We got right to work today with a morning lecture about nuclear physics from Ryan, one of the very helpful and knowledgeable assistant teachers. The first couple slides were about the history of nuclear energy and the discovery of x-rays. Ryan went on to explain the physics behind alpha decay, beta decay, and gamma radiation (during this part of the presentation, our previous lecture about the standard model came up again and it was necessary to recall the concept of leptons and quarks). The remainder of the lecture was devoted to explanation of applications of radiation that are highly important both within and independent of the realm of physics. We discussed the benefits and waste products of uranium mining, the breakthroughs and limitations of radiation as a cancer treatment, briefly touched on the subject of mass spectrometry and how radiation can be a helpful tool in studying the origins of the universe. Towards the end, the lecture transformed into more of a discussion that was so lively and obviously relevant, that I found myself more engaged than I had been during any previous first-thing0in-the-morning lectures.
After Ryan's talk, we were given a short break to let the information soak in a little and to give us time to prepare for our presentations of the Hershey Park Rides. It was a very different experience hearing from groups of fellow classmates as opposed to professors and teachers. Each group went on a different ride, so the data was unique in that regard, but each team's presentation and analysis of data varied greatly as well. Some groups were able to record videos and sync them to their data, others calculated the resultant total acceleration based on the x, y, and z values they collected. One group even had a three dimensional animation of altitude v. y acceleration v. time. By the end of the day, I had learned a lot from my fellow class mates about creative ways to handle data in a way that makes sense to your particular experiment and goals.
When all the presentations were over and we returned from our lunch break, we prepared for our guest lecture by watching "Elegant Universe", the PBS show on string theory. As I was watching, I realized that I had seen parts of the show before; my fifth grade teacher played if for our class. At that time it had come out only a few months ago. I remembered the movie distinctly because it was a moment in my life when I realized both how incredibly cool science could be, and at the same time, how very little I understood about the complexities of it. Watching the film this time around, I understood many more of the concepts, but the sense of wonder was not lost.
Only moments after watching the program he was quoted in, we got to hear from string theorist Burt Overt himself. He described to us, in much greater detail than the movie, the basic concepts of string theory, the implications that the theory has, why it makes sense in the real world, and the ways in which it can be tested.
The basic definition of string theory is the hypothesis that the smallest components that make up the universe are not particles but tiny strings that vibrate at different frequencies to create different kinds of matter. The mathematical calculations that have been done suggest that such a theory means that there must be 6 other dimensions besides the three spacial dimensions and time. The concept of extra dimensions is a hard one to grasp, but it made more sense to me today than it ever has before when Dr. Ovurt did a demonstration with a rolled up piece of paper. Another implication of string theory he discussed was the concept of supersymmetry, meaning that for every particle, there is a so-called "sparticle" that also exist. These particles have yet to be found because they do not appear in low-energy circumstances, but Ovurt has high hopes that CERN will provide the environment necessary to make significant breakthroughs in the subject.
It was fascinating listening to an expert talk about a field that is at the very outer edges of the scientific frontier. The fact that people in the class asked questions that no one in the world has answers to, but that Ovurt is actively working on discovering was almost too much to comprehend.
After class, we had a few hours to wander campus before we went out to dinner with Mr. Miranda and the Yale chaperone. We ate at City Tavern, a place I had been interested in visiting since our initial tour of the city. The food they serve is all based on the typical cuisine of the taverns of the 18th century that our country's founders used to eat. While we munched on some sweet potato pecan rolls (apparently one of Thomas Jefferson's favorites) we discussed not the past, but the future: our plans for senior year, applying to colleges etc. When dinner was over, we visited an ice cream parlor, a great end to one of my last days here at Penn.