“Crackle”: The fifth derivative of position

I wanted to look up "crackle" because I wondered from a poem by Ada Limón if it might be the name of a bird (as the context of the poem suggested). It's not, but it is a name for "the fifth derivative of position". In order, the derivatives of position from the first to the sixth are velocity, acceleration, jerk (or jolt), jounce (or snap), crackle, and pop. Yes, the fourth to sixth derivatives are named after the characters in advertisements for Kellogg's Rice Krispies: snap, crackle, and pop. The latter don't come up often, but according to Wikipedia, reduction of snap, the derivative of jerk, to zero improves railway tracks. (Andrew Shields, #111Words, 1 November 2024)