Linked Questions

0
votes
1answer
58 views

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 ...
0
votes
0answers
35 views

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 ...
67
votes
9answers
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 ...
28
votes
14answers
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 ...
15
votes
2answers
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 ...
13
votes
1answer
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 ...
8
votes
2answers
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 ...
1
vote
5answers
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 ...
4
votes
1answer
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: ...
1
vote
1answer
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 ...
4
votes
0answers
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 ...
2
votes
1answer
110 views

Maximum entropy: an assumption or a fact

From what I gather (and please correct me if I'm wrong), Jaynes argues that thermodynamic and information entropy are the same since the assumption in statistical thermodynamics that the energy ...
3
votes
0answers
137 views

What is the physical intuition behind this definition of entropy? [closed]

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 ...