On 1/27/2012 12:43 PM, Evgenii Rudnyi wrote:

On 27.01.2012 21:22 meekerdb said the following:On 1/27/2012 11:21 AM, Evgenii Rudnyi wrote:On 25.01.2012 21:25 meekerdb said the following:On 1/25/2012 11:47 AM, Evgenii Rudnyi wrote:...Let me suggest a very simple case to understand better what you are saying. Let us consider a string "10" for simplicity. Let us consider the next cases. I will cite first the thermodynamic properties of Ag and Al from CODATA tables (we will need them)## Advertising

S ° (298.15 K) J K-1 mol-1 Ag cr 42.55 ą 0.20 Al cr 28.30 ą 0.10 In J K-1 cm-3 it will be Ag cr 42.55/107.87*10.49 = 4.14 Al cr 28.30/26.98*2.7 = 2.83 1) An abstract string "10" as the abstract book above. 2) Let us make now an aluminum plate (a page) with "10" hammered on it (as on a coin) of the total volume 10 cm^3. The thermodynamic entropy is then 28.3 J/K. 3) Let us make now a silver plate (a page) with "10" hammered on it (as on a coin) of the total volume 10 cm^3. The thermodynamic entropy is then 41.4 J/K. 4) We can easily make another aluminum plate (scaling all dimensions from 2) to the total volume of 100 cm^3. Then the thermodynamic entropy is 283 J/K. Now we have four different combinations to represent a string "10" and the thermodynamic entropy is different. If we take the statement literally then the information must be different in all four cases and defined uniquely as the thermodynamic entropy is already there. Yet in my view this makes little sense. Could you please comment on this four cases?The thermodynamic entropy is a measure of the information required to locate the possible states of the plates in the phase space of atomic configurations constituting them. Note that the thermodynamic entropy you quote is really the *change* in entropy per degree at the given temperature. It's a measure of how much more phase space becomes available to the atomic states when the internal energy is increased. More available phase space means more uncertainty of the exact actual state and hence more information entropy. This information is enormous compared to the "01" stamped on the plate, the shape of the plate or any other aspects that we would normally use to convey information. It would only be in case we cooled the plate to near absolute zero and then tried to encode information in its microscopic vibrational states that the thermodynamic and the encoded information entropy would become similar.I would say that from your answer it follows that engineering information has nothing to do with the thermodynamic entropy. Don't you agree?Obviously not since I wrote above that the thermodynamic entropy is a measure of how much information it would take to locate the exact state within the phase space allowed by the thermodynamic parameters.Does this what engineers use when they develop communication devices?It would certainly interesting to consider what happens when we decrease the temperature (in the limit to zero Kelvin). According to the Third Law the entropy will be zero then. What do you think, can we save less information on a copper plate at low temperatures as compared with higher temperatures? Or more?Are you being deliberately obtuse? Information encoded in the shape of the plate is not accounted for in the thermodynamic tables - they are just based on ideal bulk material (ignoring boundaries).I am just trying to understand the meaning of the term information that you use. I wouldsay that there is the thermodynamic entropy and then the Shannon information entropy.The Shannon has developed a theory to help engineers to deal with communication (Ibelieve that you have also recently a similar statement). Yet, in my view when we talkabout communication devices and mechatronics, the information that engineers areinterested in has nothing to do with the thermodynamic entropy. Do you agree or disagreewith that? If you disagree, could you please give an example from engineering whereengineers do employ the thermodynamic entropy as the estimate of information.

`I already said I disagreed. You are confusing two different things. Because structural`

`engineers don't employ the theory of interatomic forces it doesn't follow that`

`interactomic forces have nothing to do with sturctural properties.`

Brent

My example would be Millipede http://en.wikipedia.org/wiki/Millipede_memoryI am pretty sure that when IBM engineers develop it, they do not employ thethermodynamic entropy to estimate its information capabilities. Also, the increase oftemperature would be destroy saved information there.Well, I might be deliberately obtuse indeed. Yet with the only goal to reach a cleardefinition of what the information is. Right now I would say that there is informationin engineering and in physics and they are different. The first I roughly understand andthe second not.EvgeniiBrent

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