantic writing 2015 AD is actually a lie for them.
What do you suggest the Chinese and Japanese to do, for example?
I think there is a difference when people try to get better.
Some insist in their fairy tales in face of all evidence, and some actually change their minds when they see evidence that goes against their beliefs.
8/10 trolling, I'd say. The strawman is a bit of a long shot, but it connects well with the Godwin line, and so it is likely to give you passionate replies.
It is creating a legal framework for deciding these things, because the law currently lacks one.
And why is that a good thing? More lawyers, regulations, court cases? I don't think creating rules is something good in itself, on the contrary.
But anyway, don't you think parliament is the proper place to debate such a deep question? I feel that a judge really shouldn't have the power to decide whether chimps deserve to be treated as humans.
Matlab is the worst piece of shit I ever had the displeasure of working with. I only use this crap because the SDP interpreters I like (YALMIP and CVX) don't support anything else.
Once I had a bug in a code I had been writing for more than a month, and after lots of work I tracked it down to a vector declaration of the kind
v = [a, b +c];
You know what Matlab thought this meant?
v = [a, b, c];
Yep. It interpreted a whitespace between 'b' and '+' as creating a new vector element. And it's not even consistent, if I type [a, b + c] if gives again a two-element vector instead of a three-element one.
The fact that the programmer who introduced this "feature" was not instantly smitten by a thunder is proof that Zeus does not exist.
Btw, if you know any sensible SDP interpreter that does not require Matlab, I'd really like to know.
Thanks for the book reference, seems cool, I'll check it out.
Well, there will be major social changes, that's for sure. But bringing people back from the dead it's a minor thing, as realistically we'll never be able to bring back anyone that did not take precautions to be ressucistable, and these will remain a small minority for the foreseeable future.
I think the largest impact will be when technology to radically extend lifespan and life quality (cure ageing) becomes widespread.
Honestly, I think the whole religious industry ought to be frogmarched to jail and never let out. Is it quackery, fraud, and cruel, preying on grieving relatives, selling false hopes, engaging in grotesque experiments with human remains.
There, fixed that for you. The major point of most religions is to comfort people from their fear of death. All the religions I can think of prey of grieving relatives, sell them false hopes of an afterlife, and perform some grotesque ritual with human remains.
The difference is that unlike religions, cryonics is actually based in reality. Everything else is guaranteed to not work; but according to our current knowledge, cryonics is the best shot we have to actually cure death.
Of course it is highly unlikely to work, but it is a completely different league than burying (or burning) a body and hoping that some god will grant that soul eternal life in some paradise.
Sounds strange, I use owncloud to collaborate on my papers between 4 authors and nobody reported this problem. I guess it depends on the server you're using (mine is the University itself), rather than the software owncloud.
Typical case of religion obstructing the progress of science. Luckily in this case it is a minority religion that the local administration does not take seriously anymore. Imagine if that was a place sacred to christians, like the Mount of Olives, or to buddhists, like Sri Pada (also known as Sri Kanda). The poor telescope would never have a chance.
This is true; a measurement always returns a definite result, never a "smearing" or a "blur". But I'd like to point out that the issue is a bit deeper, as there is no physical distinction between "determinate" and "indeterminate" states. For example, a photon with vertical polarization is in a "determinate" state if you measure it in the vertical/horizontal basis. But if you measure it in the diagonal/antidiagonal basis it is in a "indeterminate" state, a equal superposition of diagonal and antidiagonal.
I wish people would stop speculating about the fucking cat and just read what Schrödinger wrote. Come on, it's four paragraphs.
What Schrödinger is doing is pointing out how ridiculous it is to accept the "quantum blurring" because "it only affects microscopical particles anyway and they're just weird". The problem is that one cannot consistently keep the blurring confined to the atomic domain. As Schrödinger points out very clearly, if we accept that the atomic nucleus is "blurred", then this blurring can be easily amplified to the macroscopic domain and make the cat be simultaneously dead and alive. Since we don't observe cats to be blurred, we cannot accept atomic nucleus to be blurred.
That's what Schrödinger states one line after introducing the fucking cat. Since I know nobody is gonna click the link and RFTA I'm going to quote:
It is typical of these cases that an indeterminacy originally restricted to the atomic domain becomes transformed into macroscopic indeterminacy, which can then be resolved by direct observation. That prevents us from so naively accepting as valid a "blurred model" for representing reality.
I never knew that Schrödinger joined at some point in Einstein quixotic quest for a classical unified field theory. Cool story, bro.
But I'm annoyed about the portrait of Schrödinger as Sancho Panza to Einstein's Don Quixote. Schrödinger was a major genius! He invented quantum mechanics, for fuck's sake! I'm particularly riled up by the statement
Embarrassed by the incident, Schrödinger would give up his quest for unity altogether and turn to other topics. Similarly, he would never collaborate again with a prominent physicist.
This seems to imply that Schrödinger never accomplished anything after he stopped collaborating with Einstein. Well, he helped discover DNA.
As far as I know the Cuban government wanted to exchange this guy for Cuban prisioners kept by the US, the Cuban Five. The US refused.
These Cubans went to the US to disrupt the operations of anti-Castro terrorist organizations based on Miami, and for that they were sentenced to 15 years in jail, the same sentence that befell the American guy.
So I do understand that Cuba wouldn't want to give up on their only bargaining chip to free its agents. It's a sad state of affairs, really. So much could be gained if there were a little bit of goodwill on both sides.
I'm finding quite curious the contrast between the comments that appeared the first time this story was discussed in /. and now. Whereas in the first time the comments were balanced and generally positive, now most comments are violently against it. I wonder what caused this change. Perhaps now that it is clear that they are getting money and have a chance of making a difference the corporate shills have woken up?