# The Virtual Laboratory

What follows is a list of physics related Java Applets (also some VRML and Shockwave stuff) available on the Net. If you have made an applet available please register it here! It will appear on this page immediately!

You are also welcome to join the Java/Physics mailing list. The list is devoted to discussions on development and use of Java in physics education and research.

If you have comments please send them to the author or maintainer of that particular resource (not to us!). Most of this software is free, but some require licensing (up to you to check!).

### On-Line Physics Java Applets and VRML Resources

You can control an experiment online, the diffraction of electrons: Do the experiment by yourself or watch other people accelerate electrons. Parameter: acceleration voltage / Required: Java and JavaScript capable browser / Notes: work in progress, beta version
Lissajous Figures
Two independent, linear and perpendicular to each other oriented oscillations can create a two dimensional oscillation. The path of this resulting oscillation describes a so called Lissajous figure. The periods of oscillations, the amplitudes and the phase difference can be changed and the resulting effects can be observed. Daniel Roth - www.netzmedien.de
The Stern-Gerlach Experiment
This applets illustrates the measurement process in Quantum Mechanics through a simulation of the Stern Gerlach experiment for spin 1/2 atoms. The following aspects are depicted: difference between pure states and statistical mixtures; splitting of the wave packet; state vector reduction.
GeoPad is a general, modular, and open-source tool for visually manipulating vector and/or phasor relationships. For instance, the vectors that participate in a particular equation can be manipulated by dragging them. The expressions used to describe the results of the manipulations are typed in by the user, and may be arbitrarily complex.
Rotating Frame of Reference
While moving over a rotating frame of reference an object is leaving track marks. The user can change the initial position and velocity of the object and the rounds per second the rotating frame of reference should rotate with. Please note, that this applet ist a beta version (some bugs, too much bytes to download), so please read the accompanying notes. Thank you! Daniel Roth - www.netzmedien.de
Law of Refraction
A beam of light crosses the border between two media, its refraction can be observed. The user can change the angle of the inbound ray and the index of refraction of the two media. Daniel Roth - www.netzmedien.de
Projectile Motion in Two Different Frames of Reference
The motion of a projectile can be observed from two different frames of reference, a stationary and a free falling one. The user can change the value and angle of the initial velocity of the projectile and measure flight time. Daniel Roth - www.netzmedien.de
Creation of Polarized Waves
Two perpendicular polarized plain waves can be used to create a resulting wave, which is polarized in a different way. The user can change the amplitude of the plain waves and their phase difference. The resulting wave can be shown in isometric and projective perspective. Daniel Roth - www.netzmedien.de
Creating Interference with Transparencies
Black circles are printed onto two transparencies. The user can change the position of one of the transparencies and create interference patterns this way. Daniel Roth - www.netzmedien.de
Damped Harmonic Oscillator
A mass, attached to a spring, can oscillate in a damped, harmonic way. The user can change the initial position of the mass, the strength of the spring and the damping (Newton friction ~ velocity). The effect of the change of these parameters can be observed in a location versus time plot. Daniel Roth - www.netzmedien.de
Leonardo : interactive virtual science museum
Mathematical and physics interactive applications (mostly java applets) for educational purposes. The presentation of the material classified by time of acquisition and area of interest,is written in italian .A kind of ever changing virtual Exploratorium with new material added every day.
Evolution of Fermi-Dirac distribution with T
Fermi-Dirac distribution, Thermally excited electrons, 3D Electrostatic potential, The black-body, Double slit experiment of Young, Mott conductivity.
Motion of centre of mass
Applet shows the behaviour of centre of mass of a dumbbel shaped object projected in to the air. Mirror site http://surendranath.tripod.com/CM/CM.html B.Surendranath Reddy. Hyderabad (INDIA)
Fundamentals and harmonics of a vibrating system
Sodaplay: The online toy where you can build and play with things made out of masses, springs and muscles
Interactive Java Applet from the Institute for Transuranium Elements allows the simulation of the radioactive decay of over 2000 radionuclides using standard colour schemes (Karlsruhe, Strasbourg, General Electric). Basic decay data can be viewed by holding the mouse over a nuclide and consists of half-lives, modes of decay, and branching ratios. "Blinking" nuclides indicate strong gamma emitters with energies above a user-definable threshold value.
The location of a supersonic airplane
What will you hear if a supersonic airplane flying over you? Do you know where the airplane is when you hear it? Can you point out the direction of the airplane (just from hearing the sound)? (Fu-Kwun Hwang)
Effective index mode solver for dielectric multilayer rib waveguides
Similar to its 1-D counterpart (see "Mode solver for planar dielectric multilayer waveguides"), this applet calculates and visualizes the guided fields of dielectric integrated optical waveguides with two-dimensional light confinement. Note the remarks on the effective-index approximation the mode solver relies on.
Mode solver for planar dielectric multilayer waveguides
Following the definition of a 1-D dielectric waveguide in terms of refractive indices, layer thicknesses, and the vacuum wavelength, the applet calculates the propagation constants of guided modes and allows to inspect the corresponding optical field patterns. Beeing intended as a basic (illustrative) tool for integrated optics design, i.e. in Electrical Engineering, the applet may find some interest in Applied Physics as well.
Electric Field Lines
Java applet helps visualise electric field lines and equipotentials due to a pair of charges. Surendranath Reddy. B. Hyderabad, India.
Visualization of the Orientational Order-Disorder Phase Transitions in Plastic Molecular Clusters
We have animated the disorder-order transformation s that occur in tellurium hexafluoride clusters at different temperatures. In these clusters the octahedral TeF6 molecules are reorienting in a complicate way that depends on the intermolecular interactions and the cluster temperature and behave as hindered rotors.
Image formed from rays of refraction or total internal reflection
If you like my previous applet (world viewed under the water), you will like this one even better. You can draw any shape and the applet will find the image for you. You can be an observer above water surface or under water. Total internal reflection make the world viewed under water different from what you have in mind. Come and play with it. (Fu-Kwun Hwang 062400)
Encyclogram - plots harmonograms, spirographs, Lissajous figures.
Encyclogram draws harmonograms, spirographs, and Lissajous figures. The decaying motion of the plot fills in the shapes with their spiralling-in echo. Encyclogram can also draw the curves in varying colors against a black background, resulting in breath-taking works of art that can be as beautiful as fractals.
Multiple reflections from two plane mirrors
Check out how multiple images were formed with two plane mirrors. Play with it and learn physics behind the animation! Fu-Kwun Hwang (050600)
Game to play with mirror. Play with it and learn physics behind the animation! Fu-Kwun Hwang (050600)
Mirror, reflection and image
A mask with different colors and a point source show you how an image is formed. Play with it and learn physics behind the animation! Fu-Kwun Hwang (050600)
Digital Embryo
Review: The multi-dimensional human embryo project has an extensive collection of magnetic resonance images of both human and mice embryos at different stages of development.
Ising Model and Chaos
Demonstrate some basic idea of physics simulation about Ising model, Monte Carlo simulation , bifurcation map and Chaos.
Charged particle 2D motion in uniformed magnetic field
This java applet let you play with 3 charged particles. Drag particle to differ region and change its velocity, then RIGHT CLICK to start the animation. Learn how charged particle moved in the uniform magnetic field. Come and visit Virtual Physics Laboratory at NTNU with more than 60 physics applets. (FU-Kwun Hwang 031400)
VRML model of a flexible sheet showing 2d waves
A VRML model of a flexible sheet which can be disturbed using the mouse. The 2D wave propagation can be observed as the wave equation is solved in real time.
VRML model of magnetic chaotic pendulum
A VRML model of a pair of magnetic pendulums. One of two final states are possible for each pendulum. A fractal basin of attraction is shown. The model is fully interactive: initial conditions, strength of gravity & magnets can be set. Sensitive dependence on initial conditions is demonstrated.
Wave Interference
This Macromedia ShockWave applet illustrates visually the concept of interference of transversal waves. The user can set the shape of two wave and watch the interference pattern. (12/30/99, Pascal Renault )
Composition of Velocities
This Macromedia ShockWave applet illustrates visually the concept of velocity composition by showing the velocity vectors relevant to the motion of a boat on a river. (12/30/99, Pascal Renault )
Particles Diffusion
Simulation of the brownian diffusion of particles into a fluid, measuring the standard deviation and a graph of the radial density.
RLC circuit - Complex impedance
This Macromedia ShockWave applet illustrates visually some aspect of complex impedance in RLC series circuits. The user adjusts the values of R, L, C, and f using sliders. The applets displays the corresponding complex impedance diagram and the conducdance versus frequency graph. (11/20/99, Pascal Renault)
Real-time acceleration and velocity
This Macromedia ShockWave applet allows the user to click and drag a puck on the computer screen. The applet displays the velocity and acceleration vectors in real time. (11/20/99, Pascal Renault)
Accommodation
This Macromedia ShockWave applet illustrates the principle of accommodation in the eye. The user adjusts the distance between eye and object by clicking and dragging. The applets updates the ray tracing diagram, the image size, and the lens shape in real time. (11/20/99, Pascal Renault)
Vector Composition
This Macromedia ShockWave is an adding machine for vectors. The vectors to be added can be adjusted by clicking and dragging. The applet displays the polar and rectangular coordinates for the two vectors to be added and for their resultant. The head to tail vector addition principle can be verified graphically. (11/20/99, Pascal Renault)
4 nodes DC-VRLC circuit simulation
This is a 4 nodes DC circuit simulation java applet. You can drag DC voltage source, Resistor, Inductor, Capacitor or connector between any two nodes. You can change parameters for the selected element. When the circuit is complete, it will turn into simulation mode. You can watch the voltage variation of each node as a function of time. Enjoy it! Fu-Kwun Hwang 09/28/99
Visual Aided Physics
Development, Implementation and Evaluation of a Module to teach Physics via Internet using Java Applets to simulate General Physics Problems and Solutions. Ongoing project at Dept. of Physics,Universiti Putra Malaysia. Please give your feedback to improve this site. Thank you.
Composite Laminate damage evolution VRML/java applet
This is a website using advanced simulation techniques to model the behaviour of materials. In particular, the evolution of damage in a composite laminate is simulated. A Java applet allows input of model parameters and the results of the simulation modify a VRML model of the cracked laminate. There is also technical background to the system and simulation techniques. There are also surface visualisations using VRML, a simulation of electron backscattered patterns and a few experimental models.
CAOS - one-dimensional binary cellular automata
CAOS simulates one-dimensional binary cellular automata. Beside general rules it also features symmetric and totalistic rules. Rules can be specified either by clicking on checkboxes or entering the numerical representation. CAOS supports also several display modi: scrolling, wrapping or page display.
Some General Physics Java Applets
Java applets to help understanding of some basic physics ideas. Applets deal with simple harmonic motion, wave motion, planetary motion etc. (Surendranath Reddy. B., Hyderabad, India, 27th March 1999)
Mixing light beams or paint pigments / magic of color
Thomas Young, in the early 1800s, showed that a broad range of colors can be generated by mixing three beams of light, provided their frequencies were widely separately. When three such beams combine to produce white light, there are called primary colors. This java applet let you mixing light beams or paint pigments, and fine out the magic of color TV/computer screen. (032299 Fu-Kwun Hwang)
The Northwestern Virtual Physics Lab
Java Applets from the department of Physics and Astronomy at Northwestern University
Quantum states of the light field, introduction and experiment
The page intends to give a non-technical, intuitive introduction to the quantum theory of the light field. Recent measurements are employed to illuminate abstract quantum mechanical concepts such as the uncertainty relation, the wave packet, quantum noise, squeezed light, Wigner functions etc. using the concrete experimental example of the freely propagating light field.
Wavemotion Applet
Applets to help bring home the concepts of Longitudinal and Transverse Wave Motion (Surendranath Reddy.B, Hyderabad, India)
Fermat principle
This java applet let you visualize "the path of a ray of light between two points is the path that minimizes the travel time" (known as Fermat principle). Try/play with it and learn physics! (Fu-Kwun Hwang 120898)
Physics of reflection and refraction
This java applet illustrate the physics of a beam of light impinging on water/air surface. You can select flashlight or laser pointer as light source, toggle between flat/rough surface ... Enjoy/Play this java applet and learn some physics behind it!(113098 Fu-Kwun Hwang)
The IFMSA WebLab
Mathematical and physics java applets for educational purposes. It is written in italian and the applets are classified by area of interest. Contribution is free, a link is the price. A web course always "work in progress".
Three body dynamics simulation
The programs simulate and visualize classical two-dimensional dynamics of three bodies. Particle positions are shown with disappearing trails and that allows to track their trajectories without hampering the view and to visualize particle chaotic movement.
Phase and Group Velocity
This applet allows you to change the group velocity of a sine wave with constant phase velocity. It is a simple visual aid.
Orrery Applet - Gravitation Simulation
Gravitation simulation applet. Zoom or center on any body. Solar system model of 70 planets and moons with orbits and bodies to scale. Demos of Lagrange points, solar system instability, gaps in the asteroid belt and more. Destroy and recreate bodies with the mouse. Make your own models by editing HTML files. Requires Java 1.1 capable browser.
Newton's Cannon
Newton described the possible trajectories of a cannonball shot from a tall mountain. The applet lets the user fire cannonballs around the earth at different velocities. It is a good picture of how a satellite falls around the earth.
Projectile Motion
This applet shows the traditional problem of shooting a cannonball. While there is no pretty cannon, it does use correct units and gives a clear picture of trajectories. There are options to show trails of the projectile or to turn on a simple air friction.
Brownian Motion
This is a simple demonstration of Brownian Motion. It shows little particles batting about a more massive one and what it would look like if you could see only the massive one through a microscope.
One-dimensional One-atom Gas
This applet describes a single atom gas moving in one dimension. It accelerates or decelerates only through classical collisions with the moving piston on its container. This alone is enough to explain why the gas gets warm when compressed and cool when expanded.
Two-dimensional Collisions
Watch the collision of two balls simultaneously in a lab frame and a center of mass frame. Change the impact parameter and ratio of masses.
Generator
Simulation of a simple AC or DC generator. The applet illustrates the explanation of the induced current by the Lorentz force. You can change the rotational speed and see the influence on the induced voltage.
Direct Current Electrical Motor
Simulation of a simple DC electrical motor. The applet shows the directions of current, magnetic field and Lorentz force and illustrates the function of the commutator.
Optics Bench
Simulate a standard optic bench with lenses, mirrors, dielectrics, and sources and observe the ways that light rays propagate through these elements. The applet is designed to be scripted but may also be used to construct optical systems using a click and drag metaphor.
Space and Time in Special Relativity
The special theory of relativity is the result of two postulates: 1. The laws of physics are the same in all initial reference frames. 2. The speed of light in empty space is the same for all inertial frames. From the above two postulates, our understanding of space and time has to be modified. This java applet invites you to the world of space and time in special relativity. (Fu-Kwun Hwang 091498)
Multimeter(Voltemeter/Ohmmeter/Milliemeter)
Ammeters measure current, voltmeters measure voltage, and ohmmeters measure resistance. These devices are often combined into one instrument called a multimeter or VOM(volt-ohm-milliemmeter). Analog versions of ammeters and voltmeters typically utilize a galvanometer, which relies om megnetic effect. A needle is deflected by an amount proportional to the current passes through the device(coil). This java applet shows how to utilze a galvameter into a multimeter. (Fu-Kwun Hwang 090398)
Refraction and reflection
Shine a light from a ray-box into a semicircular glass block and observe refraction and internal reflection, just like the traditional experiment. Aimed at students around 12-15 years old. I hope this is useful in the classroom environment - Gareth James.
Sun & Earth Applet
The applet displays the position of the sun (height and azimuth) for any date, time and location, and an interactive world map with day and night areas. The times of sunrise and sunset, the declination, the Greenwich hour angle of the sun and the equation of time are computed.
The Pendulum Lab
The Pendulum Lab is a combination of a virtual laboratory (with Java applets) and a mini-course in nonlinear dynamics. In the lab you can do hands-on experiments at a rigid pendulum driven in four different ways. Together with the material presented in a lecture room, you can learn basic issues like harmonic oscillator and resonance but also advanced topics like parametric resonance, nonlinear dynamics, and chaos.
Billiards and Physics
This java applet show you how to use the law of reflection (for optics) in playing pool. Enjoy it! (Fu-Kwun Hwang 070998)
En beskrivning av mekaniken med hjälp av Java
This is an attempt to visualise physics with the help of Java applets. The site is completely in Swedish, so also this abstract. Meningen är att man ska introduceras i fysiken med hjälp av Java och sedan kunna fördjupa sig genom att läsa någon av de tillhörande html sidorna.
Brownian Motor
Java applet which simulates a Brownian motor. A Brownian motor turns a random walk (i.e., Brownian motion) into a directed motion without violating the second law of thermodynamics. You can do hands-on experiments by changing the parameters interactively during the motor is running. This allows you to get a feeling under which condition a Brownian motor works as a motor.