File Archive Double

The GR Embedding program displays a representation of the curvature of space near a massive object. GR Embedding is part of a suite of Open Source Physics programs that model aspects of General Relativity. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the...

The GR Classical program simulates orbits of objects around a central mass using Newtonian mechanics. It also displays a plot of the effective potential well in which the orbiting particle resides. GR Classical is part of a suite of Open Source Physics programs that model aspects of General...

The STP IdealBoseGasIntegral program numerically determines the value of the chemical potential of an ideal Bose gas for a given temperature and density. STP IdealBoseGasIntegral is part of a suite of Open Source Physics programs that model aspects of Statistical and Thermal Physics (STP). The...


Platforms: Mac

The Falling Cup with Ball model shows a mass attached to the inside of a cup with a light spring. The cup is held upside down with the mass hanging out of the cup, then released from rest. What happens when the cup is released? 1. The mass will extend the spring, like a parachute, due to air...


Platforms: Mac

The GR Schwarzschild Particle program simulates orbits of objects around a black hole using the Schwarzschild metric. It also displays a plot of the effective potential well in which the orbiting particle resides. GR Schwarzschild Particle is part of a suite of Open Source Physics programs that...


Platforms: Mac

The STP IdealGasNumberOfStates program numerically evaluates the number of states of an ideal gas and demonstrates finite size effects by plotting the actual number of states and the asymptotic expression. The default is two-dimensional system (d=2). STP IdealGasNumberOfStates is part of a suite...


Platforms: Mac

The Ejs Wave Packet model displays the motion of an approximate wave packet. The simulation allows an arbitrarily wave packet to be created. The default dispersion relation, with the frequency equal to the wavenumber, results in a wavepacket that does not spread. The amplitude, maximum and...


Platforms: Mac

The EJS Earth Orbit model illustrates the Copernican theory of Earth's orbit around the sun. The top window shows a view from outside the celestial sphere. The simulation shows the moving Earth along with its axis or rotation and the line of sight from Earth, through Sun, to the Celestial Sphere....


Platforms: Mac

The Ejs Three Charged Particles model displays three charged objects, one at each corner of an equilateral triangle. The charges have different magnitudes - your job is to rank the charges based on their magnitudes, from largest to smallest. You can drag the charges around to see the effect on...


Platforms: Mac

The Local Coordinates model displays the position of a star in local (Altitude/Azimuth) coordinates. The horizon is shown along with the four cardinal directions (N, E, S, and W). The latitude of the observer is set at 35.5 degrees which sets the location of the north celestial pole (teal)...


Platforms: Mac

The Ejs Wave Representations model displays two representations of a sinusoidal wave on a string. One shows a movie of the wave traveling along a string - you can think of this representation as a sequence of photographs. The second representation is a plot of the displacement as a function of...


Platforms: Mac

The EJS Molecular Dynamics Demonstration model is constructed using the Lennard-Jones potential truncated at a distance of 3 molecular diameters. The motion of the molecules is governed by Newton's laws, approximated using the Verlet algorithm with the indicated Time step. For sufficiently small...


Platforms: Mac

The Noon Shadow model shows the geometry of the shadow cast by a gnomon at noon. Users can change the orientation of the gnomon as well as its latitude. The height of the gnomon and its shadow length are displayed in Earth radius units. It is a supplemental simulation for an article by Barbara...


Platforms: Mac

The Ejs Orbiting Mass with Spring Force model displays the frictionless dynamics of a mass constrained to orbit on a table due to a spring. The simulation displays the motion of the mass as well as the effective potential energy. The initial velocity, k/m, and the proper or natural length of the...


Platforms: Mac

The Ejs Duffing Poincare model computes the solutions to the non-linear Duffing equation, which reads, x'' + 2?zN*x' - x (1 - x2) = f cos(?Ya* t), where each prime denotes a time derivative. The simulation displays the solution Poincare plot. The evolution parameters can be changed via textboxes....


Platforms: Mac

The Spring Motion Model shows the motion of a block attached to an ideal spring. The block can oscillate back-and-forth horizontally. You can change the mass of the block, the spring constant of the spring, and the initial position of the block. You can then see the resulting motion of the block,...


Platforms: Mac

The Thin Film Interference model investigates reflection and transmission of light through a thin film. The user can change the thickness and index of refraction of the thin film as well as the incident light wavelength. The Thin Film Interference Model was created using the Easy Java...


Platforms: Mac

The EJS Ballistics and Orbits model displays ballistic trajectories near the Earth. The model shows the trajectory with respect to the inertial coordinate system and the trajectory as seen from a point of view that is co-rotating with the Earth. You can examine and modify this simulation if you...


Platforms: Mac

The Ejs Standing Waves on a String model displays the motion of a standing wave on a string. The standing wave can be augmented by adding the zero line and the maximum displacement of the string. The number of standing waves shown can be changed via a slider. You can modify this simulation if you...


Platforms: Mac

The Falling U-Shaped Chain model simulates the dynamics of a discrete falling chain with total length L and n links. Each link is acted on by the force of gravity mg and by the link-link interaction. A freely falling object is released near the last link for comparison. The surprise is that the...


Platforms: Mac