Cyclical phenomena refer to events or patterns that repeat over time in a predictable manner. These cycles can be found in various fields, such as economics, where business cycles of expansion and recession occur, or in nature, where seasons change in a regular pattern. In addition to natural and economic cycles, cyclical phenomena can also be observed in astronomy. For example, the phases of the moon repeat approximately every 29.5 days, creating a cycle that influences tides and cultural events. Understanding these cycles helps in predicting future occurrences and managing resources effectively.