Finding new ways to see the world
Modern Physics
Jump to:
Jump to:

Modern physics deals with many concepts that elude simple visualization. The following applets are designed to help address some critical points in a student's understanding. Most are still under development and many have accompanying lesson plans and ancillary files. You can view them from here but will need to go to the downloads page to download these applets.

Motion of Charged Particles in Magnetic and Electric Fields

These 2 applets allow the user to to examine the effects of magnetic fields alone or both magnetic and electric fields on a charged particle. Each applet has a measuring tool that enables the user to measure the radius of the trajectory of the particle. The user may also select particle type as well as vary the velocity and field strengths. Relativistic calculations are used throughout. Click on the links to run these applets (make sure pop-up windows are enabled on your browser). Teaching lessons are available by clicking on the Resources menu.

Particle in a Magnetic Field (2D)

Particle in Magnetic and Electric Fields (2D)

Android and iOS apps available! Go to GooglePlay or iTunes


Motion of Charged Particle in Magnetic and Electric Fields - 3D

Examine how magnetic and electric fields affect the motion of a charged field in three dimensions. Run Applet


The Cloud Chamber
cloudchamber This applet simulates the operation of a cloud or bubble chamber. The user can select a number of decay modes, adjust the magnetic field to match the mode and measure radii or tracks in the chamber. A built in calculator assists the user in measuring particle energy. Run Applet

Compton Scattering
The fundamental particle-aspect of light is illustrated in this applet. Users can select an x-ray photon and observe momentum and energy conserving collisions with an electron. A simple measuring tool enables users to measure the scattering angle for both the photon and electron.
Run Applet

The Cyclotron
This applet simulates the operation of a cyclotron and helps reinforce the concept of the cyclotron frequency. A variety of particles can be accelerated and the change in energy can be observed graphically. When the cyclotron frequency is not achieved some very interesting trajectories result! Run Applet cycltron

Thomson's e/m experiment
Thomson Experiment Applet

An interactive schematic of Thomson's Experiment. The user can recreate the entire experiment by modifying current and voltage. The user may also choose to view an electron beam, or a moving particle, charge and magnetic pull representations. For comparison and graphing, the data can be collected systematically into a list to be used in projects or other programs. Run Applet You may also wish to explore the following JAVA applet from the Modular Approach to Physics (MAP) project go to Charge/Mass.

The Photoelectric Effect

This applet simulates von Lenard's and Millikan's experiments which provided the experimental understanding of the photoelectric effect and eventual acceptance (albeit reluctant) of Einstein's quantum hypothesis. The applet permits data acquisition for simulated photoelectric effect experiments and contains a library of commonly used metal cathodes.

(JS version temporarily unavailable)

Android and iOS apps available! Go to GooglePlay or iTunes

If running this applet on a Mac, follow this link.


Particle in a 1-Dimensional Box
1dbox This applet helps users to visualize the strange world of the quantum. In this case the classic particle in a 1D box is shown, along with the connection between the box, wave functions, and energy levels. Users can also relate the 1D-box model to actual molecules that can be described as 1D boxes. Run Applet

Nuclear Stability
This is a beta version of an applet that helps students visualize the conditions for nuclear stability. A graphical comparison is made of the affects of the strong nuclear and electrostatic forces as well as the effect of asymmetry in nuclei. The applet can also be used to estimate nuclear binding energies. Run Applet

Radioactive Decay
In this applet, radioactive decay is illustrated via a simulated Geiger counter. A database of radioactive elements (sorted as alpha, beta or gamma emitters) provides sample data. Students can plot the decay and fit a decay curve to the data and from this determine the half-life of the element.Run Applet

Nuclear Potential - Strong Interactions
This is a beta version of an applet that helps to illustrate the forces involved in the binding of nucleons. In the current case a pair of protons are brought together. The resulting potential energy for the configuration is displayed in a graph. Run Applet

Millikan-Like Experiment

This is a beta version of the classic Millikan experiment. It is not, however, as complex as the actual experiment. The user sees one drop at a time and the assumption is that it falls in a vacuum. By adjusting the voltage between the plates, the student attempts to have the drop reach terminal velocity. From this the charge on the drop can be deduced.

Follow this link to a complete suite on Millikan which includes a demonstration of air resistance effects and a link to a much more realistic JAVA applet simulating the Millikan experiment.
Run Applet

If running this applet on a Mac, follow this link.

The Scanning Electron Microscope

This applet simulates the operation of the Hitachi TM3000 scanning electron microscope. You can look at many different objects with the applet and try some detailed science lessons that help you to understand how an SEM can be used to understand the world at the microscopic scale. This applet is a joint product of KCVS and the National Institute for Nanotechnology, Edmonton.

Run Applet


The Rutherford Experiment

This applet allows users to visualize what Rutherford believed would happen when he conducted his famous gold-foil experiment by interacting with a "raisin-bun" model of the atom.
Run Applet

This applet presents a historical recreation of the Geiger-Marsden experiment in which the existence of the nucleus was first established. The applet can be used to generate data for student analysis. Run Applet

After performing the Geiger-Marsden experiment, Rutherford theorized a new, nuclear model of the atom. By interacting with his model, users can test his model and compare it to the Thomson model. Run Applet

In this applet the user can investigate the behaviour of alpha particles as they interact with various nuclei. Data can be represented graphically or in tabular form for further analysis.
Run Applet
Scattering from various shapes and force laws can be illustrated with this applet. The applet can be used to help illustrate how scattering experiments can be used to elicit information about underlying structure. Run Applet
A link to a complete suite of digital learning objects as well as a brief introduction to the Rutherford experiment and links to literature about the experiment. Run Applet
© The King's Centre for Visualization in Science