"In some respects, information is a qualitatively different sort of entity from all others in terms of which the physical sciences describe the world. It is not, for instance, a function only of tensor fields on spacetime (as general relativity requires all physical quantities to be), nor is it a quantum-mechanical observable. But in other respects, information does resemble some entities that appear in laws of physics: the theory of computation, and statistical mechanics, seem to refer directly to it without regard to the specific media in which it is instantiated, just as conservation laws do for the electromagnetic four-current or the energy-momentum tensor. We call that the substrate-independence of information. Information can also be moved from one type of medium to another while retaining all its properties qua information. We call this its interoperability property; it is what makes human capabilities such as language and science possible, as well as biological adaptations that use symbolic codes, such as the genetic code. Also, information is of the essence in preparation and measurement, both of which are necessary for testing scientific theories. The output of a measurement is information; the input of a preparation includes information, specifying an attribute with which a physical system is to be prepared. All these applications of information involve abstraction, in that one entity is represented symbolically by another. But information is not abstract in the same sense as, say, the set of all prime numbers, for it only exists when it is physically instantiated. So the laws governing it, like those governing computation – but unlike those governing prime numbers – are laws of physics. In this paper we conjecture what these laws are. Also, despite being physical, information has a counter-factual character: an object in a particular physical state cannot be said to carry information unless it could have been in a different state. As Weaver (1949) put it, this word ‘information’ in communication theory relates not so much to what you *do* say, as to what you *could* say…." D.Deutsch, Constructor Theory, Arxiv
> Il 21/01/2024 01:28 +01 Brent Meeker <[email protected]> ha scritto: > > > The problem with this is that information, like complexity, has no physically > definite operational meaning. You can't go into the lab and ask what's the > information content of "this". > > Brent > > On 1/19/2024 10:46 PM, 'scerir' via Everything List wrote: > > > > > Interesting quote about all that (and information) > > > > Frank Wilczek: "Information is another dimensionless quantity that plays a > > large and increasing role in our description of the world. Many of the > > terms that arise naturally in discussions of information have a distinctly > > physical character. For example we commonly speak of density of information > > and flow of information. Going deeper, we find far-reaching analogies > > between information and (negative) entropy, as noted already in Shannon's > > original work. Nowadays many discussions of the microphysical origin of > > entropy, and of foundations of statistical mechanics in general, start from > > discussions of information and ignorance. I think it is fair to say that > > there has been a unification fusing the physical quantity (negative) > > entropy and the conceptual quantity information. A strong formal connection > > between entropy and action arises through the Euclidean, imaginary-time > > path integral formulation of partition functions. Indeed, in that framework > > the expectation value of the Euclideanized action essentially is the > > entropy. The identification of entropy with Euclideanized action has been > > used, among other things, to motivate an algebraically simple (but deeply > > mysterious "derivation" of black hole entropy. If one could motivate the > > imaginary-time path integral directly and insightfully, rather than > > indirectly through the apparatus of energy eigenvalues, Boltzmann factors, > > and so forth, then one would have progressed toward this general prediction > > of unification: Fundamental action principles, and thus the laws of > > physics, will be re-interpreted as statements about information and its > > transformations." http://arxiv.org/pdf/1503.07735v1.pdf > > https://l.facebook.com/l.php?u=http%3A%2F%2Farxiv.org%2Fpdf%2F1503.07735v1.pdf&h=6AQGH8JQz > > > > > > > Il 20/01/2024 01:10 +01 Jason Resch <[email protected]> > > > mailto:[email protected] ha scritto: > > > > > > > > > I put together a short write up on the relationship between physics, > > > information, and computation, drawing heavily from the work of Seth Lloyd > > > and others: > > > > > > https://drive.google.com/file/d/124q3ni51E3sf9kMC_sNKgP3ikcl8ou1t/view?usp=sharing > > > > > > I thought it might be interesting to members of this list who often > > > debate whether our reality is fundamentally computational/informational. > > > > > > Jason > > > > > > > > > > > > -- > > > You received this message because you are subscribed to the Google Groups > > > "Everything List" group. > > > To unsubscribe from this group and stop receiving emails from it, send an > > > email to [email protected] > > > mailto:[email protected]. > > > To view this discussion on the web visit > > > https://groups.google.com/d/msgid/everything-list/CA%2BBCJUgRo-xNors%2BWZbDVpboT3QwiHC_NS24_uQ9_QkiTd3fyQ%40mail.gmail.com > > > > > > https://groups.google.com/d/msgid/everything-list/CA%2BBCJUgRo-xNors%2BWZbDVpboT3QwiHC_NS24_uQ9_QkiTd3fyQ%40mail.gmail.com?utm_medium=email&utm_source=footer. > > > > > -- > > You received this message because you are subscribed to the Google Groups > > "Everything List" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to [email protected] > > mailto:[email protected]. > > To view this discussion on the web visit > > https://groups.google.com/d/msgid/everything-list/1890352135.1654730.1705733200088%40mail1.libero.it > > > > https://groups.google.com/d/msgid/everything-list/1890352135.1654730.1705733200088%40mail1.libero.it?utm_medium=email&utm_source=footer. > > > > > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > mailto:[email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/bafbd2d4-e18f-4be3-93fd-ddf8145128ca%40gmail.com > > https://groups.google.com/d/msgid/everything-list/bafbd2d4-e18f-4be3-93fd-ddf8145128ca%40gmail.com?utm_medium=email&utm_source=footer. > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/1059517988.1741745.1705818185432%40mail1.libero.it.
