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0answers
29 views

What discrete form of the wave equation do you need to use to make a wave simulation?

I'm working my way through these blog posts about the wave equation. All has made sense up until now. The wave equation is $$ \frac{\partial^2h}{\partial t^2} = c^2 \frac{\partial^2h}{\partial x^2} ...
2
votes
1answer
130 views

Can two distinct events occur at precisely the same moment in time?

I am writing a simulation and am having difficulty resolving the order in which two distinct forces occur. The simulation will give different results if the forces are applied to the state in ...
1
vote
1answer
27 views

Meaning of imaginary eigenvalues in advection equation

I'm reading the book Fluid Simulation for Computer Graphics (Amazon link), and stumped by the following sentence in Chapter 3: what's happening is that the eigenvalues of the Jacobian generated ...
0
votes
1answer
82 views

Leapfrog method in Particle-in-cell

Recently I wanted to write a 3D electromagnetic Particle-in-cell code with c++.I know that I should use leapfrog method.For example,when I calculates the position and velocity of particles,i should ...
4
votes
1answer
235 views

Boundary conditions on current carrying wire

I'm trying to simulate by finite elements method Maxwell equations for a current carrying wire. My 3d geometry consists of a cylinder and a box containing it. I will use a mixed formulation and ...
3
votes
0answers
16 views

Ocean surface mean current flow meaning

I tried to simulate the trajectory of an drifting object in the oceans by using the data of the OSCAR project http://www.oscar.noaa.gov/. The dataset actually used consist of grid sampled mean 2d ...
0
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0answers
18 views

Explicit Ewald equations for dipole-dipole interaction in a simulation

I'm starting to work with spin ice simulations and I found that it is usual to use the Ewald method for the long-range interactions computation (dipole-dipole in this case). Although I've been reading ...
0
votes
1answer
80 views

Is the dimension “number of particles” a fundamental, or derived dimension (based on mass), or does it depend on the context, or is it dimensionless?

I consider "fundamental quantities" to be those that have dimensions that are are like length, mass, time, temperature, and so on. "Derived quantities" have dimensions that can be written in terms of ...
0
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0answers
30 views

Computer simulation/visualization of a ray of light passing near a massive object

I'd like to write a computer program that simulates and visualizes the trajectory of a ray of light as it passes near a massive object (e.g., neutron star). In other words, I'd like to model light ...
-1
votes
2answers
141 views

Simulating a car in an intersection

I'm somewhat confused. I want to simulate in real-time an intersection where cars have to turn left, right or go straight. What I have are 2 way points: One at the beginning of the intersection on ...
8
votes
1answer
1k views

physics of wet hair

I'm curious about the physics behind the clumping of wet hair. More specifically, how the amount of water in hair and distance between hairs affect the clumping process. I know intuitively that when ...
2
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0answers
32 views

How to find the maximum torque to apply to a robot joint to have realistic movement? [closed]

I am a computer science student. I am trying to simulate a locomotion of a legged robot. The weight and dimensions of the robot: A rectangular torso has 1 Kg, (0.15m*0.3m*0.03m) (width * length * ...
1
vote
1answer
36 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 ...
0
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0answers
18 views

Inhomogeneous scattering from a dielectric box in 2D?

I wrote an E&M simulator and need to verify the accuracy. My simulator evaluates a 2D grid (which is what my camera measures), and would like to test an object that is minimally perturbed by ...
1
vote
1answer
62 views

Determing Velocity of Moons

I have a question that I believe is relatively easy to answer, I am working on an $N$-body simulation of a fictional star system and am having trouble finding the velocity of moons so that they will ...
0
votes
1answer
214 views

My python trajectory calculator for a small mass in a gravitational field - why is energy conservation violated?

I wrote this thing to calculate the next position of a small mass, given its current position and velocity, and a vector field determines acceleration. It sort of works - except I can never get the ...
1
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0answers
36 views

Quantum Monte Carlo for harmonic oscillator

I'm trying to calculate harmonic oscillator using quantum monte carlo (path integral and metropolis algorithm). It's one particle in harmonic potential. I know the theory. One divides the partition ...
0
votes
1answer
33 views

Finding radius of turning car to calculate the centripital force

I'm writing a program to simulate a car driving. I'm wondering how I should find the radius when calculating the centripital force. If we let the car travel at a constant speed, then $F_{net} = ...
2
votes
1answer
581 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 ...
3
votes
1answer
43 views

Is there an algorithm for N body simulations in General Relativity [duplicate]

I am new to general relativity but have a background in computer science. Why is it so hard to do n-body simulations in GR? For example, there could be a program which takes the properties (mass, ...
0
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0answers
27 views

What are the limitations of simulating grand unification theories of elementary particles in condensed matter settings?

What are the limitations of simulating grand unification theories of elementary particles in condensed matter settings? I know that condensed matter systems can be constructed to be described by any ...
0
votes
0answers
20 views

What is the justification for the minimum image convention in periodic boundary condition?

As the distance between first particle-second particle and first particle-image of the second particle are not same. How is it justified to use the distance from the nearest image to compute ...
0
votes
1answer
54 views

How to simulate pendulum movement with high amplitude

I need to make a C# simulator for a simple pendulum. I have been searching the web for 3 days and I am stuck. The problem is I have found many equations that would give the angle position as a ...
0
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1answer
166 views

Boltzmann Distribution of Electrons in Confining Potential

I have a particle simulation wherein many non-interacting electrons are trapped in a electric potential well. I would expect, and therefore I initialize according to this, that the electrons would ...
0
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1answer
93 views

What is the general definition of signal acceptance?

Suppose I have a beyond Standard Model theory and want to test it. I want to test if some experiments, say conduced in LHC, show signals of the theory. In this case, what is "signal acceptance"?
3
votes
1answer
77 views

Atmosphere model

Im working on project where I should simulate glider soaring. The goal is to create gliders that will look for regions with hot upwinds using evolution algorithms. That shouldn't be problem. What I ...
1
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0answers
65 views

Magnetic force between two point charges

I tried to derive the magnetic force between two point-charges for iterative computation. Starting out with Lorentz force and Biot–Savart law for a point charge. $$ \vec F = q_2( - \Delta \vec{v} ...
0
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1answer
22 views

plasma and infinite acceleration

I am trying to set up a simulation of particles (they are not any particular kinds of particles, they are just points that repel each other). All the particles repel each other through the inverse ...
0
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0answers
26 views

Q: Any standard terminology for “gold standard” Monte Carlo solutions

The "standard" way in our field to compute scattering statistics in wave propagation problems is via a "deterministic" wave prop code operating in a Monte Carlo context where we iterate over many ...
2
votes
1answer
154 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 ...
0
votes
1answer
164 views

Particle-in-cell (PIC) code Virtual Laser Plasma Lab (VLPL)

I am writing a simulation code to model betatron X rays produced by electrons accelerated using laser wakefield acceleration (LWFA). I have heard about 3D PIC (Particle-in-Cell) code VLPL (Virtual ...
1
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0answers
60 views

How do I model this Quantum Cascade Laser (QCL) using COMSOL? [closed]

I'm trying to model this: GaAs on-top of a heat-sink made of Copper. It's trying to simulate a type of Quantum Cascade Laser, I'm looking at the effect the temperature has by running a 10V voltage ...
0
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2answers
66 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 ...
6
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4answers
3k views

Trampoline physics - what is the right time to crouch and to jump to maximize your height?

Please bear in mind that I'm neither a physics guy nor particularly a math guy. So I will probably need a bit more hand-holding than just a complex equation. For a game, I'm trying to calculate a ...
0
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3answers
145 views

Can universe or anything be simulated with absolute accuracy? [duplicate]

In a simulation everything is known which makes any apparent random event a pre-calculated event. Taking that into account is it possible to simulate the universe with absolute accuracy in a way that ...
1
vote
1answer
77 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
1answer
22 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 ...
3
votes
1answer
76 views

Physics simulator based on conservation laws?

Reading the article: http://en.wikipedia.org/wiki/Newton%27s_laws_of_motion#Relationship_to_the_conservation_laws there's a section stating that: ...
0
votes
1answer
27 views

Searl effect generator simulation

This is an scheme of SEG: https://www.youtube.com/watch?v=pUUvhuQtba4 https://www.youtube.com/watch?v=wAMrTxMzrds This mechanism change the electrons around the conversor. Would be really nice to ...
7
votes
3answers
1k views

Most True to Life Physics & Biology Simulation Engine? [closed]

I'm a programmer. I code in C++, C#, HTML5, and PHP. There are many graphics engines I have at my disposal. The question is: Does there exist a graphics engine that is as true to our reality as ...
1
vote
1answer
81 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
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0answers
40 views

Is there any free open source planetary orbit simulator software?

I need a free open source planetary orbit simulator software that should be able to calculate orbit stability for a couple simple planetary systems. Basically, I need to calculate orbit durations for ...
5
votes
1answer
109 views

Optical mode leakage through a layer of gold

The geometry of my semiconductor device is given below. The blue regions are gold, the grey ones - gallium arsenide (n-doped to $2.9 \times 10^{15} \mathrm{cm^{-3}}$). The dimensions are μm, i.e. it ...
1
vote
0answers
21 views

Introduction material for lattice field simulation

I am looking for introductory material of lattice field theory simulation. It is better start from simple example (e.g. \phi^4) and include some source code. Is there any on-line or book which is ...
1
vote
1answer
39 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
0answers
82 views

Funny relation with Quantum Tunneling and Newtonian Simulation [closed]

I just finished my first QM class, and have also been working on a 2d game engine for a while now. I learned about Quantum Tunneling, and the equations involved in calculating the odds of that ...
1
vote
2answers
95 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 ...
0
votes
1answer
35 views

kinematics: parabolic movement [closed]

How does the formula $ax^2$ is affected by the angle and the power of the launch of, let's say, a cannon ball, (regardless of its mass)? I am trying to create a simulation, and everything I have to ...
0
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3answers
66 views

Force causing diffusion

I was curious if there was an equation describing the force acting on a particle (say, sitting in a fluid) that causes it to diffuse. If so, does it include the diffusion coefficient D? Based on ...
0
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0answers
45 views

Difference between molecular dynamics and direct simulation Monte Carlo

I just started studying about rarefied gases and I came across the concepts of Molecular Dynamics (MD) and Direct Simulation Monte Carlo (DSMC); so here is my question: How are these two fields ...