SimuLab 11: Building an Aggregate by Computer
Can the aggregate building process be made faster? Of course! Let the computer make random choices and move the walker. The computer moves the walker much faster than we can, but uses the same simple process.
Open the Aggregation Kit program (see Java Applet Page. On the right is a black screen with a so-called "seed'' molecule in the center.
2. Press Go (upper left button).
A random-walking "molecule'' is released far away from the seed and staggers
back and forth, up and down, until it finally touches and sticks to the seed.
Immediately a second random walker is released, ultimately touching and sticking
to the pair at the center. Then the third, fourth, fifth, hundredth walker
is added to the growing pattern. In order to speed up the process, if the
walker is too far from the pattern, the computer does not continue the random
walk step by step. Instead, it places the particle at a point nearer the seed,
as if it reached this nearer point by a random walk.
3. Now try new settings: faster speed, smaller cell size.
4. Find settings for which the resulting pattern looks like the result of
your electrodeposition experiment. When you grow such a pattern, choose Save
under the File menu, using a name you can remember. You will need this
saved pattern later.
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