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Quantum Trickery - Einstein's Strangest Theory
breckinshire writes "The New York Times is running an interesting story on Einstein's strangest theory. The theory was brought to light this past fall when 'scientists announced that they had put a half dozen beryllium atoms into a "cat state." [...] These atoms were each spinning clockwise and counterclockwise at the same time.' It is an interesting writeup for even the uninitiated and also concentrates on Einsteins role as a 'founder and critic of quantum theory.'"
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Einstein said there would be days like this.
This fall scientists announced that they had put a half-dozen beryllium atoms into a "cat state."
No, they were not sprawled along a sunny windowsill. To a physicist, a "cat state" is the condition of being in two diametrically opposed conditions at once, such as black and white, up and down, or dead and alive.
These atoms were each spinning clockwise and counterclockwise at the same time. Moreover, like miniature Rockettes, they were all doing whatever it was they were doing together, in perfect synchrony. Should one of them realize, like the cartoon character who runs off a cliff and doesn't fall until he looks down, that it is in a metaphysically untenable situation and decide to spin only one way, the rest would instantly fall in line, whether they were across a test tube or across the galaxy.
The idea that measuring the properties of one particle could instantaneously change the properties of another one (or a whole bunch) far away is strange to say the least -- almost as strange as the notion of particles spinning in two directions at once. The team that pulled off the beryllium feat, led by Dietrich Leibfried at the National Institute of Standards and Technology, in Boulder, Colo., hailed it as another step toward computers that would use quan- tum magic to perform calculations.
But it also served as another demonstration of how weird the world really is according to the rules known as quantum mechanics.
The joke is on Albert Einstein, who, back in 1935, dreamed up this trick of synchronized atoms -- "spooky action at a distance," as he called it -- as an example of the absurdity of quantum mechanics.
"No reasonable definition of reality could be expected to permit this," he, Boris Podolsky and Nathan Rosen wrote in a paper in 1935.
Today, that paper, written when Einstein was a relatively ancient 56 years old, is the most cited of Einstein's papers. But far from demolishing quantum theory, that paper wound up as the cornerstone for the new field of quantum information.
Nary a week goes by that does not bring news of another feat of quantum trickery once only dreamed of in thought experiments: particles (or at least all their properties) being teleported across the room in a microscopic version of "Star Trek" beaming; electrical "cat" currents that circle a loop in opposite directions at the same time; more and more particles farther and farther apart bound together in Einstein's spooky embrace now known as "entanglement." At the University of California, Santa Barbara, researchers are planning an experiment in which a small mirror will be in two places at once.
Niels Bohr, the Danish philosopher king of quantum theory, dismissed any attempts to lift the quantum veil as meaningless, saying that science is about the results of experiments, not ultimate reality.
But now that quantum weirdness is not confined to thought experiments, physicists have begun arguing again about what this weirdness means, whether the theory needs changing, and whether in fact there is any problem.
This fall, two Nobel laureates, Anthony Leggett of the University of Illinois and Norman Ramsay of Harvard University, argued in front of several hundred scientists at a conference in Berkeley about whether, in effect, physicists are justified trying to change quantum theory, the most successful theory in the history of science. Leggett said yes; Ramsay said no.
It has been, as Max Tegmark, a cosmologist at the Massachusetts Institute of Technology, noted, "a 75-year war." It is typical in reporting on this subject to bounce from one expert to another, each one shaking his or her head about how the other one just doesn't get it.
"It's a kind of funny situation," N. David Mermin of Cornell University, who has called Einstein's spooky action "the closest thing we have to magic," said, referring to the recent results. "These are extremely difficult experiments that
The theory of relativity doesn't work right in Arkansas.
This is just further proof that we are living in the Matrix. With each and every absurd observation, man is getting closer to the truth that we are the cat in the box.
Burn Hollywood Burn
"To a physicist, a "cat state" is the condition of being two diametrically opposed conditions at once, like black and white, up and down, or dead and alive."
Or something happy to have its tummy rubbed only to bite you seconds later.
It says "a founder", not "the founder". Einstein and Planck can both be considered joint founders of quantum theory, along with Bohr, Heisenberg, Schrödinger, and others.
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As Richard Feynman pointed out, "why" is a question of philosophy, not science. The question why has no end. Why do electrons repel each other? That no one knows, they just do. I might go so far as to say it can't be known. Most people stop asking why when they get an answer they're familiar with. Science deals with questions of how. How do electrons repel each other? Well, current theory says that photons travel from one electron to another and push them apart.
AccountKiller
"Most physicists agreed with Bohr, and they went off to use quantum mechanics to build atomic bombs and reinvent the world."
Why do they always have to use the atomic bomb as an example of the applications of quantum mechanics? It really gives it a bad name.
In fact, the spin stay the same from any perspective. I.e. the particle is "spinning" exactly the same way whatever the angle you look at it : you watch it from the top, from the left, from behind, you always see it spinning clockwise, a bit like if it turns to face you. It's call the "spin" because its property _looks_ like it was spinning, but the particle doesn't really move or turn. Actually, a particle doesn't have a form, it isn't a sphere. Form is like temperature : temperature being the average speed of individual atoms inside a set of atoms, temperature only exist at a macro level, that is for a large set of atom. For a single atom, temperature doesn't exist. It's the same for form, thus for "spinning". Those are called _emergent_ properties (i.e. properties of a whole that cannot be predicted from properties of the parts), and they are meaningless for particles. In the case of this weird instant remote "action", the two linked particles are in fact a _single_ entity. There is no sending of information since the two are only one "thing" : the two don't have the same property, the particle pair have a property. Indeed, for the same reason particles doesn't have a form, their _identity_ is not what you may think. If two particles have exactly the same property, they, err, _it_, is the same particle. And, since it is a property of the pair, you cannot choose it, thus sending information, the particle pair just has it. Of course you can select particle pairs with the property you want before sending them apart, but then they have to travel at the speed of light, no instant communication is possible. And whatever you do by acting on one won't do anything to the other, they just share the same property. Thus, what is troubling is not this but the fact that before you "look" at a particle property, the particle has all the values this property can take at once (e.g. clockwise AND counterclockwise). When you "look" at it, when you try to measure the property, one of this value is then selected. The paradox is while the previous experiment seems to tell us this value is chosen from the beginning (particles seems to share an initial property, revealed once you look at them), the quantum mechanics proves the actual value you observe is randomly selected at the time you observe it and not before. What is tranported by the particles from the time they are emitted is not the value of the property but the very property itself. Another reason why a particle properties define this particle identity : particles doesn't have a "soul", an inner hidden self thing, they only are what they appear to be.
Kirinyaga
The real kicker is that evolutionary theory makes sense on an intuitive level. Random variation + natural selection = genetic change. Genetic change + time = a lot of change. Divergent change = speciation. I'm no scientist--I'm not even that bright. But the ideas are simple and elegant if you make even a token effort to understand. Not so with quantum mechanics. It means what again? If any thse creationists or ID advocates were actually moved by their supposed skepticism about methodologial naturalism, they would be up in arms about quantum mechanics. Instead you hear what from them? Silence. The only branch of science that their profound, deeply conscientious, implacable intellectual integrity can concern itself with is the only one that has implications for a simplistic reading of Genesis. Every time I read "I'm no creationist, but I can't stand by when our children are sold half-baked theories as fact!" I want to crack up laughing. Quantum mechanics is such an easier target because maybe 50 people worldwide really understand it (okay, I'm exaggerating, but by how much?) and high school teachers probably don't make a large percentage. If the issue were just the nature of methodological naturalism, or the limits of human knowledge, or the nature of science, then evolution would never be the easiest target. But as it is, it's the only target.
Perhaps I'm coming late to this realization. Despite my noted cynicism, the very act of debate requires a little respect for the opposing view. But if the opposition is just flat-out lying, not only about their facts, but about their very motivating premises, then what is there to talk about? I guess it had to come to this eventually--if the other side really thinks you are working for the devil, you can't help but call them kooks sooner or later. What else is there?
No, this post o' mine didn't address quantum mechanics. It's just that the sheer inscrutability of the subject (to me) got me to wondering--where are all the gadflies who normally come out of the woodwork with dire warnings about passing off rank theory as fact? Where are the lessons in the scientific theory, the exhortations to "prove" it before we poison the minds of the next generation?
Quite easy. A. Einstein took the Quantum Theory and tried to get very, very strange predictions from it. Basicly he did what Science is about: To test the theory, he used it to predict the outcome of certain experiments.
Most of the predictions appeared completely absurd to him, and he wrote papers about those (like the Bose-Einstein-Condensate or the synchronous state as mentioned in the article). Because of the counterintuitive results he was getting from applying Quantum Theory he doubted its validity.
But most of the described experiments weren't feasible at the time they were thought out. Some of them are right now, and the Bose-Einstein-Condensate is a reality, and this article in the NYT describes another one of the strange predictions being proved.
So with doubting the predictions of Quantum Theory and describing experiments to falsify them A. Einstein in fact lead the way to the advancement of the same theory he had his problems with. That's a fine example of how Science is supposed to work: Always try to find contradictions to the theories and describe experiments which might falsify the theory. Advancement of Science doesn't care if you believe the theories to be correct. Every new hypothesis has its bugs and rough edges which can only be corrected if someone actually finds experiments where the bugs show up.
This article, in it's attempt to maximize the "weirdness factor", ignored what I find to be the most palatable explanation of quantum uncertainty. That is that the universe is five-dimensional. What makes everything seem so wierd is that we are not neutral observers. Our conciousness is created by phenomena that only exist when confined to a three-dimensional snapshot of that universe. We percieve the fourth dimension as time, because it allows our three dimensional snapshot to change as we move in the fourth dimension. We perceive the fifth dimension as probability because it allows multiple possible paths into the future. When an experiment, like determining the spin of one electron out of a pair of emitted electrons shows a particular outcome, the spin of the other particle is not magically changed. Instead we are simply determining which of two possible paths into the future our three-dimensional snapshot of reality happens to have taken. When we compare our results to a distant test of the spin of the other electron, we are not experiencing super-luminal communications, we are simply limited from seeing any other spin for that electron because of our limited three-dimensional conciousmess which can encompass only one state for that particle, which has to be compatible with the state discovered for its fellow electron.
The real surprise here is how very limited our intelligence is, and how little of the true universe we are able to percieve. It is a terrible conceit to believe that we are a neutral observer capable of impartially observering the universe. We literally create our reality by observering it because our reality is a tiny three-dimensional slice of all possible realities. The universe isn't weird, we are just hopelessly myopic.
This interpretation has the benefit of proving Einstein right. God does not play dice with the universe. Since it is commonly accepted that God would transcend the Universe, his conciousness would be at least five-dimensional. He would be simoultaneously aware of all possible paths into the future. When we pick one, we experience a true free-will choice, but the transcendent observer knows which path we will pick - without affeting the nature of the choice iteself. As a side benefit, free will and omniscience are reconciled, and one of the major arguments against the existence of God crumbles into dust.
We aren't programs in the Matrix, we are ants in an ant farm - trapped in a tiny little slice of reality.
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Planck, Heisenberg, Pauli, Dirac, Schrodinger and Einstein are each the single founder of quantum mechanics in different superimposed universes. It is impossible for us to find out in which of these universes we live without killing all the cats,