--%>

What is Maxwells demon

Maxwell's demon (J.C. Maxwell): A contemplation experiment describing the concepts of entropy. We contain a container of gas that is partitioned into two equivalent sides; each side is in thermal equilibrium with the other. The walls and the separation of the container are ideal insulators.

Now suppose there is a very small demon who is waiting at the separation next to a small trap door. He can close and open the door with slight (negligible) work. Let's state he opens the door to permit a fast-moving molecule to travel from the left side to the right, or for a slow-moving molecule to travel from the right side to the left, and remains it closed for all other molecules. The total effect would be a flow of heat -- from left side to the right -- even although the container was in thermal equilibrium. This is obviously a violation of the second law of thermodynamics.

Thus where did we go wrong? It turns out that information has to do with entropy also. In order to sort out the molecules according to speeds, the demon would be containing to keep a memory of them -- and it turns out that rise in entropy of the maintenance of this simple memory would be more than make up for the reduction in entropy due to the flow of heat.

   Related Questions in Physics

  • Q : Development of Missile technology Name

    Name the women scientist who played the essential role in the development of Missile technology of India and is nick named as the ‘Missile Woman’?

  • Q : Describe Solar water heating Solar

    Solar water heating: Solar water heaters are simple, reliable, famous and widespread. They are probably the Low Carbon technology closest to being commercially practised. The most efficient designs concentrate solar radiation onto a small diameter tub

  • Q : Explain Lagrange points Lagrange points

    Lagrange points: The points in the vicinity of two massive bodies (like the Earth and Moon) with each others' relevant gravities balance. There are five, labeled L1 via L5. L1, L2, and L3 lie all along the centerline among the centers

  • Q : What is Farad or SI unit of capacitance

    What is Farad or SI unit of capacitance? Farad: F (after M. Faraday, 1791-1867): The derived SI unit of the capacitance stated as the capacitance in a capacitor that, when charged to 1 C, contains

  • Q : Explain Superposition principle and

    Explain Superposition principle and their illustrations? Superposition principle: The common idea that, whenever a number of influences are performing on a syst

  • Q : Define Eddington limit Eddington limit

    Eddington limit (Sir A. Eddington): The hypothetical limit at which the photon pressure would surpass the gravitational attraction of a light-emitting body. That is, a body emanating radiation at bigger than the Eddington limit would

  • Q : Why Cadmium rods are given in a nuclear

    Cadmium rods are given in a nuclear reactor. Explain why?

  • Q : What do you mean by the term nucleus

    What do you mean by the term nucleus? Describe in brief.

  • Q : Define Tau-theta paradox Tau-theta

    Tau-theta paradox (1950s): Whenever two distinct kinds of kaons, tau and theta (nowadays tau refers to a totally different particle) decay, tau decays into three particles, whereas the theta decays into two. The tau and theta vary onl

  • Q : What is Standard quantum limit Standard

    Standard quantum limit: It is the limit obligatory on standard techniques of measurement by the uncertainty principle in quantum mechanics.