Quantum Mechanics
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
Contrary to popular opinion quantum mechanics doesn't actually answer the question of whether or not the universe is deterministic. Bell's Theorem shows that it cannot be both local and deterministic. Most physicists today elect to give up the deterministic part and keep the locality. However, there are interpretations which do just the opposite. The Bohm Interpretation is currently the most popular among these. This theory is an example of a Hidden Variable Theory. While these theories have fallen out of favor with the physics community the very first documented explanation of quantum phenomenon was of this kind. The Matter Wave interpretation, proposed by Louis de Broglie in his 1924 PhD thesis, preceded the currently fashionable Copenhagen Interpretation by several years. Interestingly enough the Copenhagen Interpretation denies physical meaning to the central construct in quantum mechanics, the Wave Function, while the nonlocal theories tend to embrace it.
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My verbage isn't that great, but I think I get my point accross ok... Every action has an equal and opposite reaction. This can be taken as true in any form from an atomic level to a macro level (solar systems and galaxies). As far as I know, you can safely say that each molecule affects the molecule next to it, to some degree, and in the same regard each atom reacts from interaction with other atoms around it. Like a game of marbles, each flick of a marble has an impact on all the other marbles near it; you project the marble with force, and based on so many variables such as gravity, speed, acceleration, mass, velocity, surface area, etc, etc, it hits another marble sending it moving along it's OWN course. Obviously losing energy through other resistances such as friction the second marble may hit a third marble, repeating these effects, but to a lower degree, until all that energy is disipated and the marbles no longer move. You could say that throwing that marble a billion times will NEVER render the exact same results; there will always be some kind of "randomness" associated with the event, and this is completely true. Throw it forever, and you will no doubt never see the same outcome. However, this does not mean that true randomness exists in our universe. Say we were using the big bang as a point of origin for an event. Similar to the marbles, the explosion sends debris, rocks, elements, gasses, energy, etc eminating, rather speeding away from the event horizon heading out into the universe (or as some presume, CREATING the universe itself by expanding at the speed of light). Now at a macro level these bits and pieces hitting each other cause enormous explosions and other major disruptions in space-time, which in turn ricochet off on their own courses, causing more explosions, et al. Imagine, however, what is happening at an atomic level. Atoms changing, breaking apart(?), forming molecules, etc, but importantly, the path of each individual atom is governed entirely by the forces and resistances surrounding it, and of course in large part by other atoms hitting it (or coming close and deterring them electromagnetically(?)). If you knew the position of every single atom in existence at any one point in time :wtf: , you could without error predict the movement of the entire universe, or the exact, and i mean EXACT path of a marble that has been hit by another marble, that was itself hit by a marble being flicked.... You could predict EXACTLY the movement of the leaves on a tree, an
MichaelGallagher wrote:
Every action has an equal and opposite reaction. This can be taken as true in any form from an atomic level to ...
I take it you're not too familiar with probability distribution. Say hi to Heisenberg for me.
I wanna be a eunuchs developer! Pass me a bread knife!
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
The problem is, QM only proves true complexity, not true randomness. In other words, a limit to what human beings, working in four dimensions, can know. To prove true randomness, you'd have to account for *all* possible causes, including those that appear from our frame of reference to move backwards in time (like quantum entangled particle spin, or certain waves that appear to break the light speed barrier). True randomness requires uncaused events to happen. And that's about as easy to prove as the existence of God. Having said that, there is a third possibility pointed to by probability and quantum mechanics that is in between you and your friend; quantum universes. That way the future (and perhaps even the past, since there were many possible paths to get to the current state) is an infinite state machine; but every state gets "hit" someplace in the tangled wobbily bits of the multiverse. Ok, now that I'm talking like Doctor Who, I'd better stop. But it would be wise of both of you to consider the possibility that a lack of randomness does not necessarily imply predeterminism.
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4D? Only 4? I think you'll find you need a few more dimensions than that :(
Jane Williams wrote:
4D? Only 4? I think you'll find you need a few more dimensions than that :(
You may need more than 4d to describe full brane existence in string theory, but 4d is the minimum number to fry a mind by trying to visualize it. :laugh: Outside of string theory, 4D is the appropriate number. Even curvature of space-time is considered to be a property of space time, not really curvature of extra dimensions on top of the 4. So 4d is a minimum description of what we see, and is useful as a way of describing space time as a unified, unchanging (outside of the 4d) object.
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Jane Williams wrote:
4D? Only 4? I think you'll find you need a few more dimensions than that :(
You may need more than 4d to describe full brane existence in string theory, but 4d is the minimum number to fry a mind by trying to visualize it. :laugh: Outside of string theory, 4D is the appropriate number. Even curvature of space-time is considered to be a property of space time, not really curvature of extra dimensions on top of the 4. So 4d is a minimum description of what we see, and is useful as a way of describing space time as a unified, unchanging (outside of the 4d) object.
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Worryingly, back in my college days, I know I used to visualise in 4D without too much trouble. I'd hate to try to now, though.
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
As I recall, an early biology class instructor mentioned that everything tends toward randomness. And if the physics of Quantum Mechanics goes towards randomness, how does one explain something as complicated as a human being. A human is not the perfect result of randomness (or evolution), but fairly well along the way. Even it if humans required well over a billion years to evolve, even given the best of conditions, if random behavior of the molecules were the norm, then how could we be here now. Could it be some very early design technique well before our time (and well beyond our comprehension) is in place that provided just the correct conditions for the current outcome? It is like playing a game pool with the design of how the board is to be laid out for every shot (until the last ball is sunk) before the balls are even racked. It is interesting to philosophize how everything up to now, including Man’s history played out. Did it just evolve through random happenstance or was there a design in place that is executing according to plan?
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But aren't they one in the same? If you played a game of snooker, and slowed it down to one atomic movement per frame, you could see the interaction between all of the molecules, on every level from what you see as the pool ball all the way down to the most finite part, an atom. Each of those interactions, frictions, movements and collisions would all cause a determined reaction on the next atom, and the angle at which that atom flies off would be determined by the angle of approach by the previous atom, just like the white ball hitting another ball, hitting another, and then hitting the black, etc. From a macro view, watching and playing the table, you have a certain amount of control, to put the ball in the hole using other collisions before hand. If you had control at an atomic level, you could direct each ball with 100% certainty in any direction, and DETERMINE exactly where it should go, and therefore know exactly where the hits after that would go also, assuming you had no other resistances such as the pool table itself, etc. Apart from all of that, string theory says that, since there may be something smaller than an atom, randomness may exist after all. If the string theory determines the properties of an atom, or of the nucleus, proton, electrons or something else, then if the absolute smallest element of matter should be studied to see how IT affects the overall nature of energy and mass itself. :confused:
But what combination of friction, movement, and interaction determines the player's choice of expletive when he flubbs the shot?
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
Watch the Dr. Who episode: Blink - 2 June 2007 It has an interesting slant on the 'is observed' property. :-D
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Maxxx_ wrote:
My understanding is that yes, that's exactly what it means - in the 'slit' experiment with a single photon going through the slit, its state does not exist until it is measured.
It's state must surely exist all the time. How else can it interact with everything else in a meaningful manner? Regardless of whether anyone is looking or not... This thing about canging models (wave or particle) and behavior depending on who (if any) is looking is just pure nonsence to me.
That is what Schroedinger was demonstrating - state is meaningless and non-existent until actualized by interaction: it is the very observation or other interaction tht creates state! Tough to get the head around, but experimentaly demonstrable!
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Kick him in the shin, they say "Hey! I'm sorry, you were right all along, it's all predetermined, I couldn't prevent it". Then see what he says ...
Randomness must be defined with respect to predictability. If you have a good random-number generator, you won't be able to predict the numbers, and it will be random. BUT, if you get the algorithm used by the random-number generator, you WILL be able to predict them, and THEY WILL NO LONGER BE RANDOM. If you knew the state of every particle in the universe, you could predict everything. In a sense everything is predetermined. But since in reality we don't have that predictability, everything's random for all practical purposes.
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Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
achimera wrote:
Does not the physics of QM provide for "true randomness" in the Universe? I'm debating a friend who seems to think everything is predetermined, period. My argument against, is that his proposal would be a finite machine, one which could be moved either forward or back. Additionally, my argument continues, if true randomness exists, then it can't be predetermined nor undone. Am I incorrect? Any thoughts?
Well, Einstein is on record as agreeing with your friend: "God does not play dice with the Universe." That said, quantum mechanics doesn't establish randomness as the rule - it simply establishes the limits to our ability to observe with certainty what is going on. Read this for some thoughts about what this means: Concept of 'hypercosmic God' wins Templeton Prize . Whatever the answer is, it cannot be established within the physical framework we know.
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Worryingly, back in my college days, I know I used to visualise in 4D without too much trouble. I'd hate to try to now, though.
Yeah, it is an exercise, and your body adapts to what it does. I used to be able to run fast, now, I pay if I even try and run. I spent a six month period waiting to be cleared for a job, and they really had no work for us to do until the clearances came in. I admit it, I slacked during that time. The clearances came in and they threw me on a mentally challenging project, and for the first week, when I went home, my mind was fatigued. I learned my lesson, and now, when I have spare time, I use it for mentally challenging things - like this conversation ;P If you work at for a while, it comes back, you get back in shape. Of course, getting back in shape is much harder than staying in shape.
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No. You can't sit there and watch each of the atoms, electrons, protons, etc. To 'watch' them, you have to interact with them (throw photons at them, for instance). Interacting with them only allows you to get so much information about them - it has to do with how small a wave length you use to interact with the particle is. If you want to find out 'exactly' where it is, you have to use a high frequency wave packet. In QM, high freq means high energy. So you throw this high energy wave packet at the atom, and it localizes the interaction, but adds some indeterminate momentum to the atom. Since (as it turns out) you don't know exactly what the wave packet was doing, you only have a statistical understanding of it's motion - that is, you are uncertain of the 'real' location and momentum of the wave packet - you only have a statical understanding of the momentum of the particle it interacts with. You can not know where something at that scale is, and know it's momentum - there is a trade off, so you can know location to any degree you wan, but it costs you information on the momentum. You can use as large a wavelength as you want to find it's momentum, but the large wave length means you don't know where it is. So no, you can't know where everything is, and how fast it is moving, so you can't know what everything is going to do.
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This place seems to be full of computer scientists... The point of view of many responses assumes an ACTUAL point of view: some tool, person or other physical object to actually witness the event. The fact of the matter is, that none of us, nor any tool we can make, can measure every atom at every given time, so one needs to step out of the box that is science. I am not talking religion (definitely not!), but quantum mechanics is a scientific notion, and science is itself a man-made concept, so the only way we can measure anything as a result of a discussion around it, is by using man-made restrictions. To truly understand, we must put aside what we know about time and space and matter because absolutely everything we base our present and future understandings on is from past definitions of measurements that scientists needed to make up in order to provide an answer to their question. If we could truly step back and witness things from a distance, we wouldn't be interacting with the environment, we would, in communicable terms, actually no longer exist... I love the philosophical debate around predeterminism, because it shows us as humans, really have no clue :)
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I am 1 graduate course away from a phd in Quantum Mechanics.... Dictionary.com says: ran⋅dom /ˈrændəm/ Show Spelled Pronunciation [ran-duhm] Show IPA –adjective 1. proceeding, made, or occurring without definite aim, reason, or pattern: the random selection of numbers. 2. Statistics. of or characterizing a process of selection in which each item of a set has an equal probability of being chosen. o.k. in order: :doh: 1; quantum particles behave according to their "nature" they usually are "aimed" (at the lowest local energy state), the reason is entropy(usually) and they have a pattern(albeit poorly defined: See Heisenberg uncertenty principle.. which basically says that if a particle is then it exists somewhere in the universe, but you will never know where it is... ) 2; the positions of any given quantum particle can never be know, however it is to all reasonable approximations residing in bounding frustrum in space-time(its physical extent..from a certain perspective). However the exact probability that a quantum particle is ever in any position is 0 (i.e. it doesn't exist). [Check this out^] so to answer your debate: (if you believe in string theory and that there exists a grand unified field theory) everything in the universe is pre-determined by something that is so complicated that we percieve it as random, although were we capable of peering into an alternate dimension we could (knowing absolutely EVERYTHING) possibly account for all particles(assuming that that universe exists of only one sub atomic particle.. (n=9)^27 after that (n=81)^27 the calculation becomes .... unstable or simply to big to compute... but even if you could compute it it wouldn't matter because that universe would have already cooled and you would need to recompute the answer... (if you only go to quantum theory) then yes there is randomness in this universe (below the quantuum classical barrior aproxamatly less then 200 microns ) (if you believe that newton was the last scientist ever) then no there is no randomness. your finite machine depend on scale if it's "pointer" is >200 microns your friend is absolutely correct(sorta) if your below the threshold but still greater then one particle(in a universe)
Really? I thought the basic axioms of quantum measurement pretty much stated that measurement is a random process.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
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This place seems to be full of computer scientists... The point of view of many responses assumes an ACTUAL point of view: some tool, person or other physical object to actually witness the event. The fact of the matter is, that none of us, nor any tool we can make, can measure every atom at every given time, so one needs to step out of the box that is science. I am not talking religion (definitely not!), but quantum mechanics is a scientific notion, and science is itself a man-made concept, so the only way we can measure anything as a result of a discussion around it, is by using man-made restrictions. To truly understand, we must put aside what we know about time and space and matter because absolutely everything we base our present and future understandings on is from past definitions of measurements that scientists needed to make up in order to provide an answer to their question. If we could truly step back and witness things from a distance, we wouldn't be interacting with the environment, we would, in communicable terms, actually no longer exist... I love the philosophical debate around predeterminism, because it shows us as humans, really have no clue :)
And, in not existing, we would no longer be able to observe, thus losing the ability to 'step back and witness things'. Bringing God into it, God does not lie, and His creation expresses QM down to its very essence, as far as we can see, and as far as we are even able to conjecture. You can go ahead and throw out all thinking and measuring that has ever been done, up to this point, but, even within your argument, it does not buy you anything. We measure thing the way we do, because we have a limited set of sensors - we sense change in pressures (sound, touch) a limited band of the EM spectrum and some chemical receptors. We translate those to sight, touch, hearing, taste/smell and some temperature. Unless you think that you have more insight than all of previous humanity, put together, you are, at best, going to just walk your way through human discovery, making the same mistakes that have been made historically. After 50 to 70 years of discovery, you will die, having moved your way up to classical physics, and maybe have dim view of QM, if you are truly brilliant. But mu guess is that you would have not gotten that far, since our senses are prone to making us make the same mistakes that were made in the historical analysis of the world. "If I have seen further it is only by standing on the shoulders of Giants." Newton realized this 430+ years ago. Are you smarter than him?
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And, in not existing, we would no longer be able to observe, thus losing the ability to 'step back and witness things'. Bringing God into it, God does not lie, and His creation expresses QM down to its very essence, as far as we can see, and as far as we are even able to conjecture. You can go ahead and throw out all thinking and measuring that has ever been done, up to this point, but, even within your argument, it does not buy you anything. We measure thing the way we do, because we have a limited set of sensors - we sense change in pressures (sound, touch) a limited band of the EM spectrum and some chemical receptors. We translate those to sight, touch, hearing, taste/smell and some temperature. Unless you think that you have more insight than all of previous humanity, put together, you are, at best, going to just walk your way through human discovery, making the same mistakes that have been made historically. After 50 to 70 years of discovery, you will die, having moved your way up to classical physics, and maybe have dim view of QM, if you are truly brilliant. But mu guess is that you would have not gotten that far, since our senses are prone to making us make the same mistakes that were made in the historical analysis of the world. "If I have seen further it is only by standing on the shoulders of Giants." Newton realized this 430+ years ago. Are you smarter than him?
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In the scientific definition of not existing, yes, that is fundamentally true... It's not about having insight, it's about thinking about things in a different way. Don't get me wrong, I have a very mathematical mind, and I like that science can explain much of the world today. My point really was that, we can't prove or disprove predeterminism with quantifiable measurements based on modern day science - just like scientists of old used to do: we need to look toward philosophy. Imagining yourself in the shoes of someone viewing the changing world still results in human restrictions (which is anything finite - clearly the universe doesn't obey any rules of finity!)Step beyond existence, and you are in the realm of philosophy, where argument can lead to scientific discovery.
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achimera wrote:
the uncertain portion would lead to "randomness"
I don't think that that is correct. Being uncertain about the properties something does not correlate to its being, or behaving, randomly. It is entirely possible that its behaviour is pre-determined, although I personally don't think so, but it appears to be random because of our inability to fully understand the forces acting on it.
Henry Minute Do not read medical books! You could die of a misprint. - Mark Twain Girl: (staring) "Why do you need an icy cucumber?" “I want to report a fraud. The government is lying to us all.”
It's not just uncertain, it's "information not actually in existence". Observation changes the observed, it's one of the most perplexing points of QM. It's not just that the act of observation disturbs the particles in question because we're big dumb monkeys playing with tiny things. Even large enough groups of atoms become self observant, (Not self aware, just self observant). Try not to consider the whole observation thing for too long though. PETA gets upset about contraptions involving cats and radio-active materials.
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At what point does unpredictable determinsim become randomness?
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In the scientific definition of not existing, yes, that is fundamentally true... It's not about having insight, it's about thinking about things in a different way. Don't get me wrong, I have a very mathematical mind, and I like that science can explain much of the world today. My point really was that, we can't prove or disprove predeterminism with quantifiable measurements based on modern day science - just like scientists of old used to do: we need to look toward philosophy. Imagining yourself in the shoes of someone viewing the changing world still results in human restrictions (which is anything finite - clearly the universe doesn't obey any rules of finity!)Step beyond existence, and you are in the realm of philosophy, where argument can lead to scientific discovery.
I agree that you can not prove, or disprove, predetermination with 'modern day science'. We have available to us certain types of knowledge, and none of those seem to be enough for us to understand why the wave function collapses. Once we know enough to really say that we understand why it collapses the way it does, and correctly predict that the way it will collapse in the future, we have, in essence, proved predetermination. But every indication we have now is that there is no extra underlying information there for us to find. If we prove that, we have 'disproved' determinism. As far as 'philosophy' vs 'science', I think you are looking with a prejudiced eye: If I understand your description, philosophy is thinking things out, not being constrained by current dogma (dogma is different from 'science'). QM, relativity, even classical physics result from thinking things out, unconstrained by current dogma. Yet they are 'science', even if they are also philosophy. So, I think that you are short changing 'science' by making it a limited activity, and implying that it does not include 'philosophy'. Also, I don't think that you can actually prove or disprove, something with philosophy. You can think hard about it, but, short of experimental evidence, you have only come up with a thesis, a theory, that than requires proof or disproof in the real world. Otherwise you are just arguing about how many angels can dance on the head of a pin. Albert Einstein, Neils Bohr, Werner Heisenberg, Isaac Newton, Thag Simmons*, all those folks who came up with every theory, going back to 'the day'(thousands of years ago) that explains the world, have to submit their ideas to the razor of predicting results and getting consistent answers. That is one reason a lot of people don't yet believe string theory - it doesn't yet predict anything that is different from what our current models predict (at least the most successful, the less successful do not even correctly predict things we know are reality). "clearly the universe doesn't obey any rules of finity" What does this mean? I am asking to find out, I am not belittling, but trying to understand. *Thag is well know for coming up with the theory, which he than proved (at the cost of his life) that getting pounded by a Stegosauria tail can hurt you (see thagomizer[^])
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Really? I thought the basic axioms of quantum measurement pretty much stated that measurement is a random process.
I can imagine the sinking feeling one would have after ordering my book, only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon
Only if your looking down on it (from a Newtonian path length), if your looking up at it (from the scale of string theory) that is not correct(if you believe that there exists a Grand Unified Theory ) but your not looking at the information theoretic perspective... if you know that there is something there to measure, a measurement has already been made, and as such nothing which happens afterwords is random... until that is you "forget" the information and then it may.. MAY act in a "random" manor.. but this is more of semantics.. Eurandom numbers are essentially theoretical the best we can hope for is a good pseudorandom number generator^. Yes there are those that offer isotopically derived RNG's^ However they only work on a non-geologic time scale.. not on the cosmological time scale(again the issue or scale). The quality of the random number will always tend to "decay" sorry the pun until it approximates a steady state.. So there is a pattern, albeit poorly defined. The issue is that the entropy involved in "knowing" a random number cools the universe, and as a result the number is no longer Eurandom because the universe had to cool a certain amount to get it.. but yes you are correct in that to take the information from the universe to get the measurement, you have changed the object being measured, but that value is not random it is a finite slice(at time t) from an infinity dimensional space ( t one of the dimensions) . however you cannot control which dimensions you are sampling from... were you argument correct (as stated) we couldn't target a buckminister fullerene(which obviously we can) in an Atomic Force Microscope^ because they can be considered quantum particle (from a certain perspective)see quantum mechanics heading at wikipedia^. we can also target electrons, however we can't say which electron we are targeting due to degeneracy, however we can say that we are targeting the UP electon "here" and do it without getting the DOWN electron over there (unless we are trying to see quantum teleportation in Nature physics^(yes a reputable