Physics: Diffusion helps you to build your intuition for the diffusion process. Diffusion is a fundamental process in nature and has many applications: medicine delivery in the body, formation of transistors for computer chips, even the concentration of neutrons in a nuclear reactor are all explained by the diffusion process. Since heat conduction is governed by the same equation, you can also get a better understanding for how heat flows in a material.

This app simulates the one-dimensional diffusion process and allows you to create your own concentration profile, source/sink profile, and even varying diffusivity. Just select the parameter to vary, draw the profile with your finger, and run. Try different concentration profiles to see how - and how quickly - they change. Add sources/sinks to increase/decrease the concentration profile over time. Change the diffusivity to model different materials. Try different combinations to understand how they behave together.

To speed up the simulation (and editing the profile) on slower phones, press the 'hide' button. Then only the concentration profile will be shown while running, and only the profile you are editing will be shown while editing, making the app faster.

A source will be higher than the middle of the plot, a sink will be lower. In simulation, if a source causes the concentration to go higher than the plot limits, a red line will be shown. The simulation still correctly models the concentration, it just does not draw it.

This app is totally free, and no ads!

Note that this app will only work correctly in the landscape orientation.