Tuesday, July 19, 2011

Physics is Beautiful

Class this morning was made incredible by the excitement of analyzing our roller coaster data, the many creative demonstrations that Bill had set up for us for his lecture, a very interesting guest speaker, and beginning to collect some very interesting data for our interest group afternoon labs.

First thing in the morning, we broke into our Hershey Park groups and downloaded the data we collected on our accelerometers and video cameras to the computers and making sensible graphs out of them. I was really impressed at how well our data came out and how interesting it is to compare acceleration in the x, y, and z direction as well as altitude versus time, especially once we have synced it to the first person video we took from the front car of the ride (which is admittedly mostly the grab rail, but there is definitely some useful information lurking in the background). We really only spent enough time with that to get the data on to Logger Pro, fix up the graphs and save it. The rest of the work for the presentation of Friday will be done outside of class.

After that, Bill gave a really interesting lecture on magnetism and its interactions with electricity. As always, his unique analogies and awesome demos gave me an even deeper understanding (in an enjoyable way) of a subject I was already familiar with. The first demo was one I had already seen; he sprinkled iron filaments on a magnet and we noted the patterns they aligned themselves in. In my high school course, that's as far as we went but because we have access to Penn's numerable resources, today we also got to see magnetic fields in three dimensions with tiny iron particles suspended in oil, forming a magnetic fluid. The shapes formed were more than interesting, they were beautiful. Bill also showed us how a moving current can form a magnetic field, and a moving magnetic field can form a current. The demo he used for this was an electron beam (visible through neon) between two loops of current carrying wire forming a circle. It was all really amazing to look at.

After morning lecture, Doug Smith, a medical doctor gave a talk about Traumatic Brain Injury. The lecture focused a lot on the biology that went hand in hand with the physics of the collisions we endure. It was a very interesting and probably the most applicable talk to our every day lives. I have always known the importance of wearing a helmet, but now I understand not only the physics but also a little bit about the biology behind why that it.

As the day progressed, things just got more exciting. Today was our first day of data collection in out interest groups. First, we used the radii we found with our electron deffraction patterns on phosphorous screens and the De Broglie formula to find the distance between the muclei in our crystal filter. We also played around with the voltage and the location of the beam and got some really beautiful patterns.After that, we hooked a photo multiplier to a counter and a double slit interference chamber that contains only one photon at a time. We adjusted the position of a small shutter by half a millimeter and took new data samples at each place so that we could understand the deffraction pattern that occurs even when only one photon is moving at a time. In esenc, what this means to us is that even though light can be thought of in photons, or massless particles, each of those can behave as a wave independantly of any other photons and with no medium to travel through, which is impossible in large scale mechanics so we do not fully understand whats going on. It's mindblowing.

After class, I had a couple hours to chill in my dorms and get dressed up before our dinner with the Yale ILC group, Charles Ramsey, Madeline Kronenberg, and an admissions councilor at Swarthmore. The food was delicious especially compared to the dorm food, but the conversation was even more satisfying. Although I still don't see myself thriving at a college as small as Swarthmore is, what our guest said about all the options available for courses and the freedom undergraduates have in choosing their own path was really appealing to me and I hope to be able to find that same system at a slightly more busy place with more of a focus in research.

When we got back to the quad, it was already past 10, so we spent a little time introducing our friends from the Yale porgram to our classmates at Penn and then we said goodnight. I am very excitid for tomorrows guest lecture on the physics of neuroscience because those are the two fields that I have the most interst in and I am curious to see how they can be combined.

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