https://blog.wongcw.com/2022/05/01/%e5%8c%97%e6%a5%b5%e5%85%89%e7%9a%84%e4%be%86%e6%ba%90%ef%bc%9a%e9%9b%bb%e5%ad%90%e5%9c%a8%e9%98%bf%e7%88%be%e6%96%87%e6%b3%a2%ef%bc%88alfven%ef%bc%89%e4%b8%8a%e8%a1%9d%e6%b5%aa/