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2
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0answers
173 views

Trying to make a realistic simulation of 'breaks' (Pool)

I'm working on a 2D pool simulation project right now, and I'm trying to create good looking physics that are also performant. After collisions are detected, I update the velocities of the balls. So ...
2
votes
1answer
224 views

Unexpected eccentricity in moon orbit simulation

I've used Mathematica's NDSolve function to calculate the orbit of the Moon around the Earth. I used the following initial positions (perigee): ...
2
votes
0answers
94 views

M-Theory and computer simulation

I have a question. Is it possible to perform computer simulations based on the M-Theory? I was looking for such simulators or source codes but I have not found anything. However, M-theory must have ...
2
votes
0answers
94 views

Particle Collision with Static System

I have a system of particles with equal distance with each other and another at random positions which is moving with time. What I want to know is : The method by which I can reduce the number of ...
2
votes
1answer
182 views

Heuristic equation for Friction force between materials

I'm programming a game where different types of objects will be sliding over different types of terrains (Top-down in two dimensions). At my current level of physics education we are given the ...
2
votes
2answers
306 views

How to simulate a full-suspension bike? [closed]

As a fun project, I would like to roughly simulate the suspension operation of a full-suspension mountain bike. This is not another one of those "How does a bicycle stay upright?" questions. Follow ...
2
votes
0answers
55 views

Calculating gravity with inclometer?

How would one calculate the gravity vector for [X,Y,Z] by using an inclinometer which gives Pitch, Yaw and Roll. A little explanation of the goal: I have a accelerometer I was planning to use to map ...
2
votes
1answer
639 views

Moment of inertia of rotating particles in center of mass frame?

I am trying to simulate a collision between two molecules. I know the energy for every position/orientation, from which I can calculate the forces. The treatment is classical and the molecules are ...
2
votes
0answers
231 views

Air resistance of a general shape object

I'm trying to code a simple physics simulator in C++ but I'm stuck on the air resistance issue. Surfing the Internet I only find a drag coefficient for very basical area shapes when the air is ...
2
votes
0answers
413 views

For two planets in a 2:1 mean motion resonance , where will their periastron and apastron points be?

I want to animate the changing orbits of planets when they enter a mean motion resonance. Using a 2:1 resonance, I want to show a low-mass inner planet and a low-mass outer planet being tugged by a ...
2
votes
0answers
341 views

simple MHD simulation code for (self) education and play with [closed]

I would like some super simple computational code for solving magnetohydrodynamics problems. High accuracy nor performance is not my concern. I wan't it just to visually explore qualitative behavior ...
2
votes
0answers
108 views

What is the correct way of integrating in astronomy simulations? [closed]

I'm creating a simple astronomy simulator that should use Newtonian physics to simulate movement of plants in a system (or any objects, for that matter). All the bodies are circles in an Euclidean ...
2
votes
0answers
209 views

2D Car Physics including Throttle

For a simulation for testing on automatic cruise control, I came across the equation: $$ v_{n+1} = (1 - k_1 / m) v_n + (1 - k_b) \begin{pmatrix} T_n \\ θ_n \\ \end{pmatrix} $$ where: $T$ = ...
2
votes
1answer
132 views

Creating/Downloading a large Galaxy Dataset

I was wondering where I can get a more or less complete set of a galaxy to test an n-body simulation (preferably two colliding galaxies with approx 300k to 1M elements). Is it possible to extract ...
2
votes
0answers
96 views

Gibbs Ensemble initial densities

I'm trying to calculate coexistence curves and get a rough estimate for the critical point of simple fluids using the well-known Gibbs Ensemble Monte Carlo (GEMC) (c.f. Panagiotopoulos, Molecular ...
2
votes
3answers
557 views

Finite difference formulation of the heat equation with thermal conductivity in 1D

This may seem trivial, but I'm having some trouble deriving the finite difference form of the heat equation with a thermal conductivity function $a(x)$ depending on $x$: $$\frac{\partial u(x, ...
2
votes
1answer
667 views

$N$-body simulation in General Relativity

How would one perform an $N$-body simulation in General Relativity (GR) for something like galaxy formation or galactic dynamics? Suppose one wants to simulate the rotation curve $v(r)$ for galaxies ...
2
votes
0answers
64 views

Degenerated Anderson Model Simulation

I'm trying to simulate the degenerative Anderson model. So depending on an energy difference first orbital and afterwards spin magnetism occurs. First i try to solve an easier ansatz with a limitation ...
2
votes
2answers
180 views

How do you measure numerically the central charge of a system?

Let's say that you are doing some Monte-Carlo simulations of a statistical system on a lattice and you observe scale invariance, meaning that you are at a conformal point. Can you get a numerical ...
1
vote
1answer
515 views

Are We Living in a Simulated Universe? [closed]

If the universe is just a Matrix- like simulation, how could we ever know? Physicist Silas Beane of the University of Bonn, Germany, thinks he has the answer!. His paper “Constraints on the Universe ...
1
vote
1answer
42 views

Difference between Enzo & Gadget astronomy simulation codes

Enzo and Gadget are simulation codes used in astronomy. What are the largest differences between them both in terms of physics they simulate and in their implementations?
1
vote
2answers
485 views

Lattice QCD and attempt to prove that the universe is a simulation [closed]

Assume that we have access to a computer with unlimited computing power. As with the Lattice QCD can try to prove that we live in a simulated universe? Apparently, one may use the issue of cosmic ...
1
vote
1answer
311 views

I'm getting weird autocorrelations when simulating an Ising model below the critical temperature

So I'm simulating an Ising model using Monte Carlo and the Metropolis algorithm. After letting it reach equilibrium, I try to calculate the autocorrelation of the magnetization. As long as the system ...
1
vote
2answers
1k views

How do I integrate the Poisson equation to determine the electric potential along a particular direction (e.g., $z$)?

This question is a sequel of sorts to my earlier (resolved) question about a recent paper. In the paper, the authors performed molecular dynamics (MD) simulations of parallel-plate supercapacitors, ...
1
vote
2answers
87 views

Calculating temperature from molecular dynamics simulation

My understanding is that temperature is an inherently macroscopic quantity, but I've seen a number of people talk about calculating the temperature of ideal-gas simulations like this one. To take one ...
1
vote
2answers
655 views

Acceptance probability 2D Ising Model

Disclaimer: I just found a possible solution - eventhough i don't really understand, whats wrong with my prior approach. Edit: I just tried to calculate it from scratch and found the following: $E ...
1
vote
1answer
160 views

Why NPT ensemble is used for solid state phase transitions?

In Monte Carlo simulations of solid state phase transitions, why often Isobaric Isothermal ensemble (NPT) is used ? Why not NVT ? Here, N is number of atoms, P is pressure, T is temperature and V is ...
1
vote
1answer
124 views

Finding the initial velocity vector of an orbiting body

I'm writing a program that simulates Newton's law of universal gravitation by simply calculating the force and applying it on the objects. The simulation works very well, but now I want to simulate ...
1
vote
2answers
35 views

Possiblity of predicting behavior of system when properties described as functions over space?

Suppose I am given a system that consists of a distribution of charged particles(which are all over space and are point-charges). They are described by a set of functions instead of variables. These ...
1
vote
2answers
78 views

Photon striking a molecule and getting reflected

I am writing a simple simulator which simulate absorption of UV light in solution. The idea is to see if I can see Beer-Lambert laws in my model. It is not intended to be a precise simulator but ...
1
vote
2answers
128 views

My orbiting body is orbiting about the wrong focus of it's elliptical orbit… why?

I am coding in c++ and am computing the position of an orbiting body as a function of time. Everything is almost working. I have a nice elliptical orbit. Except, my orbiting body speeds up as it ...
1
vote
2answers
1k views

Simulator for electrostatics [closed]

I am searching for a tool that visualizes the electric field/potential for simple electrostatic configurations like conducting/polarized sphere in an uniform electric field conducting/polarized ...
1
vote
1answer
4k views

Where can I find open-source weather forecast software? [closed]

Are there any software packages/frameworks for running weather forecast numeric models on a single PC? I've found at least two instances, but I'm interested to know whether there are more and where I ...
1
vote
2answers
117 views

Incompressible Navier-Stokes pressure solve in simulations

I am a complete newcomer when it comes to fluid simulations. I'm currently working through some tutorials to understand the idea of of the discretized Navier-Stokes equations for numerical ...
1
vote
1answer
54 views

Where would be the source of thrust for a rocket thruster in space?

I am making a game that involves spaceships and I was building an engine block. That engine block spawns a "thruster fire" under it that represents the...thruster fire. My question revolves around ...
1
vote
1answer
82 views

Can the insertion of impurities (doping) influence optical properties of ZnS?

I am currently trying to simulate a scintillator system with silver doped zinc sulfide (ZnS:Ag). To simulate the propagation of photons inside the crystal accurately, optical properties like index of ...
1
vote
1answer
70 views

Is there any physical simulator precise to atomic levels and quantum effects? [duplicate]

There are tons and tons of physics simulators for classical/large scale physics. I'm interested in a simulator in which you feed an input as atoms and positions and it simulates the evolution of the ...
1
vote
1answer
1k views

Radians to Rotate Earth to Match ECI Lat/Lon with ECEF Lat/Lon

I am attempting to model GPS Satellite positions on the globe for a set of ephemerides. I have a verified set of ECI ( http://en.wikipedia.org/wiki/Earth-centered_inertial ) XYZ Coordinates and a ...
1
vote
1answer
213 views

Determine if an object is in orbit

I am planning on doing a space simulation program with full physics and as part of a hack to avoid too many issues with number precision I was going to switch orbiting objects to a calculated orbit ...
1
vote
1answer
138 views

Deriving the change in the Helmholtz free energy in the context of the free energy perturbation method

I am reading Free Energy Calculations: Theory and Applications in Chemistry and Biology by Chipot and Pohorille. At the beginning of the text (page 19, for example), the authors define the Helmholtz ...
1
vote
1answer
112 views

Simulating an orbit, primary is not at focus

I've been toying around with some -very- simple orbital simulators, mostly using preexisting physics libraries (I took a layman's stab at doing it with vectors too). The thing that is confusing me is ...
1
vote
2answers
354 views

How to decide convergence of the ensemble average in a Monte Carlo process

I am simulating electromagnetic scattering off a rough surface. The usual process is to do a Monte Carlo simulation, which is briefly described as follows. Generate a randomly rough surface, and ...
1
vote
3answers
616 views

Numerical simulation of mechanics problem

Say I have a planet and shoot something with a given velocity, which is a significant portion of the escape velocity, in a given angle into the sky. It has some initial velocity and there is the force ...
1
vote
1answer
45 views

Create a star system fit to conic equation

For simulation purposes, I'm trying to create a binary star system. If I have a conic equation such as $ax^2 + by^2 = c$, and the masses of two stars, how would I find the $x$- and $y$- velocity ...
1
vote
1answer
74 views

Molecular simulation applied to astrobiology

There is some research group which use molecular dynamics simulations to study the origin of life according to the hypothesis of abiogenesis? I'm just beginning to know this subject so I don't know ...
1
vote
2answers
149 views

Units in gravitational $N$ body simulations

I am trying to write a code in Python to simulate $N$ bodies interacting through gravity. In particular I am trying to see whether a system of particles with random initial positions and zero velocity ...
1
vote
2answers
44 views

Particle motion characteristic

I'm making a particle motion raffling normal numbers. The normal random numbers raffled are the angles of the directions that the particle is going. The particle speed is constant. Look how this is ...
1
vote
1answer
49 views

Reaction-diffusion. From kinetic parameters in 3D, can we infer their equivalent in 1D?

I am studying a reaction-diffusion system : $A+B ⇌_{k_{-}}^{k_{+}} C$. From experimental data I have all the kinetic parameters : diffusion coefficients $d$ and reaction rates $k_+$, $k_-$. Beside I ...
1
vote
1answer
51 views

Can a unique position be inferred by measuring the magnetic field around a disk magnet?

I was wondering, assuming we have a disk magnet and we measure the magnetic flux density components at ANY point around the magnet (where it is still relevant), is it possible to conclude which point ...
1
vote
1answer
24 views

How do we force a turbulent fluid to keep the input energy rate equal to energy dissipation rate?

If I want to do a DNS (direct numerical simulation) for turbulent fluid, and I know $\nu$, how can I add an external force so that the input energy rate is equal to the energy dissipation rate? If ...