Bioluminescent dinoflagellates, small single-celled organisms in the ocean, rely on sunlight to establish their circadian rhythm, showing how light plays a role in the cycle of life. Bioluminescence is a chemical reaction that occurs when luciferin reacts with oxygen, resulting in the emission of bioluminescence by living organisms. As a result, bioluminescent plankton glows and shimmers with the flowing seawater at night. Dinoflagellates synthesize luciferin independently and produce bluish-green light in the dark under the rhythm of a 24-hour light cycle. The light emitted by bioluminescence demonstrates the sleep-wake cycles of microorganisms. This project sheds light on how sea sparkles illuminate the ocean and the interdependent relationship between these tiny marine organisms and light. With a circle of light, eternal life's cycle is in sight.