--%>
Assignment Help - homework help

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 : Define Zeeman Effect or Zeeman line

    Zeeman Effect: Zeeman line splitting (P. Zeeman; 1896): Zeeman Effect is the splitting of lines in a spectrum whenever the source is exposed to the magnetic field.

    		•
  • Q : Define Uniformity principle Uniformity

    Uniformity principle (E.P. Hubble): The principle which the laws of physics here and now are not dissimilar, at least qualitatively, from the laws of physics in preceding or future epochs of time, or somewhere else in the Universe. This principle was

    		•
  • Q : Define Kelvin or basic SI unit of

    Define Kelvin or basic SI unit of thermodynamic temperature: Kelvin: K (after Lord Kelvin, 1824-1907): The basic SI unit of thermodynamic temperature stated as 1/273.16 of the thermodynamic temperature of triple point of the water.

    		•
  • Q : What is Loschmidt constant or Loschmidt

    Loschmidt constant: Loschmidt number: NL: The total number of particles per unit volume of an ideal gas at standard pressure and temperature. It has the value of 2.687 19 x 1025 m-3.

    		•
  • Q : Describe Wiedemann-Franz law

    Wiedemann-Franz law: It is the ratio of the thermal conductivity of any pure metal (substance) to its electrical conductivity is just about constant for any specified temperature. This law holds pretty well apart from at low temperatures.

    		•
  • Q : Problem on multi level TDM Ten sources,

    Ten sources, six with a bit rate of 200 Kbps and four with a bit rate of 400Kbps are to be combined using multi level TDM  with no sync bits. Answer the questions below about the final phase of multiplexing: a

    		•
  • Q : How fireworks turn to shapes similar to

    Briefly illustrate how do fireworks turn to shapes similar to hearts and stars?

    		•
  • Q : Brewster's law Brewster's law (D.

    Brewster's law (D. Brewster) - The extent or level of the polarization of light reflected from a transparent surface is maximum whenever the reflected ray is at right angle to the refracted ray.  

    		•
  • Q : Describe Wien displacement law Wien

    Wien displacement law: For a blackbody, the product result of the wavelength corresponding to the maximum radiances and the thermodynamic temperature is constant, then the Wien displacement law constant. As an outcome, as the temperature increases, th

    		•
  • Q : What is Maxwells demon Maxwell's 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 separatio

    		•