Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: CZARCAR on 02/12/2011 20:38:50
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just found "entangled swapping" which may suggest the BIGBANG resulted in all being entagled?
Assuming a neutrino [mass] can outrun a photon[massless] then the accelerating entropial edge of the universe would disappear cause the mass is outrunning the massless light which needs to be reflected to see the mass? atom1 & atom2 are entangled but a2 has exceeded C whereas a1 gets hit with a photon so their entangled interaction suggests a1 photonic shell jump + a2 no photon, & the average= 1/2 exactly & thats exactly where the shell has to be?
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Yep, we can have a lot of fun with this, and still be discussing 'physics' :) Maybe that's why my shadow grow longer? My mass outrunning the light? And entanglements is a cool idea, but 'swapping how'?
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Assume that mass actually can be faster than light. And at Cerns level of energy too, which isn't that much really, cosmically seen. Kind of spooky action isn't it? Frames of reference will still hold, as light is a constant. And how about 'time travels' here? If we assume that it is a 'instant jump at its creation' then a neutrino the first 18 meters take no 'time' at all? But it can't arrive any faster than that, no matter how you measure it? What about at nine meters :) is the instantaneous effect then 'negative'? And how about measuring relative different 'frames of reference'?
I'm sure I can get a headache here.
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There is also the scenario in which you (A) send something FTL to 'B' Which then 'instantly' responds FTL to you. B's message, according to some views, now arriving earlier than your first FTL transmission ::))) Meaning that 'B' indeed are a spooky son of a gun, or a woman :) Depending on your definition of different 'frames of reference' (time slices) and their 'time' relative each other ( Brian Greene loves this :)
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http://www.physorg.com/news/2011-12-quantum-world-diamonds.html No FTL needed.Theres other, earlier entanglement experiments i aint read including the details of this 1....so to not get too confused. also aint sure if only the electrons are entangled or if it can involve atoms but entanglement seems real so with these 2 crystals [c1 c2] with entangled electrons, c1 gets a photon & c2 also reacts then c1+1photon interacts with c2+ 0photon & the shell has to be @ exactly 1/2 for both c1 & c2. This is just a reason as to why the shell exits where it is as displayed by Bohr's gas experiment?
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A very confusing article Czarcar. In what way was they 'entangled'? Either they were from 'one undifferentiated original' or the assumption is that they were 'identical' although not of the exact same origin? And under that assumption nothing stops me from defining everything as 'entangled', assuming that I find them 'identical' in some property/aspect, although each one of them being unrelated before my inducing some state that I find/believe to be replicated.
"Quantum entanglement in the motion of macroscopic solid bodies has implications both for quantum technologies and foundational studies of the boundary between the quantum and classical worlds. Entanglement is usually fragile in room-temperature solids, owing to strong interactions both internally and with the noisy environment. We generated motional entanglement between vibrational states of two spatially separated, millimeter-sized diamonds at room temperature.
By measuring strong nonclassical correlations between Raman-scattered photons, we showed that the quantum state of the diamonds has positive concurrence with 98% probability. Our results show that entanglement can persist in the classical context of moving macroscopic solids in ambient conditions."
"The vibrations of the second diamond reacted to what happened to the vibrations of the first. Performing the experiment with ultrafast laser pulses enabled the researchers to catch entanglement, which is usually very short-lived in large objects at room temperature.
When zapping one artificial diamond with ultrashort laser pulses they managed to change the vibrations of a second diamond sitting a half a foot away without touching it. They chose diamonds because they are crystals, so it was easier to measure molecular vibrations, and because they are transparent in visible wavelengths. Light from the lasers altered a kind of mass vibration in the diamond crystal called phonons, and the measurements showed they were entangled: "
Or do they mean that they 'created' a entanglement by their laser for two unrelated diamonds, where none was before? Reminds me of the way you find clocks (pendulum) to synchronise in a clock shop actually? So should I now call that a entanglement?
I thought that one belonged to chaos theory?
I'm not sure how they define a entanglement here?
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To say that, when using a beam splitter or similar to split one 'photon' into two, they are entangled seems reasonable, but this is a new one to me.
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It's a interesting way to view it though. Because thinking like that there is no need for any 'identical origin' to a entanglement. The only definition then existing for a entanglement is if you statistically, or measuring directly, can prove it to change its 'state' to gain a same property.
Which then should mean that I can entangle my telly with my coffee-cup, if I can find a way to replicate what I do on my telly, to what my coffee-cup experience in my measurement. So, from observing entanglements to creating them, everywhere :)
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There are lots of situations where waves move faster than the speed of light see http://en.wikipedia.org/wiki/Faster-than-light for detailed descriptions. The cut off waveguide (a good classical analogue for quantum mechanical tunnelling) is probably the simplest to replicate in the lab. The one important feature of all these processes is that information cannot be transmitted faster than light and it is information transfer that determines the flow of time
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i read where entanglement requires electrons to have proper mutual polarity & spin to entangle & entangled swapping is real/proven as pursued with quantum computing?
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Can you link it Csarcar? I've seen so many different propositions to what should be considered entanglements and their definitions so I'm quite confused nowadays :) Once I thought I knew the definition but now?
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This is my (old) definition as I understood it once.
"One of the principal features of quantum mechanics is the notion of uncertainty: not all the classical physical observable properties of a system can be simultaneously determined with exact precision, even in principle. Instead, there may be several sets of observable properties–position and momentum, for example–that cannot both be known at the same time. Another peculiar property of quantum mechanics is entanglement:
if two photons, for example, become entangled –that is, they are allowed to interact initially so that they will subsequently be defined by a single wave function–then once they are separated, they will still share a wave function.
So measuring one will determine the state of the other: for example, with a spin-zero entagled state, if one particle is measured to be in a spin-up state, the other is instantly forced to be in a spin-down state."
Einstein and the EPR Paradox. (http://www.aps.org/publications/apsnews/200511/history.cfm)
Since that I've been introduced to a lot of different concepts, and the one presented by the experiment you linked too? Well, it's definitely new to me. Not that I mind that much, but my headache keeps growing trying to see how all those definitions mean/think, and how they got from the original definition to ... ->
ahem. :)
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You're essentially right, yor_on. A definition of entangled particles is that they cannot be described independently--they are all part of the same wave function. The other properties such as the effects of measurements come from this property.
I know its not terribly helpful to hear "learn the math," but entanglement is one case where things are so weird and so non-intuitive that to really get an intuition of what's going on, you need to go to the math build up from there.
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You're correct JP, and I've looked, that's also why I wonder what a wave function 'really' and I mean 'really really' is :)
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http://en.wikipedia.org/wiki/Singlet_state this aint what i read but applies?
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http://en.wikipedia.org/wiki/Quantum_entanglement
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Thanks Czarcar :)
Assume two particles colliding, as they do it they will become 'entangled' through the definition QM use about then getting a common 'wave function' describing them. As all particles do bump into each other in my body for example, does that make me entangled :)
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So lets make it simple :) I like simple..
Entanglements are 'bumps'. The question is how the 'bumps' can correlate over a 'distance'. Einstein didn't find the idea of those 'bumps' being correlated through a common wave function (like a ordinary particle can be 'described', through its wave function.) to then fall out, as in constantly expressing opposite spins, as trustworthy.
Either QM was not describing this in the full sense, which meant that something was missing from the description, or Einstein was wrong in expecting interactions to be locally. That as the particles could be very far away in your measurement of one.
And it all goes back to HUP (Heisenbergs Uncertainty Principle) which is a statement of indeterminacy to me, stating that you can't know all parameters/properties simultaneously.
Then we come to more murky stuff. If you have a particle 'A' and a particle 'B' that is entangled in some way, then it is not right, according to some, to state that you by measuring A know B. You need to measure B too. Now this may sound intuitively correct but what it means is that your subsequent measurement on B is the one defining the entanglement here, all as I understands it. Not your first measurement on A.
And if that doesn't give you a headache? Then you have a even thicker head than mine :)
So what is the wave function in this case? and when does it fall out?
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When it comes to the diamonds it is simpler if we define through inducing a same property. The problem here is how the property 'transmits' as they only induce it on 'A', so to speak? Maybe it is the same phenomena as in that 'clock shop' they used?
Because there was no same wave function for those two diamonds before they induced 'A'. "When zapping one artificial diamond with ultrashort laser pulses they managed to change the vibrations of a second diamond sitting a half a foot away without touching it."
Which introduce yet another twist.
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That is if you don't define them as being 'the exact same'? But that one can never be fully proven as I think of it. And that's the difference between 'splitting light' into two 'photons', from making two bowls out of clay. You might want to say that your bowls are the exact same, but the more complexity that goes into creating those bowls, as their atoms, molecules etc, combined with you being able to prove that you had the exact same procedure, size etc.
Although inducing the same (QM) property in two different, whatever, might be defined as a entanglement, if we assume that it is enough with one property being the same for them? But the inducing of the diamonds made me confused.
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You could of course turn this reasoning around, and say that as B became entangled with A, when A was zapped 'prove' that they must be 'the exact same', maybe?
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thanx. 1 comment was that the diamonds were probably tested for similarities be4 the experiment, another that entanglement has been effected with a 18km separation in another experiment.
4fun= whats the name for the psychic? phenomena biological twins seem to have more of than nontwins?
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Yep the 18 km worked but that was splitting light transmitted in fibre optics if I remember right. and that one is interesting but not about two macroscopic objects (diamonds) where you by inducing a vibration in A then finds B sitting some way apart (mysteriously) 'entangled'.
Although, I still don't know how/what their definitions for the experimental setup was, and how they saw the entanglement as transferred by? And that one needs to be explained as I otherwise will have to presume that we not only find entanglements in 'bumps', but now also 'teleported' by two objects having a 'exact same? Material? Size? Smell?
I don't know? There is no doubt that entanglements exist, the question is what the he* it means :)
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And it all goes back to HUP (Heisenbergs Uncertainty Principle) which is a statement of indeterminacy to me, stating that you can't know all parameters/properties simultaneously.
How does entanglement go back to the uncertainty principle?
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This is how I see it JP. And there it had to do with how Einstein viewed HUP. He didn't like the view of how it was implicit in HUP that you couldn't get all parameters, simultaneously, from a particle, so he devised thought experiments in where he meant that you could get all parameters.
But he lost out to Bohrs reasoning, and so devised the EPR paradox to create another angle in where you could assume a underlying 'realism', guaranteeing no mysterious 'action at a distance' as the entanglement might be seen as, loosely speaking, even though we assume that information can't be transferred.
In his thought experiments (later ones, the one that's most famous was drafted by his companions without him, and he wasn't wholly happy with its statements as I understands it) he tried to envision situations in where you could say that all parameters was 'known' for a entangled particle. This is from memory though, no links to it, but I'm sure it is as correct as my memory, hopefully :)
And that's what I see as a more accurate description to how EPR came to be historically. Still, the debates they had are well known, looked on the internet and found Bohr–Einstein debates. (http://en.wikipedia.org/wiki/Bohr%E2%80%93Einstein_debates.)
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This might give an insight in how Einstein thought. Einstein's Reply to Criticisms. (http://www.marxists.org/reference/subject/philosophy/works/ge/einstein.htm)
"The attempt to conceive the quantum-theoretical description as the complete description of the individual systems leads to unnatural theoretical interpretations, which become immediately unnecessary if one accepts the interpretation that the description refers to ensembles of systems and not to individual systems." - Albert Einstein:
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Btw: Isn't this the idea that 'weak measurements' resurrects? That you can 'know' all parameters? I'm not sure what I think of 'weak measurements' myself, I have some problems with accepting it.
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Ah, thanks. That makes it clearer.
I was (mis)reading your statement to mean that entanglement is a consequence of the uncertainty principle. I don't think its fair to say that. Entanglement is a consequence of QM, and as such it has to play by the rules of the uncertainty principle, as does every other quantum system.
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No, that wasn't my intention. Although I find both HUP and entanglements as thought provoking, and so similar in 'intent' to me, as they both question 'reality'. And I guess Einstein saw it that way too. I think that what Einstein didn't agree on was the assumption that as causality disappear we replace it with statistics and probabilities, in some way defining that as 'real' as the causality chains we observe macroscopically.
Albert Einstein. “Physics and Reality.” Journal of the Franklin Institute 221 (1936), 349-82.
"Consider a mechanical system consisting of two partial systems A and B which interact with each other only during a limited time. Let the Ψ function before their interaction be given. Then the Schrödinger equation will furnish the Ψ function after the interaction has taken place. Let us now determine the physical state of the partial system A through a measurement which is as complete as possible. Then quantum mechanics allows us to determine the Ψ function of the partial system B from the measurements made, and from the Ψ function of the total system.
This determination, however, gives a result which depends upon which of the state variables of A have been measured (for instance, coordinates or momenta). Since there can be only one physical state of B after the interaction, which state cannot reasonably be considered to depend upon the kinds of measurements I carry out on the system A separated from B, it is thus shown that the Ψ function is not unambiguously correlated with the physical state. This correlation of several Ψ functions to the same physical state of system B shows again that the Ψ function cannot be interpreted as a (complete) description of a physical state (of an individual system)."
And
"Now it appears to me that one may speak of the real state of the partial system S2. To begin with, before performing the measurement on S1, we know even less of this real state than we know of a system described by the Ψ-function. But on one assumption we should, in my opinion, unconditionally hold fast: The real situation (state) of system S2 must be independent of what is done with system S1, which is spatially separated from the former. According to the type of measurement I perform on S1, I get, however, a very different Ψ2 for the second partial system. (Ψ2, Ψ'2, . . .) But now the real state of S2 must be independent of what happens to S1. Thus, different Ψ-functions can be found (depending on the choice of the measurement on S1) for the same real state of S2.
(One can only avoid this conclusion either by assuming that the measurement on S1 changes (telepathically) the real state of S2, or by generally denying independent real states to things which are spatially separated from one another. Both alternatives appear to me entirely unacceptable.)
If now the physicists A and B accept this reasoning as sound, then B will have to give up his position that the Ψ-function is a complete description of a real situation. For in this case it would be impossible that two different types of Ψ-functions could be correlated with the same situation (of S2)."
(Corrected the text slightly, missed a 'sub')
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What is really weird, is that some complaining over the theory of relativity seems to accept QM logic on face value. They don't seem to get that Einstein was a realist after all. He wanted stuff to make sense, and causality chains to exist and be accounted for. He didn't like spooky actions at a distance as entanglements, he wanted an accounting for all we see. Not theoretical, but understandable in classical terms.
And that's what's his 'ensembles' try to do, as I see it. In it he accepts what we experimentally see but he does not try to define QM as causality chains from a classic perspective. Whether he thought of it as existing a 'hidden causality' or not is not important there. I call it the 'rules of the game', including 'c' and Planck constants as one and the same (constants) even though one is classical, the other QM. And that goes for the conservation laws too, because that's what we build on.
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. . . he wanted an accounting for all we see. . . in classical terms.
Yep. He didn't accept many features of QM that make it distinct from classical mechanics. If you think of two entangled particles classically, then they're two separate particles that either can send information faster than light or have some extra internal variables that they each carry which specify how they're correlated. If you think of them as a quantum state, however, they are no longer separate particles, but rather are two particles described by one quantum state, so they can be correlated through that state, without having to send information or carry around extra variables.
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Yeah, and that's one of the hardest nuts there are to crack :) to me. Because it invalidates 'distance', although, depending on how you define information, not 'c' as the constant defining what is 'useful/understandable information' to us.
But if 'c' was considered a pure clock beat, instead of something signifying the combination of a 'clock' creating a distance? That as any distance needs a 'clock' to exist for us, on any conceptual level I can think of.
distances are weird, both in relativity and QM.
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It doesn't invalidate distance. It invalidates our classical idea that two entangled particles can be described as two separate physical objects. The two measurements are still separated by a physical distance, which behaves in the usual way.
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well yeah, that is how I see it. :)
It is two definitions, one macroscopic and one quantum mechanical, but if you want something leading from one to the other? I don't find my assumption weirder than to assume they are connected through a waveform ignoring SpaceTime distances and 'c'.
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You can see it how you like, but that doesn't change the fact that they're still separated by a distance. QM may be weird, but it follows rules. Throwing out distance because they're entangled breaks the rules of QM and relativity!
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I'm not throwing it out JP, I should have wrote 'question' instead of invalidate. Bad choice of words there. And it also depends on from where you look at it. If I look at it from Relativity you find Lorentz contractions, if you look at it from QM you find tunnelings and entanglements. But we have distances, and they work.
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And that's weird :)
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Ah, but if you look at it from QM, you find tunneling, entanglement AND Lorentz contractions. Time and space still exist in QM just as they do in SR. Two particles undergoing "spooky action at a distance" doesn't change anything about space-time any more than two non-entangled particles do.
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Are you telling me that Lorentz contraction is a quantum mechanical effect? That was a new one to me? Not that I mind that much, physics huh :)
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Or maybe not so new thinking again? Although I haven't thought of it that way.
I've thought of it as a macroscopic effect, coupled to mass, although some might argue there, and relativistic 'speeds/velocities'.
I better get some sleep here :)
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Had to look again and.
I do have thought of it that way. Strange that I forgot, probably it's because it was you saying that JP :) not me. And as you said it, it became new to me. But I've only considered it as a very weak possibility, in that it should be so incredibly hard to define experimentally. But it makes very good sense existing on a Quantum mechanical scale too, well, as I see it. Although depending on your choice of measuring there, assumably.
Not so hard measuring in 'motion', maybe? Or maybe I'm grossly bicycling in the blue younder there:)
But as I also expect it to be a constant opposite 'mirror' to time dilations, a sort of 'symmetry', I've wondered if it may exist even 'at rest', as in a particle of rest-mass able to be defined as being at rest. But there indeterminacy comes in, and?
So I do hope that was what you meant..
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What I meant was that QM is a model telling us how particles behave in space and time. Another model has to define space and time, so you can have norelativistic QM for slow moving particles or relativistic QM for fast-moving particles. In the latter, Lorentz transformations are obeyed. If you have entangled particles, it doesn't change anything about the distance because distance is defined by another theory, not by QM.
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JP, is there experiments done on relativistically moving particles, proving a Lorentz contraction? That would be a very nice experiment to me, or is it 'time dilations' we can see.
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Anything done in particle accelerators indirectly tests Lorentz contractions. I don't think anyone's specifically tested for only length contraction in QM, but the standard model requires Lorentz transformations in order to work.