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Defeating Heisenberg's Uncertainty Principle
eldavojohn writes "As we strive closer and closer to quantum computing, physics may need to be improved. A paper released in Nature Physics suggests that the limit defined by Heisenberg's Uncertainty Principle can be beaten with quantum memory. From the article, 'The cadre of scientists behind the current paper realized that, by using the process of entanglement, it would be possible to essentially use two particles to figure out the complete state of one. They might even be able to measure incompatible variables like position and momentum. The measurements might not be perfectly precise, but the process could allow them to beat the limit of the uncertainty principle.' Will we find out that Heisenberg was shortsighted in limiting the power of quantum physics or will the scientists be surprised to find that such a theoretical scenario — once conducted — performs unexpectedly in Heisenberg's favor?"
1st and second post simoultaneously :-)
America, Home of the Brave.
the uncertainty principle is in doubt.
Taking guns away from the 99% gives the 1% 100% of the power.
...the Heisenberg Compensator.
Now we know how the Heisenberg Compensators work.
uncertainty is about defeating determinism. i don't see this small exception to break uncertainty - you still can't determine the precise state of the universe with this.
Wasn't this the whole basis for the EPR paradox? Using two different measurements of location and momentum with entangled particles to build a complete state?
If not, what am I missing?
It is reality that needs to be improved.
Who knows? Maybe both?
I want to delete my account but Slashdot doesn't allow it.
Why do people have to pitch stories like this as ego conflicts? If they get around the uncertainty principle, they'll be erasing it no more than classical mechanics. It's like Relativity is just a more accurate description, an improvement, a super theory on top of Newtonian physics. It doesn't 'defeat' Newton. We use his work as a valid framework all the time anyways. And when we need to go beyond it, we take up Einstein's work. Similarly, getting around the uncertainty principle won't really 'defeat' Heisenberg's work, it'll just build on it. These writers just sound stupid when they frame stories as simple binary conflicts.
I would love to see the results of this experiment. No matter how it turns out, we're going to learn SOMETHING about how the world works - either giving new evidence to reinforce old uncertain ideas or shattering them with new possibilities.
... but I thought entanglement meant for properties such as spin and polarisation, not position and momentum? Quite obviously 2 particles can't share the same position so measuring 1 will do you no good in finding out the position of the other but do they share momentum?
They demoed the Ferrari 458, and one of the "features" that Jeremy Clarkson highlighted was that the dash mounted display could show you either the speedo or the GPS Sat Nav, but not at the same time - my immediate thought was "Heh, someone at Ferrari has a sense of humour and knows what the Heisenbergs Uncertainty Principle is." :)
Perform an experiment and see if you can get a result that contradicts the uncertainty principle. It's science, not religion. Heretics welcome.
Its about time we started work on moving technology into the 25th century and beyond.
After the "Heisenberg Compensator" I suggest we try to move forward on injectors.Dilythium
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Nature:Physics is pay-for, but this appears to be the same paper on arXiv:
http://arxiv.org/abs/0909.0950
Well, I let that darn Schrödinger guy cat-sit while I'm on vacation and everytime I call him, he refuses to tell me if "mittens" is dead or alive. And when I call Heisenberg, all he says is that my cat is really fat, not if it's moving. Hopefully this new discovery will help all of us pet owners who let their neighborhood physicists cat-sit.
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There should be something like the godwin-law for self-startreking articles! It's way to obvious to just turn on the heisenberg compensator :-P
While we're modifying physics, may I submit feature requests for anti-gravity and faster-than-light travel, please?
Also, do they have a public bug tracker up yet? I think I found a division-by-zero bug involving a cat and butter, but I'm having trouble reproducing it (as I am running out of band-aids.)
Yesterday on the BBC during top-gear there was a review of the new Ferrari 458
Apparently one of the LCD displays in the cockpit functions as EITHER the speedo, or the satnav. So you either know where you are, or how fast you are going.
Looks like the Ferrari engineer in charge of the 458 cockpit was a Heisenberg fan :P
People, what a bunch of bastards
A true religion has no fallacies, and God does not fear scrutiny from the very same brilliant minds he himself created.
IANAP, but I've read quite a bit over the years, and my understanding was that the uncertainty principle wasn't a limitation in our "measurements" per se, but rather how the world itself works. To take the classic example of momentum and position, for example: the problem isn't that we can't measure both the speed and position of an electron (like our tools aren't "fine" enough or something), but rather that an electron doesn't have both speed and position in the sense that we think about it. If we attempt to measure one of those two aspects, by that measurement we define the electron in a particular way and therefore blur the meaning of the other measurement.
My money is on Heisenberg, but then, I'm just a caveman.
Is that the one where you don't know whether or not your will get shot for killing meth dealers that work for your boss or something?
So, perhaps if you took two entangled particles, and measured the momentum of one, and the position of the other, you could extrapolate the total state of one of them. JUST LIKE THE SUMMARY SAYS
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
Commenting on whether or not the uncertainty principal will be broken is like asking if i get enough fiber in my diet. No one knows for sure.
It's more like this:
I want to know the name and date of birth of a particular person, but I'm only allowed to ask one question per person. If that person has a twin, I can ask the person i'm curious about their name, and the twin their age, thus circumventing the one question limit in this case.
It's sort of a cheat, it probably can't be used to get arbitrarily accurate information regarding a particle of interest, and it may only work on a small subset of particles (they need to have entangled partners).
For those interested, the preprint of the Nature article can be found at: http://arxiv.org/abs/0909.0950
:).
However, I don't really see what the fuzz is about. What they are in fact demonstrating is a relationship between conditional von Neumann entropies, which they claim is a measure of "uncertainty" (it is in a specific meaning of the word "uncertainty"). However, there is a difference between von Neumann entropy and the variance of a physical observable as used in the Heisenberg uncertainty principle. On the other hand, if you label a physical property such as entropy "uncertainty" and demonstrate a relationship between those entropies, then you can indeed call that an "uncertainty relation" but that's just a cheap way of attracting attention.
Also, I am not sure if it is possible to obtain the Heisenberg uncertainty relation from their equation. I would expect that, for example by entering pure, disentangled states in their equation, that Heisenberg should be recoverable (because of course, Heisenberg also applies to pure states). I don't immediately see how that can happen since the von Neumann entropy for a pure state is zero. Perhaps I am just missing something and perhaps my QM is a bit rusty
Now that we can build Heisenberg compensators?
...that the limit defined by Heisenberg's Uncertainty Principle can be beaten with Heisenberg Compensators.
Isn't that the whole point of Heisenbergs Uncertaintly Principle?
That it's not possible to *PRECISELY* measure an attribute of something?
We all know it's possible to measure it reasonably accurately... (otherwise we wouldn't have speeding tickets) but Heisenbergs is not about "reasonably accurate" but "absolutely accurate".
Now we know the first steps that were made to make the Heisenberg Compensators out of Star Trek.
Physics is not merely an evolutionary process; occasionally, the models are simply wrong, and must be replaced. For example, consider epicycles. For the purpose of calculation, they were adequate, if expensive. However, a simpler and better theory was found, and they were replaced entirely. Unfortunately, history has shown us that most people will bitterly defend the accepted theory, rather than consider possible alternatives.
As Feynman once said, "If I were forced to sum up in one sentence what the Copenhagen interpretation says to me, it would be 'Shut up and calculate!'." Anyone with common sense would consider the currently accepted interpretation of quantum mechanics to be nonsense. Useful nonsense perhaps, but certainly not a suitable description of the world that just needs some refinement.
...or more likely if you measure the position of one, then it will affect the momentum of the other and so you cannot infer the momentum of the first ....
Just like the Summary says ....
Puteulanus fenestra mortis
Except theory says that once you've measured one, the wave function collapses and the 2 particles are no longer entangled.
Because this seems to indicate that information has traveled at a velocity greater than the speed of light, Einstein (and others) weren't too happy with it.. Hence the EPR paradox.
Einstein believed there was a locally hidden variable. However that was dismissed by Bell's inequality theorem.
Achievement Unlocked: You've just invented the Heisenberg Compensator.
Next step? Transporters.
The Ars Technica article links to the paper on the Nature web site, where it's paywalled. The authors have posted the article here, where you can access it without paying.
The Ars summary is also inaccurate.
First off, this paper does not "topple Heisenberg's uncertainty principle." If you look at the paper, equation (1) is the Heisenberg uncertainty relation, while equation (2) is a similar, but different, uncertainty relation. The paper claims to demonstrate a violation of (2), not (1). Since (1) was proved mathematically 80 years ago based on standard quantum mechanics, disproving it would require either detecting an error in the original proof (which the authors don't claim to have done) or doing the disproof using some foundational theory other than standard quantum mechanics (which the authors didn't do).
And in my opinion the authors' depiction of their own result is an extreme over-selling of what it really says. On p. 1 of the paper, they interpret equation (2) in terms of a game in which Bob tries to predict something as accurately as possible -- more accurately than permitted by (2). To accomplish this, they have Bob store his prediction in a quantum memory device. The quantum memory device is in a superposition of states, sort of like Schrodinger's cat. The memory is partially in a state where it makes prediction P, and partially in a state where it makes a different prediction Q. Only when you read out the memory later do you force the memory to collapse its wavefunction into either state P or state Q. It seems to me that by any reasonable standard, this is not really a prediction at all. If you redefine "prediction" to mean something this weak, then you get all kinds of silly possibilities. For instance, I could entangle my quantum memory's wavefunction with the quantum state of a uranium nucleus, in such a way that I "predict" when the nucleus will decay. Well, I haven't really found a technology for predicting when the nucleus will decay; all I've done is weaken the definition of "predict."
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Calling it now: before the year 2030 we will be able to move a chunk of matter from point A to point B faster than the distance between A and B divided by the speed of light.
And quantum teleportation doesn't count.
Talkin' about some Heisenberg who owns the Market now.
I thought they would just use the Heisenberg Compensator...
... Schrödinger's cat found alive.
Have gnu, will travel.
Would this have any useful implications?
Any chance of this meaning the law of conservation of energy is flawed, for example?
If Pandora's box is destined to be opened, *I* want to be the one to open it.
Position: Where in space something is at a single time (t)
Momentum: Mass * Velocity
Velocity: Position[t2] - Position[t1]
"Position" by definition requires "t" to be only one value, while "Velocity" (and so, momentum) by definition requires "t" to be more than one value.
Meanwhile, "Velocity", by definition, requires that we know two Positions.
So: how can we ever talk about velocity and a single position? Aren't the uses here mutually exclusive? Are we actually talking about certainty of velocity vs the certainty of both positions? Are we talking about the position at t1.5?
-- 'The' Lord and Master Bitman On High, Master Of All
This is absolutely incorrect. Experiments have already demonstrated that changes to one entangle particle affect the other; a violation is not possible by these means.
Source please for both claims? If you have god's phone number, that would simply matters greatly. Heck, I can ask him about the problem with the Uncertainty Principle too!
Where is this Heisenberg University and who is this uncertain principle? And isn't it a bit cruel to beat him with quantum memory until he makes up his mind?
Isn't the term "true religion" an oxymoron?
Time makes more converts than reason
I think that about sums up the uncertainty principle in a nutshell, for those who don't know the specifics of QM.
"If a nation expects to be ignorant and free in a state of civilization, it expects what never was and never will be."
was my first thought...
Yes, no matter how this turns out, Heisenberg was as short-sighted as Newton in defining his laws.
Oh wait, the scientific process involves making observations and improving on/revoking the results of others by based on repeated and varied control experiments? Nah.....
There are now millions of drooling star trek fans muttering Heisenberg Compensator to themselves
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