Compadre

The MDApproachToEquilibriumThreePartitions program simulates a system of particles in two dimensions interacting via the Lennard-Jones potential. The program shows the particles in the box as a function of time once the partitions dividing the box into three sections are removed.... Platforms: Mac

The STP SecondVirialCoefficient program numerically evaluates the second virial coefficient for the Lennard-Jones potential at various temperatures. The default is temperature range is 0.5 to 5. STP SecondVirialCoefficient is part of a suite of Open Source Physics programs that model aspects of... Platforms: Mac

The STP XY Model program implements a Monte Carlo simulation of the planar ferromagnet or XY Model of spins on a lattice. The simulation returns the configuration of spins with the option of showing the vortices. The default system is a lattice of linear dimension L = 20 at temperature T = 0.89.... Platforms: Mac

The QM Probability program displays the time evolution of the position-space wave function and the associated probability density. The default wave function is the n = 5 state in a ramped infinite square well. Additional states and other potential energy functions can be specified using the... Platforms: Mac

The Monte Carlo Pi program program uses a Monte Carlo routine to approximate pi by approximating the area of a unit circle. The program is distributed as a ready-to-run (compiled) Java archive. Double-clicking the ejs_stp_MonteCarloPi.jar file will run the program if Java is installed on your... Platforms: Mac

The Statistical and Thermal Physics (STP) Package contains read-to-run computer models and curricular materials for the teaching of statistical and thermal physics. You can choose from many different simulations and calculations ranging from probability distributions to Ising models. The STP... Platforms: Mac

The EJS Cellular Automata (Rule 90) model displays a lattice with any one of a finite number of states which are updated synchronously in discrete time steps according to a local (nearby neighbor) rule. Rule 90 is a specific nearby neighbor rule following the classification scheme developed by... Platforms: Mac

The EJS Radioactive Decay Distribution Model simulates the decay of a radioactive sample using discrete random events. It displays the distribution of the number of events (radioactive decays) in a fixed time interval. If each event is assumed to occur independently and spontaneously with a... Platforms: Mac

The EJS Binomial Distribution Model calculates the binomial distribution. You can change the number of trials and probability. You can modify this simulation if you have Ejs installed by right-clicking within the plot and selecting "Open Ejs Model" from the pop-up menu item. The Binomial... Platforms: Mac

The Ejs First Law model displays the dynamics of a ball subject to no net force. The initial conditions for the ball are an initial velocity in the x and y directions. The initial position of the ball can be changed by dragging it when the simulation is paused. You can modify this simulation if... Platforms: Mac

The EJS Kac Model simulates the relaxation of a gas to equilibrium by randomly selecting and then colliding gas molecules but without keeping track of the molecules' positions. As long as the collisions are consistent with spatial isotropy, the Boltzmann speed distribution will emerge. You can... Platforms: Mac

The QM Position Measurement program displays the time evolution of the position-space wave function and can be used to simulate the quantum-mechanical measurement of position. The default wave function is an equal-mix four-state superposition in the infinite square well. QM Position Measurement... Platforms: Mac

The EJS Radioactive Decay Model simulates the decay of a radioactive sample using discrete random events. It displays the number of radioactive nuclei as a function of time. You can change the initial number of nuclei and the decay constant as well as changing the plot to a semi-log plot. The... Platforms: Mac

The RandomWalk2D program simulates a random walk in two dimensions. The default number of walkers is 1000, and the probability of going right, left up or down at any step is the same. RandomWalk2D is part of a suite of Open Source Physics programs that model aspects of Statistical and Thermal... Platforms: Mac

The Ejs Hard Disk Gas model displays a two-dimensional gas made out of hard disks. Particles are initialized with a speed v=1 in a random direction and move with constant velocity until a collision occurs. You can modify this simulation if you have Ejs installed by right-clicking within the plot... Platforms: Mac

The Phase Matters package is a self-contained file for the teaching of phase and time evolution in quantum mechanics. The file contains ready-to-run OSP programs and a set of curricular materials. The material focuses on when and how, for arbitrary quantum-mechanical states, the phase of the wave... Platforms: Mac

The GR Kerr Light program simulates the path of light in the equatorial plane near a rotating black hole using the Kerr metric. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the gr_kerr_light.jar file will run the program if Java is installed. The default setting is... Platforms: Mac

The STP LJ2DMetropolis program is a Monte Carlo simulation of Lennard-Jones particles in two dimensions in contact with a heat bath. The default initial condition is a rectangular configuration of N=64 particles in a box of length L = 18 and a temperature T= 1. STP LJ2DMetropolis is part of a... Platforms: Mac

The Ejs Lagrange Top model displays the motion of a heavy symmetric top under the effect of gravity. The top has an initial angular speed that provides the precessional, nutational, and rotational speeds. The ratio of Lz to Lx can be set via slider and the initial angular position and angular... Platforms: Mac

The STP Hard Disks Metropolis program is a Monte Carlo simulation of hard disks in two dimensions. The default initial condition is a rectangular configuration of N=64 particles in a box of length L = 40. You can slowly increase the density of the gas (by setting the minimum scale length between... Platforms: Mac