Basically the experiment has an imaginary container divided into two parts by an insulated wall, and a door that can be opened and closed by this “Maxwell’s Demon”. The demon is only allowed to let “hot” molecules of gas into one side of the chamber. The effect is that this side seems to spontaneously heat up and the other side cools down. The second law of Thermodynmaics says that if two bodies of differing temperature are brought together and insulated from everything else, that they will equalise to the same temperature.
Researchers in Japan lead by Eiro Muneyuki from Chuo University and Masaki Sano from the University of Tokyo have used a tiny roto and a small electric field to construct this experiment in real life.
They have shown using small foam balls and an electric field, that by simply observing and altering the electric field based upon the observation, they can cause this small rotor to behave in a way that seems to prove Maxwell’s Demon.
“The researchers worked out that the exchange rate between energy and information matches theoretical predictions: at room temperature, one bit of information converts to about 3 x 10-21 joules.”
The full explaination is below in the New Scientist article: