About 120 years ago, james clerk maxwell introduced his now legendary. Maxwells demon was an instant source of fascination and led to many important results, including the development of a thermodynamic theory of information. Information theory is a branch of applied mathematics, electrical engineering, and computer science which originated primarily in the work of claude shannon and his colleagues in the 1940s. As the dictionary entry above shows, maxwells demon is no more than a simple idea. Entropy, information, computing princeton series in. The classical paradox of maxwells demon has been around for a century and a half and has had a strong influence on the study of the second law of thermodynamics and statistical mechanics in general in addition to the area of quantum dynamics and information theory. Information theory studies the quantification, storage, and communication of information. In letters from 1867 and 1871 and then in his 1871 theory of heat, james clerk maxwell described a tiny demon who could reverse the second law of thermodynamics. It was originally proposed by claude shannon in 1948 to find fundamental limits on signal processing and communication operations such as data compression, in a landmark paper titled a mathematical theory of communication. If successful, they decrease the total entropy of the universe, thereby violating the. A later tradition sought to exorcise maxwells demon by assessing the entropic cost of the demons processing of information. He realized that the extra work that can be extracted from the demons action has a cost that. 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. All these guys, you know, they all meddle in everything.
Try searching on jstor for other items related to this book. And it has a very tantalizing name, maxwells demon. Fascination with the demon persisted throughout the development of statistical and quantum physics, information theory, and computer science, and links have been established between maxwell s demon and each of these disciplines. Maxwells demon is a thought experiment created by the physicist james clerk maxwell in. A classic source for exploring the connections between information theory and physics, this text is geared toward upperlevel undergraduates and graduate students. 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. It was imagined by james clerk maxwell in 1871, to illustrate the possibility of violating the second law of thermodynamics. The experiment first appeared in an exchange of letters between maxwell and peter tait around 1867. 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. The demon simply opened and closed an opening between two portions of a vessel filled with air so. This was presented in his 1871 book theory of heat and is as follows. The author, a giant of 20thcentury mathematics, applies the principles of information theory to a variety of issues, including maxwells demon, thermodynamics, and measurement problems.
Maxwells demon was the invention of scottish mathematician and theoretical physicist james clerk maxwell, who wanted to contradict the second law of. Entropy, information, computing by harvey leff, in like new condition. Maxwells demon in its many forms has captured the imagination of both scientists and the general public. Here, we present the history of the demon and a variety of interesting consequences of the second law of thermodynamics, mainly in quantum mechanics, but also in the. Leff 2016, hardcover at the best online prices at ebay. Because its primary literature is scattered throughout research journals, semipopular books, monographs on information theory and a variety of specialty books, maxwell s demon is somewhat familiar to many but well known only to very few. But a particularly important insight came in the 1960s from the ibm researcher rolf landauer. This book gives a concise overview of maxwells demon and its impact on the. What maxwells demon does is allow heat to flow backwards reverse the arrow of time, if you like by using information about the molecular speed. Maxwells demon 2 entropy, classical and quantum information, computing.
It was later unveiled to the public in maxwell s book on thermodynamics titled theory of heat, published in 1872. Fascination with the demon persisted throughout the development of statistical and quantum physics, information theory, and computer science and linkages have been established. Buy maxwells demon 2 entropy, classical and quantum information, computing on. Demon in the title refers to an idea in physics called maxwells demon who is a tiny sentient entity who in theory could reverse the direction of entropy if he could open or close a door, keeping hot molecules on one side and letting cold ones escape to the other. Topics include brownian motion, thermal noise, information theory, entropy, and the authors personal view of maxwells demon. Maxwells demon, a hypothetical being that appears to violate the second law of thermodynamics, has been widely studied since it was first proposed in 1867 by. Well, it turns out that living organisms are packed full of maxwell demons. The author, a giant of twentiethcentury mathematics, applies the principles of information theory to a variety of issues, including maxwells demon, thermodynamics, and measurement problems.
An annotated chronological bibliography provides a colourful perspective on maxwells demon and a rich trail of citations for further study. Discarding it leads to immediate increase in entropy but the demon cannot. 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. Maxwells demon was born in 1867 and still thrives in modern physics. About 120 years ago, james clerk maxwell introduced his now legendary hypo. Fascination with the demon persisted throughout the development of statistical and quantum physics, information theory and computer science, and links have been established between maxwells demon and each of these disciplines. If the supernatural demon knows which half of the box the particle is in equivalent to a. Over years ago, james clerk maxwell introduced his hypothetical demon as a challenge to the scope of the second law of thermodynamics. Maxwells demon and the golden apple will appeal to leaders of multinational corporations and government.
Its impact has been crucial to the success of the voyager missions to deep space. A discussion of the negentropy principle of information introduces brillouins renowned examination of maxwells demon. This second law normally says that heat flows only from hot to cold. He plays important roles in clarifying the connections between two theories. Entropy, information, computing makes the key literature easily available and helps with the crossfertilisation of ideas in different disciplines. By detecting the positions and velocities of gas molecules in two neighboring chambers and using that information to time the opening and closing of a trapdoor that separates them, a tiny, intelligent being could, in theory, sort molecules by velocity.
Weinberg on the decrease of entropy in a thermodynamic system by the intervention of intelligent beings l. Schematic figure of maxwells demon thought experiment. Fascination with the demon persisted throughout the development of statistical and quantum physics, information theory, and computer science, and links have been established between maxwells demon and each of these disciplines. Maxwells demon, hypothetical intelligent being or a functionally equivalent device capable of detecting and reacting to the motions of individual molecules. Quantum dynamics, entropy and quantum versions of maxwell. Maxwells demon demonstration turns information into energy. About 120 years ago, james clerk maxwell introduced his now legendary hypothetical demon as a challenge to the integrity of the second law of thermodynamics. In his 1867 thought experiment, maxwells demon, james clerk maxwell. Entropy in thermodynamics and information theory wikipedia. The book is named for james clerk maxwells little imaginary genius, who could make your latte boil out of your travel mug given a chance. Concluding chapters explore the associations between information theory, the uncertainty principle, and physical limits of observation, in addition to problems related to computing, organizing information, and inevitable errors.
Entropy, information, computing in 1990, maxwells demon has been the subject of renewed and increased interest by numerous researchers in the fields mentioned above. Because its primary literature is scattered throughout research journals, semipopular books, monographs on information theory and a variety of specialty books, maxwells demon is somewhat familiar to many but well known only to very few. Exorcism of maxwells demon university of pittsburgh. Apparently, though, it was not maxwell who called it a demon. It deals with concepts such as information, entropy, information transmission, data.
And this is the same maxwell famous for maxwells equation, so he obviously dealt with a lot of things. We then computed the entropy decrease created by this demon using the refrigerated. Maxwells demon news newspapers books scholar jstor march 2012 learn how and when to remove this template message. Fascination with the demon persisted throughout the development of statistical and quantum physics, information theory, and computer scienceand linkages have been established between maxwell s demon and each of these disciplines. Fascination with the demon persisted throughout the development of statistical and quantum physics, information theory, and computer scienceand linkages have been established between maxwells demon and each of these disciplines.
The simplest exorcism of maxwells demon no information needed. Essentially, this law states that heat does not naturally flow from a cool body to a warmer. Many new ideas and paradigms have been introduced as a result of this paradox. The most successful exorcism of maxwells demon is smoluchowskis 1912 observation that thermal fluctuations would likely disrupt the operation of any molecularscale demonic machine. Here, we present the history of the demon and a variety of interesting consequences of the second law of thermodynamics, mainly in quantum mechanics, but also in the theory of gravity. Interweaving his theory of global disorder with issues on the world stagecoupled with a disquisition on board games and the cell phone app angry birdsschwellers thesis yields astonishing insights. Denbigh on the relation between information and energy systems. As individual gas molecules approach the door, the demon quickly.
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