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1answer
161 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 ...
0
votes
1answer
26 views

kinematics: parabolic movement [on hold]

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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0answers
19 views

MCNPX for nuclear simulation [closed]

Anyone here expert in MCNPX? I need someone help. I run MCNPX. I try to calculate f4:n using nps:1000. But, it stop directly before culculate f4. There is comment: stack trace terminated abnormally. ...
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3answers
50 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
41 views

Increasing Lattice Size in Quantum Espresso [closed]

Quantum Espresso, a DFT simulation software, currently simulates only 8 atoms. How can be increase the number of atoms to say 64? Do we manually insert the ...
0
votes
1answer
37 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 ...
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0answers
16 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 ...
0
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0answers
21 views

Differential Equations for Two-Dimensional N-Body Simulation

So I recently asked a question about improving the stability of a two-dimensional orbital simulation (as before I was using Euler integration). I was told to use Runge-Kutta 4 for a more stable ...
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0answers
21 views

What's the cause of this gap in this simulation of the Nice model?

A previous question brought me to this video (which has a spectacular change at about 0:34). It shows the orbits of Jupiter, Saturn, Uranus, Neptune, and what appear to be trans-Neptunian objects. ...
1
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1answer
41 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 ...
0
votes
1answer
48 views

Two body problem with given start positions and velocities [duplicate]

I am trying to program a $n$-body problem simulation. To calculate the position and velocity after a time-step I want to split it in multiple 2 body problems. Now I am stuck, trying to find the ...
5
votes
1answer
103 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 ...
0
votes
1answer
185 views

Optics simulation software for iypt #12 question thick lens [duplicate]

(As I'm writing these I viewed previous posts about optics simulation) me and some of my friends are working in iypt problems. one of the problem is named "thick lens" which says: A bottle filled ...
3
votes
1answer
50 views

Calculating a two-dimensional orbital path with infinite granularity (non-Euler integration)

For a game I am making, I am trying to calculate the position of an orbiting object around one or more bodies. I have successfully implemented this gravity simulation by calculating the force, then ...
4
votes
1answer
228 views

How to calculate the new positions of other vertices in spring-mass system graph, when one vertex is actively moved by the user?

I am developing an android based game. I have 10 soldiers uniformly spaced in the scene using some kind of formation. Example - banks of 3 3 and 4 or banks of 4 4 2 or banks of 4 2 and 4 etc... Now ...
0
votes
1answer
18 views

How do we define capillary number in 2D (two dimensions)

In 3D the capillary number $Ca$ is defined as: $$Ca=\frac{\nu \rho U}{\gamma}$$ where $\nu$ is the kinematic viscosity ($m^2/s$), $U$ is the velocity ($m/s$)and $\gamma$ is the interfacial tension ...
2
votes
1answer
133 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
81 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 ...
0
votes
1answer
141 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 ...
2
votes
3answers
144 views

Is simulating the entire universe possible?

Is it concievable that we may one day simulate the entire universe with every single particle, field and law of physics factored in? Can n number of particles (say the number of particles that make up ...
1
vote
1answer
58 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 ...
4
votes
1answer
207 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 ...
0
votes
2answers
65 views

Integrate the law of universal gravitation to get position [closed]

I'm trying to write Physics simulation software which simulates gravitational and electric forces between $n$ bodies. I know how constant acceleration is integrated to get distance, but I have no ...
0
votes
0answers
68 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 ...
3
votes
1answer
59 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 ...
0
votes
1answer
30 views

2D room with electron-point-charges (stability)

Is there a fast way to find out stable #"point charges" & constellation for this kind of Simulation. The 2D repeating itselve in each direction till infinity, so i've a kind of symetrie here. ...
1
vote
2answers
37 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 ...
0
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0answers
21 views

Heat sink simulation with a fan

I am trying to solve this problem using advection-diffusion model and finite element method for solving it due to the complex geometry. Basically the problem i'm trying to solve using OpenFOAM is see ...
0
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0answers
30 views

Density functional theory and partial charge transfer

When density functional theory is used to simulate a molecule adsorbed on a surface, it turns out that due to their interaction, a fraction of an electron is transferred from the surface to the ...
0
votes
0answers
30 views

Literature on semiconductor modeling

Analysis and Simulation of Semiconductor Devices by Selberherr (Amazon link) seems to be the book on the basics of the craft, yet it was written in 1984. Are there any more recent books or have the ...
4
votes
3answers
163 views

How many celestial bodies could be in stable orbit at roughly the same distance from a star?

How many planet-like celestial bodies of roughly the same mass (say within 50%) could orbit a star at roughly (say within 10%) the same distance from the star and be in stable orbits. By stable I ...
1
vote
1answer
32 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 ...
2
votes
0answers
135 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 ...
0
votes
1answer
59 views

Possibility of simulating quantum physics and relativity [closed]

I must be clear; this is not a 'specific' question, but rather a hypothetical one. As of now, computer physics simulations are becoming more and more advanced, and I am programming one now. I was ...
1
vote
1answer
34 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 ...
0
votes
1answer
71 views

Are there more reasons why we can not be part of an $n$ dimensional Game Of Life?

After talking with a colleague about the possible nature of the limitation of information propagation to c, and how everything can be seen relative to it, we wondered if the nature to this could be ...
3
votes
3answers
324 views

Computation theory and the simulation argument

Can physical states be treated as information (strings over some alphabet)? If (1) is true, isn't this a trivial conclusion that the universe can be simulated by a Turing machine or a cellular ...
1
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0answers
76 views

Lattice Gas Cellular Automata - HPP model square lattice

In the HPP model of LGCA, a square lattice is used and there is only one collision configuration as mentioned in figure (taken from the book Lattice Gas Cellular Automata and Lattice Boltzmann models ...
6
votes
1answer
368 views

Cellular automata rules for quantum mechanics

My limited understanding of quantum theory is that a quantum system is completely described by its wave function, which deterministically evolves according to Schrödinger's equation until wave ...
2
votes
1answer
67 views

How to get the linear and angular acceleration generated by a force vector field?

I am working on a physics simulation and I have to calculate the angular acceleration in degrees per seconds squared around the point on the object located relatively to the center of a vector field ...
2
votes
1answer
65 views

Curvature of a particle move

I'm simulating a particle movement following a normal distribution. How this is done: My particle has a constant speed v and every step the particle move, I ...
1
vote
0answers
13 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 ...
0
votes
1answer
59 views

How experimentalists put bounds on new physics at the LHC?

I would like to understand how experimentalists search for new physics at the LHC. Lets imagine I want to use the LHC data to put a bound on the coupling of some new physics effective operator, say, ...
0
votes
2answers
50 views

Gaussian beam modelling, location of the beam waist?

In reference to the specifications of a laser diode below: http://www.thorlabs.de/thorcat/11900/L780P010-SpecSheet.pdf I wish to be able to model it as a gaussian laser beam. I understand there is a ...
0
votes
0answers
32 views

Need to Zero Angular Momentum

I'm writing a molecular dynamics simulation and need to zero the angular momentum of a collection of particles. For each particle I know the location, mass and velocity. My rotational physics is a ...
1
vote
1answer
26 views

Computing the Initial Velocity of an orbiting body

I'm working on a simulation program that replicates the movement of planets around a large celestial body (the sun). This is a three dimensional simulation that uses vectors. At present, I'm ...
0
votes
1answer
43 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"?
6
votes
1answer
89 views

How close to the critical point is sufficient close for measuring critical exponents?

I am learning Monte Carlo and just manage to simulate a phase transition by computing the heat capacity or the susceptibility. I wish I can also compute critical exponents.To this purpose, I have read ...
0
votes
1answer
110 views

Monte carlo simulation for continuous spin model (e.g. XY or Heisenberg model)

Unlike the Ising model, the XY model and the Heisenberg model have a continuous spectrum. So one need discretize them for a numerical simulation. But how to make sure the discretization procedure ...
0
votes
1answer
34 views

Ideas for physics-related simulations to code up as weekend (or monthly) projects [closed]

What are some good ideas for simulations that I could try to implement/code in my spare time just for educational purposes? I'm thinking that it would be a good way for me to delve into the underlying ...