Editing Holographic principle (section)

===Unexpected connection===

Bekenstein's topical overview "A Tale of Two Entropies"<ref>{{Cite web|url=http://ref-sciam.livejournal.com/1190.html|title=Information in the Holographic Universe by Jacob D. Bekenstein &#91;July 14, 2003&#93;}}</ref> describes potentially profound implications of Wheeler's trend, in part by noting a previously unexpected connection between the world of [[information theory]] and classical physics. This connection was first described shortly after the seminal 1948 papers of American applied mathematician [[Claude Shannon]] introduced today's most widely used measure of information content, now known as [[Shannon entropy]]. As an objective measure of the quantity of information, Shannon entropy has been enormously useful, as the design of all modern communications and data storage devices, from cellular phones to [[modems]] to hard disk drives and [[DVD]]s, rely on Shannon entropy.

In [[thermodynamics]] (the branch of physics dealing with heat), entropy is popularly described as a measure of the "[[Order and disorder (physics)|disorder]]" in a physical system of matter and energy. In 1877, Austrian physicist [[Ludwig Boltzmann]] described it more precisely in terms of the number of distinct microscopic states that the particles composing a macroscopic "chunk" of matter could be in, while still "looking" like the same macroscopic "chunk". As an example, for the air in a room, its thermodynamic entropy would equal the logarithm of the count of all the ways that the individual gas molecules could be distributed in the room and all the ways they could be moving.