Goldilocks conditions are a concept that derives from the popular children's story, "Goldilocks and the Three Bears." In the story, the titular characters find bowls of porridge. All three bears find porridge of varying degrees of warmth while Goldilocks finds a bowl that is "just right" for eating. This is used as a metaphor for Earth's fortunate spot in the Sun's circumstellar habitable zone. This is the distance that allows for warm and cold waters full of life as well as a rocky crust that facilitates continental drift. Continental drift creates the opportunity for the atmosphere to be absorbed in the crust and redistributed through volcanic blasts, replenishing the atmosphere and creating cycles that produce and sustain life.