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My understanding was always that this was a result of time evolution preserving measure in state space. So we have a space of states $\mathcal{P}$ with measure $\mu$ and there is an ensemble of states in $\mathcal{P}$ distributed according to some other measure $\nu$. We also have a dynamical system discribing time evolution $f:\mathcal{P} \times \mathbb{R} ... 0 In a quantum context, or more generally in a statistical context, one may say that conservation of information is related to the fact that the sum of probabilities is$1$For instance, suppose that the interactions of 2 particles$A$and$A'$could only produce these same particles$A$and$A'$, but with different characteristics (momenta, polarizations, ... 2 Maybe I'm wrong, but it seems to me a trivial consequence of quantum system evolution by means of unitary transforms and, thus, reversibility. 7 this is a broad, complex, somewhat tricky question with many angles that an entire survey or book could be written on but unfortunately it seems one hasnt yet. heres a "grab bag" of some deep parallels noticed over the years that such a book might cover & "research leads" for further inquiry. Modelling and simulation. as computing capability has ... 3 The link between Computer Science and Physics can be very subtle sometimes. For example, consider this article: http://arxiv.org/abs/1010.0128 The point is the following. Consider a quantum algorithm in order to solve an NP-complete problem (i.e.: a hard problem, which is conjectured not to be solvable in polynomial time). Now, consider a classical ... 5 There are numerous examples of people using genetic algorithms, for example, to optimize some output where an actual solution of the equation would be otherwise impossible. Information entropy, which is a generic computing concept, has some hold on statistical physics. But I cannot think of a case I have seen where a concept from cutting edge computer ... 3 A monochromatic plane wave is simply: $$x(t) = A \sin\left(\omega t + \phi\right)$$ where$A$,$\phi$, and$\omega\$ are fixed, never-changing quantities. Because the properties of this wave never change, there is no way to use it to transmit information. Consider this: suppose you point a laser pointer from one building to another, so that you can see ...

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Virtual particles, whether photons or electrons or... are, in the context of QFT, particles that are off-shell, i.e., their associated energy and momentum are not related by the relativistic energy-momentum relation. Please read this to get an idea of how virtual particle exchange can create attractive or repulsive forces. Photons are quanta of the modes ...

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I have confirmed with Zurek, he told me that it was wrong (at least the period-wise) and it has been pointed out many times by other people including Animesh Dutta.

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See http://arxiv.org/abs/quant-ph/0512105. It gives a derivation of Landauer's Principle from the two postulates of the Second Law of Thermodynamics, and shows how Landauer's Principle follows from the second postulate.

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Things become irreversible when you start ignoring certain degrees of freedom. What we call heat and friction is just our wilful ignorance of the trajectories of countless atoms. But the fact that the underlying equations of motion are time symmetric deals with microscopic phenomena. Sure, the time-reversed process is equally probable, which leads into the ...

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However, the simplest operations in computation, reset as well as the binary AND and OR operators, are irreversible. So? Their implementation in terms of CMOS logic is not irreversible, one can trackback the voltage levels. Sure, we can simulate irreversible systems with computers, but these aren't physically valid. However, because of the ...

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