# Physics 6805: Simulations and specialized software

• 21-Aug-2017 --- New and updated simulations.
• 18-Aug-2015 --- Created this separate page for Simulations and other software. Please send your suggestions for additions!

## Contents

### PhET Simulations

The PhET interactive simulations are produced at the University of Colorado, Boulder. They are written in Java, HTML5, or Flash and can be downloaded or run online. While they are mostly introductory in nature, they are accurate simulations that can be used for all levels of students. The descriptions in quotes are taken from the PhET website.

Fourier: Making Waves "Learn how to make waves of all different shapes by adding up sines or cosines. Make waves in space and time and measure their wavelengths and periods. See how changing the amplitudes of different harmonics changes the waves. Compare different mathematical expressions for your waves."
Wave on a String "Explore the wonderful world of waves! Even observe a string vibrate in slow motion. Wiggle the end of the string and make waves, or adjust the frequency and amplitude of an oscillator."
Wave Interference "Make waves with a dripping faucet, audio speaker, or laser! Add a second source or a pair of slits to create an interference pattern."
Photoelectric Effect "See how light knocks electrons off a metal target, and recreate the experiment that spawned the field of quantum mechanics."
Quantum Tunneling and Wave Packets "Watch quantum "particles" tunnel through barriers. Explore the properties of the wave functions that describe these particles."
Quantum Bound States "Explore the properties of quantum "particles" bound in potential wells. See how the wave functions and probability densities that describe them evolve (or don't evolve) over time."
Quantum Wave Interference "When do photons, electrons, and atoms behave like particles and when do they behave like waves? Watch waves spread out and interfere as they pass through a double slit, then get detected on a screen as tiny dots. Use quantum detectors to explore how measurements change the waves and the patterns they produce on the screen."
Double Wells and Covalent Bonds "Explore tunneling splitting in double well potentials. This classic problem describes many physical systems, including covalent bonds, Josephson junctions, and two-state systems such as spin 1/2 particles and ammonia molecules."
Build an Atom "Build an atom out of protons, neutrons, and electrons, and see how the element, charge, and mass change. Then play a game to test your ideas!"
Atomic Interactions "Explore the interactions between various combinations of two atoms. Turn on the force arrows to see either the total force acting on the atoms or the individual attractive and repulsive forces. Try the "Adjustable Attraction" atom to see how changing the parameters affects the interaction."
Isotopes and Atomic Mass "Are all atoms of an element the same? How can you tell one isotope from another? Use the sim to learn about isotopes and how abundance relates to the average atomic mass of an element."
Energy Skate Park: Basics "Learn about conservation of energy with a skater dude! Build tracks, ramps and jumps for the skater and view the kinetic energy, potential energy and friction as he moves. You can also take the skater to different planets or even space!" [Basics version.]
Alpha Decay "Watch alpha particles escape from a polonium nucleus, causing radioactive alpha decay. See how random decay times relate to the half life."
Beta Decay "Watch beta decay occur for a collection of nuclei or for an individual nucleus."
Nuclear Fission "Start a chain reaction, or introduce non-radioactive isotopes to prevent one. Control energy production in a nuclear reactor!"
Radioactive Dating Game "Learn about different types of radiometric dating, such as carbon dating. Understand how decay and half life work to enable radiometric dating. Play a game that tests your ability to match the percentage of the dating element that remains to the age of the object."
Simplified MRI "Is it a tumor? Magnetic Resonance Imaging (MRI) can tell. Your head is full of tiny radio transmitters (the nuclear spins of the hydrogen nuclei of your water molecules). In an MRI unit, these little radios can be made to broadcast their positions, giving a detailed picture of the inside of your head."
Stern-Gerlach "The classic Stern-Gerlach Experiment shows that atoms have a property called spin. Spin is a kind of intrinsic angular momentum, which has no classical counterpart. When the z-component of the spin is measured, one always gets one of two values: spin up or spin down."
Rutherford Scattering "How did Rutherford figure out the structure of the atom without being able to see it? Simulate the famous experiment in which he disproved the Plum Pudding model of the atom by observing alpha particles bouncing off atoms and determining that they must have a small core." [original non-HTML5 version]
Blackbody Spectrum "How does the blackbody spectrum of the sun compare to visible light? Learn about the blackbody spectrum of the sun, a light bulb, an oven, and the earth. Adjust the temperature to see the wavelength and intensity of the spectrum change. View the color of the peak of the spectral curve."
States of Matter: Basics "Heat, cool and compress atoms and molecules and watch as they change between solid, liquid and gas phases." [original non-HTML5 version]
States of Matter "Watch different types of molecules form a solid, liquid, or gas. Add or remove heat and watch the phase change. Change the temperature or volume of a container and see a pressure-temperature diagram respond in real time. Relate the interaction potential to the forces between molecules."
Plinko Probability "Play Plinko and develop your knowledge of statistics. Drops balls through a triangular grid of pegs and see the balls random walk through the lattice. Watch the histogram of final positions build up and approach the binomial distribution. Inspired by the Virtual Lab in Probability and Statistics at U. Alabama in Huntsville (www.math.uah.edu/stat)" [original non-HTML5 version]
Calculus Grapher "Draw a graph of any function and see graphs of its derivative and integral. Don't forget to use the magnify/demagnify controls on the y-axis to adjust the scale."
Estimation "Explore size estimation in one, two and three dimensions! Multiple levels of difficulty allow for progressive skill improvement."
Curve Fitting "With your mouse, drag data points and their error bars, and watch the best-fit polynomial curve update instantly. You choose the type of fit: linear, quadratic, cubic, or quartic. The reduced chi-square statistic shows you when the fit is good. Or you can try to find the best fit by manually adjusting fit parameters."
Least-Squares Regression "Create your own scatter plot or use real-world data and try to fit a line to it! Explore how individual data points affect the correlation coefficient and best-fit line."

### Applets for specific topics (Java or HTML5)

Single-Slit Difraction "This applet shows the simplest case of diffraction, i.e., single slit diffraction. You can change the color of the light by draging or clicking the spectrum selector. You may also change the width of the slit by dragging one of the sides. " [Java]
2D Ising Model From Daniel Schroeder. "This is a simulation of an idealized two-dimensional magnetic material in which each particle can have only two possible alignments, represented by the two colors." [HTML5]
2D Ising Model "Simulation of the Ising model. You can choose between two update methods - metropolis and Wolff algorithm. Several measurements are stored while running including the current energy and magnetization, their averages, and their variances."
Single and double slit simulation From Andrew Duffy at http://physics.bu.edu/~duffy/classroom.html. Observe the diffraction/interference pattern when you adjust slit size/separation and screen distance and light wavelength for one or two slits.