# Computational Physics Applets

### Bilingual Chaotic Scattering

Classical scattering from four (attractive or repulsive) force centers. See the hypersensitivity of scattering angle to impact parameter (or view the source code: Disper2.java).

### The Wave Equation (Hyperbolic PDE)

eqstring.c, .java: A string is pulled and released. The initial string shape can be adjusted with the aid of scroll bars. (Standing wave if plucked in middle, travel at end.)
strsin.java: A normal mode solution to the wave equation (initial string shape is a sine wave).
twopeaks:The solution for two initial peaks.

### Heat Flow (Parabolic PDE)

eqheat.c, .java: The cooling of a bar initially at 100 degrees when it its end are set to 0 degrees.
twobars.java: The cooling of two bars in contact with different initial temperatures and ends fixed to 0 degrees.
barsin.java: The cooling of a bar with an initial sine distribution of temperatures and ends fixed to 0 degrees. Red denotes positive temperatures and blue negative.

### Quantum Wavepackets (Complex PDE)

harmos.f, .java: Wave packet in harmonic oscillaton potential.
sqwell.f, .java: Wave packet in infinite square well. (Eventually becomes chaotic.)
Asymetric wavepacket.f, .java: Asymetric wave packet in infinite square well.
Potbar.f, .java: Adjustable Wavepacket hitting adjustable barrier.
KronP.f , .java: Wavepacket hitting Kronig Penny potential.

### Quantum (or Very Simple) Monte Carlo

qmc.c, .f, Feynman path integral calculation (Monte Carlo simulation) of harmonic oscillator ground state. See the fluctuations in the classical trajectories as they generate the wave function.

area.c, .f, .java. Calculation of area of any shape via Monte Carlo "stone throwing" (basis of vonNeuman rejection).

### KdeV Solitons (Non Linear PDE)

soliton.f, .c, .java Solitons form as wavefront propagates.

### Fractals & Statistical Physics

sierpin.c, .java: Sierpinski Gasket. (Watch it grow.)
tree.c, .java: A fractal tree.(Watch it grow with an apple and moon.)
fern.c, .java: A fern fractal.
film .c, .java: Bilingual ballistic deposition of a film onto a surface with determination of fractal dimension.
column.c, .java Ballistic deposition onto a surface with correlated growth. The new deposited particle attracts other particles.
dla.c, .java: Diffusion limited agregation. A particle starts at a random point in a circle, a Gaussian random walk is generated, and if it finds another particle, it sticks to it. (Bell rings at center.)

### Bilingual General Physics Applets

Chaotic Scattering
Young's 2 Slit Interference
Hertzsprung-Russell Diagram
Photoelectric Effect
Lissajous Figures