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Quantum Theory Experiment Said to Prove "Spooky" Interactions (economist.com)
universe520 writes: Albert Einstein was troubled by how two particles can communicate with each other even if they are on opposite sides of the galaxy. Today researchers in the Netherlands have closed the final two loopholes in how quantum entanglement works. The Times reports: "The new experiment, conducted by a group led by Ronald Hanson, a physicist at the Dutch university’s Kavli Institute of Nanoscience, and joined by scientists from Spain and England, is the strongest evidence yet to support the most fundamental claims of the theory of quantum mechanics about the existence of an odd world formed by a fabric of subatomic particles, where matter does not take form until it is observed and time runs backward as well as forward."
"and time runs backward as well as forward."
It had to be published today, right Doc?
and this is the basis of the flux capacitor and all of time travel. About time it got discovered.
Don't we have an intractable Chicken-and-Egg problem here?
quiquid id est, timeo puellas et oscula dantes.
Does this mean faster than light communication is actually possible? Maybe the best way to connect with extraterrestrial intelligence is to figure out how faster than light communication works, then make a call. What do you have to do to pair the particles to begin with?
I've abandoned my search for truth; now I'm just looking for some useful delusions.
Spooky action at a distance is only spooky if one assumes distance is real and not an emergent property of a projected/holographic universe. In the same way in a computer simulation/game the distance between objects in no way represents the "distance" between them in the computers memory, perhaps our universe works at a similar level of abstraction.
The two particles are actually ONE particle.
Yours In Peace,
K. Trout, Novosibirsk
P.S.: Re-elect Bill Clinton ( see the 22nd amendment ) !
Spooky
Shhh, don't observe it, or you will crash the simulation. And then we are all gone... I'm telling you ... gone! Your friends - gone; your wife - gone; you - gone! Don't crash the simulation white it is paging, we must not become aware of it.
This just in: Schrödinger's cat found dead!
I've abandoned my search for truth; now I'm just looking for some useful delusions.
It's because they're stupid, that's why. That's why everybody does everything.
-Homer Simpson
I thought all this means is that you can entangle two particles when they are close. Basically this means all you know is one is + and one is -. Then if you separate them and measure one you know what the other one is. That doesn't seem so spooky.
I love Jesus, except for his foreign policy.
But what if our knowledge about the speed of light is wrong?
"Does this mean faster than light communication is actually possible?"
Nope. See no communication theorem. Basically you cannot communicate *any* information whatsoever.
C. Sagan : A demon haunted world:
http://www.amazon.com/gp/product/0345409469/
visit randi.org
Information IS exchanged. Absent a hidden variable that is carried along with both entangled particles, they have to communicate their state when observed. We cannot use that process to communicate arbitrary information of our choosing faster than light.
This just in: Schrödinger's cat found dead!
Onlooker confirms cat actually alive!
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
And that's it. I haven't encountered anything that says "Change P1 and P2 changes too" except in speculation and headlines.
Yup. Indeed. Quantum entanglement CANNOT be used for faster-than-life communication.
If my description above is right, then it's "split a pea in two, and if you measure the first half, you'll know that the other half will be a hemisphere with opposite orientation" which isn't too useful.
(with the subtle difference that the real quantum pea isn't actually split in advance. You end-up with a have only the moment you look at it, until that moment both half of the quantum pea exists with 0.5 distribution at both P1 and P2 places)
But basically yes "you'll know that the other half will be a hemisphere with opposite orientation" is a decent simplified explanation of why you can't use it directly for faster-than-light communication.
(But can use it for secure password communication in quantum cryptography).
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
Quantum Mechanics is a Great Tease.
At first it looks like you can do wonderful things, like send messages faster than light or travel back in time. BUT when you look at the details or actually try it, there's always a catch that limits the usefulness.
Me thinks Quantum Mechanics was designed by Oracle lawyers: it looks like you got a great big powerful database...until you go to use it and find out the contract does something ridiculous like count "transaction" as each table cell read, NOT per query, filling your license quota the first week*.
Reminds me of a joke:
Q: "What's the difference between Larry Ellison and God?"
A: "God doesn't think he's Larry Ellison."
Maybe he does.
* Hypothetical example only based on patterns of more complex actual examples. Don't sue my tail off.
Table-ized A.I.
This does not permit actual communication. Communication would require that information be transmitted from one end to the other.
Knowing that the state that you observe is also appearing inverted on another particle somewhere else doesn't help you because the state of the particle is random until you observe it. Therefore, while both sides understand that they are viewing the inverse of the other particle,
1. Since, the value observed is random you can't choose what it will be ahead of time. That prevents you from having a protocol to send information.
2. Also, as a consequence, there is no way of knowing if the particle was previously observed by the other side, or for the first time by your side
3. Therefore, you not only don't know what the content of the message is, you don't even know that the person on the other side has even tried to send a message.
4. All you can be sure of is that, if and when the other side looks at their particle, it will have the expected value.
That does have uses, it just does not have uses for communication.
Someone else mentioned "perfect" encryption as one use, since you don't have to worry about sending a one-time key insecurely to your correspondent, you just observe your particle and the other side instantly knows what the sending key was without the possibility of it being intercepted in transit.
However, the information about what particle you chose and the message itself still have to arrive via light speed or slower means.
Did you read the article? It gives a pretty good description of the experiment.
They create two electrons, A and B, completely independently, in two different, widely separated labs. They use those electrons to produce a photon each (Ap and Bp), and send those photons to a third lab. The properties of the photons will depend on the properties of the electrons, but the electrons were created independently so the properties of the photons should not be correlated with each other. In fact, if at this stage you test the electrons and photons, you find that A and B and Ap and Bp are not correlated.
That third lab entangles the photons. Then the two original labs test their electrons. Now they discover that the properties of A and B ARE correlated.
You just need someone to see you are there, and poof, you are there. No travel needed at all.
I only look human.
My mother is a halfling and my dad is an ogre, so that makes me an Ogreling
Because the science might be right but the engineering is still extremely far away.
We might be able to entangle two particles in an lab experiment and test them at distance, doing so as a matter of routine with enough particles to form a reliable communication channel across millions of km's with inch-wide precision with something that you can put into a craft? That's still just science fiction. And any mission you launch will still take years to bring that technology to even Mars, let alone anywhere else.
Honestly, it's like saying we've invented a battery, why don't we just light up the entire planet right now? It takes at least decades and more likely hundreds of years of engineering to fill that gap.
And then you'll find that it's not all that useful compared to, say, sending radio communications.
Though you can entangle photons/particles in theory, there is STILL not way to send information using that faster than the speed of light. It's as simple as that. And that's still an 8-minute delay to the Sun at the very least, and stupendous delays if you try to go out towards the outskirts of the solar system.
Fortunately, the people in charge of such things are physicists and engineers and not random commentors on Slashdot.
But what if the universe follows deterministic bohmian mechanics:
Wikipedia article about Bohm's interpretation of quantum mechanics
Video of bohmian pilot waves.
Every quantum mechanical phenomenon can be explained via bohmian mechanics.
Wave functions don't collapse. They just evolve with time. A state of superposition is equivalent to oscillating between states in a reversible way. Some interactions lead to state changes that are functionally irreversible because changing back to an earlier state becomes exceedingly impossible. For instance emitting a real photon.
As for observers this is just an interaction like any other. The observing particle becomes entangled with and interacts irreversibly with the observed. There is nothing special about conscious observers. Any irreversible interaction is an observation.
Since you could have a pair of random and shifting strings that nonetheless stayed in sync with eachother, well, that seems like with a bit of effort it could be pretty damn great for certain cryptographic uses.
I remember sigs. Oh, a simpler time!
The same can be said about sending people to Mars
but if time can be observed moving both forward and backward, what is the per seconds part of the speed of light value? time has been shown to not be static in this observation, so 1 second could be observed in 100 seconds or .001 seconds... so what is the observed time dimension for the speed of light?
The problem with your question is that you are assuming that time is the same in frames of reference that are moving relative to each other. The short answer is they are not. Take this example from special relativity...
You are in a car driving to run-over an enemy watched by your friend on a nearby grassy knoll. You turn on your headlights and light from your headlights goes forward "at the speed of light" to illuminate your enemy and see his eyes illuminated as you race forward at 100km/h. Your friend on the grassy knoll is not moving at all and sees the light apparently travel at the "speed of light" from your car even though he is stationary. At first, you might think that your friend must see the light going "at the speed of light + 100km/h". However, he measured it and confirms it travelling at the only speed of light (not +100km/h). What gives?
Is the distance wrong, or the time wrong? In special relativity, you can treat things as if time dilated, or space contracted, but general relativity (e.g., when you take in consideration acceleration instead of constant velocities) actually suggests that both happen.
The wacky thing about this is that from the point of view of a photon (which is always travelling at the speed of light), there effectively isn't any distance at all to travel (it effectively exists at all points on its world line simultaneously), even though it is only travelling at the speed of light relative to other observers.
If I'm reading the paper correctly, that's because the results of each experimental run are discarded unless the measurements of Ap and Bp show that A and B are correctly lined up with one another. (Or the experiment isn't performed until the measurements show that A and B are correctly lined up with one another, it isn't entirely clear.)
The Economist article, unsurprisingly, kind of skimmed over that part. :-)
To extend the pea analogy, Alice and Bob both have a half-pea, oriented at random. They both tell Carol which way their half-pea is facing, and if they aren't lined up, Carol tells them to try again. When you're done, the alignment of the two half-peas is definitely correlated, but that doesn't mean that the two half-peas were talking to one another..
It's a much more complicated theory, with no obvious advantages, so Occam's razor suggests that we shouldn't get too excited about it.
Also, you can't posit that the pilot wave propagates at the speed of light, because it doesn't propagate through space at all. As per the article: "In de Broglie–Bohm theory, the velocities of the particles are given by the wavefunction, which exists in a 3N-dimensional configuration space, where N corresponds to the number of particles in the system."
In short, it is because the nature of spin itself is non-classical. Whenever you look at the electrons, they are always either pointing either up or down - never left or right, because there isn't any such thing.
The way in which the is-it-up-or-is-it-down property transforms as you look at the electron from different angles makes it impossible for the spin to be predetermined for more than one angle at a time. If measuring it at one angle would definitely produce a spin-up result, the result of measuring it at any different angle has to be uncertain.
Maybe time runs backwards for them, maybe all particles were in sync in the beginning (end from our perspective), and collision just throws them out of sync? Just woke up..
These kinds of experiments don't really say much about how large scale matter behaves in real world applications. It might have applications in quantum computing but these things are statistical or probability effects that easily collapse. This is important because you still can't send a 'coherent' message faster than light. The signal to noise ratio ends up making the result to noisy to get a signal.
But what happens to Alice and Bob?
Guns don't kill people; Physics kills people! - John Lithgow as Dick Solomon on Third Rock From The Sun
If not, then here is your experiment flaw.
It may be that the correlation exists due to the time the electrons are fired. I.e. when two electrons are fired at the same time, then there spins might be corellated.
By same time, I mean the same light cone, as defined by GR.
If particles are fired in different time cones and then we find out they are not correlated, then it means that correlation is somehow linked to the frame of reference.
Anothet possible explanation is that entangling two photons creates some gravity waves that travel through the connected wires backwards to the electrons, affecting their spin.
Could it be that entangled particles could be communicating to each other forward in time, that way we perceive the action as FTL and it does not break any rules?
"A potential weakness of the experiment, he suggested, is that an electronic system the researchers used to add randomness to their measurement may in fact be predetermined in some subtle way that is not easily detectable, meaning that the outcome might still be predetermined as Einstein believed." "To attempt to overcome this weakness and close what they believe is a final loophole, the National Science Foundation has financed a group of physicists led by Dr. Kaiser and Alan H. Guth, also at M.I.T., to attempt an experiment that will have a better chance of ensuring the complete independence of the measurement detectors by gathering light from distant objects on different sides of the galaxy next year, and then going a step further by capturing the light from objects known as quasars near the edge of the universe in 2017 and 2018" If the universe if predetermined, then this wont help one jot and is no less predetermined by the electronic system used in this experiment. Smells like those NSF trying to jump on the bandwagon to me.
if one spends more and more resources , looking for , i shall use this as an example " something extinct " one can look forever ! how many of you have read the FEYNMAN lectures ? for you to make up your mind about me , you need to know i have no formal education , but for work in kind , have had private lessons from 3 Prof. , and a lot of employers i respect , the choice is in your hands
the power of men in charge of words over men in charge of machines surpasses all wondering S WEIL
i can see no paradox , did not life start thru evolution ? if yes then obviously the egg in the form of a first cell . i'm still deciding about god , however i read on this site that the Pope stated evolution is real .
the power of men in charge of words over men in charge of machines surpasses all wondering S WEIL
are not both the chicken and egg products of evolution ? so starting at the beginning , the chicken would have to be the result of single cell at the start of evolution !
the power of men in charge of words over men in charge of machines surpasses all wondering S WEIL