5 Mirages

By starting with optical illusions, you may have misled some of your audience. The phenomena you described were all examples of refraction, and are optical illusions only in the sense that using lenses to magnify objects, or seeing what appears to be a bend in a stick immersed in water, are optical illusions. Most of us think of psychological explanations for optical illusions, such as our use of perspective to judge distance, etc., not physical ones such as refraction. From there on, your presentation seemed to try to list all possible types of mirages, with the names of each, rather than carefully exploring the physics involved. Too much reading, to little communicating, but the images used in your presentation were very good. Also, your web page covered most of the material well.

6 Waves and currents

By trying to describe every possible wave, its geometry, origin, etc., you were unable to convey the most elementary aspects of wave motion. For instance, I didn't notice any mention of the restoring force, or a simple harmonic oscillator. We would all have learned much more, of greater value, if you had explained carefully how one simple type of wave were produced, what controlled its amplitude, speed, etc., and how and where one would go to observe it. By the time you threw in surface currents and tides you had totally swamped us, and I doubt that anyone left class feeling that they understood any of these subjects better. Many probably left class thinking the subjects were too complex to even try to understand. This is the opposite of what we are hoping for. Your web page reproduces this unfocused chaos.

1 Phases of water

A good production. You seemed able to convey the complexities introduced by hydrogen bonding without making everything seem too difficult. The demonstration worked for me, and I got the impression that everyone in the group really knew what you were trying to get across. I would have like to see at least a mention of the heats of fusion and vaporization, but at the level you were presenting things, it is probably reasonable to have omitted this. Your web page did not do justice to your presentation - it fails to even mention hydrogen bonds, for instance.


3 Crayons

Excellent. You managed to let each member of your group expound on their own favorite part of the crayon story, while keeping the presentation focused and informative. It definitely seemed that everyone KNEW what they were talking about, had actually learned a lot in the process of preparing for this presentation, and were keen on conveying what they had learned to us. Congratulations.


9 Chromatography

This is the way I like to see demonstrations. Surely, students would learn more doing the experiment themselves, and we can assume that in a real classroom the students would have been involved in a "hands-on" sense, but with only ten minutes, no lab equipment, etc., it is much better to see some pictures of the experiments, and pass around the results. My hunch is that the quantitative stuff about retention factors, etc., fell on deaf ears, but it was nice to know that such simple equations could be applied to the results. The background on your Powerpoint slides was distracting. Still no web page.


7 Fireworks

I got the impression that you were close, but not quite at the point where everyone really knew the subject matter well. It was clear that you had prepared well, and that there was a real desire to convey what you had learned, but you just didn't seem entirely comfortable with what you were saying, and relied too much on reading, rather than on telling us what you had learned. Perhaps if you had run through the whole thing a few more times in advance, your comfort level would have improved. (And maybe you would have trimmed a few things, and concentrated on others.) The web page did a fine job of representing your work.

2 Glow Sticks

Also excellent. Everyone seemed to know a lot, know it well, and wanted to tell us about what they knew. The presentation was well organized, with enough chemistry, but not so much that we'd be left dazed. When the first demonstration did not cooperate, you proceeded, unperturbed, which was great. The second demonstration worked well, and was more than sufficient. Your web page was adequate, but the image should have been smaller, and you should check the spelling.

4 Bridges freeze faster than roads

Very nice. You covered the essentials on your first slide, but then went on to some other interesting aspects of the ice on roads issue. I felt the issues of bridge freezing, road salt, and black ice were covered well, and we all should have been able to follow it easily. Unfortunately, the issue of Calcium Acetate (CMA), which may have been the most demanding, technically, was quite difficult to follow. In fact, I remain confused - does it melt ice, or prevent ice from sticking to a road? The web page needs proofreading, and does very little to clear up the confusion.

8 How do crystals form?

The presentation was hurt by your treatment of the seven crystal systems. What separates these systems are the angles made by the different crystallographic axes with each other, and the size of the lattice cell along each axis. I appreciate your effort to draw these systems, and not copy someone else's drawings, but you did not succeed in preserving the important characteristics. It is difficult, in fact, to figure out which system you are trying to portray with each image. In this case I think it would have been better to just mention that there are seven systems (your book combines trigonal and hexagonal, to get six systems) and go on. The rest of your discussion centered on sugar, and the isometric or cubic system, so you didn't need the others. I also felt that by talking only about crystallization from solution, and not from a melt, you made the connection between your presentation and the earlier one about snow difficult to see. Those involved in the presentation seemed to know what they were doing, and I sensed good teamwork. Your web page has yet to be submitted.