--%>

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 : Weak equivalence or principle of

    Weak equivalence principle: principle of uniqueness of freefall: The idea in general relativity is that the world-line of a freefalling body is sovereign of its composition, structure, or state. This principle, hold by Newtonian mechanics and gravitat

  • 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 : Radioactive dating-Determining of age

    In the radioactive dating we use half life to find out the age of a sample however not average life why? Describe.

  • Q : Define Hoop conjecture Hoop conjecture

    Hoop conjecture (K.S. Thorne, 1972): The conjecture (as so far unproven, although there is substantial proof to support it) that a non-spherical object, non-spherically compressed, will only form a black hole whenever all parts of the

  • Q : Bragg's law Bragg's law - Whenever a

    Bragg's law - Whenever a beam of x-rays strikes a crystal surface in which the layers of ions or atoms are often separated, the maximum intensity of the reflected ray takes place when the complement of the angle of incidence, theta (θ), the wave

  • Q : What is Hawking temperature Hawking

    Hawking temperature: The temperature of a black hole is caused by the emission of the hawking radiation. For a black hole with mass m, it is illustrated as: T = (hbar c3)/(8 pi G k m).

  • Q : What is Cosmic censorship conjecture

    Cosmic censorship conjecture (R. Penrose, 1979): The conjecture, so far wholly undemonstrated in the context of general relativity, that all singularities (that is with the possible exception of the big bang singularity) are attended

  • Q : What is Complementarity principle

    Complementarity principle (N. Bohr): The principle that a specified system can’t exhibit both wave-like behavior and particle-like behavior at similar time. That is, some experiments will reveal the wave-like nature of a system,

  • Q : What is balmer series Balmer series (J.

    Balmer series (J. Balmer; 1885): An equation that explains the emission spectrum of hydrogen whenever an electron is jumping to the next orbital; four of the lines are in visible spectrum, and the remainder (residue) are in the ultraviolet.

  • Q : What nucleons altogether in a nucleus

    Explain what does held the nucleons altogether in a nucleus?