# Tag Info

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Is there a step in your code that takes an inverse trig function? Each inverse trig function has two answers, a positive and a negative. Calculators and presumably program functions probably just take the positive automatically. I made this mistake once in calculating a gravity assist trajectory for a class problem and your description reminded me of my ...

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PIConGPU is fully open source and includes inline generation of far field radiation using Lienard Wiechert Potentials. https://github.com/ComputationalRadiationPhysics/picongpu Best, Michael

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Standard cosmology assumes homogeneity (as well as isotropy) of the universe. Though we know that this is only an approximation, we also know that for cosmic scales it is a good one. This can be seen in the cosmic microwave background radiation (CMB). However, the initially small inhomogeneities are responsible for galaxy and star formation through ...

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I found the answer to my question myself. Simply put, the answer is 'no'. The reason lies in the definition of the lattice sum (equation 2 in Beenakkers original paper 'Ewald sum of the Rotne-Prager Tensor' from 1986). Due to the symmetry of the system, it can be reduced to a 3Nx3N matrix that includes the hydrodynamic interactions of the entire system, ...

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If you want to actually simulate the behavior of the planet as it experiences the (vector) force as it moves around, then you need to find a stepping method and write your velocity vectors and position vector in terms of coordinates. I recommend a Verlet velocity method. Others at this site have their favorites, too. Euler's method is not good enough for ...

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I haven't given this enough thought yet, but at a first glance, I would say no, a potential having $\mu, V, E$ as natural variables would not be a valid one. One possible attempt to obtain such a thermodynamic potential $Q$ that is a natural function of $\mu,V,E$, would be a Legendre transform of the entropy $S(E,V,N).$ We have: \begin{align} dS = ...

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I will add another recommendation: CP2K. It is not written C/C++, it is written in Fortran; this might require a bit of time to adapt if you want to actually modify the code and have not encountered Fortran before. However, CP2K can do both quantum and classical mechanics simulations, and it can scale well. For example, a presentation by Jürg Hutter from ...

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A theory must not only explain the existing data, but it must explain it in quantitative terms. Furthermore, it must make testable predictions that differ from other theories. The Simulation Hypothesis does neither. In that respect, it is worse even than String Theory. If you believe ouyr universe is a simulation, the only thing you can trust is mathematics ...

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A good theory is something that doesn't have 100% overlap with another theory, meaning like a Venn Diagram, there are areas where you can test the validity of that theory. While it's true that you can't decisively prove a theory right or wrong, this doesn't mean you cannot demonstrate the correctness of a theory over another. Presumably if the entire ...

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The first thing to realize is that there are no "true" phase transitions (in the sense of non-analytic behaviour of thermodynamic potentials) in finite systems. This is the main difficulty one faces when analysing phase transitions using (most) computer simulation schemes. In particular, such simulations are only reliable as long as the observed correlation ...

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By now - 2015 - I found a lot of public codes: I'm exploring the very well documented CESAM2k (you can find it). It is very complete, graphics output via PGPLOT, but it is 1D and no MHD- MagnetoHydroDynamics . I'm glad it is not huge, as mesa is, because I intend to include a new module, had the time, patience and skill. Here is a 2014 review of the ...

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It seems to me what you're asking is pretty simple. You say you can control the angular velocity of each wheel. That, times the wheel radius, give you the forward velocity of each wheel on the ground. That tells you the robot's forward speed (the average of the forward speeds of the wheels), and it tells you the rate at which the robot is turning (the ...

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1- Is it right to say "the motion of the robot can be described as a transitional motion of center of mass plus a rotational motion about that point?" Pick a point on (or off) your robot; pick any point. The motion can always be described in terms of the translational motion of that point plus a rotational motion about that point In general, the ...

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