Ay 20 was definitely my favorite class this term ( although, I will admit to a bias since I'm an Astrophysics major :P ). Any class that has anything to do with space is automatically more interesting in my book. More importantly, the material was well taught and clearly presented.
Doing regular problem sets with hard deadlines is a huge part of the normal daily life of a Caltech student. Sometimes the problem sets are good at teaching the material. Sometimes they seem irrelevant. Regardless, when life becomes too hectic, there isn't always enough time to really understand the concepts behind the questions. In this class, we didn't have hard deadlines. Instead, we dedicated most of our class time as well as an additional four hours a week to problem solving in small groups. The problems were carefully picked so that instead of just speeding through proofs in books, I could see first-hand how many of the key theories/equations were derived. Whenever we'd get stuck, Professor Johnson or Jackie were always there to give us just the right amount of guidance so that we could continue solving the problem on our own. This was a completely new style of class for me, but I feel like I learned a lot more than I would have in the standard "lecture" class. Also, thanks to the partner-work, Juliette and I became good friends :]
Caltech is arguably the best place in the world to study Astrophysics. I wouldn't trade the opportunities and experiences I have here for anything. At the same time, Caltech has a terrible habit of taking a subject that I love and trying to beat that passion out of me. In my case, this was physics. I had a fairly poor physics background coming in to Caltech and have been playing catch-up in my physics classes because of it. Since Astrophysics is basically a specialized physics major, I was starting to get discouraged. Professor Johnson and Jackie had a lot of faith in me and my future as an astronomer, which was incredibly encouraging. At the beginning of term I was on the fence between staying in astrophysics and switching to regular physics. After this class, I'm definitely staying in astro :]
Another awesome part of class was getting regular visits from leading astronomers. It was really interesting to hear from very different types of people with very different career paths that were all united by their passion for astronomy. Through our interactions with them, we also learned how to approach these professionals (and that they were, in fact, just people like you and me!).
The labs were really interesting. In the first one, we measured the radius of the earth using nothing but a stopwatch and the sunset (and we got to take a trip to the beach during the school year!). For the second lab, we analyzed a picture of mercury transiting the sun to find properties of its orbit. I ended up doing a third optional lab in which I used real data online to analyze stars and find their transiting planets. The lab write ups were the most painless I've had to do in a very long time. I'm not the biggest fan of formal writing (to say the least), and I hate when the formalities of lab write-ups take away from the excitement of actually doing the lab. The labs for this class made me feel like I was solving real-world problems instead of fulfilling some class requirement that was said ages ago.
The final was also a really good gauge of what I learned in class - which was refreshing. It also left me feeling encouraged and that the amount I studied was proportional to the amount of material I understood (which isn't always the case). Instead of a usual 4+ hour take-home written exam, we had a 30 minute oral exam. This might be difficult to implement in classes that have 200 students, but it was perfect for a small class like this.
I'm going to really miss this class next term :( I hope that more of my future astro classes will be this fun!