This is part of a larger collection of simulations from the "Dance of Chance
Exhibit". The focus of the exhibit is the emergence of patterns in Nature from
physical and biological processes which on the microscopice level appear to be
dominated by chance. Many of these patterns are fractals.
The purpose of the site is to illustrate (especially in view of the larger collection of similar effects) the peculiar and beautiful nature of fractal growth in chemistry and physics.
Target Student Population:
This module can be used for Middle school, High school and introductory level
courses in Chemistry, Biology, Physics and Earth Science
Prerequisite Knowledge or Skills:
There are no prerequisite skills required to study the site and its companions on the larger composite web site. However, some knowledge of chemistry and standard chemistry safety procedures will be necessary before the recipe provided for growth of crytals of zinc (or copper) can be carried out, particularly because of the toxicity of the solution materials.
Type of Material:
Images and an illustrative animation provide a molecular level view of dendritic growth, leading to a recognition of fractacl patterns in a multitude of natural phenomena.
The best use of this work is as a self viewed study item for a first year chemistry student, thereby getting them to realize that fundamental characteristics describe phenomena as diverse as fluid intrusions into narrow confines and crystal growth on or at surfaces.
While the experiments can be carried out with some effort in the lab, the colocation of powerful animations guides the students towards a particle view of these natural fractal processes.
Level 2011 browsers are sufficient, although the ability to use Quicktime movies through the popular movie player is required.
Evaluation and Observation
Simple-well designed modules with good introductory narratives and good visuals. The movie illustrating copper crystal growth is intriguing and captures the imagination.
There is no reason given for the nature of the growth and this is a real weakness of the site. Furthermore, there is a brief description of the experiment but not enough to enable a student to duplicate the experiment. There should also be chemical safety warnings attached to the page.
The language is on occasion somewhat less than precise. For example, The narrative occassionally uses the words "ions" and "atoms" interchangeably,
and it is not clear to the user which specific word is applicable at specific
places in the narrative
Potential Effectiveness as a Teaching Tool
This item will be much used because students are amazed at the kinds of crystals that grow and will want to try the experiment for themselves.
The graphics on the site only enhance this experience for the students, and are versatile enough to be used with a wide variety of audience learning levels (middle school through to 1st year college level).
The site is greatly hampered by the failure to present an effective explanation at the level of learning of the intended user (a student). Furthermore, there should be a reference available for the student to actually reproduce the illustrated experiments.
Ease of Use for Both Students and Faculty
The site is clean and simple providing easy navigation and a link back to the larger collection of equivalent fractal patterns generated in other natural phenomena.
Related modules are easy to access from the "Dance of Chance"
exhibit at http:/polymer.bu.edu/museum.
The authors could have placed a little more attention into the link to the larger web site. As it is, the user must scroll down to the bottom of the page to a rather nondescript link ..... the move to the linked site may or may not happen, diminishing the effectiveness of the site.
Other Issues and Comments:
This collection of simulations, movies, hands-on activities is a good learning tool for introduction of patterns occuring in Nature.