Skip to main content

Stopping is not enough

Earthquake in Kyusyu, Japan still continues. No one knows when it completely stops yet. I care the people there and I also afraid the nuclear reactors they are still running there. (Japan only has two running reactors now, both are in Kyusyu area where the earthquake continues. The number of earthquakes more than scale 1 is 770 times so far.)

There are several petition to stop the reactors now. I also joined. But, technically stopping them are not enough. Most of Japanese facility only have water cooling pools for nuclear fuels. If such pool had a crack by an earthquake and lost the water, it is dangerous. How do they stably supply cooling water, the earthquake can be a cause of trouble. Just loosing the electricity of the pumps causes an accident. All the reactors in Fukushima stopped when the earthquake came, but they could not maintain to cool the fuels. That we saw five years ago.

To avoid an accident, we need to think about after stopping the reactors. I agree, let's first stop them. But that is not enough for safety.

Labels:

Comments

Post a Comment

Popular posts from this blog

Why parallelogram area is |ad-bc|?

Here is my question. The area of parallelogram is the difference of these two rectangles (red rectangle - blue rectangle). This is not intuitive for me. If you also think it is not so intuitive, you might interested in my slides. I try to explain this for hight school students. Slides:  A bit intuitive (for me) explanation of area of parallelogram  (to my site, external link) . 
Post a Comment
Read more

Geometric Multiplicity: eignvectors (2)

If eigenvectors of a matrix A are independent, it is a happy property. Because the matrix A can be diagonalized with a matrix S that column vectors are eigenvectors of A . For example, Why this is a happy property of A? Because I can find A's power easily. A^{10} is not a big deal. Because Λ is a diagonal matrix and power of a diagonal matrix is quite simple. A^{10} = SΛ^{10} S^{-1} Then, why if I want to compute power of A ? That is the same reason to find eigenvectors. Eigenvectors are a basis of a matrix. A matrix can be represented by a single scalar. I repeat this again. This is the happy point, a matrix becomes a scalar. What can be simpler than a scalar value. But, this is only possible when the matrix S's columns are independent. Because S^{-1} must be exist. Now I come back to my first question. Is the λ's multiplicity related with the number of eigenvectors? This time I found this has the name. Geometric multiplicity (GM): the number of in...
Post a Comment
Read more

Tezuka Osamu's Black Jack, "Shrinking"

I like several novel authors. My first favorite author is probably Teduka, Osamu. I still love him. The list grows by adding Hoshi, Shinichi, Agatha Christie, Hermann Hesse, and so forth. My first favorite article of Tezuka was Atom as most of the (boy's) Tezuka fans did. But my favorite is Black Jack. I try to summarize one story, it is still quite vivid in my memory. I first read this story when I was 13 - 15 years old. I re-read it at least several times since Black Jack is composed of many short episodes. The title should be "ちぢむ (SHRINKING)" or it might be "縮む(Shrinking)". (It is not so convenient to translate this to English, since English does not have a system to say the exact same word in several ways. So I just simulate it with capital letters.) Black Jack is a genius surgeon, but he does not have the license. In short, his medical activity is illegal. His skill is top level in the world, but, the fee is also out-of-law expensive. In the story ...
Post a Comment
Read more