We present an analysis of szilards onemolecule maxwells demon, including a detailed entropy accounting, that suggests a general theory of the entropy cost of information. About 120 years ago, james clerk maxwell introduced his now legendary hypo. In theory, maxwells demon can decrease the entropy of a system by opening and closing a door at appropriate times to separate hot and cold gas molecules. Here we propose a szilard engine setup without featuring an explicit maxwells demon. Discarding it leads to immediate increase in entropy but the demon cannot store it indefinitely. The demon can perform his task with the aid of auxiliary equipment, which measures and stores information. In 1867 james clerk maxwell suggested that a sentient being capable of observing molecular motions might be able to bring about a violation of the second law of thermodynamics through a systematic sorting of molecules. It is shown that the entropy of the demon increases during the expansion step, due to the decoupling of the molecule from the measurement information. Selecting this option will search all publications across the scitation platform selecting this option will search all publications for the publishersociety in context. Its a thought experiment which demonstrates that the concept of entropy from information theory and the concept of entropy from thermodynamics are really about the same thing, and connected in a very physical way. Entropy, classical and quantum information, computing find, read and cite all the research you need on researchgate. Yet it has challenged some of the best scientific minds, and its extensive literature spans thermodynamics, statistical physics, information theory, cybernetics, the limits of computing, biological sciences and the history and philosophy of science.
An annotated chronological bibliography provides a colourful perspective on maxwells demon and a rich trail of citations for further study. It is also shown that there is an entropy symmetry between the. Entropy, information, computing in 1990, maxwells demon has been the subject of renewed and increased interest by numerous. An introductory chapter summarizes the demons life, from maxwells illustration of the second laws statistical nature to the most recent exorcism of the demon based on a need periodically to erase its memory. The demons seductive quality makes it appealing to physical scientists, engineers, computer scientists, biologists, psychologists, and historians and philosophers of science. In 1867 james clerk maxwell suggested that a sentient being capable of.
A cognitivebehavioral treatment program client workbook treatments that work by steven a. An annotated chronological bibliography provides a colourful perspective on maxwell s demon and a rich trail of citations for further study. Landauers principle, often regarded as the basic principle of the thermodynamics of information processing, holds that any logically irreversible manipulation of information, such as the erasure of a bit or the merging of two computation paths, must be accompanied by a corresponding entropy increase in noninformationbearing degrees of freedom of the informationprocessing apparatus or its. Recalling maxwells demon, we see that his task of sorting molecules into the left half of a partitioned box is equivalent to erasing a computer memory. Maxwells demon is a thought experiment created by the physicist james clerk maxwell in. Scientists in japan are the first to have succeeded in converting information into free energy in an experiment that verifies the. Since the second law is taken by many to provide an arrow of time, the threat to its universality threatens the account of temporal directionality as well. Pdf quantum computing for everyone download full pdf. Information gain and loss for a quantum maxwells demon. Maxwells demon is a thought experiment devised by j.
Now it is appropriate to return to the roots of the problem. Rex over years ago, james clerk maxwell introduced his hypothetical demon as a challenge to the scope of the second law of thermodynamics. Video also covers reconciling the information theory of entropy with. The existence of maxwells demon is a direct threat to the second law of thermodynamics. In this paper, we will provide a clear insight using standard thermodynamics rule, such as, thermodynamics potential, gibbs free energy, and entropy, and will show that the maxwellsdemon will never be able to break the. Here we realize a maxwells demon acting on a superconducting quantum circuit. Maxwells demon is a hypothetical character that uses information about a system to reduce its entropy. Relating thermodynamic entropy to information entropy with maxwells demon. Maxwell s demon, but eddington reminds us that this work is not easy and that the price of failure can be high.
How to reconcile maxwells demon with the second law of. Notes on landauers principle, reversible computation, and. He imagined a being capable of monitoring the positions and velocities of the individual molecules in a container of air at uniform temperature, divided into two chambers by a partition. Maxwells demon 2 entropy, classical and quantum information, computing maxwells demon 2 entropy, classical and quantum information, computing pdf, epub ebook d0wnl0ad over years ago, james clerk maxwell introduced his hypothetical demon as a challenge to the scope of the second law of thermodynamics. Maxwells demon demonstration turns information into energy. You must be logged in to scitation to activate your free access.
Maxwells demons brain is also a finite size, and he needs to delete information to make room for more when it gets full. Once you do that, we can all agree that we have a successful demon. James clerk maxwells idea for violating the second law of thermodynamics. A century and a half ago, maxwell introduced a thought experiment to illustrate the difficulties which arise in trying to apply the second law of thermodynamics at the level of molecules. Maxwells demon can use quantum information to generate work. If you want to convince me that you have built a maxwell s demon, then give me a computer that i can plug into my bathtub. In this paper, we will underline the flaw that exists in maxwells demon paradox using chemical. Szilard engines are in general operated by a maxwells demon where landauers principle resolves the apparent paradoxes. Maxwells demon fundamental problem on thermodynamics and statistical mechanics since the 19th century j. Chapter 1 provides a historical overview of the demons origin and solutions to the paradox. As the dictionary entry above shows, maxwells demon is no more than a simple idea. If the supernatural demon knows which half of the box the particle is in equivalent to a. Maxwell 18311879 observe the velocities of each molecules, and open or close the door create a temperature difference.
Since then this being, dubbed maxwells demon by lord kelvin, has been an active topic of scientific inquiry and speculation. Entropy, information, computing princeton series in physics on free shipping on qualified orders. James clerk maxwell physics and mathematics, quantum physics, electromagnetic field, quantum mechanics. In the history of science, laplaces demon was the first published articulation of causal or. Relating thermodynamic entropy to information entropy with. Maxwells demon and the thermodynamics of computation. The computer in the bathtub includes many relevant parameters, such as heat, entropy, and information. Maxwell first introduced the demon in a letter to tait dated 11 december 1867.
He imagined an entity since personified as mawells demon which could sort molecules into hot and cold and thereby create differences of temperature spontaneously, apparently violating the second law. Maxwell in 1867 in order to show that the second law of thermodynamics is not universal, since it has a counterexample. So, we must sooner or later pay the energyentropy cost to erase a classical bit. Maxwells demon and the entropy cost of information. Entropy, classical and quantum information, computing retains many of the seminal papers that appeared in the first edition, including the original thoughts of james clerk maxwell and william thomson. So, we must sooner or later pay the energy entropy cost to erase a classical bit. Pdf maxwells demon and the second law of thermodynamics. An introductory chapter summarizes the demons life, from maxwells illustration of the second laws statistical nature to. From maxwells demon to landauers eraser eric lutz is a professor of theoretical physics at the university of erlangennuremberg in erlangen, germany.
Entropy, information, computing makes the key literature easily available and helps with the crossfertilisation of ideas in different disciplines. Overview introduction the demon and its properties szilards model. Entropy, classical and quantum information, computing 1 by leff, harvey, rex, andrew f. In the language of information what maxwells demon does is that it decodes gathers or brings back information and the system uses this decoded information to output more work. Entropy, classical and quantum information, computing harvey leff, andrew f. Schematic figure of maxwells demon thought experiment. Everyday low prices and free delivery on eligible orders. Informationtowork conversion by maxwells demon in a. As individual gas molecules approach the door, the demon quickly. Entropy, classical and quantum information, computing.
Maxwellsdemon in various systems where the validity of second law of thermodynamics has been questionedfavored 1234. Entropy in thermodynamics and information theory wikipedia. The thought experiment of maxwells demon reveals the profound connection between information and energy in thermodynamics brillouin. Quantum szilard engine constitutes an adequate interplay of thermodynamics, information theory and quantum mechanics. By knowing the positions and velocities of each molecule in a gas, the demon can sort hot and cold particles without performing any work, in apparent violation of the second law. In a recent twopart article, earman and norton 5, 6 reject the the use of informationtheoretic notions to exorcise maxwells. Maxwells demon is a thought experiment created by the physicist james clerk maxwell in 1867 in which he suggested how the second law of thermodynamics might hypothetically be violated. Maxwells demon wikimili, the best wikipedia reader.
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