* Earth's Rotation: The Earth spins on its axis, completing one full rotation approximately every 24 hours. This rotation is what causes day and night.
* Earth's Orbit: The Earth orbits the Sun, taking approximately 365 days to complete one orbit. The Earth's tilted axis and its orbit around the Sun cause the variations in the length of days throughout the year.
How Refraction Affects What We See:
Refraction, however, plays a role in how we perceive the sunrise and sunset. When sunlight enters the Earth's atmosphere, it bends due to the changing density of the air. This bending makes the Sun appear higher in the sky than it actually is, both at sunrise and sunset.
* Sunrise: We see the Sun appear above the horizon slightly earlier due to refraction, making the day seem a little longer.
* Sunset: Similarly, we see the Sun disappear below the horizon slightly later, again making the day seem a little longer.
In Summary:
While refraction affects how we perceive sunrise and sunset, it doesn't actually change the length of the day. The length of the day is determined by the Earth's rotation and its orbit around the Sun.
