What is Simulations: Definition and 116 Discussions

A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of models; the model represents the key characteristics or behaviors of the selected system or process, whereas the simulation represents the evolution of the model over time. Often, computers are used to execute the simulation.
Simulation is used in many contexts, such as simulation of technology for performance tuning or optimizing, safety engineering, testing, training, education, and video games. Simulation is also used with scientific modelling of natural systems or human systems to gain insight into their functioning, as in economics. Simulation can be used to show the eventual real effects of alternative conditions and courses of action. Simulation is also used when the real system cannot be engaged, because it may not be accessible, or it may be dangerous or unacceptable to engage, or it is being designed but not yet built, or it may simply not exist.Key issues in modeling and simulation include the acquisition of valid sources of information about the relevant selection of key characteristics and behaviors used to build the model, the use of simplifying approximations and assumptions within the model, and fidelity and validity of the simulation outcomes. Procedures and protocols for model verification and validation are an ongoing field of academic study, refinement, research and development in simulations technology or practice, particularly in the work of computer simulation.

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  1. D

    Multidimensional time simulation

    If there are computer simulations of four-dimensional space are there any possibilities to digitally simulate a space -time with time having more than one dimension? Please, leave some related links, if possible.
  2. S

    Engineering FEA Results interpretation for these 3 simulations

    Hi Im slightly stuck not sure what i put is ok. FEA was used to carry out analysis on 3 structures and diagram results obtain (no data) Explain where the first point of failure is likely to originate, and why. An analysis of the studies, do you think that they will be an accurate...
  3. Z

    A Order of rotations due to torque in 3DOF in simulations

    Hi, I am running a computational fluid dynamics (CFD) simulation. Supposed I have a symmetrical rigid body in space experiencing torque in the global x,y,z axes. It is stationary at t = 0. I also constrain it to only allow rotations in 3DOFs, and no translation. It will rotate and I need to...
  4. C

    A N-Body Simulations of Chaos in the Orbits of Trappist System Planets

    As a retired physics professor with a long experience in complex simulation software for high energy physics experiments (e.g. the LHC) I revisited last July the n-body planetary simulations which I taught in an undergraduate physics course during the Spring 2017. It was then that the...
  5. N

    Building My Physics Intuition: Seeking Good Simulations

    TL;DR Summary: Seeking good simulations to build my intuition Hi everyone, I am currently teaching myself classical mechanics, and am 3/4 of the way through "Vibrations and Waves," a textbook from 1971 which was used in the MIT course. It's going okay - I feel like I have a decent grasp of...
  6. user366312

    Polymer simulation source code in C++ and Python

    I am absolutely new to Polymer simulation. I am trying to understand the simulation by analyzing source code written by others. Can anyone tell me what are the differences between the following three source code in terms of their objectives? Monte-Carlo-simulation-of-polymers...
  7. e2m2a

    Creating Physics Simulations in Geogebra

    Does anyone know where one can find complete documentation on how to create physics simulations using Geogebra. I have searched everywhere on the internet and there really isn't any books or complete tutorials on the subject.
  8. E

    Electrostatic vs DC Conduction Simulations for E-field Analysis

    Hi, I am doing e-field simulations and have came across two types; electrostatic and dc conduction. I know that electrostatic means there is no changing field so I'm just hoping for discussion on when one is more appropriate than the other and when one definitely should or should not be used.
  9. U

    COMSOL: stress on a sensor, how to use infinite element domain?

    At the risk of waiting hours on simulations of a sensor, I was wondering if I could use infinite element domain on COMSOL to simplify it. The first image consists of what I would like to simulate but found out that the simulation time is a huge factor as I have a lot to simulations to conduct...
  10. KyleGranger

    Best high performance computer build for finite element simulations

    I want to build a high performance computer optimized for FEA. If anyone has any suggestions or experience with this, please chime in. I'm looking for suggestions on processors, RAM, video card, ALL of it!
  11. cindersky

    B Looking for Simulations of Exoplanets

    Is there any good simulation to test out radial velocity and/or maybe mess around with exoplanets? If there is please let me know! I want to try out this simulation where I change the luminosity of a star and see how the accuracy of the radial velocity changes, but a basic simulation would...
  12. S

    A All-atom simulation and coarse-grained simulations

    I am currently reading this [paper by Noid et. al.](https://doi.org/10.1063/1.2938860) on the rigorous bridge between atomistic and coarse-grained simulations. In the paper, he defined a linear map from the atomistic coordinates and momenta $$\mathbf{r}^n, \mathbf{p}^n$$ to the coarse-grained...
  13. J

    Best Environment/Programming Language for simple physics Simulations

    Hello, I am looking for something to simulate/visualize simple particles and classical physics equations, preferably moving in real time Requirements: -Able to turn matrices/functions into geometric representations(visualize sphere, visualize a cylinder etc.) -Can do the classic ball bouncing...
  14. M

    What computer setup for CFD simulations 1000$-2000$ budget?

    I'm running computational fluid dynamic simulations and am looking into building a desktop. But there are so many options. At this budget, what would you buy? Is it better to buy used CPUs, etc?
  15. S

    Periodic Boundaries in Molecular Dynamics Simulations

    In molecular dynamics people use periodic boundaries to confine particles being simulated. I read here that they are used to simulate large "infinite" particle systems. How can I know that the periodic boundary is simulating actual molecular outcomes for a finite particle system that had a large...
  16. Eagle9

    Advice Needed: 3D Programs for Biological Simulations

    Good day! I need your advice in computer graphics :smile: I have been studying and working in Autodesk 3ds Max for years, mainly for my pleasure. Now I want/need to study some new 3D program in CG, however not for just fun but for science. Particularly I need such program that enables showing...
  17. Arman777

    What Should I learn to do N-body simulations?

    What Should I learn in terms of concepts to do N-body simulations ? Is there any books that I can follow in this process ? Thanks
  18. J

    Calculating drag and pressure forces from numerical simulations

    So as stated, I am calculating the pressure and drag forces on an obstacle, but have trouble with which velocities to take. This is my geometry: http://shrani.si/f/3l/13P/2Tihb3iM/projekt2.png . I am guessing that I have to take pressure just before the obstacle and just after the obstacle and...
  19. B

    Physics Jobs in numerical simulations with a BSc in Physics?

    Just finished my Bs.c with a minor in CS. At the end of my degree I did a reserch project where I numerically solved a nonlinear PDE and enjoyed the numerical simulation work. What is the best path to do similar work in the industry? I don't mind simulating models from outside of physics, such...
  20. T

    Computational Physics Simulations

    I am currently learning python and c++ and interested in the near distant future on exploring some computational physics simulations. But have seem to hit a road block. I have just finished my undergrad in physics and have some time to explore physics concepts that were never really cleared up...
  21. Spinnor

    I Most-detailed-ever simulations of a BH solve long standing mystery

    "An international team has constructed the most detailed, highest resolution simulation of a black hole to date. The simulation proves theoretical predictions about the nature of accretion disks—the matter that orbits and eventually falls into a black hole—that have never before been seen. The...
  22. A. Neumaier

    I Numerical simulations in Bohmian mechanics

    With respect to the following posts from a now closed thread, https://www.physicsforums.com/threads/copenhagen-restriction-on-knowledge-or-restriction-on-ontology.968982/post-6169047...
  23. BryanCasanelli

    A Dissociative ionization Monte Carlo simulations

    Hi, I'm wondering if there any exists a Monte Carlo free code that can simulate dissociative ionization, per example a beam of protons on water, and then track the fragments (from water) and their energy. Thanks in advance!
  24. J

    Fortran Physical time (years) in simulations

    Hello My name is Joseph I am a physics student, I am new to Fortran, I know how to write a code for solving differential equations, but now I have a physics equation for evolving star rotation as a function of mass. and I do not know how to evolve (using any numerical method, such as Euler) so...
  25. K

    I Simulations that disprove the PBR theorem

    What is an example of an experiment that if you were to simulate using hidden variables would violate the PBR theorem's conclusion? If you were able to simulate the EPR experiment using photons, one entangled photon pair at a time, and get results that are indistinguishable from experimental...
  26. Syed Alam

    Pin-by-pin core simulations without spatial homogenization

    How can we achieve "higher-resolution" 3D pin-by-pin core simulators "without spatial homogenization" for the nuclear reactor core (PWR/BWR) calculations? In regards to this question, is it okay to perform "pin-by-pin fine-mesh core calculation" and/or "cell-heterogeneous detailed transport...
  27. A

    I Uncertainty of MonteCarlo Simulations: Weight and Error Bars

    Hello everybody, I need a help, primarly a confirmation about my reasoning. I have data from a MonteCarlo simulation of collisions between particles at LHC (made with Madgraph). I have plotted some variables, for example the angle between two final leptons. Then I have normalized the plot to a...
  28. G

    A How can I simulate 2D correlated data with continuous-valued variables?

    Not sure this is the right area to post this. Let's say I have particles on a lattice, and they all have some property (ie, color) that is correlated at some known correlation length. I want to simulate this! In 1D I could do something like have color be a random walk in the given dimension...
  29. G

    A Phase Space and Its Use in Monte Carlo Simulations of Radiation Beams

    In the field of medical physics, specifically in monte carlo simulation of radiation beams produced by electron accelerators, people call ‘phase space’ to a file that contains the data of a large number of particles when they traverse a reference surface in the machine (usually a plane), i.e...
  30. SchroedingersLion

    Exploring the Nosé Hoover Thermostat for MD Simulations

    Hi, is anyone here familiar with the Nosé Hoover Thermostat for the realization of a canonical ensemble in a molecular dynamics simulation? I have a few questions to the derivation and I only have the original paper of Nosé where the basics are derived. I uploaded it here...
  31. Ranku

    I N-body Simulations: Density vs Circular Profiles

    N-body simulations of rotating galaxies involve density profile and circular profile. Would it be accurate to say that the essential difference between density profile and circular profile is that the former involves gravitational mass while the latter involves inertial mass?
  32. O

    What is the Best 2D Physics Engine for a Real-Time Simulation Program?

    Hello! I'm trying to write a 2D program that uses simple physics. I was wondering what would be the best 2D physics engine to use in my case, and if it even matter what engine I choose. I also want my simulation to run in real time, so at least 30 fps on a decent home computer. I prefer a fast...
  33. M

    I Orbit simulations, tidal forces and planetary oblateness

    How does one correct for tidal forces when (classically) simulating the orbits of solar system bodies?
  34. X

    Velocity of the center of mass for MD simulations

    When calculating the center of mass for an MD simulation, I've seen a few codes that subtract the average velocity from each atoms velocity. I think the reasoning behind this is that you want the velocity of center of mass for the simulation to be zero, which I understand, but I don't understand...
  35. lpetrich

    Weather/Climate and Ocean-Circulation Simulations?

    I'm curious about the amount of computing that it takes to do weather/climate and ocean-circulation simulations. Does it usually take some supercomputer? Has anyone ever tried doing both climate and oceans? That's because poleward circulation warms high-latitude areas, something familiar for...
  36. lpetrich

    I How much number crunching is necessary in some simulations?

    I've seen simulations like these, simulations that were done in *very* gory detail, and simulations that apparently required a large number of CPU cycles and a large amount of memory space. Cosmological structure formation and galaxy formation Collisions of galaxies Formation of planetary...
  37. P

    A GADGET2 Simulations: Fixing N-GenIC Error

    So this is a pretty specific technical question - but if anyone has experience running the N-body simulation GADGET2, I'm generating initial conditions using N-GenIC, and trying to turn on gas particles in the makefile gives the same error as described here...
  38. P

    Simulations and Experimental Physics

    I'm an undergrad trying to figure out what career I want to pursue. I consider myself very good at math and physics and enjoy them, however I know that I definitely do not want to go into purely theoretical physics. I have been thinking about what I want to do for a while now and it occurred...
  39. S

    I Exploring Structure Formation with Cosmological Simulations

    Hello! i am an undergraduate and I started working with a professor doing numerical simulation of cold dark matter. I understand (more or less) the physics behind and the results are very close to observations, which is a good support for the existence of dark matter. However, I can't see the...
  40. M

    "Fluid particle is an abstraction" (ANSYS simulations)

    What does "fluid particle is an abstraction" mean? https://confluence.cornell.edu/display/SIMULATION/Big+Ideas%3A+Fluid+Dynamics In the second vid. Thank you.
  41. A

    Software for laser simulations

    Hello everyone, I'm searching for a software for simulating laser beams, their intensity, power, reflections, arrangement of mirrors, etc. I searched for a while but I couldn't find what I need. Any suggestions would be appreciated.
  42. N

    I Why Monte Carlo Simulations? What do they tell us?

    I am an undergraduate working in my university's high energy physics lab. I'm still new to particle physics, so I have to learn/understand a bunch of things on the fly. We are currently searching for a new state theorized to occur in a specific decay process. I know we have to work with data...
  43. Kaura

    Engineering Software for Mechanical Simulations

    I am a first year Mechanical Engineering Major I am wondering if there are any good computer program that I could use to simulate the physics and properties of potential designs The other day I saw something about Da Vinci's famous cryptex and this peaked my interest into designing and building...
  44. S

    Mathematica Numerical Simulations with Mathematica: A Beginner's Guide

    I'm very new to Mathematica/programming and I want to do a theoretical calculation using Mathematica, suppose I have, ##Y=CX,~~~C=constant## Now, I want to plot Y vs. X but X should run at every point since every point is a solution for Y, how should I do this? Before, I was thinking maybe I...
  45. K

    Changing circuitry of analog computer *During* simulations?

    I am wondering whether it would be possible for the analog circuitry itself to change DURING the time an analog computer does computations. Over and above the above mentioned question, is it possible that the circuitry itself can change DURING simulations, while this change in the circuitry is...
  46. R

    B Stat Problem that I solved using simulations; verify answer

    Someone posed this Stat / Probablity problem to me: Two teams A vs B play a tournament of seven games against each other. First team to won 4 games wins the tournament. The games are split over each team's home stadium as A A B B B A A. Historically the home team wins a game 55% of the time...
  47. A

    C/C++ Getting Started with C++ (for N-Body Simulations)

    Hello all. I don't really know what to exactly ask from any of you other than how I should get started with C++ programming to hopefully create N-body simulations down the road. How to exactly start, I'm not entirely sure. For a little about what I know, I know python extensively. I use it...
  48. ElPimiento

    Cosmology Book for someone new to N-Body Simulations

    Hi, I'm interested in research on the formation of dark matter halos and was hoping that I might, in the future, run an N-Body simulation on the subject. However, I do not have any experience with N-Body simulations. I only know C, but I am learning Python. So, does anyone have a suggestion for...
  49. A

    Understanding F6 Tallies in MCNP Simulations

    Hi, I'm working on a MCNP simulation where I have to use F6 tallies. According to the manual: "In the F6 and +F6 tallies, material density is available for the chosen cells, and normalization is MeV/gm/source-particle." To which source-particles is this value normalized: the source-particles...
  50. ChrisVer

    A How reliable are MC simulations when it comes to jets?

    I have been reading in papers here and there, that di/multi-jet MC generated or even other process that have one or more associated jets are used for tag-and-probing or for training several BDTs and so on. Some experiticians (theoreticians who produce experiments) are also relying on how well...