Field of Science

Maxwell's demon

James Clerk Maxwell was a Scottish mathematician and physicist. He is perhaps most famous for his extension and refinement of Faraday's equations describing magnetic and electric fields. He reduced the necessary set of equations to four simple partial differential equations, the eponymous Maxwell equations, publishing the work in 1873.

He also worked in thermodynamics, lending his name to another set of four key differential relationships (the Maxwell relations). He also independently derived the Boltzmann distribution of the kinetic energies of gas molecules. Maxwell's demon, a "finite being" who opened a door between to a box of molecules, letting them in and out depending on the amount of energy they had was a rhetorical device Maxwell used to show that entropy and heat flow were, at their core, statistical phenomena.

Lord Kelvin (aka William Thomson) applied the demon tag, Maxwell used the term "finite being"!


  1. It should be mentioned that Maxwell originally had 20 equations, which were later condensed to 4.

    I originally came across this blog when your posts on chirality were recent. You have a follower!

  2. Ah...I didn't know that there were originally 20! It's nice to know there is someone out there reading, too!


Markup Key:
- <b>bold</b> = bold
- <i>italic</i> = italic
- <a href="">FoS</a> = FoS