In the 1970s, Hawking and Jacob Bekenstein showed that the information stored in a black hole is proportional to its surface area rather than its volume. This encoding of three-dimensional information on a two-dimensional surface came to be called the holographic principle. In 1997, Juan Maldacena of the IAS formalized the principle, showing that the string theory description of a black hole is mathematically equivalent to a quantum field theory without gravity that describes the surface of the black hole. more »

Verlinde uses the holographic principle to consider what is happening to a small mass at a certain distance from a bigger mass, say a star or a planet. Moving the small mass a little, he shows, means changing the information content, or entropy, of a hypothetical holographic surface between both masses. This change of information is linked to a change in the energy of the system. Then, using statistics to consider all possible movements of the small mass and the energy changes involved, Verlinde finds movements toward the bigger mass are thermodynamically more likely than others. This effect can be seen as a net force pulling both masses together. Physicists call this an entropic force, as it originates in the most likely changes in information content. more »

If it smells like entropy, and it behaves like entropy, it probably is entropy. more »