前回の動画 https://www.nicovideo.jp/watch/sm45383404?ref=garage_share_other 引用・参考文献 https://www.quora.com/How-did-ships-pass-under-low-bridges-like-the-Brooklyn-and-Golden-Gate-bridges-in-the-past
http://www.nicovideo.jp/watch/sm45392927
