crazy – adj. very unusual

white-knuckle ride – n. an experience marked by, causing, or experiencing intense worry or nervousness

indication – n. something, such as a sign or signal, that points out or shows something

potential – n. a chance or possibility that something will happen or exist in the future

significant – adj. large enough to be noticed or have an effect

rapid – adj. happening quickly

polar – adj. of or relating to the North or South Pole or the region around it

incredible – adj. difficult or impossible to believe