This morning, we had two guest speakers as well as two mini lessons. Bill started the day with a lesson on the Doppler Effect and the Doppler Shift. Pitch changes as sound moves toward or away from you, and color changes as light moves toward or away from you. Then, we were joined by Dr. Doug Smith from UPenn's Head Trauma department. He talked about the long-term effects of head injuries, the different types of trauma, brain structure, and roller-casters. I was surprised to learn how damaging a simple concussion can be; in some cases it can lead to Alzheimer's. As he spoke, visions of my numerous mountain biking crashes danced through my head. I enjoyed learning about Biophysics, an up-and-coming field that I may pursue in the future.
Next, Bill talked about the physics of rock climbing. He is a big recreational climber, and many of the pictures in his slideshow featured him. Climbers use friction, normal force, and lots and lots of ropes to safely scale rock faces. I couldn't believe how high up some of these climbers can get and I am seriously impressed with their courage.
Our next guest speaker was Professor Mark Trodden who presented on modern cosmology. Last year, I wrote a term paper on Dark Matter and many of the topics I researched came up in his talk. He explained that the universe is expanding at an accelerated rate due to Dark Energy, and what types of research his department does in this topic. I can never truly wrap my head around how huge our universe is and how much we don't know about it. The talk was so interesting, I was on the edge of my seat the whole time and I really didn't need the coffee I bought on the way to class.
After we broke for lunch (can you believe that all happened before lunch?), we went into our interest groups. I love my interest group, we are mellow, but productive, and we work very well together. Today, we gathered data for a photon stream shot through a single slit. The data was consistent with a particle. We got to leave pretty early, so I took a leisurely stroll back home, went on a run, skyped with Teddy and his family, and relaxed for the rest of the evening.