December 26, 2004. On this day, the worst tsunami in living memory pummeled Indonesia and shocked the world. The first tsunami to occur in the age of mobile camera phones, it was experienced by people all over the world through the shaky handheld videos that emerged of the catastrophe. The footage of the tsunami conveyed the ordeal through the eyes of the survivors, but it also had a practical benefit. Video footage enabled scientists to understand tsunamis more. Here's how.