You and the World

Published Monday, March 21, 2011 by Tarang

College has changed me as it changes everyone, hopefully for the better. One of the most valuable lessons I learned in college was that I should always stay up-to-date with current events. As a science major, I should be aware of some of the science behind what I see in the news. In high school, I was not always fully aware of what was happening with the world. This changed when I entered UC Berkeley, and I am glad for it. One class that helped me along the way was a class called Physics for Future Presidents, which teaches the science of important, relevant topics in politics: space, nuclear energy, etc.

The course was interesting to say the least as we studied physics and current (or past) events side by side. It is one of the most popular courses on the Cal campus, and due to its popularity, all of the lectures are offered online for the public. The course is so popular that similar courses have popped up at other universities. Check out one of the lectures:

Also, with all the events taking place in Japan regarding the Fukushima-Daichii nuclear power plant, it might be important to understand how nuclear power plants work: http://www.howstuffworks.com/nuclear-power.htm

While you may peruse the article at your own leisure, I will provide a basic summary here. A nuclear reactor contains a nuclear core, containing 2-3% percent more Uranium-235 than a natural sample. U-235 undergoes radioactive decay naturally by emitting an alpha particle (2 neutrons and 2 protons). Nuclear fission can be induced in the plant by firing a free neutron at the core; this neutron makes U-235 unstable and it splits into two lighter atoms. The split also releases a free neutron, keeping the nuclear reaction going (nuclear chain reaction). While the energy from one fission reaction is not that much, there are tons of atoms in the core undergoing fission and releasing a large amount of combined energy. The uranium is arranged into rods, and the rods are arranged into bundles. The bundles are submerged in water, which serves two purposes: it keeps the rods cool and it turns into steam and powers the turbine. At the same time, control rods adjacent to the nuclear rods absorb the free neutrons of the reaction (remember free neutrons are needed to start the reaction). The control rods control the rate of the nuclear reaction depending on how many free neutrons they absorb. The nuclear power plant also has layers of protection to prevent radioactive materials from escaping into the environment. The first layer is a concrete liner; the second layer is a steel vessel which contains the concrete liner. The last layer is the concrete building which houses the steel layer.

If you want to jump straight to understanding what happened in Japan and Chernobyl: http://science.howstuffworks.com/nuclear-power5.htm

Staying current and understanding what is happening in the world is part of adulthood and being responsible. The word “nuclear” scares many people, so it’s important to know what nuclear power really is. To illustrate the importance of not being ignorant, here is a true story: doctors used to use a machine called Nuclear Magnetic Resonance to scan images of the brain. People got scared of the word “nuclear” so much so that the machine’s name was changed to Magnetic Resonance Imaging (MRI). I heard this anecdote through my course, and it always amazed me how little effort people put into understanding the background of something.


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