Blog 21: Independent Component 2

I, Hannah Seymour, affirm that I completed my independent component which represents 30 hours of work.

I first learned about cloud chambers from Caltech physicist Sean Carroll. He also taught me how to extract the tiny radioactive americium-241 disk from an ionizing smoke detector. For the experiment procedure I used this website: http://www.bizarrelabs.com/cloud.htm.

A cloud chamber is a very basic particle detector. To build a simple cloud chamber, you need a see-through container (I used a glass jar for science labs involving poisonous materials, as I was sure it would be radiation-safe,) very pure alcohol (I used 91% isopropyl rubbing alcohol,) a piece of blotter paper or sponge, a piece of black cloth, a block of dry ice, and a small radioactive piece. In this case, I used Fiestaware which contains uranium, and the americium from a smoke detector (if you want to try this, please use a broken smoke detector like I did.)

The cloth is glued to the bottom of the lid and the sponge is soaked in the alcohol. The radioactive source is placed in the lid and the jar is screwed upside-down onto it. Then the jar has to sit for 10-15 minutes or so. After that, the jar is placed lid-down onto the dry ice so the alcohol can saturate the jar and vaporize. After 15-20 minutes, when the jar becomes very cold, particle trails will begin to appear. A mist also forms and sinks to the bottom of the jar. Alpha particles leave heavy, dense trails and beta particles leave thin, wispy trails. This works because when a charged particle enters the chamber (from the radioactive source) it ionizes the vapor and produces a mist. There are so many ions produced around these relatively high-energy particles that when the vapor around them condenses a trail is left. 

The cloud chamber was one of the very first particle detectors and was used to discover muons and kaons among others. However, interestingly enough, today's high-tech dark matter searches actually utilize many of the same principles that the old-school cloud chamber does. For example, a popular type of experiment uses extremely pure, extremely cold germanium atoms in a controlled environment sealed off from the outside world, sometimes buried deep within an old abandoned mine. Theoretically, a dark matter WIMP (Weakly Interacting Massive Particle) should hit these supercool germanium atoms, which are very still, and leave a trail in the form of it's interaction with the germanium by causing it to "move," in a sense. 

Supersymmetric particles are excellent candidates for WIMPs, and I believe the best way for them to be detected is through a dark-matter detection experiment like the germanium one. And if they are found in this way, we are well on the road to solving two of the most elusive problems in physics-dark matter and the existence and nature of supersymmetric particles. From this, I have the third answer to my essential question, "Why is finding supersymmetric particles an important task for physicists to undertake?" "Because supersymmetric neutralinos provide the most accurate candidate for Cold Dark Matter."

Cutting the sponge-diameter 6.5 cm

Sponge layer 

Completed parts-notice new lid

Set-up at school 

The Geiger counter goes nuts around these two

Fiestaware-don't handle with your bare hands!

Letting sit-right before I put it on the dry ice

Broken smoke detector

I had to take this apart wearing gloves

The americium is the tiny, tiny button resting on the center disk

Letting it sit before it goes on dry ice

Blog 15: Independent Component 2 Approval

For my second independent component, I plan on building a cloud chamber. A cloud chamber was one of the first particle detectors ever built. The positron (anti-matter electron) and the muon were actually found using a cloud chamber. A basic cloud chamber consists of a sealed environment and a supersaturated vapor of alcohol or water (I will probably use methanol.) Charged particles interact with the vapor, ionizing it. After condensation one can start to see "tracks" left by the particles and then you can deduce what they are.

I want to build something a little better than your standard classroom cloud chamber, and I don't want to do it from a kit. Obviously I can't get any kind of radioactive material so it will be more limited in the types of particles it can see. However, I want actual chamber to be fairly large, sturdy, and reliable (so I want it to be VERY much sealed) and this will take time and there will be math involved in building it. Also, when I am finished, I want to make a print of the particle tracks, and then I will identify what they are.

I feel that this will help me answer my essential question because a big part of finding supersymmetric particles is actually building something to find them with. I think that this experiment will give me a taste for the experimental side of physics that I really haven't gotten yet (because obviously I can't build a Large Hadron Collider in my backyard.) Also, this is a good exercise in identifying particles based on what they leave behind, which is how we would identify sparticles if we found them in a particle detector.

Thanks to Professor Sean Carroll from Caltech for this idea!

Blog 14: Independent Component 1

I, Hannah Seymour, affirm that I completed my independent component which represents 30 hours of work.

My professor for the Physics 132 course was Dr. Jamshid Armand. He can be contacted via email at jarmand@csupomona.edu. I am very grateful to Professor Armand for letting me take this course, especially since I did not have the prerequisites for it. I also completed Physics 299A, which was a group activity class associated with the 132 lecture. I completed this with Linda Shareghi (lcshareghi@csupomona.edu) to whom I am also very grateful. She introduced me to some excellent people at the physics department.

Physics 132 is the second level of General Physics (there is 131 before it and 133 after it.) It is calculus-based and covers gravity, fluid dynamics, simple harmonic motion, waves, and thermodynamics, among others. The class consisted of two midterms and a final, weekly homework, weekly quizzes, and challenging problems (these I did very well on-if I can find them I will post them.) We learned mostly about the mathematical concepts in this class. In the activity class, we worked in groups to solve concept-based worksheets and mathematical problems.

I will email the unofficial transcript to Mr. Purther, as I do not want to post that for all the world to see (I am paranoid about the interwebs.) I did not miss a single hour and fifty minute lecture the whole quarter (they were twice a week)-that alone represents 30 hours of work. The homework (the most challenging part of the class) typically took me 2-3 hours a week to complete. I tried to study the material for at least 30 minutes-1 hour every week to prepare for the big tests. The activity class was every Friday and was 2 hours and fifty minutes. I usually didn't have homework for this class since my group would always finish the assigned problems. This is a difficult class, and many people are unable to pass it. I believe the average grade in the class was a D, when all was said and done.

These courses helped me understand more basic-intermediate physics concepts that I would not be familiar with otherwise. For instance, the explanation Professor Armand gave about constructive and destructive interference helped me understand particle wave cancellation and thus, supersymmetry. It also helped me understand what I'm good at and what I need a little more work on. It also helped me become more familiar with basic calculus (I am better at math in an applied setting like this.) Also, without this class I would not have gotten such a good score on the Physics SAT Subject Test. Now that I have been exposed to college-level physics, I feel more confident entering that world. I used to have so little intellectual confidence I refused to try anything I didn't think I would be perfect at right away. So I am very proud of the risk I took and the work I put in for these classes.

Blog 10: Senior Project Update

Independent Component: I will be taking my final for Physics 132 on Thursday. In addition, I am starting to build a Cloud Chamber as extra credit. Professor Sean Carroll at Caltech gave me the idea.

Research: I read this article a couple of weeks ago. Apparently, the LHC has observed particles called B mesons decaying into two particles called muons. These are ordinary particles, nothing special, but this decay hasn't been observed before. If supersymmetric particles are supposed to exist, this decay should happen way, way more often (so far, for every billion times they see a B meson decay, they only see it happen this way three times.) Ah, woe for my supersymmetric heart! But fear not, Professor Clifford Cheung of Caltech says this is not the end and does not rule out supersymmetry. I shall not abandon my science project because of this news.
(One of the Professors quoted in the article said the discovery was "really putting our supersymmetry colleagues in a spin." Heh. It's funny because particles have spin...sparticles have 1/2 spin...that's what makes them sparticles...I'm going to stop now.)

Proof: Well, shoot. Here is a picture of me watching "How the Universe Works" for more research.

Good on you, David Spergel.


The Cosmic Microwave Background. This is part of radio and television static. When you hear static you are listening to something that is ~14 billion years old!

Blog 7: Independent Component 1 Approval

Currently, I am taking Physics 132 at Cal Poly Pomona with Professor Jamshid Armamd, as well as the corresponding activity class, 299A, with Linda Shareghi. This is what I plan on using for my 1st independent component. The 132 class meets every Tuesday/Thursday from 2:30 to 3:45, and the activity class meets every Friday from 1:00 to 2:50, to this will more than satisfy the 30-hour work requirement. 

Since this is a foundational physics class, this will help me make sure I am completely comfortable with the basic physical laws so I can tackle the more complex problems in my working EQ, what is the most important unsolved physics problem? For example, we recently covered basic laws of gravity and orbits in class-one of the possible answers to my EQ is a theory of quantum gravity. I can now use my foundational knowledge of these basic laws of gravity and work them into relativity and try and visualize a way in which they could work at the subatomic level. 

I'm not saying this class will make me discover the answer to life, the universe, and everything (which is 42, of course,) but it will certainly help give me a solid foundation to move ahead in the world of physics.