Wednesday, July 13, 2011

Modern Physics is Mind Blowing

It was hard to get out of bed this morning. I think I hit the snooze button about 4 times. It all worked out though because instead of walking to the dining hall, I grabbed a quick bagel at WaWa's (the Philadelphia version of a super seven-eleven) and ate it in the shade of the huge tree in the center of the quad. It was quite relaxing.

When my morning picnic was over, I walked to class with one of my current lab partners who is from LA. We had a nice chat about how interested we were in attending Penn as an undergraduate. It was very cool hearing his opinion of the place.

The class was lecture heavy today, which is not to say that it was boring. Whatsoever. In fact, today was probably one of the most interesting and thought provoking days of the entire course. We started out with a concept that is slightly counter-intuitive: particle/wave duality. Ryan, one of the student teachers, set up a very helpful PowerPoint in order to aid our understanding. We discussed the uncertainty principle and all that in entails. He showed us a diagram of Shrodinger's thought experiment involving a cat in a box. As long as the cat is in the box, you know where it is, but because it's in the box with a breakable vile of poison, you can not know if it is dead or alive, and so, for all intensive purposes, it is both dead and alive. It was a very strange scenario, but it definitely helped the entire concept make a little bit more sense.

After we all got headaches from wrap our minds around the concept of light as both a wave and a particle, Bill set aside an hour or so when we might normally do a lab to talk a little bit about what our past labs entail. He stressed that data is not important unless it is contemplated, analyzed and discussed.

The next lecture was a guest speaker by the name of Mark Trodden who is an expert in the field of cosmology. He talked a lot about galaxies and how he uses them to better understand gravitation, even applied to life on earth. He also discussed interesting concepts like the Doppler Effect, Hubble's constant, and dark matter and energy. He basically told us the entire story of scientist's current theory of the creation of the entire universe in less than two hours. I was fascinated by it all and how the study of the universe can be both humbling and helpful in appreciating just how special life on earth is. It's a touch of psychology mixed into physics.

We were released to go to lunch only about five minutes late, but almost everyone stayed behind at least thirty more minutes to ask fascinating questions that received equally as thought-provoking answers.

When we returned from our late lunch, we separated into lab groups to wok on labs as usual, except today, not only did we get to decide who our partners would be, we also got to decide what our experiment was going to be about and we were able to set it up ourselves. The only constraint put on us was to investigate the relationship between two non-linear variables and determine whether or not the relationship was exponential. Brian, Alex, and their floor mate Onour and I chose Newton's law of cooling. We graphed the curve of temperature vs. time of a probe first starting in hot water then cooling to room temperature, then starting from ice and warming to room temperature. Next we used two probes, one in the ice and one in the boiling water and switched them to see how their curves intersected. It was my favorite lab so far because of how independent and exploratory it was. Next Friday, once we collect our data and organize it, our job is going to be to give a presentation to the class about our findings, which sounds interesting, but not nearly as interesting as it will be to hear all the other group's findings.

After class, I took another quick nap before dinner, followed by what is becoming a fairly routine game of ultimate Frisbee. I'm proud to say I've improved quite a lot since the first day. Today was especially cool because we played with some students taking art classes here at Penn who were very fun to talk to (they were stressing about finishing their Mona Lisa).

After the game, we walked down to Seven-Eleven for some refreshments, then back to the quad where the weather was nice enough, even by 9:30 that we could just lay on the grass for a while before heading back to our rooms to sleep.

Not Enough Time in the Day...

Today seemed to fly by. Ever since I woke this morning, things seemed to be non-stop. I felt rushed while walking around campus, it felt like our activities came and went, and even time just sitting talking seemed to be fleeting. However, this didn’t make the day any less enjoyable. I still had a great time in class and after class.

Today Mary (one of our class TA’s) announced that we would be cutting back on the amount of labs we do in class. The reason we had been doing two labs per day in the beginning was to make sure that everybody had the basic knowledge that we would need for the rest of the course. Looking back at what we had learned, it makes sense. Mechanics is the very first step to a physics class and optics really helps us understand perspective, which can help us with our observation in other labs. Now that we have covered the basics, we are ready for the more intense labs, such as measuring the speed of light. Today we discussed waves and particles. This lecture was a lot different than the others because it was more theoretical than the rest. With our other discussions, we had been learning about things that could actually be measured and tested accurately. With waves and particles, there is a lot of guess work involved because we are dealing with things that are either invisible or too minute to see. Despite these obstacles, Bill and Ryan explained particle physics (a small part of it anyway) with extreme detail. Near the end of the lecture, Bill informed us that we would be performing our own research on a topic of our choosing next week. This project will be done in groups and we have to assemble a presentation upon its completion. We then got a fifteen minute break from the lecture to choose our groups and topic. I will be researching Newton’s Law of Cooling with Julia, Brian, and Onur. I am very excited about working together and learning about a topic that I have never studied before.

After the break, we had our first guest lecture. Dr. Mark Trodden, a professor here at Penn, came to talk to us about astrophysics and cosmology. Dr. Trodden received his PhD at Brown University and now teaches at Penn, as well as lectures other universities. I had never dealt with astrophysics or cosmology before today so this was completely uncharted territory. I was very lost at first, but with careful note taking, I was able to get a slight handle on Dr. Trodden’s lecture. The majority of the lecture revolved around light, energy, and how the two interact and behave in space. He also discussed the movement of galaxies and a few aspects of the big bang theory. One of the most interesting things that he said today was that the galaxies are accelerating, and that is proof of a big bang. The idea is that if the galaxies are accelerating outward, there had to be something to propel them outward in the first place, which is where the idea of a big bang comes in. Dr. Trodden was very thorough and was able to cover a massive amount of information into only an hour. That is something I really admire about college professors – they can talk at length about almost anything and still manage to make even the most complicated of topics interesting and engaging.

Dr. Trodden giving his lecture.

After the guest lecture, we had lunch, and following lunch was another brief lecture. We did not really cover any new concepts, but it was more an explanation of how we would have to conduct ourselves while researching our new topics. This research will be much different than the other labs that we have done. They will give us the materials, but we will have to come up with procedures and tests to run on our own. They are giving us complete control, which is something I’m not quite used to in a lab setting. Immediately after Bill gave us our instructions and guidelines for the project, we went into the lab to perform our first tests. We observed how fast thermometers would adjust to different temperatures after being placed in or removed from hot and/or cold water. Our graphs showed exponential changes in the changing temperatures of the thermometers. We have only taken a few steps, but I am already looking forward to this project.

After class, Brian and I returned to our dorm and reorganized our room. We maximized our floor space and made a few more areas for guests to sit. Since our room is the biggest out of all of our friends, it is kind of a central hub. After organizing, we went to dinner with Fred, Alison, Julia, Abheek, and Onur. Afterwards we decided to get a little exercise and throw around our Frisbee. Somehow we wound up in a game of ultimate Frisbee with another summer program at Penn right now. We won 15-10 in the end. We all went to get victory slurpees at 7-11 again. We decided to make it a tradition that whenever we play an intense game of ultimate Frisbee, whether we win or lose, we grab a slurpee after the game. We spent the remainder of the night relaxing out on the quad, and later in our new lounge when it got too dark.

Although everything that happened today seemed to go by so fast, I still had a great day. They say time flies when you are having fun. Today I experienced that first hand, and I loved every speeding minute of it.

Mark the Man

As I like to say, an adventure a day keeps the boredom away. Today was a great day right from the beginning. Blessed with a full 8 hours of sleep because of the cereal stash in our room, I felt ready to go from the moment I woke up. The cereal wasn’t quite filling enough however, so I grabbed a bagel from the food cart outside of our classroom and took my seat. While much of the last week’s work has been on fundamentals such as mechanics and basic optics, today was time for our introduction to modern physics. After a brief lecture, Bill introduced us to Dr. Mark Trodden so that he could introduce us to some modern physics. Assisted by his slight British accent and charismatic oratory, Mark was very easy to listen to and understand. Mark began his lecture by introducing his field of study-particle cosmology-. He soon began to discuss one of the most important particles/waves in his field, the photon of light. We sped through some introductory stuff, the majority of which I already knew, about the Doppler Effect. The Doppler Effect takes place when there is a moving source or receiver of some kind of waves. For example, a car that is driving along the street and passes by a person standing on the sidewalk exhibits the Doppler Effect. What happens is that as the source and observer become closer while the source is emitting waves, the sources waves continually get scrunched up because each successive wave emitted is closer to the source than the last one. By definition, closer waves meant that the waves that the observer observes are at a higher frequency than they were emitted. Based on the shifts in the spectrum of emitted light from objects such as stars, astronomers can tell how quickly distant objects are moving.

The next topic that Mark spoke about was one that everyone used to think they understood perfectly- gravity-. For hundreds of years, Newton’s Law of Gravitation had worked great at describing every application that was thrown at it. Soon enough, people realized that it didn’t accurately describe the orbit of Mercury. During Einstein’s amazing burst of science, he came up with the Theory of General Relativity which envisions gravity as bending space and time.

To continue his discussion, Mark began to talk about an area of physics that he dedicates a huge amount of his time to, the Big Bang. He discussed how immediately after the Big Bang atoms would form for fractions of a second and then get hit by a massive amount of light that would break them apart. A few seconds after the Big Bang, protons had enough energy to collide and make nuclei without being torn apart by light. While this phase lasted less than a minute after the Big Bang it was the only window where atomic nuclei were formed. Scientists made careful theories to predict the abundance of light elements in the universe due to the Big Bang. In one of the greatest documented successes of science, the model fit the actual data almost perfectly. This occurrence was a great success for science because of how well the model and actual data lined up.

Finally, Mark introduced several questions that he is researching because particle cosmology currently fails to explain them.

Why is there more matter than antimatter?

Why didn’t the universe begin in a higher state of entropy?

Does dark energy really exist, or does General Relativity break down on universal scales?

I found Mark’s lecture very informative and above all, it made me want to learn more about our universe. In the afternoon we had a lab to learn about things in nature that display exponential properties. My group decided to try the lab where you try to find if object’s cool and heat up at exponential rates. Using a thermometer linked to Logger Pro and containers of hot and cold water, we graphed the change in temperature versus time and found an exponential relationship. While many people are uncomfortable with exponential relationships, they are vastly important to science. As Albert Bartlett put it, "The greatest shortcoming of the human race is our inability to understand the exponential function." While this might seem over exaggerated, in order to understand nature, we have to understand exponents and today I learned about many of these relationships in the lab which was great.