Salt Diffusion

What does this Model Represent?

When scientists wish to probe the wood of ancient shipwrecks, they must first remove the salt that has accumulated within it from years of exposure to the ocean. They do this through diffusion - by submerging the wood in fresh water, the salt is slowly diluted to negligible traces.

What are the elements of this Model?

This model represents a recursive simulation of salt concentrations in areas, represented by numbers in Excel cells. The values in Column B determine the qualities of the model. The initial concentration determines the initial “salt value” of each cell at the beginning of the model. The start value is used to refresh the simulation, while the iteration value counts the number of iterations of the simulation.

How do I use this Model?

First, set the value to zero and press [Ctrl] [=] to restore all values to the initial concentration. Then, set the value back to 1 to begin. Pressing [Ctrl] [=] moves the simulation forward one iteration.

What should I expect?

The cells without numbers are considered to be “fresh water” and always have an effective salt value of zero. Thus, the salt concentration of the other cells will continually decrease and approach zero as well. This decline is exponential, so doubling the initial concentration will only slightly increase the number of iterations required to reach zero.

Download the model file.