Monday, July 18, 2011

An Intro to Quantum Mechanics

Today was an especially exciting day in the physics classroom for a number of reasons. First of which was that our morning lecture was on a particularly fascinating and thought-provoking realm of physics: the Theory of General relativity. It was only a few moths ago, towards the end of my physics course at El Cerrito, when I first started really understanding the concept of motion bending time and space. The explanation I was given back then was that it was impossible to go faster than the speed of light and that the speed of light never changed, which allowed me to understand the vague concepts, but didn't offer any real-world explanations as to how we know that or why that is.

The morning lecture today discussed some of the experiments that were performed with rotating mirrors and other methods of diffraction that measured the speed of light and proved that it is a constant. We also watched a video depicting one of Einstein's thought experiments that explained that things that are thought of as simultaneous from the viewpoint of a stationary observer are not perceived that way from one who is in motion. It was all very fascinating and it definitely helped to further re enforce my understanding of relativity.

Another reason today was particularly exciting was that we heard from a guest speaker named Mark Devlin, a graduate from Princeton who did graduate work at our very own UC Berkeley and is now a major player in the UPenn faculty. He studies cosmic background radiation, energy left over in the universe from the big bang. Before he came to talk with us, we watched a documentary about some of the research he has done in the last ten years. The film showed Delvin and his crew of fellow researchers and grad students launching extremely sensitive microwave detectors with huge focusing parabolic mirrors and a Helium 3 refrigerated heat sensor. They launched BLAST (Balloon-borne Large Aperture Sub-millimeter Telescope) using a huge balloon that inflates to the size of a football field instead of launching it with rockets because it allowed them to perform the experiments using only 1 or 2 percent of the funds. They chose to do most of their launches in Antarctica where there are fewer thing to hit and the winds are circumpolar so after a week or so, if all goes well, the balloon should drop the telescope back off where it was launched.

That's in theory. However, the movie described the mechanics of actually launching the thing, and showed the perils and possible disastrous situations involved on attempting to collect data in Antarctica. It turns out, it's tricky business and the methods used to reduce error are really quite amazing. I recommend checking out the movie "BLAST" it is very entertaining and informative and definitely worth an hour of your time.

The talk given right after the movie was even more so. While the film focused of the mechanics of the experiment, Delvin himself talked to us a little bit more about the physics behind the data collection and the implications of the analyzing that they were able to do with it. He discussed how we can learn about the formation of stars by recording images of galaxies billion light years away, and therefore studying light that is reaching us just now but was originally emitted billions of years ago. It was really cool hearing about what Delvin did from the formation of his experiment to the collecting and analyzing of data.

It was especially cool because after lunch, we got a taste of how we are going to be experiencing that process first hand this week in the first day of our special interest groups (which is the third reason why today was particularly interesting). I ended up in my third choice which was quantum mechanics where we will be studying the diffraction patterns of electrons and singular photons and discussing what those patterns tell us about the way the world works on a sub atomic level. Even though it was not my first choice, it is clear that I am going to learn a lot and that every day of the four-day course will be packed full of interesting material and experiments. Today we set up a laser beam in a photon multiplier and we could hear the electrical signals hat were being sent as singular photons were interacting with the electrons. It was very cool and I was actually sad to return to my dorms.

I only had a few minutes after class to gather my things and tidy my dorm before we all met in the quad to go the the admission session regarding Undergraduates at UPenn. The admissions councilor who came to speak to us was very friendly and told us very useful information about the four undergraduate colleges, the admissions process, what specifically UPenn is looking for in perspective students and other useful and interesting information. I'm surprised how many of these information sessions I can go to and still learn something new. It's incredible.

Afterward, we ate dinner in a particularly crowded dining hall and threw a football round. I went back to my dorm and looked over some of the information about what we will be doing tomorrow in our photon/electron lab before I went to sleep. I can honestly say I am excited for class tomorrow.

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