Given the task definition and input, reply with output. In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

Question: What kind of process occurs without the need for a continual input of energy from some external source? Answer: spontaneous process

Spontaneous process kind of process occurs without the need for a continual input of energy from some external source.