Thursday, July 14, 2011

Physics with a Side of Entropy

Today, class seemed very sporadic. Our topics of discussion were all over the place. First, we began with a discussion about gravitation, which seemed to come out of nowhere. I had learned gravitation in my high school physics class, but we did not spend a very long time on it. We basically only covered a few formulas and constants that we needed to know for standardized testing, but other than that we did not, delve very deeply into the topic. Today was quite different though. Bill was not only thorough in covering the math side of gravitation, but also the conceptual side, despite how vague this subject really is. He explained the inverse square relationships that are involved with gravitational strength and even began discussing Roche Limits. My high school physics teacher told me a little bit about Roche Limits before, but I really wanted to learn more. Today, my thirst for this knowledge was finally quenched. We learned that Roche Limits are the distance within a celestial body, held together by its own gravity, which will disintegrate due to a second celestial body’s tidal forces exceeding the first body’s gravitational attraction. Basically, one object can basically be ripped apart by another object’s gravity if it is pulled upon by a strong enough force. This was my favorite part of today’s lecture.

Following the lecture, we began talking about our field trip to Hershey Park tomorrow. We were presented with a list of rides that we could use for our tests as well as the parameters for our testing. We will have to chart data on the position and acceleration of certain points on our ride. My group, which is composed of Brian, Julia, and Mike, will be collecting data from a ride called the Sooperdooperlooper. We will have to ride the coaster several times to get different sets of data, and then we are free to do as we please in the park. The trips in this program are the best educational field trips I have ever been on.

We continued discussing Hershey Park until our guest lecturer, Dr. Randy Camien, arrived. Dr. Camien is a Soft-Condensed Matter Theoretician…even after his lecture I am still lost as to what that means. His lecture dealt with topology in physics, which concerns the continuous deformation of an object using stretching. The bulk of the information discussed interactions between light and liquid crystals. He explained, at great length, how and why liquid crystals (which are what make LCD screens work) operate the way they do. Liquid crystals operate by blocking certain colors of light and only letting other types through as they contract and expand. Dr. Camien was very interesting to listen to because he was able to draw analogies and examples from a lot of different places and still relate them back to topology. I find that I am enjoying our guest lecturers very much because they bring a new perspective to our class-wide discussion of physics.

Following the guest lecture and lunch, we performed a lab in which we had to measure the speed of electrons. We did this by using microscopic bubbles of oil that were suspended in a confined space using electric current. By increasing or decreasing the voltage, we could get the bubbles of oil to rise or fall, and our task was to measure how fast these bubbles moved. Once Onur, Mike, Lindsey, and I collected our data, we plugged our values for the velocity of the oil bubbles into Excel. Thankfully, the tables were already set up to evaluate the rest of the data that we would need once we plugged in the values for velocity. So, aside from having to strain my eyes by trying to find a tiny bubble of oil through a microscope, this lab was fairly easy. I’m finding that my new lab group is much more efficient than my old one. However, this could just be because we are all in a familiar space and are used to all the equipment by now. Either way, my group is working well.

The rest of the day was very relaxing. Brian and I hung out in our room for a while after class. Later our group enjoyed dinner together, played some Frisbee afterwards, and then we watched the movie Garden State, with Zach Braff and Natalie Portman. It was a great way to conclude the day, especially after the randomness of class. Moving from one topic to another that quickly can be disorienting at first, but I can certainly see the value in it. It forces me to think on my feet and adapt to a new idea or concept. It takes a while to get used to thinking like this, especially since things are so structured in my high school classes, but I am getting used to it. Despite today’s abnormal level of entropy (the physics term for randomness or chaos), it was still enjoyable and I learned a lot from our lab and two lectures. I love this class more and more each day because I am finally able to be immersed in a subject that I am truly passionate about.

Light, Lectures, and Labs. Oh My!

Today was another day where I was very glad to get some extra sleep. Alex and I slept in until eight and then got breakfast at the WaWa store. I picked up a couple of bagels with cream cheese and filled my bottle with water and then we headed to class. Over the last couple of days, we realized that we have been walking two sides of a triangle to get to class so using our amazing mathematical knowledge we decided that we should start walking along only one side because it’s much more efficient. Even though we woke up later than usual, we made it to class on time and took our seats.

Bill started off the day by talking about Newton’s Law of Gravitation. While it might seem a bit backwards because we were discussing special relativity yesterday, today we were going over very specific examples of how Newton’s Law of Gravitation works. The first thing to note about this law is that it is an inverse square law. What this means is that for two masses at a distance r apart that have some gravity that when they are twice as far apart, they will have four times less gravity. Bill furthered his discussion by talking about the rings of Saturn which clearly display some of the more interesting effects of gravity. One cool thing about Saturn’s rings is just that-that Saturn has multiple rings. There is a gap between these rings because there are meteors and moons that orbit Saturn a bit further out than these gaps in the rings and their gravity pulls the stuff further away from Saturn and clears out gaps between Saturn’s rings.

The next thing that we talked about in class is our upcoming field trip. Tomorrow, we will be visiting Hershey Park which is a large amusement park. There, we will bring along all sorts of weird looking electronics that will take an hour or so to get through security to convince them that they are science tools and not weapons. These strange looking electronics are really data loggers and 3 dimensional accelerometers. On our field trip, our job is to bring this data logging equipment along with us on a ride and take data of the acceleration on the ride we choose. In order to choose which rides we ride, we formed into 8 groups of four people each. Each group was then assigned a number, an in the interest of both fairness and geekiness, Craig used a random number generator to choose which group would pick which ride they would analyze first. To the surprise of many of us, the first group to choose did not choose a huge roller coaster but instead chose the Merry Go Round. Each group after continued to choose, and we were pleased to get our second choice, the Sooper Dooper Looper. While spell-check did not like the name of that roller coaster, I am really looking forward to spending time tomorrow riding and analyzing its motion. Of course the day will not be all work, because Bill encourages us to get our data collection finished before lunch so that we can have several hours after lunch to play and enjoy the park.

After our lunch break, we returned to do a lab. For those that are familiar with the foundation of chemistry and physics, we repeated the Millikan Oil Drop Experiment. The basic idea of the experiment is to spray tiny atomized droplets of oil into a chamber where you can see them with a microscope. Then, you can apply an electric field to the droplet to see how quickly it moves in one direction, flip the field and then see how quickly it goes that direction. With some logic and a bit of fancy math, we were able to calculate the charge on each electron. What impressed me so much was that Millikan came up with this extravagant experimental design and got such accurate data that it was used for many years. This was a fascinating lab to repeat, and it was much more interesting than the 5 times I have read about it in science classes.

I’m sure I’ll have an extensive blog about Hershey tomorrow, but for now it’s time for me to rest up for the big day. Goodnight.

I've Never Though of Oil as Beautiful Before...

Just to mix things up this morning, I actually got out of bed early so I had enough time to grab breakfast with my floor at the dinning hall (the blueberry pancakes today were almost as good as I get them at home) and then return to the quad to collect up the lab data that was due today. It was a nice, leisurely start to my day.

The first lecture of the morning was about Saturn's rings and what they tell us about the way gravity behaves. Bills presentation explained Newton's Law of Gravitation only after we understood the general concept based on what er know about the way Saturn looks (and also, the way the position of the moon affects the tides). It was a short talk, but there was a lot of really valuable and accessible information packed into it.

We then took care of some logistics. We went over the lab that we would be performing that afternoon (measuring the magnitude of a singular charge) as well as some information we needed for tomorrow and the weeks to come. Mary showed us pictures and gave a short shpeel of all the rides available for us to analyze at Hershey Park. We split up into the groups we would be working with for the acceleration experiment, discussed our options, and got familiar with the accelerometers we will be using tomorrow while we waited for our guest speaker.

They also discussed with us the options we had for the groups we are going to break up in for next weeks afternoon labs. These groups are not chosen based on who we think we would work best with, but rather, which group in investigating a subject we are interested in. We are going to be studying and experimenting with the same subject for the entire week in order to really be able to get into some investigative labs and theories. Some of the options that seemed especially cool were radio wave astronomy, wave/particle duality, and Non-Newtonian fluids. I am still having trouble deciding on just one topic because they all seem extremely interesting,

When our guest speaker showed up, things really picked up. His name was Randy Kamien and he is an expert on soft condensed matter. He started his lecture off with a magic trick where he unlinked together two solid rings (he later admitted that, in fact, one was not solid he was just covering the gap with his hand). He tied the trick into his lecture about topology (which he described simply as the science of counting) by telling us that the trick was magic because the ring originally intersected at one spot that you could count and it is impossible to change that in a loop. He went on to talk about liquid crystals in display screens and how lights ability to pass through the screen depends on the orientation of the molecules in the liquid crystal. To be honest, I don't think anyone understood all of what he was saying (he started involving fourth and fifth dimensions in his hypothetical looped path situations) but I could tell that he did a good job of making it much more accessible than it could otherwise be and I learned a lot of really cool stuff the things I didn't fully grasp only sparked my interest in physics more. Once again, we ate lunch only after all of our questions had been asked so we ate a little late, but it was definitely worth it.

When we returned for our afternoon labs, microscopes and perfume-like spray bottles filled with watch oil was waiting for us on the table. We recreated the experiment Millikan performed in order to find the charge of one electron. By looking at the speed of minuscule oil droplets falling through space and comparing it with the time it took them to rise when a known voltage was applied, we found that the average charge was very close to the accepted value of 1.6x10^-19. It was really fun looking through the microscope and timing these tiny droplets of oil illuminated on a black background. My eyes did start to hurt after a while (I can only imagine how Millikan must have felt) but the little specks of light moving around in the microscope was actually quite beautiful.

After class was over, I hung out in my room with my room mate and a couple other girls from our floor, One of them played a couple pop songs on the french horn that she brought. She was very talented so it was good fun listening to them (it is not easy to make a french horn sound that nice). Afterward, I grabbed some dinner and met up with Brian, Alex, and one of their floor mates and we watched another movie in the lounge before bed.