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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.'"
I suppose that is why Planck's Constant is named after him.
"It is not how things are in the world that is mystical, but that it exists." -Ludwig Wittgenstein
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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
"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."
Wouldn't that be Schroedinger's strangest theory?
The theory of relativity doesn't work right in Arkansas.
"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.
Don't expect to understand. We evolved to run around on a plain and throw spears at antelopes, so we shouldn't be suprised when we don't understand complex things.
I believe the existance of a working quantum theory means that the universe can be considered as a simulation insofar as there might exist a universe without quantum physics and just particle physics.
Now assume someone with insufficient knowledge about such a universe who tries to model a simulation to get predictions, much like having for of war in a strategy game - when a unit disappears into fog of war (since x turns ago), it would be essentially in all places that in could reach in x turns at once.
An interesting question then might be, is then human knowledge and usage of quantum theory a desired property of the simulation, or an artifact that invalidates the simulation results?
I'm still trying to figure out what people mean by 'social skills' here.
One thing I got from the article is that physicists don't really care that the Quantum mechanics doesn't make sense at the macro level, nor that there isn't a clear boundary between big systems and quantum systems.
That's the whole point of the cat-in-a-box: if an electron can be superposed, why not a whole cat? And what does that say about reality, if the quantum theory makes no sense? E.g. our sense of reality says the cat is either alive or dead, not both. Hence, shouldn't an electron be one or the other? Q.T. says no.
That "why" issue is the sort of thing that troubled a philosopher-type like Einstiein --- someone who wonders "why?" compulsively is likely to keep on digging. The physicists seem happy to crunch the numbers, do an experiment and see if it agrees with the numbers.
Which is in keeping with my observations of physicists: they are essentially applied mathematicians. Mathematicians (like Einstein) are a different sort.
http://www.thebricktestament.com/the_law/when_to_
If you were to look at a clock backwards, the hands would be moving counter-clockwise from your perspective. It's all relative. So in theory, both could be happenning at the same time.
Strange that you bring up that entangled atoms allow faster than light communication.
The known problem with this is that no information actually is transferred as far as we know; it is is only acquired at both ends at the same time (that is, you can't decide what you read).
Entangled atoms allow safe FTL cryptography though, because uncovering and reading the state of the atom creates a bit of a key that is shared at both ends.
I'm still trying to figure out what people mean by 'social skills' here.
Bohr and Heisenberg made a popular interpretation of the duality paradox called The Copenhagen Interpretation. Needless to say, Einstein disagreed with this interpretation.
"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.
It's like saying, something happens in reality only the very moment you know it. Turn on CNN, and all what they are reporting on, just happened at that very moment you learnt of it, and if you did not hear it or know it, then it did not happen! Crack!
An electron has a specific velocity, whether any person knows it or not. The probability distribution of the electron's velocity (wavefunction) is not a property of nature as Heisenberg states, but a property of our minds (lack of complete information). When that value is finally measured, we have a single value rather than a wavefunction (complete information). It is our minds that have changed, not reality. Therefore it is crack to say the electron has many velocities (wavefunction) before measurement but as soon as it is measured, it collapses (wavefunction collapse) into a single value.
The strangest part of this is that this blatant confusion has not totally incapacitated the usefulness of quantum mechanics. Imagine what will happen if more physicists could get their ducks in line and properly understand why Quantum mechanics works. Einstein was on track. Others have followed him and been able to do great things, although clearly disagreeing with the "spooky action at a distance" "copenhagen" interpretation. Such as Schrödinger, Edward Thomson Jaynes, the father of "maximum entropy".
ET Jaynes wrote about the possibility of doing a thesis under Oppenheimer:
http://bayes.wustl.edu/etj/etj.html
Oppy is Oppenheimer.
Quantum mechanics works, there is no question about it. The question is why does it work. IMHO, the majority of physicists today are backing up the wrong tree -- the copenhagen interpretation. Further progress is, thus being hindered.
"Fighting terrorists with millitary might is like killing a mosquitor on your Dad's forehead with a rifle."
Anytime quantum mechanics is brought up among a non-science crowd (sorry, desipte the geekyness of slashdot, the moderation and general comments I see indicate it's a non-science crowd) you wind up getting half-truth mystical garbage like this and this. The more hard to understand it is, the more people will come up with their own, wrong interpretations.
AccountKiller
If I remember some of the stuff I've read correctly, it's a bit more complicated than the article's summary made it seem, and no, it doesn't make FTL communication possible.
What the experiments have shown is that if A and B are "entangled," then whatever state A is observed to be in, B will be in that state also, regardless of whether A and B are too far apart at the time the observation is made to have any communication with each other. This can be thought of as Einstein characterized it, as "spooky action at a distance," i.e., the observation of A somehow affects B (which is what makes the action spooky, since there is no known way for any information to be communicated between the two). However, it can also be thought of in other ways - for instance, that A and B were in the same state when they were entangled (though there's no way to determine that for sure, since the states aren't observed at that time), and the observations of A and B are just showing the states they've "always" been in. In the latter way of thinking, the spooky part is that these randomly selected particles always turn out to have the same state when observed. It's like sticking your hand into your sock drawer 100 times at random and always coming up with matched pairs.
Not quite. That would be what's called a hidden variables system: the unit still does have a real location, which is tracked by the program, even if it's inaccessible to an observer within the system. However, that doesn't appear to be the way our universe works; the Bell inequalities show that hidden variables are incompatible with locality.
Real Daleks don't climb stairs - they level the building.
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?
Yes, but wouldn't the act of observing the slip up change it's state?
Cogito, ergo sig.
Such an influence, or disturbance, would have to travel faster than the speed of light. "My physical instincts bristle at that suggestion," Einstein later wrote.
Bohr responded with a six-page essay in Physical Review that contained but one simple equation, Heisenberg's uncertainty relation. In essence, he said, it all depends on what you mean by "reality."
This reminds me of the quote by the great Neil Peart "the more we think we know about, the greater the unknown."
He who knows best knows how little he knows. - Thomas Jefferson
"I've been curious what is the justification for support of: particles are in multiple simultaneous states until measured causing the distributed probabilities to collapse into a definite known state"
The famous double-slit experiment demonstrates the problem very well. Imagine shooting electrons through a wall with two slits. The slits are close enough that each electron, given the vagueness of its exact position, could go through either slit. After going through the slits, the electrons register themselves on a detection screen of some kind.
Well, if you have a sensor at each slit watching to see where the electrons go, they each go through either one slit or the other quite nicely, and they register their impacts on the screen in a nice bell distribution.
However, if you don't check which slit the electrons go through, there is equal possibility of going through both. Therefore, bizarrely enough, they actually *do* go through both slits at once. The detector then records a more complicated ripple pattern of impacts, as each electron's ghostly half interferes with the other half in a wave pattern.
So when we say there are two opposite states existing at once in the quantum world, it is actually true, and the effect is often bizarre. But the state of a particle behaves itself when you decide to "look" at it.
"Alternately, if schroedinger's cat is in an alive/dead superposition in the box, then if the cat experiences a sane and straightforward set of experiences yet the outside-of-box observer claims it to be in an alive/dead combo state, then outside the box observer and inside the box observer's consciousness lines must potentially deviate."
Schödinger introduced the cat just to point out this weirdness. What does the cat see? Is he both alive and dead at once? Does the universe split into two timelines? Adherents of the "Copenhagen Interpretation" would, I think, argue over whether or not the cat qualifies as an observer, and can collapse the quantum randomness on his own.
Another, more intriguing interpretation, is that at last, when you look at the cat and see whether he died or not, your observation propagates a randomness-collapsing wave *backwards in time* that forces the past action of the cat living/dying to resolve itself. There are variations of the double-slit experiment (like measuring the slits after the electron's already through) that reinforce this idea.
Note that I'm not a physicist, and not necessarily good at explaining things.
He who lights his taper at mine, receives light without darkening me.
The known problem with this is that no information actually is transferred as far as we know; it is is only acquired at both ends at the same time (that is, you can't decide what you read).
Entangled atoms allow safe FTL cryptography though, because uncovering and reading the state of the atom creates a bit of a key that is shared at both ends.
Not really FTL, it's more like a read-once OTP. You entangle two atoms, which is like creating two identical OTPs (even though you do not know the values). You then split the atoms (OTPs) at sub-light speed. You can then read out the same OTP at both ends. You still need to encrypt/send at sub-light speed/decrypt. The big point is that the OTP is verifiably *one time*, it can not be read twice. I suppose you can call it "security by quantum obscurity", since the entire point is that the key is kept behind a veil of quantum mechanics.
Live today, because you never know what tomorrow brings
Sorry man, but you're just wrong. If this was actually just an incompleteness of information, then the classic double slit experiment wouldn't work. When the experiment is done emitting just one photon at a time, if the particle always has a specific location and speed in time then the experiment would break and you wouldn't get the interference pattern, you'd just get two bands of light on the target. However, since the position of the photon actually is indeterminist until measurement, it interferes with itself, thus creating the interference pattern, even though only one photon at a time is being emitted.
It has withstood rigorous experimentation. Just because you do not understand Quantum Mechanics (very few people, if that, would claim to understand Quantum Mechanics) doesn't make it false.
A hammer and 20 minutes later it'll be fixed.
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.
"Sic Semper Path of Least Resistance"
Actually this is proof that the article is in a quantum state. It is a dupe while at the same time it is not a dupe.
Instincts are wonderful, until you apply them to a situation in which they aren't appropriate. Then they'll help you be wrong more often than you would otherwise. In such a case you need to develop new instincts. Saying quantum mechanics doesn't make sense in the context of my life of baseballs and refrigerators and therefore must be wrong may be a useful starting point to test a theory, but is not a scientific way of judging it.
Science isn't an accumulated body of knowledge. It is a method for generating that knowledge. The method may be followed to a greater or lesser degree by scientists.
Some people commenting on this thread will find the transactional theory of quantum mechanics (powerpoint) of interest. (Less clear cut paper in HTML here).
In my opinion, this is the most reasonable, extant interpretation. From my perspective, it says that the paradoxes of QM are perceptual, arising from our perception of time as entirely forward moving. If waves move backwards in time (as in the transactional theory), everything makes sense, though it won't appear to make sense to us.
"Speaking the Truth in times of universal deceit is a revolutionary act." -- George Orwell