In the photonic version, the physicists replaced the boxes of gas particles with two pulses of light. They implemented the demon using a combination of a photodetector, which can measure the number of photons from each pulse, and a feed-forward operation, which like the open door can escort the brighter beam (with more photons) in one direction and the dimmer beam (with fewer photons) in the other. The different beams fall on different photodiodes, which generate an electric current that goes to a capacitor, but from opposite directions. If the pulse energies were equal, they would cancel out. But the imbalance in the pulse energies—and in the resulting photoelectric charge—is what charges the capacitor.Even though the researchers did not aim to realize optimal work extraction, it's possible that some type of Maxwell's demon could one day have practical applications."Often we have more information available than thermodynamics supposes," Dahlsten said, explaining that things are normally not fully random and have a degree of predictability. "We can then use demon set-ups such as this one to extract work, making use of that information. Similarly, we can use extra information to reduce work costs of, for example, cooling systems. Personally I think that sort of technology will have a real impact on meeting the energy challenge facing the world."Due to differences between the photonic implementation and previous implementations of Maxwell's demon, traditional theoretical models do not provide a clear path for connecting work extraction to the information acquired by measurement in a fundamental way. So the researchers derived a new model that accounts for the subtleties of the new set-up, in which they relate work extraction to the information acquired by measurement.The researchers hope that the new model will lead to a better understanding of the link between information and thermodynamics, which is necessary for understanding thermodynamics at the microscale and below. As the scientists explain, recent developments of technologies consisting of just a single or few particles require a better understanding of microscale thermodynamics, similar to how the steam engine drove scientists to better understand macroscopic thermodynamics in the 19th century.A theory of of microscale thermodynamics could have a variety of applications, including making energy-harvesting technology more efficient. It could also allow researchers to investigate the role of quantum coherence in thermodynamics, with applications in quantum information technologies."We are already thinking of ways in which features such as entanglement can be introduced in future experiments based on this one, as our interests gravitate around quantum information," Dahlsten said.
Maxwell's Demon, postulated by James Clerk Maxwell in 1867, is believed to be impossible because it violates the 2nd Law of Thermodynamics.According to 2nd Law, you can't extract energy/work from the "sink" (likewise, you can't extract it from the Vacuum)
But if we had a magical Maxwell's Demon, we could. And if, say, I wanted to push off the Vacuum and its random fluctuations, I could use my pet Demon to keep track of each and every fluctuation, to push off each and every one as it appears, to propel myself without expending any propellant.Yet of course Maxwell's Demon is supposed to be impossible.
Scientists now claim to have implemented a photonic version of Maxwell's Demon -- a Maxwell's Ghost, if you will.https://phys.org/news/2016-02-physicists-photonic-maxwell-demon.htmlQuoteIn the photonic version, the physicists replaced the boxes of gas particles with two pulses of light. They implemented the demon using a combination of a photodetector, which can measure the number of photons from each pulse, and a feed-forward operation, which like the open door can escort the brighter beam (with more photons) in one direction and the dimmer beam (with fewer photons) in the other. The different beams fall on different photodiodes, which generate an electric current that goes to a capacitor, but from opposite directions. If the pulse energies were equal, they would cancel out. But the imbalance in the pulse energies—and in the resulting photoelectric charge—is what charges the capacitor.Even though the researchers did not aim to realize optimal work extraction, it's possible that some type of Maxwell's demon could one day have practical applications."Often we have more information available than thermodynamics supposes," Dahlsten said, explaining that things are normally not fully random and have a degree of predictability. "We can then use demon set-ups such as this one to extract work, making use of that information. Similarly, we can use extra information to reduce work costs of, for example, cooling systems. Personally I think that sort of technology will have a real impact on meeting the energy challenge facing the world."Due to differences between the photonic implementation and previous implementations of Maxwell's demon, traditional theoretical models do not provide a clear path for connecting work extraction to the information acquired by measurement in a fundamental way. So the researchers derived a new model that accounts for the subtleties of the new set-up, in which they relate work extraction to the information acquired by measurement.The researchers hope that the new model will lead to a better understanding of the link between information and thermodynamics, which is necessary for understanding thermodynamics at the microscale and below. As the scientists explain, recent developments of technologies consisting of just a single or few particles require a better understanding of microscale thermodynamics, similar to how the steam engine drove scientists to better understand macroscopic thermodynamics in the 19th century.A theory of of microscale thermodynamics could have a variety of applications, including making energy-harvesting technology more efficient. It could also allow researchers to investigate the role of quantum coherence in thermodynamics, with applications in quantum information technologies."We are already thinking of ways in which features such as entanglement can be introduced in future experiments based on this one, as our interests gravitate around quantum information," Dahlsten said.
Maybe Musk is right - maybe we're about to "summon the Demon" - or perhaps its Ghost.As we learn to harness quantum systems for information processing, will we also learn to harness them to do work, and even to obtain energy?
Will we one day be able to travel by Space Ghost from Coast-to-Coast?
Serra and co-workers considered a two-level quantum system based on the nuclear spin of a carbon atom. Preparing this spin system in an equilibrium state and then driving it out of equilibrium using magnetic fields, the researchers focused on controlling the associated entropy production. They did so by implementing a Maxwell’s demon in the form of a feedback control mechanism. In a nutshell, the mechanism works as follows: it acquires and stores information about the state of the carbon atom using an auxiliary hydrogen nucleus; it then applies magnetic fields to the carbon nucleus that are conditioned on the state of the hydrogen nucleus. The authors demonstrate that, by performing such conditioned manipulations, the entropy production can be controlled and even reduced. They also show that the amount of entropy production is in excellent agreement with models of nonequilibrium thermodynamics that account for both thermal and quantum fluctuations and the feedback control mechanism.The acquisition of thermodynamic quantities in a nonequilibrium setting, such as the entropy produced in the authors’ experiment, is notoriously difficult in its own right (as demonstrated in a previous study). Serra and colleagues’ inclusion of a feedback control unit into such a setting represents an important development in the growing interdisciplinary field of quantum thermodynamics. The techniques employed by the authors in this work could be used to help control and enhance the performance of the thermal machines of the future. And when combined with current progress in machine learning, studies such as this promise to inspire a new era of what one might call quantum cybernetics.
Kind of like how a heat pump works.This has been done in limited form as a thermal sink for LED lights (helped the entrepreneur at N.V. Phillips get out the patent and sell his company, about five years ago.
I remember when I was pretty young, and learned that gas was mostly empty space full of particles bashing around like cannonballs, wondering if you could have a material that acted like a grid of one way trapdoors.With particles bouncing off only one side and going straight through from the other, you could have a sheet of cloth that felt up to 10 tons of pressure on just one side.
Since then I have wondered if there would be ( analogous to a heatpump ) a version of this material that did not violate the 2nd law of thermodynamics but could still be more efficient than brute force ways of pushing air such as a propeller.
"Although the violation is only on the local scale, the implications are far-reaching," Vinokur said. "This provides us a platform for the practical realization of a quantum Maxwell's demon, which could make possible a local quantum perpetual motion machine."
Yeah, no.The violation is only a local illusion. Globally the second law is just fine. The uncertainty principal looks like a violation of conservation of energy but isn't. Bell's theorem looks like faster than light communication but isn't. QM makes things complicated in ways that make it hard to put into words.
And I don't think there is any use for quantum computers in high speed trading. What counts is how fast you can communicate trades and quantum computers do not help here.
I've read that these HFT companies co-locate on the same premises as the trading exchange, trying to be put on the same or adjacent network nodes, for minimum latency. But processing time counts too. Imagine if you could use quantum computing to perform more sophisticated calculations instantaneously to optimize your chances for profitable trades.
But it isn't clear what calculation in the financial sector would benifit from quantum computers. On most problems quantum computers can be no faster than classical computers. In fact there is no proof that quantum computers are faster on any problem.
"Maxwell's Angel" I like it!
If you don't mind - could you please explain what you mean by "pasta lasagna" surface? It sounds like a very appetizing way to refer to a kind of spacetime manifold.Are you referring to the Calabi-Yau manifold?
Can I also ask why you reference the DeLorean in your pic? Is there a time-travel angle to this idea? Wouldn't it have to be limited to affecting events beyond the light cone?
the Dynamic Vacuum embodies absolute chaos and non-correlation. There are a vast myriad of miniscule effects happening at a small scale, in a completely chaotic and uncorrelated way, which we aren't ordinarily supposed to be able to take advantage of, as with any sink.Yet the concept of Maxwell's Demon was posited to deal with this very type of situation. That's why we should look at this approach for dealing with the Vacuum.
...Quote from: sanman the Dynamic Vacuum embodies absolute chaos and non-correlation. There are a vast myriad of miniscule effects happening at a small scale, in a completely chaotic and uncorrelated way, which we aren't ordinarily supposed to be able to take advantage of, as with any sink.Yet the concept of Maxwell's Demon was posited to deal with this very type of situation. That's why we should look at this approach for dealing with the Vacuum.We will be exploring a wide array of Maxwell demon relationships in varying states, as this phenomena not only applies to 'baths' but also spin states. The chaos and non linear effects I would suggest to be firstly focused on through turbulence equations and fractals in reflective and refractive interactions. Here is a very simplified introduction into formulating quantum hydrodynamicsDerivation of quantumhydrodynamic equations withFermi-Dirac and Bose-Einsteinstatisticshttp://calvino.polito.it/~mmkt/barletti.pdfHere is an image of negative effective mass in an SOCBEC, and you can more clearly see the secondary spin property of the electro hydrodynamics.
The smooth and growing deviation from theHermitian starting point A = 0 ends at a certain critical A(crit) where the two energiesmerge. Next, they form a conjugate pair which moves further in the complex plane.The PT symmetry of the system becomes spontaneously broken. The phenomenonof this type has been detected by the various methods in the spectra of many differentPT symmetric Hamiltonians
Quote from: ppnl on 10/26/2017 05:56 amYeah, no.The violation is only a local illusion. Globally the second law is just fine. The uncertainty principal looks like a violation of conservation of energy but isn't. Bell's theorem looks like faster than light communication but isn't. QM makes things complicated in ways that make it hard to put into words.Oh well, maybe one day DeBroglie-Bohm will help make things feel less complicated for all of us. Globally, the 2nd Law is fine, as the universe does continue to expand. But entropy only increases for the macroscopic universe - for the quantum universe, time is symmetric, there is no arrow, and quantum processes are reversible.But quantum objects and their statistical behaviors seem to be able to affect each other behind the scenes, and that's how we're able to have things like quantum computing. If we can extract information from quantum systems, why can't we extract energy? QuoteAnd I don't think there is any use for quantum computers in high speed trading. What counts is how fast you can communicate trades and quantum computers do not help here.I've read that these HFT companies co-locate on the same premises as the trading exchange, trying to be put on the same or adjacent network nodes, for minimum latency. But processing time counts too. Imagine if you could use quantum computing to perform more sophisticated calculations instantaneously to optimize your chances for profitable trades.
Researchers feel confident that they can overcome the 2nd Law of Thermodynamics through the Quantum Photonic implementation of Maxwell's Demon:https://www.anl.gov/articles/argonne-researchers-posit-way-locally-circumvent-second-law-thermodynamicsQuote"Although the violation is only on the local scale, the implications are far-reaching," Vinokur said. "This provides us a platform for the practical realization of a quantum Maxwell's demon, which could make possible a local quantum perpetual motion machine."https://www.nature.com/articles/srep32815Just as EMdrive has been accused of opening the door to free energy, likewise a free energy perpetual motion machine based on Maxwell's Demon could likewise open the door to massless propulsion. Maxwell's Demon is about obtaining information and exploiting it for a random chaotic system to selectively act upon it and turn it into a less chaotic system. Likewise, it should be possible to apply this approach to the chaos of the Dynamic Vacuum and its fluctuations, by selectively pushing off them to achieve coherent motion in a particular direction.Why am I reminded of High-Frequency Trading on the stock market?In that case, your trading software is your Maxwell's Demon, and it's intelligently acting to exploit local short term movements/fluctuations in the stock market, to quickly cash in on them with trades that generate small profits. Such tiny little exploits, if carried out over and over again at high speed, can generate lots of profit at lower risk. (Which tells me that if Quantum Computing is ever applied to trading on the stock market, then the days of trading will be over.)