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How much information is encoded in a ball on a field?

Just a rough estimate. Let's take a standard soccer field dimensions $100~\text{yard} \times 50~\text{yard}$. Assuming a ball can be placed anywhere within this field with a $\delta x = 1~mm$ ...
Agnius Vasiliauskas's user avatar
0 votes

How much information is encoded in a ball on a field?

If I understand correctly, this question reduces to "how much information can be stored in a point in a plane?" My answer would be: the amount of information that can be stored in a point at ...
Lagrangiano's user avatar
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1 vote

At what size of matter does the second law of thermodynamics breakdown?

(Not an expert) In a statistical experiment the noise (i.e., the random fluctuations) is also known as Poisson noise, and it can be shown to be proportional to $1/ \sqrt{N}$, where $N$ is the number ...
Allure's user avatar
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1 vote

High fidelity implies low entropy

This is easiest to see if you diagonalise the state \begin{align} \rho = \sum_j p_j |\phi_j \rangle\langle \phi_j|, \end{align} where the $|\phi_j\rangle$ are orthogonal and normalized, and the $...
ors's user avatar
  • 409
1 vote

Is the 2nd law a reason for the irreversibility of natural processes or a consequence of it?

So, is entropy just a function to describe the nature and has no say on the cause behind the observations about irreversibility of natural processes? That's right. Entropy is a concept, a function of ...
Ján Lalinský's user avatar
2 votes
Accepted

Entropy change of an isolated system consisting of two thermally conductive blocks of equal isochoric heat capacity at different temperatures

The first analysis is an approximation for cases in which only a small amount of heat is transferred between the blocks (after which they are separated). The second analysis applies to the cases ...
Chet Miller's user avatar
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1 vote

Entropy change of an isolated system consisting of two thermally conductive blocks of equal isochoric heat capacity at different temperatures

You've solved the case of a finite temperature change to the arithmetic mean, for finite objects. The first equation gives the entropy increase for an infinitesimal amount of heating (equivalently, ...
Chemomechanics's user avatar
0 votes

Why must solids in equilibrium become crystalline?

I think the issue lies with the definition of a solid. If you define a solid to be a crystalline material, all solids will be crystalline materials. However, if you define a solid via its elastic ...
leapsheep's user avatar
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7 votes
Accepted

Why must solids in equilibrium become crystalline?

I wouldn't think a regular configuration is the most entropic one It is a common mistake to believe that a regular configuration corresponds to a low entropy value. First, thermodynamic and ...
GiorgioP-DoomsdayClockIsAt-90's user avatar
0 votes

What exactly does the quantum mutual information measure?

The QMI measures both quantum and classical correlations at the same time. So in your example, you get two bits because there is both the classical correlation of the spins being anti-aligned, but ...
11zaq's user avatar
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0 votes
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Is von Neumann entropy symmetric?

Let $\mathcal H_A,\mathcal H_B$ and $\mathcal H_C$ be three Hilbert spaces and write $\mathcal H_{ABC} = \mathcal H_A\otimes \mathcal H_B \otimes\mathcal H_C$ (and likewise define $\mathcal H_{BAC}$). ...
SolubleFish's user avatar
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-1 votes

Is von Neumann entropy symmetric?

For bipartite pure states the answer is yes, directly from the Schmidt decomposition. We decompose \begin{align} |\psi\rangle &= \sum_j \alpha_j |a_j\rangle|b_j\rangle, \end{align} then the ...
ors's user avatar
  • 409
1 vote

Use of Clausius theorem to prove entropy inequality in Fermi's Thermodynamics

The easiest way to understand the Clausius inequality is to recognize that entropy is a state function and that, for a closed system (no mass in or out during a process between two thermodynamic ...
Chet Miller's user avatar
  • 33.9k
0 votes

Entropy in irreversible adiabtic process

But , we know that between two themodynamic states there exists many reversible paths becauseof which the value of $δQ_{rev}$ can vary beacuse of heat being a path function which will then lead to ...
Bob D's user avatar
  • 72.9k
1 vote

Use of Clausius theorem to prove entropy inequality in Fermi's Thermodynamics

If we trust that temperature is a positive quantity and heat "goes from hot bodies to cold bodies", everything should follow quite naturally. In this answer, I'm focusing on the elementary ...
basics's user avatar
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4 votes
Accepted

Use of Clausius theorem to prove entropy inequality in Fermi's Thermodynamics

With all this in mind, to which 'part' of the universe (i.e., the system or the surroundings) is Fermi referring when he writes (in his notation) $$ 0 \ge \oint \frac{\mathrm{d}Q}{T} =…$$ The ...
Bob D's user avatar
  • 72.9k
7 votes

Use of Clausius theorem to prove entropy inequality in Fermi's Thermodynamics

All mysteries go away if you realize that when you say $dQ$ (or $\delta Q$) heat is supplied from the reservoir whose temperature is $T_e$ then along with said heat the reservoir supplies $dS_e=\frac{\...
hyportnex's user avatar
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2 votes

Use of Clausius theorem to prove entropy inequality in Fermi's Thermodynamics

Start by the definition of entropy. By definition: $$ S(B)-S(A) = \int_{Rev,\,A\to B}\frac{\delta Q}{T_e} $$ for any reversible path from $A\to B$. The definition is well posed since Clausius' ...
LPZ's user avatar
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1 vote

What causes the latent heat of solidification?

The crystal arrangement is the lowest energy arrangement at that temperature. During the phase transition, think about one atom that is not part of the crystal yet. When it finds its spot in the ...
Francesco Citterio's user avatar
6 votes
Accepted

What causes the latent heat of solidification?

Think of the atoms in a solidifying liquid as being like magnets snapping together. Magnets starting even at rest (with no kinetic energy) can, as they come together, develop quite a bit of speed. The ...
HTNW's user avatar
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5 votes

What causes the latent heat of solidification?

Maybe the thing seems weird to your physical intuition because you are muddling cause and effect. It's not that configuring the atoms causes heat to be produced, it's that if heat is removed then the ...
Andrew Steane's user avatar
1 vote
Accepted

What does life (photosynthesis) change for entropy? A thought experiment

Let me first point out that the entropy production in non-equilibrium open systems has been studied - it is not fully understood, but some things are known - see, e.g., the discussion in thread ...
Roger V.'s user avatar
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1 vote

What does life (photosynthesis) change for entropy? A thought experiment

Let's first consider some basics. Does a mirror produce entropy when light shines on it? No, the entropy of the light bounces off of the mirror, or reflects. Does a broken mirror, that looks white, ...
stuffu's user avatar
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-1 votes

What is the relationship between Clausius Inequality and 2nd Law?

The Clausius inequality applies to a closed system, and does not include the surroundings. The more correct form of this inequality is $$\Delta S_{syst}\geq \int{\frac{dQ}{T_B}}$$where $T_B$ is the ...
Chet Miller's user avatar
  • 33.9k
0 votes

Entropy and gravity

I found a good example to clarify the gravity-entropy issues. We on earth get radiation from the sun(mostly light)- use the blue part in photo-synthesis and do all sorts of work with the products, ...
Riad's user avatar
  • 506
0 votes

Is an interaction-free measurement an irreversible process?

Realistically, a piece of lab equipment sitting idle undergoes irreversible changes from blackbody radiation, radionuclide decay, outgassing of surface atoms, etc. That probably goes double if it's ...
benrg's user avatar
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0 votes

What does the plot of the universe's Entropy versus Time starting from the big bang look like?

I currently feel that information is third state of universe, at one "time" it was all potential, then all kinetic, then informational energy, then collapsing back to all potential and ...
Ron's user avatar
  • 5
1 vote

Is it true that all processes where entropy increases are permitted by the second law, if the system is isolated?

This depends on what exactly you mean by permitted. If you actually have an isolated system initially out of equillibrium (say, a thermos with hot and cold water that hasn't mixed thoroughly), it ...
Kotlopou's user avatar
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