The average depth of the ocean floor is 12,000 feet. (according to my trivia calendar and Wiki, but NOAA says "about 14,000 ft....

Lightning is five times hotter than the sun. Yes, it's true.  A bolt of lightning can reach temperatures of roughly 30,000 kelvi...

From the description under the video: Fifteen uncoupled simple pendulums of monotonically increasing lengths dance together to produce visu...