Recent content by Christopher Grayce

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    A Gauge Invariance of the Schrodinger Equation

    Why not? Your exponential factor is just a number, and it commutes with every operator inside the parentheses.
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    A Non-equilibrium Statistical Mechanics of Liquids

    Start with this book: https://www.amazon.com/dp/0123870321/?tag=pfamazon01-20 But I would say the history of theories using only 2-body correlations for liquids is not great. Sometimes things work, sometimes they don't, and I don't think people have had much success predicting ahead of time...
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    Quantum Where Can I Find Rigorous Books on Physical Chemistry for Master's Level Study?

    That's why I gave you Levine. The people who study the quantum mechanics of molecules are chemists, and a rigorous book on physical chemistry is where you'll find the most careful explanation of the BO approximation.
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    What is the molar heat of self-decomposition of nitric acid?

    The reaction you want is 4 HNO3(aq) -> 4 NO2(aq) + O2(g) + 2 H2O(l). You can probably calculate a decent heat of decomposition using the heats of formation of the compounds involved.
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    Confusion about the use of partial molar Gibbs free energy

    It does seem like a strange example. In general for most simple substances dG = ‒SdT + Vdp + μ dN, so there *are* no processes that can change G of a simple substance at constant T and p, except for the trivial one of adding or subtracting some of the substance (dN != 0). So their example...
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    Quantum Where Can I Find Rigorous Books on Physical Chemistry for Master's Level Study?

    Probably Levine, "Quantum Chemistry," has what you're after. A classic textbook.
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    I What is the definition of the entropy of the Universe?

    They are comparing the number of microstates of the universe at its beginning with the number now, which is much, much greater. Perhaps you are confused because you are imagining that the correct number of microstates to count then was the number (if any) that the universe could also have been...
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    The zeroth law of thermodynamics

    What you do know, from general thermodynamic principles, is that A and B must be intensive parameters (e.g. T or P for the simplest of systems). Which they are depends on what kind of equilibrium you have established. If you only allow A and B to exchange energy, then, yes, at equilibrium the...
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    How is the energy of a zero resistance circuit converted to rotational energy?

    DC motors use a commutator and brushes to reverse the current through the armature every half turn, so the magnetic field does indeed change (grow and shrink) as it does in an AC motor, and of course that requires energy, so even if the *DC* (zero frequency) resistance of the armature is zero...
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    Why do short wavelengths carry a huge amount of data not long?

    The way electromagnetic waves carry data is by altering the base wave. So, you can bump the amplitude of the wave a bit, or the frequency, or the phase, and so forth. Every time you do that, though, you are causing the original wave to occupy a finite band of frequencies instead of just one...
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    B Does an orbiting mass exert force on what it is orbiting around?

    That's correct, the astronauts (and ISS itself) do not exert a force on the Earth other than their own gravitational pull, but you might want to bear in mind that the force of gravity is the *product* of the two masses, so the force between the astronauts and the Earth is quite significant, as...
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    Does the angle of the magnetic field affect sunlight?

    Magnetic fields only affect the motion of particles with an electric charge, or an electric or magnetic dipole (quadrupole, et cetera) moment. So, protons, yes, electrons, yes, even neutrons weakly (because while they have no electric charge they do have a magnetic dipole moment), but not...
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    I Unveiling the Mystery of Entangled Particle Spin

    How do you know you've changed the spin if you don't know its original value?
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    I Looking for deductions to find the angle between vectors

    In what form do you know the definitions of the dot and cross product of two vectors? If you know them in terms of the angle between the vectors, use that. If you know them only in terms of multiplication of the components (e.g. A.B = AxBx + AyBy + AzBz) then you can draw some triangles and...
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    Solving Particle Motion in a Rigid Box: t=0

    Expand the t=0 wavefunction (presumably the g.s. of a particle in a box) in free particle plane waves with positive momentum and having a node at the left wall.
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