Friday, August 8

After only slightly less instructions than the SAT requires, the presentations began with a bang.

The planetry capture group began with a description of the ancient theories of the solar system. Kevin continued, describing Hirchel's paper about the discovery of Uranus - supposedly a comet. With a storytelle's style, he told of th discovery of the other two planets remaining. Richard then led the students in viewing a simulation of the planets' orbits using the program Galaxsee. Their questions included why the sun appeared to move. Kevin plans to continue the research as a science fair project.

Stephen and Sanford had a web model to present with their project. After a bit of last minute debugging, the duo were able to demonstrait the effects of mant factors in PCB concentrations in the Great Lakes. PCB's are an industrial waste product which can cause dangerous health effects when they have, over time, built up in th lipids of the human liver.

"Let me give you an example of the food chain," Eric began. "Here's us. Let's saye we like to eat cows.... MOOO!" He described how a small disruption in a food chain can result in the death of all. "But then we have Mr. Sun, so that's okay." The group had written a Java applet for the food chain in Yellowstone Natural Park, including deer, elk, wolves, bears, vegetation, and hunters "who come along and kill everything." Watching the applet, Holly asked, "Did you program some advantages for deer being in big groups?" No, explained Kevin, Eric,and Justin. The deer were sinply "reproducing like crazy" faster than they couldspread outor die. Wolf pack behavior Occured naturally in the model; the gestational period for all animals is one time step (slightly inaccurate, but reasonable.) "Will hunters kill other hunters?" asked one TIPster. "No, but in real life they probably would," replied Eric. Usually, in the model, one species dominates, then dies out of starvation, the group concluded.

After Lunch, Mary introduced the "Med Group". Mary, Vanessa, Diana, and Mike all studied baroreceptors, the heart, and the systems related to the heart. They began bu defining terms, but as Diuana explained, their project revolved around advancing a model already on the web, and learning what effect varying conditions had. They displayed graphs of these effects; a series showing how changing a single variable altered the arterial pressure. Like Kevin, these students are interested in reasearching more to explain the results they found.

Next, Cyrus, Chad, Charlene, and Cameron introduced their project, on scuba diving and decompressing sickness. When one dives, they explain, the pressure on one increases by an atmosphere for every 33 feet under, making the body more readily absorbe nitrogen. If one rises too quickly, this nitrogen bubbles out of one's blood, causing decompression sickness or "the bends". Because the data was in pre-publication stages, the C's could not make web pages of it, so they got around this difficulty by using PowerPoint. They profiled divers' and pilots' risk of DCS, and noted that the risk was highest in the military, because they cannot spend time decompressing.

David, Adam, and Edward wrapped up the presentations with one on stellar lifetimes. They had created a model which showed a star's evolution from a hydrogen gas cloud. The star collapses and develops layers of fusion - Hydrogen to Helium, Helium to Carbon. Their prgram, though written up on a web page, was done behind the scenes in Pascal