Difference between revisions 23986754 and 24016422 on enwiki

'''[[Quantum mechanics]] and [[Theory of relativity|relativity]] theory''' comprise two of the foundation stones of [[theoretical physics]], and [[information theory]] is one of the most successful of all theories in [[applied mathematics]].

(contracted; show full)nrelated to gravitation''-- except formally-- but where something closely analogous to an event horizon occurs; this leads to the idea of [[analog gravity]], which includes the notions of [[optical black hole]]s and [[acoustic black hole]]s.)  In addition, in the last decade, the new concept of the [[qubit]] has been intensively developed in the new field sometimes called [[qauntum information theory]].  This work really does involve both information theory and quantum theory in essential ways.


Perhaps motivated by these developments, Carl Hewitt (Electrical Engineering, University of Michigan, Emeritus) speculates there should be a new kind of 'information theory' which addresses questions such as these:
*Fundamentally, what is information in physics?
*How can information be obtained physically?
*By what means can information be transmitted?
*Can information be complete?
Hewitt speculates further that his own [[actor model]] in the theory of [[concurrent computing]] might shed some light on these questions, although apparently few if any physics have yet taken an interest in this proposal, which does not appear to have been formulated more precisely than the vague suggestion just stated.  Nor has Hewitt clearly explained just how his speculations are related to work on analog gravity; rather he offers the following quotation from tThe following questions naturally arise:
*Fundamentally, what is information in physics?
*How can information be obtained physically?
*By what means can information be transmitted?
*Can information be complete?

The review article [Asher Peres and Daniel Terno 2004] states:

<blockquote>
[[Quantum theory]] and [[relativity theory]] emerged at the beginning of the twentieth century to give answers to unexplained issues in [[physics]]: the [[black body]] [[spectrum]], the structure of [[atom]]s and [[Atomic nucleus|nuclei]], the [[electrodynamics]] of moving bodies. Many years later, [[information theory]] was developed by [[Claude Shannon]] [1948] for analyzing the efficiency of communication methods. How do these seemingly disparate disciplines affect each other? In this review, we shall show that they are inseparably related.
</blockquote>

However, this review paper is about the relationship of special relativity and quantum information theory, and it is not entirely clear whether Hewitt really has the same notions in mind as Peres and Terno.⏎

==What is Information?==

===Information about What?===

Chris Fuchs [2004] says that quantum information is “the potential consequences of our experimental interventions into nature.”

===Interventions and observations===
(contracted; show full)
* Christopher Fuchs, ''Quantum mechanics as quantum information (and only a little more)'' in A. Khrenikov (ed.) Quantum Theory: Reconstruction of Foundations (Växjo: Växjo University Press, 2002).
*Asher Peres and Daniel Terno. ''Quantum Information and Relativity Theory'' Rev.Mod.Phys. 76 (2004) 93.

{{relativity-stub}}