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### Is physical entropy opposite to information entropy? [duplicate]

I am currently taking a class on Decision Theory where I was introduced to the notion of "entropy" in an information theoretic setting while we were studying decision trees. I was given the following ...
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### Relationship between physical and information entropy [duplicate]

This question is inspired by the following example given in Barnett's book on quantum information: (PDF here, starting at the bottom of page 5) I am not a physicist, but I'll accept that the ...
17k views

### Why are “degrees” and “bytes” not considered base units

From Wikipedia: The SI base units and their physical quantities are the metre for measurement of length, the kilogram for mass, the second for time, the ampere for electric current, the kelvin for ...
21k views

### What is entropy really?

On this site, change in entropy is defined as the amount of energy dispersed divided by the absolute temperature. But I want to know: What is the definition of entropy? Here, entropy is defined as ...
998 views

### Information entropy and physics correlation [closed]

I'm starting to study Information Theory, and the concept of entropy is not clear to me; I have already checked other posts in this category, but none of them seems to answer my indagations, so, I ...
1k views

### What's the most fundamental definition of temperature?

What's the most fundamental definition of temperature? Is it the definition concern about average energy, number of micro states, or what? By "fundamental", I mean "to be applied" in such general ...
931 views

### Spontaneous conversion of heat into work at negative temperatures

Consider a heavy macroscopic object moving in a gas. Friction causes its kinetic energy to be converted into heat. Thermodynamically, there is (effectively) no entropy associated with the kinetic ...
209 views

### Why is there less information in a written book (which makes me see things) than in a random string of letters and spaces?

If I read a book I can see with my inner eye (or ear) see the plot developing. With a random string of letters, with random spacings, this isn't the case. Then why contains the former less information ...
340 views

### What are the phenomena responsible for irreversible increase in entropy?

https://www.quantamagazine.org/20140416-times-arrow-traced-to-quantum-source This article says that entanglement drives the arrow of time of increasing entropy towards thermodynamic equilibrium: ...
423 views

### Is there an equivalence between Boltzmann entropy and Shannon entropy..?

I have already parse other posts about this subject but none of them seems to answer completely to my interogation [ this interrogation is to put in relation with this question Is there an ...
234 views

### Do information entropy and thermodynamic entropy evolve the same way?

Recently I asked a question about the relationship between Von Neumann entropy and heat transfer. The link is here. Is the Von Neumann entropy related to heat transfer? I feel as though the answer ...
In Quantum Statistical Mechanics we have the density operator $\rho$ acting on state space $\mathcal{E}$, which gives information about probabilities regarding mixed states. In that setting we define ...