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Quantum Teleportation - The Fabricated Mystery"A standard of logic that would be considered a psychiatric disorder in other fields, is the accepted norm in quantum theory" |
By Vlad Tarko, Senior Editor, Sci-Tech News
29th of December 2005, 10:32 GMT
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There are plenty of weird stuff going on in the quantum world, no doubt about it, but quantum teleportation isn't one of these weird phenomena. The quantum teleportation is neither 'quantum' nor 'teleportation'. It is in fact a made-up mystery.
Quantum teleportation is not something like the Star Trek teleportation when something disappears from one place and it appears in another place; what is presumably being "teleported" is not the object itself but only one of its properties. For example, if I have a blue ball in my pocket and you have a red ball in your pocket and I somehow manage to change, without even getting close to you, the color of your ball from red to blue, then it is said that quantum teleportation has taken place, I have teleported the color of my ball onto your ball. More or less, this is what physicists supposedly managed to do, not with red or blue balls, but with quantum particles such as photons or even atoms.
The experimental device is like this: There is a source of particles, called the EPR source, that emits two particles. One particle goes to Bob, the other particle goes to Alice. Bob keeps its particle "in his pocket", while Alice, without looking at her particle lets it interact with some other, third particle. Then, it is supposed that Bob's particle "inside his pocket" changes one of its properties, i.e. a certain property of the third particle has been teleported to Bob's particle. Then, Alice gives a phone call to Bob telling him, "Hey, teleportation has succeeded, now you may look at your particle." Get this: If Bob would
look at his particle before, teleportation wouldn't happen. Weird, right?
But how is this supposed to happen? The point is that the particles emitted by the EPR source are "entangled", i.e. there is a certain physical property such as energy or momentum or spin that is conserved. One knows e.g. the total energy of particle one plus particle two, but does not know what energy particle one has and what energy particle two has. Alice and Bob are then banned from looking at their particles precisely because they should not know what energy each individual particle has - this would brake the "entanglement"!
Then, what Alice really does with the third particle is measuring in a very indirect way the property of its EPR emitted particle, e.g. what energy or spin or whatever its ERP particle has. However, due to the conservation law, she is now able to deduce what e.g. energy Bob's particle has. But instead of giving a phone call to Bob and telling him "I have deduced what energy your particle has" she is saying to him "I have psycho-kinetic powers and I have somehow changed the state of your particle from an indeterminate state to a determinate state". You see, it is below the dignity of a quantum physicist to acknowledge that she is simply measuring something, ever since Niels Bohr, they prefer to pretend they are actively changing the state of things.
Normal people prefer to assume that things are in definite determined states but that they usually evolve in unpredictable ways, i.e. you never know exactly what is going to happen, but nevertheless things are happening regardless of whether you are watching them or not. However, quantum physicists prefer to say that unless someone observes something, that something is objectively in an undetermined state. If I roll a die and no one looks at the die, normal people would assume that nevertheless the die has fallen on one of its sides, we just don't know on which one; quantum physicists would say that, no way, until someone actually looks at the die, it remains in a undetermined state, all the possibilities are superimposed and they objectively coexist; when one looks, one of these possibilities is enforced by the act of "observation" itself.
Similarly, normal people would assume that the particles emitted by the EPR source have definite properties; we simply don't know their exact, individual values, all we know is that the conservation laws create certain constrains on what possible values they could have (they cannot be in any way). However, quantum physicists pretend that the EPR source emits particles in undetermined states, and that the conservation law causes the "entanglement"!
So, the bottom line is that the entire quantum teleportation story is not about the weirdness of the quantum world, it is about the weirdness of the quantum physicists!
This isn't even really news, this weirdness of quantum physicists and its impact on their science has long been noted, by other, more normal, physicists. Apparently with no real impact on the quantum physicists themselves. This weirdness even has a name: it is called the Mind Projection Fallacy. As E.T. Jaynes, one of the most important figures in probability theory and statistical mechanics, said:
"The current literature of quantum theory is saturated with the Mind Projection Fallacy. Many of us were first told, as undergraduates, about Bose and Fermi statistics by an argument like this: 'You and I cannot distinguish between the particles; therefore the particles behave differently than if we could.' Or the mysteries of the uncertainty principle were explained to us thus: 'The momentum of the particle is unknown; therefore it has a high kinetic energy.' A standard of logic that would be considered a psychiatric disorder in other fields, is the accepted norm in quantum theory. But this is really a form of arrogance, as if one were claiming to control Nature by psychokinesis."
With such a philosophy going on it is no wonder that more and more physicists are simply ignoring the debates in quantum mechanics and concern themselves with other matters such as thermodynamics, chaos, plasma physics, biophysics and so on. Although this is good for these field, it is somehow unfortunate for our deep understanding of nature, because the quantum world is indeed weird and interesting, just that it is not weird in such ways. Basically there are only two main weird things in quantum mechanics: one is that the usual laws of probability do not properly apply to the quantum world and thus they have been upgraded, and secondly that world seems to be "folded" in two.
| Photo credits: Julia Petschinka |
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Fair (2.9/5) |
18 vote(s) so far |
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User opinions: |
| Comment #1 by: TxTiger on 29 Dec 2005, 20:13 GMT |  reply to this comment | "this is really a form of arrogance, as if one were claiming to control Nature by psychokinesis."
This seems to be the crux and purpose of the article, but observer effect is a real phenomenon, as demonstrated by the disappearance of the interference patterns in the double slit experiment when one attempts to observe just what is happening at the slit as the photons pass through.
No observation, interference bands are seen. Observation attempted, no interference bands. The quantum realm is indeed much stranger than is proposed in the article, and varies in more than the two ways mentioned from the macrocosm with which we are familiar. |
| Comment #1.1 by: vlad.tarko on 30 Dec 2005, 12:13 GMT | The point isn't that observation does not influence the thing which is being observed. The point is that you can measure any property with any precision you want. Measuring a certain property influences some OTHER properties.
However, this isn't specific to quantum mechanics – it is something that appears in ANY non-deterministic process (quantum as well as macroscopic). The uncertainty relations are not specific to quantum mechanics either. They have been deduced in cybernetics by Norbert Wiener for the general case of any non-deterministic process.
The reason why one cannot measure e.g. position and momentum simultaneously with any precision is that the motion of quantum particles is non-deterministic, i.e. there are many possible trajectories. But, when both position and momentum are specified there remains only one possible trajectory. |
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