Final answer:
Aircraft have red and green navigation lights on their wing tips, with red on the left (port) and green on the right (starboard), which helps determine aircraft direction and enhance safety.
Step-by-step explanation:
Navigation Lights on Aircraft Wing Tips
The navigation lights on the wing tips of an aircraft serve a crucial role in ensuring the visibility of the aircraft to others in the sky, particularly during times of low visibility. These lights are similar in concept to the headlights on your car, providing illumination for safe operation. Specifically, the navigation light on the left (port) wing tip is red, while the light on the right (starboard) wing tip is green. This color coding helps other pilots determine the direction an aircraft is facing and thus its relative motion, which is essential for maintaining safe distances in the air. This system of using red and green navigation lights is standardized internationally and must be displayed by aircraft from sunset to sunrise, or during any other period when visibility is poor.
While the wing tip navigation lights serve a fundamentally different purpose from technologies utilizing thin film interference such as iridescent butterfly wings or security features on credit cards, they all relate to the manipulation or use of light to achieve an outcome, whether it's visual signaling, decorative coloration, or anti-counterfeit measures.